From 375de6bec50f95b693fa922f24a93af9ff15f56c Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:16 +0300
Subject: [PATCH 001/100] Fix jsdoc-default-matches-type in
 js/ui/editor/editor.d.ts

Widen onValueChanged, validationError, validationErrors and value to
include | null, matching the null stored in Editor._getDefaultOptions().
Widen _getValidationErrors() return type to unknown[] | null | undefined
since it directly returns the now-nullable validationErrors option.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/__internal/ui/editor/editor.ts | 2 +-
 packages/devextreme/js/ui/editor/editor.d.ts          | 8 ++++----
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/editor/editor.ts b/packages/devextreme/js/__internal/ui/editor/editor.ts
index b1fbf5a2be98..3c0b5eb5b2f7 100644
--- a/packages/devextreme/js/__internal/ui/editor/editor.ts
+++ b/packages/devextreme/js/__internal/ui/editor/editor.ts
@@ -262,7 +262,7 @@ class Editor<
     this.$element().addClass(stylingModeClass);
   }
 
-  _getValidationErrors(): unknown[] | undefined {
+  _getValidationErrors(): unknown[] | null | undefined {
     let { validationErrors } = this.option();
     const { validationError } = this.option();
 
diff --git a/packages/devextreme/js/ui/editor/editor.d.ts b/packages/devextreme/js/ui/editor/editor.d.ts
index 1fd02a867460..64ad2f85f06f 100644
--- a/packages/devextreme/js/ui/editor/editor.d.ts
+++ b/packages/devextreme/js/ui/editor/editor.d.ts
@@ -53,7 +53,7 @@ export interface EditorOptions<TComponent> extends WidgetOptions<TComponent> {
      * @action
      * @public
      */
-    onValueChanged?: ((e: NativeEventInfo<TComponent, Event> & ValueChangedInfo) => void);
+    onValueChanged?: ((e: NativeEventInfo<TComponent, Event> & ValueChangedInfo) => void) | null;
     /**
      * @docid
      * @default false
@@ -66,13 +66,13 @@ export interface EditorOptions<TComponent> extends WidgetOptions<TComponent> {
      * @default null
      * @public
      */
-    validationError?: any;
+    validationError?: any | null;
     /**
      * @docid
      * @default null
      * @public
      */
-    validationErrors?: Array<any>;
+    validationErrors?: Array<any> | null;
     /**
      * @docid
      * @default "auto"
@@ -97,7 +97,7 @@ export interface EditorOptions<TComponent> extends WidgetOptions<TComponent> {
      * @fires EditorOptions.onValueChanged
      * @public
      */
-    value?: any;
+    value?: any | null;
     /**
      * @docid
      * @default 'outlined'

From ea86e739a9755690c467fe09b1c0f6c5d6f7e619 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:17 +0300
Subject: [PATCH 002/100] Fix jsdoc-default-matches-type in
 js/ui/editor/ui.data_expression.d.ts

Widen value to include | null, matching the null stored in
DataExpressionMixin._dataExpressionDefaultOptions().

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/ui/editor/ui.data_expression.d.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/devextreme/js/ui/editor/ui.data_expression.d.ts b/packages/devextreme/js/ui/editor/ui.data_expression.d.ts
index 93d63bd52366..ca58847b3cc3 100644
--- a/packages/devextreme/js/ui/editor/ui.data_expression.d.ts
+++ b/packages/devextreme/js/ui/editor/ui.data_expression.d.ts
@@ -52,7 +52,7 @@ export interface DataExpressionMixinOptions<T = DataExpressionMixin> {
      * @default null
      * @public
      */
-    value?: any;
+    value?: any | null;
     /**
      * @docid
      * @default "this"

From 82b8fa9a3183ecad32c0ae87a2ba448ecd3f6e5a Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:17 +0300
Subject: [PATCH 003/100] Fix jsdoc-default-matches-type in
 js/ui/text_box/ui.text_editor.base.d.ts

Widen buttons to | undefined (runtime stores void 0) and onChange,
onCopy, onCut, onEnterKey, onFocusIn, onFocusOut, onInput, onKeyDown,
onKeyUp, onPaste to | null (runtime stores null), matching
TextEditorBase._getDefaultOptions().

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 .../js/ui/text_box/ui.text_editor.base.d.ts   | 22 +++++++++----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/packages/devextreme/js/ui/text_box/ui.text_editor.base.d.ts b/packages/devextreme/js/ui/text_box/ui.text_editor.base.d.ts
index e91f61d8fb7c..da499617463a 100644
--- a/packages/devextreme/js/ui/text_box/ui.text_editor.base.d.ts
+++ b/packages/devextreme/js/ui/text_box/ui.text_editor.base.d.ts
@@ -28,7 +28,7 @@ export interface dxTextEditorOptions<TComponent> extends EditorOptions<TComponen
      * @default undefined
      * @public
      */
-    buttons?: Array<string | TextBoxPredefinedButton | TextEditorButton>;
+    buttons?: Array<string | TextBoxPredefinedButton | TextEditorButton> | undefined;
     /**
      * @docid
      * @default true
@@ -98,7 +98,7 @@ export interface dxTextEditorOptions<TComponent> extends EditorOptions<TComponen
      * @action
      * @public
      */
-    onChange?: ((e: NativeEventInfo<TComponent, Event>) => void);
+    onChange?: ((e: NativeEventInfo<TComponent, Event>) => void) | null;
     /**
      * @docid
      * @default null
@@ -106,7 +106,7 @@ export interface dxTextEditorOptions<TComponent> extends EditorOptions<TComponen
      * @action
      * @public
      */
-    onCopy?: ((e: NativeEventInfo<TComponent, ClipboardEvent>) => void);
+    onCopy?: ((e: NativeEventInfo<TComponent, ClipboardEvent>) => void) | null;
     /**
      * @docid
      * @default null
@@ -114,7 +114,7 @@ export interface dxTextEditorOptions<TComponent> extends EditorOptions<TComponen
      * @action
      * @public
      */
-    onCut?: ((e: NativeEventInfo<TComponent, ClipboardEvent>) => void);
+    onCut?: ((e: NativeEventInfo<TComponent, ClipboardEvent>) => void) | null;
     /**
      * @docid
      * @default null
@@ -122,7 +122,7 @@ export interface dxTextEditorOptions<TComponent> extends EditorOptions<TComponen
      * @action
      * @public
      */
-    onEnterKey?: ((e: NativeEventInfo<TComponent, KeyboardEvent>) => void);
+    onEnterKey?: ((e: NativeEventInfo<TComponent, KeyboardEvent>) => void) | null;
     /**
      * @docid
      * @default null
@@ -130,7 +130,7 @@ export interface dxTextEditorOptions<TComponent> extends EditorOptions<TComponen
      * @action
      * @public
      */
-    onFocusIn?: ((e: NativeEventInfo<TComponent, FocusEvent>) => void);
+    onFocusIn?: ((e: NativeEventInfo<TComponent, FocusEvent>) => void) | null;
     /**
      * @docid
      * @default null
@@ -138,7 +138,7 @@ export interface dxTextEditorOptions<TComponent> extends EditorOptions<TComponen
      * @action
      * @public
      */
-    onFocusOut?: ((e: NativeEventInfo<TComponent, FocusEvent>) => void);
+    onFocusOut?: ((e: NativeEventInfo<TComponent, FocusEvent>) => void) | null;
     /**
      * @docid
      * @default null
@@ -146,7 +146,7 @@ export interface dxTextEditorOptions<TComponent> extends EditorOptions<TComponen
      * @action
      * @public
      */
-    onInput?: ((e: NativeEventInfo<TComponent, UIEvent>) => void);
+    onInput?: ((e: NativeEventInfo<TComponent, UIEvent>) => void) | null;
     /**
      * @docid
      * @type_function_param1 e:NativeEventInfo
@@ -154,7 +154,7 @@ export interface dxTextEditorOptions<TComponent> extends EditorOptions<TComponen
      * @action
      * @public
      */
-    onKeyDown?: ((e: NativeEventInfo<TComponent, KeyboardEvent>) => void);
+    onKeyDown?: ((e: NativeEventInfo<TComponent, KeyboardEvent>) => void) | null;
     /**
      * @docid
      * @default null
@@ -162,7 +162,7 @@ export interface dxTextEditorOptions<TComponent> extends EditorOptions<TComponen
      * @action
      * @public
      */
-    onKeyUp?: ((e: NativeEventInfo<TComponent, KeyboardEvent>) => void);
+    onKeyUp?: ((e: NativeEventInfo<TComponent, KeyboardEvent>) => void) | null;
     /**
      * @docid
      * @default null
@@ -170,7 +170,7 @@ export interface dxTextEditorOptions<TComponent> extends EditorOptions<TComponen
      * @action
      * @public
      */
-    onPaste?: ((e: NativeEventInfo<TComponent, ClipboardEvent>) => void);
+    onPaste?: ((e: NativeEventInfo<TComponent, ClipboardEvent>) => void) | null;
     /**
      * @docid
      * @default ""

From 937afeae1f1b31d3fed0f9ad44e55c627c25869a Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:17 +0300
Subject: [PATCH 004/100] Fix jsdoc-default-matches-type in
 js/ui/collection/ui.collection_widget.base.d.ts

Widen keyExpr, onItemClick, onItemContextMenu, onItemHold,
onItemRendered, onSelectionChanging, onSelectionChanged and
selectedItem to include | null, matching the null stored in
CollectionWidget._getDefaultOptions() (collection_widget.base.ts /
collection_widget.edit.ts).

Widen List.scrollToItem() parameter type to accept | null: isDefined()
already treats null and undefined identically at runtime, so this only
corrects the signature to match the now-nullable selectedItem consumer
in select_box.ts.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 .../js/__internal/ui/list/list.base.ts           |  2 +-
 .../ui/collection/ui.collection_widget.base.d.ts | 16 ++++++++--------
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/list/list.base.ts b/packages/devextreme/js/__internal/ui/list/list.base.ts
index 970fd478ac03..a810a73af266 100644
--- a/packages/devextreme/js/__internal/ui/list/list.base.ts
+++ b/packages/devextreme/js/__internal/ui/list/list.base.ts
@@ -1531,7 +1531,7 @@ export class ListBase extends CollectionWidget<ListBaseProperties, Item> {
     this._scrollView.scrollTo(location);
   }
 
-  scrollToItem(itemElement: number | Element | dxElementWrapper | Item | undefined): void {
+  scrollToItem(itemElement: number | Element | dxElementWrapper | Item | null | undefined): void {
     if (!isDefined(itemElement)) {
       return;
     }
diff --git a/packages/devextreme/js/ui/collection/ui.collection_widget.base.d.ts b/packages/devextreme/js/ui/collection/ui.collection_widget.base.d.ts
index ec12f01a27bc..b760d798a5d6 100644
--- a/packages/devextreme/js/ui/collection/ui.collection_widget.base.d.ts
+++ b/packages/devextreme/js/ui/collection/ui.collection_widget.base.d.ts
@@ -80,7 +80,7 @@ export interface CollectionWidgetOptions<
      * @default null
      * @public
      */
-    keyExpr?: string | ((item: TItem) => TKey);
+    keyExpr?: string | ((item: TItem) => TKey) | null;
     /**
      * @docid
      * @default "No data to display"
@@ -98,7 +98,7 @@ export interface CollectionWidgetOptions<
      * @action
      * @public
      */
-    onItemClick?: ((e: NativeEventInfo<TComponent, MouseEvent | PointerEvent> & ItemInfo<TItem>) => void) | string;
+    onItemClick?: ((e: NativeEventInfo<TComponent, MouseEvent | PointerEvent> & ItemInfo<TItem>) => void) | string | null;
     /**
      * @docid
      * @default null
@@ -109,7 +109,7 @@ export interface CollectionWidgetOptions<
      * @action
      * @public
      */
-    onItemContextMenu?: ((e: NativeEventInfo<TComponent, PointerInteractionEvent> & ItemInfo<TItem>) => void);
+    onItemContextMenu?: ((e: NativeEventInfo<TComponent, PointerInteractionEvent> & ItemInfo<TItem>) => void) | null;
     /**
      * @docid
      * @default null
@@ -120,7 +120,7 @@ export interface CollectionWidgetOptions<
      * @action
      * @public
      */
-    onItemHold?: ((e: NativeEventInfo<TComponent, PointerInteractionEvent> & ItemInfo<TItem>) => void);
+    onItemHold?: ((e: NativeEventInfo<TComponent, PointerInteractionEvent> & ItemInfo<TItem>) => void) | null;
     /**
      * @docid
      * @default null
@@ -130,7 +130,7 @@ export interface CollectionWidgetOptions<
      * @action
      * @public
      */
-    onItemRendered?: ((e: EventInfo<TComponent> & ItemInfo<TItem>) => void);
+    onItemRendered?: ((e: EventInfo<TComponent> & ItemInfo<TItem>) => void) | null;
     /**
      * @docid
      * @default null
@@ -142,7 +142,7 @@ export interface CollectionWidgetOptions<
      * @action
      * @public
      */
-    onSelectionChanging?: ((e: SelectionChangingEventBase<TComponent>) => void);
+    onSelectionChanging?: ((e: SelectionChangingEventBase<TComponent>) => void) | null;
     /**
      * @docid
      * @default null
@@ -153,7 +153,7 @@ export interface CollectionWidgetOptions<
      * @action
      * @public
      */
-    onSelectionChanged?: ((e: EventInfo<TComponent> & SelectionChangeInfo<TItem>) => void);
+    onSelectionChanged?: ((e: EventInfo<TComponent> & SelectionChangeInfo<TItem>) => void) | null;
     /**
      * @docid
      * @default -1
@@ -168,7 +168,7 @@ export interface CollectionWidgetOptions<
      * @ref
      * @public
      */
-    selectedItem?: TItem;
+    selectedItem?: TItem | null;
     /**
      * @docid
      * @fires CollectionWidgetOptions.onSelectionChanged

From dfef59786ba799483e4885b528aee1359b446dfc Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:18 +0300
Subject: [PATCH 005/100] Fix jsdoc-default-matches-type in
 js/ui/widget/ui.search_box_mixin.d.ts

Widen searchExpr to include | null: the mixin has no own default, but
consumers (list.edit.search.ts, drop_down_list.ts) store null.

Follow-on fixes required to keep check-types clean:
- data_adapter.ts: widen DataAdapterOptions.searchExpr to | null since
  tree_view.search.ts passes the now-nullable option straight through;
  verified safe (data_adapter.ts consumes it via a nullish coalescing
  fallback and passes it as an opaque filter value).
- list.edit.search.ts: remove the ts-expect-error over searchExpr: null,
  now unused after widening.
- list.base.ts: add an explicit cast at the single affected call site
  in _getSpecificDataSourceOption() to work around a TS overload
  resolution fragility in component.d.ts option() (see Known Issues
  in progres_report.md for the full root-cause writeup).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 .../js/__internal/ui/hierarchical_collection/data_adapter.ts    | 2 +-
 packages/devextreme/js/__internal/ui/list/list.base.ts          | 2 +-
 packages/devextreme/js/__internal/ui/list/list.edit.search.ts   | 1 -
 packages/devextreme/js/ui/widget/ui.search_box_mixin.d.ts       | 2 +-
 4 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/hierarchical_collection/data_adapter.ts b/packages/devextreme/js/__internal/ui/hierarchical_collection/data_adapter.ts
index 45a677eae82b..4e5370ec834f 100644
--- a/packages/devextreme/js/__internal/ui/hierarchical_collection/data_adapter.ts
+++ b/packages/devextreme/js/__internal/ui/hierarchical_collection/data_adapter.ts
@@ -47,7 +47,7 @@ export interface DataAdapterOptions {
   dataType: DataStructure;
   sort: SortOption | SortOption[] | null;
   langParams?: LangParams;
-  searchExpr?: string | Function | (string | Function)[] | ((item: ItemData) => unknown);
+  searchExpr?: string | Function | (string | Function)[] | ((item: ItemData) => unknown) | null;
 
   dataConverter: HierarchicalDataConverter;
   onNodeChanged: (node: InternalNode) => void;
diff --git a/packages/devextreme/js/__internal/ui/list/list.base.ts b/packages/devextreme/js/__internal/ui/list/list.base.ts
index a810a73af266..cad8293a979a 100644
--- a/packages/devextreme/js/__internal/ui/list/list.base.ts
+++ b/packages/devextreme/js/__internal/ui/list/list.base.ts
@@ -550,7 +550,7 @@ export class ListBase extends CollectionWidget<ListBaseProperties, Item> {
     | null
     | undefined {
     const { grouped } = this.option();
-    const dataSource = this.option('dataSource');
+    const dataSource = this.option('dataSource') as DataSourceLike<Item> | undefined;
 
     if (dataSource && grouped) {
       return getDataSourceOptions<Item>(dataSource);
diff --git a/packages/devextreme/js/__internal/ui/list/list.edit.search.ts b/packages/devextreme/js/__internal/ui/list/list.edit.search.ts
index ae9f96de4a6e..9c71ea5a5f9f 100644
--- a/packages/devextreme/js/__internal/ui/list/list.edit.search.ts
+++ b/packages/devextreme/js/__internal/ui/list/list.edit.search.ts
@@ -38,7 +38,6 @@ class ListSearch extends ListEdit {
       ...super._getDefaultOptions(),
       // @ts-expect-error ts-error
       searchMode: '',
-      // @ts-expect-error ts-error
       searchExpr: null,
       searchValue: '',
       searchEnabled: false,
diff --git a/packages/devextreme/js/ui/widget/ui.search_box_mixin.d.ts b/packages/devextreme/js/ui/widget/ui.search_box_mixin.d.ts
index d5baa4cd7e01..0345926d8f9d 100644
--- a/packages/devextreme/js/ui/widget/ui.search_box_mixin.d.ts
+++ b/packages/devextreme/js/ui/widget/ui.search_box_mixin.d.ts
@@ -31,7 +31,7 @@ export interface SearchBoxMixinOptions {
      * @default null
      * @public
      */
-    searchExpr?: string | Function | Array<string | Function>;
+    searchExpr?: string | Function | Array<string | Function> | null;
     /**
      * @docid
      * @default 'contains'

From ac92e54807b9fbf795e007bc808deca330644b19 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:18 +0300
Subject: [PATCH 006/100] Fix jsdoc-default-matches-type in
 js/ui/drop_down_editor/ui.drop_down_editor.d.ts

Verified against js/__internal/ui/drop_down_editor/drop_down_editor.ts
_getDefaultOptions():
- buttons stores void 0 -> add | undefined
- onClosed, onOpened, value store null -> add | null

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 .../js/ui/drop_down_editor/ui.drop_down_editor.d.ts       | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/packages/devextreme/js/ui/drop_down_editor/ui.drop_down_editor.d.ts b/packages/devextreme/js/ui/drop_down_editor/ui.drop_down_editor.d.ts
index 487d93f6f0a9..140f42caa15b 100644
--- a/packages/devextreme/js/ui/drop_down_editor/ui.drop_down_editor.d.ts
+++ b/packages/devextreme/js/ui/drop_down_editor/ui.drop_down_editor.d.ts
@@ -92,7 +92,7 @@ export interface dxDropDownEditorOptions<TComponent> extends Omit<dxTextBoxOptio
      * @default undefined
      * @public
      */
-    buttons?: Array<DropDownPredefinedButton | TextEditorButton>;
+    buttons?: Array<DropDownPredefinedButton | TextEditorButton> | undefined;
     /**
      * @docid
      * @default true
@@ -119,14 +119,14 @@ export interface dxDropDownEditorOptions<TComponent> extends Omit<dxTextBoxOptio
      * @action
      * @public
      */
-    onClosed?: ((e: EventInfo<TComponent>) => void);
+    onClosed?: ((e: EventInfo<TComponent>) => void) | null;
     /**
      * @docid
      * @default null
      * @action
      * @public
      */
-    onOpened?: ((e: EventInfo<TComponent>) => void);
+    onOpened?: ((e: EventInfo<TComponent>) => void) | null;
     /**
      * @docid
      * @default false
@@ -158,7 +158,7 @@ export interface dxDropDownEditorOptions<TComponent> extends Omit<dxTextBoxOptio
      * @default null
      * @public
      */
-    value?: any;
+    value?: any | null;
 }
 /**
  * @docid

From 65da09cfce5f5164bb6e8218be599b3d5c5c61f7 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:19 +0300
Subject: [PATCH 007/100] Fix jsdoc-default-matches-type in
 js/ui/drop_down_editor/ui.drop_down_list.d.ts

Verified against js/__internal/ui/drop_down_editor/drop_down_list.ts
_getDefaultOptions() (onValueChanged inherited from editor.ts):
- onSelectionChanged, onValueChanged, searchExpr, selectedItem store
  null -> add | null
- onItemClick stores noop (a function) at this level, not null; the
  type is already correct (a function), so corrected the inaccurate
  @default null tag instead of widening the type (doc-only change,
  no behavior impact)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 .../js/ui/drop_down_editor/ui.drop_down_list.d.ts        | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/packages/devextreme/js/ui/drop_down_editor/ui.drop_down_list.d.ts b/packages/devextreme/js/ui/drop_down_editor/ui.drop_down_list.d.ts
index 1680de9187a1..df34bc4af997 100644
--- a/packages/devextreme/js/ui/drop_down_editor/ui.drop_down_list.d.ts
+++ b/packages/devextreme/js/ui/drop_down_editor/ui.drop_down_list.d.ts
@@ -86,7 +86,6 @@ export interface dxDropDownListOptions<TComponent> extends DataExpressionMixinOp
     noDataText?: string;
     /**
      * @docid
-     * @default null
      * @type_function_param1 e:object
      * @type_function_param1_field itemData:object
      * @type_function_param1_field itemElement:object
@@ -106,7 +105,7 @@ export interface dxDropDownListOptions<TComponent> extends DataExpressionMixinOp
      * @action
      * @public
      */
-    onSelectionChanged?: ((e: EventInfo<TComponent> & SelectionChangedInfo) => void);
+    onSelectionChanged?: ((e: EventInfo<TComponent> & SelectionChangedInfo) => void) | null;
     /**
      * @docid
      * @default null
@@ -118,7 +117,7 @@ export interface dxDropDownListOptions<TComponent> extends DataExpressionMixinOp
      * @action
      * @public
      */
-    onValueChanged?: ((e: NativeEventInfo<TComponent, KeyboardEvent | MouseEvent | PointerEvent | Event> & ValueChangedInfo) => void);
+    onValueChanged?: ((e: NativeEventInfo<TComponent, KeyboardEvent | MouseEvent | PointerEvent | Event> & ValueChangedInfo) => void) | null;
     /**
      * @docid
      * @default false
@@ -131,7 +130,7 @@ export interface dxDropDownListOptions<TComponent> extends DataExpressionMixinOp
      * @default null
      * @public
      */
-    searchExpr?: string | Function | Array<string | Function>;
+    searchExpr?: string | Function | Array<string | Function> | null;
     /**
      * @docid
      * @default "contains"
@@ -151,7 +150,7 @@ export interface dxDropDownListOptions<TComponent> extends DataExpressionMixinOp
      * @ref
      * @public
      */
-    selectedItem?: any;
+    selectedItem?: any | null;
     /**
      * @docid
      * @default false

From befe5305ae1edaad5407eea4fecc92855f3bd41a Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:19 +0300
Subject: [PATCH 008/100] Fix jsdoc-default-matches-type in
 js/ui/select_box.d.ts

Verified against js/__internal/ui/select_box.ts _getDefaultOptions():
fieldTemplate stores null -> add | null.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/ui/select_box.d.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/devextreme/js/ui/select_box.d.ts b/packages/devextreme/js/ui/select_box.d.ts
index 8292c009cb41..9ed8d0eae740 100644
--- a/packages/devextreme/js/ui/select_box.d.ts
+++ b/packages/devextreme/js/ui/select_box.d.ts
@@ -234,7 +234,7 @@ export interface dxSelectBoxOptions<TComponent> extends dxDropDownListOptions<TC
      * @public
      * @deprecated dxDropDownEditorOptions.fieldAddons
      */
-    fieldTemplate?: template | ((selectedItem: any, fieldElement: DxElement) => string | UserDefinedElement);
+    fieldTemplate?: template | ((selectedItem: any, fieldElement: DxElement) => string | UserDefinedElement) | null;
     /**
      * @docid
      * @default null

From 2fe412c1671865376e7327ff2b5bccc3edbe3a90 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:19 +0300
Subject: [PATCH 009/100] Fix jsdoc-default-matches-type in
 js/ui/color_box.d.ts

Verified against js/__internal/ui/color_box/color_box.ts
_getDefaultOptions(): fieldTemplate stores null -> add | null.

Removed the now-unused @ts-expect-error directly above
fieldTemplate: null in color_box.ts, made stale by the widened type.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/__internal/ui/color_box/color_box.ts | 1 -
 packages/devextreme/js/ui/color_box.d.ts                    | 2 +-
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/color_box/color_box.ts b/packages/devextreme/js/__internal/ui/color_box/color_box.ts
index 46ee6b22c6b4..ff8e108b10e8 100644
--- a/packages/devextreme/js/__internal/ui/color_box/color_box.ts
+++ b/packages/devextreme/js/__internal/ui/color_box/color_box.ts
@@ -116,7 +116,6 @@ class ColorBox extends DropDownEditor<ColorBoxProperties> {
       editAlphaChannel: false,
       applyValueMode: 'useButtons',
       keyStep: 1,
-      // @ts-expect-error fieldTemplate is deprecated --- IGNORE ---
       fieldTemplate: null,
       buttonsLocation: 'bottom after',
     };
diff --git a/packages/devextreme/js/ui/color_box.d.ts b/packages/devextreme/js/ui/color_box.d.ts
index 9f63261053ec..de0d627b5642 100644
--- a/packages/devextreme/js/ui/color_box.d.ts
+++ b/packages/devextreme/js/ui/color_box.d.ts
@@ -199,7 +199,7 @@ export interface dxColorBoxOptions extends dxDropDownEditorOptions<dxColorBox> {
      * @public
      * @deprecated dxDropDownEditorOptions.fieldAddons
      */
-    fieldTemplate?: template | ((value: string, fieldElement: DxElement) => string | UserDefinedElement);
+    fieldTemplate?: template | ((value: string, fieldElement: DxElement) => string | UserDefinedElement) | null;
     /**
      * @docid
      * @default 1

From 3381c1936d610daa84056b04e871ae056531b469 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:20 +0300
Subject: [PATCH 010/100] Fix jsdoc-default-matches-type in
 js/ui/drop_down_box.d.ts

fieldTemplate is inherited from
js/__internal/ui/drop_down_editor/drop_down_editor.ts
_getDefaultOptions(), which stores null -> add | null.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/ui/drop_down_box.d.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/devextreme/js/ui/drop_down_box.d.ts b/packages/devextreme/js/ui/drop_down_box.d.ts
index 9a1157e75b12..882fdbb2d6b2 100644
--- a/packages/devextreme/js/ui/drop_down_box.d.ts
+++ b/packages/devextreme/js/ui/drop_down_box.d.ts
@@ -213,7 +213,7 @@ export interface dxDropDownBoxOptions extends DataExpressionMixinOptions<dxDropD
      * @public
      * @deprecated dxDropDownEditorOptions.fieldAddons
      */
-    fieldTemplate?: template | ((value: any, fieldElement: DxElement) => string | UserDefinedElement);
+    fieldTemplate?: template | ((value: any, fieldElement: DxElement) => string | UserDefinedElement) | null;
     /**
      * @docid
      * @public

From a63a8bc1c9c073798ef7a297c9c1bc0ca3338454 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:20 +0300
Subject: [PATCH 011/100] Fix jsdoc-default-matches-type in js/ui/lookup.d.ts

Verified against js/__internal/ui/lookup.ts _getDefaultOptions()
(fieldTemplate inherited from drop_down_editor.ts, onValueChanged
inherited from editor.ts): fieldTemplate, onPageLoading, onPullRefresh,
onScroll, onValueChanged all store null -> add | null.

Removed the 3 now-unused @ts-expect-error directives above
onScroll/onPullRefresh/onPageLoading in lookup.ts, made stale by the
widened types.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/__internal/ui/lookup.ts |  3 ---
 packages/devextreme/js/ui/lookup.d.ts          | 10 +++++-----
 2 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/lookup.ts b/packages/devextreme/js/__internal/ui/lookup.ts
index 59480ceab46c..a6825699e02d 100644
--- a/packages/devextreme/js/__internal/ui/lookup.ts
+++ b/packages/devextreme/js/__internal/ui/lookup.ts
@@ -135,11 +135,8 @@ class Lookup extends DropDownList<LookupProperties> {
       pulledDownText: messageLocalization.format('dxList-pulledDownText'),
       refreshingText: messageLocalization.format('dxList-refreshingText'),
       pageLoadingText: messageLocalization.format('dxList-pageLoadingText'),
-      // @ts-expect-error public API
       onScroll: null,
-      // @ts-expect-error public API
       onPullRefresh: null,
-      // @ts-expect-error public API
       onPageLoading: null,
       pageLoadMode: 'scrollBottom',
       nextButtonText: messageLocalization.format('dxList-nextButtonText'),
diff --git a/packages/devextreme/js/ui/lookup.d.ts b/packages/devextreme/js/ui/lookup.d.ts
index 5bd553115a91..9ef4398d7654 100644
--- a/packages/devextreme/js/ui/lookup.d.ts
+++ b/packages/devextreme/js/ui/lookup.d.ts
@@ -185,7 +185,7 @@ export interface dxLookupOptions extends dxDropDownListOptions<dxLookup> {
      * @type_function_return string|Element|jQuery
      * @public
      */
-    fieldTemplate?: template | ((selectedItem: any, fieldElement: DxElement) => string | UserDefinedElement);
+    fieldTemplate?: template | ((selectedItem: any, fieldElement: DxElement) => string | UserDefinedElement) | null;
     /**
      * @docid
      * @default false
@@ -220,7 +220,7 @@ export interface dxLookupOptions extends dxDropDownListOptions<dxLookup> {
      * @action
      * @public
      */
-    onPageLoading?: ((e: PageLoadingEvent) => void);
+    onPageLoading?: ((e: PageLoadingEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -228,7 +228,7 @@ export interface dxLookupOptions extends dxDropDownListOptions<dxLookup> {
      * @action
      * @public
      */
-    onPullRefresh?: ((e: PullRefreshEvent) => void);
+    onPullRefresh?: ((e: PullRefreshEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -236,7 +236,7 @@ export interface dxLookupOptions extends dxDropDownListOptions<dxLookup> {
      * @action
      * @public
      */
-    onScroll?: ((e: ScrollEvent) => void);
+    onScroll?: ((e: ScrollEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -244,7 +244,7 @@ export interface dxLookupOptions extends dxDropDownListOptions<dxLookup> {
      * @action
      * @public
      */
-    onValueChanged?: ((e: ValueChangedEvent) => void);
+    onValueChanged?: ((e: ValueChangedEvent) => void) | null;
     /**
      * @docid
      * @default "scrollBottom"

From 8872d89a01e80c3456cc79784308d03d1325cc7b Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:21 +0300
Subject: [PATCH 012/100] Fix jsdoc-default-matches-type in js/ui/tag_box.d.ts

Verified against js/__internal/ui/tag_box.ts _getDefaultOptions()
(onSelectionChanged inherited from collection_widget.base.ts):
onMultiTagPreparing, onSelectAllValueChanged, onSelectionChanged all
store null -> add | null.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/ui/tag_box.d.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/devextreme/js/ui/tag_box.d.ts b/packages/devextreme/js/ui/tag_box.d.ts
index ab11d35f7a07..90c880be7daa 100644
--- a/packages/devextreme/js/ui/tag_box.d.ts
+++ b/packages/devextreme/js/ui/tag_box.d.ts
@@ -243,7 +243,7 @@ export interface dxTagBoxOptions extends Pick<dxSelectBoxOptions<dxTagBox>, Excl
      * @action
      * @public
      */
-    onMultiTagPreparing?: ((e: MultiTagPreparingEvent) => void);
+    onMultiTagPreparing?: ((e: MultiTagPreparingEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -251,7 +251,7 @@ export interface dxTagBoxOptions extends Pick<dxSelectBoxOptions<dxTagBox>, Excl
      * @action
      * @public
      */
-    onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent) => void);
+    onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -259,7 +259,7 @@ export interface dxTagBoxOptions extends Pick<dxSelectBoxOptions<dxTagBox>, Excl
      * @action
      * @public
      */
-    onSelectionChanged?: ((e: SelectionChangedEvent) => void);
+    onSelectionChanged?: ((e: SelectionChangedEvent) => void) | null;
     /**
      * @docid
      * @default 'page'

From 2751e37408047cf69cd3609497da6b934c9d276d Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:21 +0300
Subject: [PATCH 013/100] Fix jsdoc-default-matches-type in js/ui/text_box.d.ts

Verified against js/__internal/ui/text_box/text_box.ts
_getDefaultOptions(): maxLength stores null -> add | null.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/ui/text_box.d.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/devextreme/js/ui/text_box.d.ts b/packages/devextreme/js/ui/text_box.d.ts
index b90560ec439e..ff52b648e20b 100644
--- a/packages/devextreme/js/ui/text_box.d.ts
+++ b/packages/devextreme/js/ui/text_box.d.ts
@@ -152,7 +152,7 @@ export interface dxTextBoxOptions<TComponent> extends dxTextEditorOptions<TCompo
      * @default null
      * @public
      */
-    maxLength?: string | number;
+    maxLength?: string | number | null;
     /**
      * @docid
      * @default "text"

From e9162cd153427b0ee78894120a91fdbe9077366b Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:22 +0300
Subject: [PATCH 014/100] Fix jsdoc-default-matches-type in
 js/ui/number_box.d.ts

Verified against js/__internal/ui/number_box/m_number_box.base.ts
_getDefaultOptions(): buttons stores void 0 -> add | undefined.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/ui/number_box.d.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/devextreme/js/ui/number_box.d.ts b/packages/devextreme/js/ui/number_box.d.ts
index 529ceeb778cc..250f28aa45f0 100644
--- a/packages/devextreme/js/ui/number_box.d.ts
+++ b/packages/devextreme/js/ui/number_box.d.ts
@@ -161,7 +161,7 @@ export interface dxNumberBoxOptions extends dxTextEditorOptions<dxNumberBox> {
      * @default undefined
      * @public
      */
-    buttons?: Array<NumberBoxPredefinedButton | TextEditorButton>;
+    buttons?: Array<NumberBoxPredefinedButton | TextEditorButton> | undefined;
     /**
      * @docid
      * @default ""

From decf954e5960a3f4225e6466e482855962bbe0b0 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:22 +0300
Subject: [PATCH 015/100] Fix jsdoc-default-matches-type in js/ui/date_box.d.ts

Verified against js/__internal/ui/date_box/date_box.base.ts
_getDefaultOptions() (maxLength inherited from text_box.ts):
- disabledDates, maxLength, displayFormat store null -> add | null
- value?: DateLike is a known linter blind spot (DateLike already
  includes null; the linter does not resolve type aliases) -> left
  untouched, no edit needed

Follow-on fixes required to keep check-types clean:
- Removed 2 now-unused @ts-expect-error above displayFormat/
  disabledDates in date_box.base.ts, made stale by the widened types.
- Widened Strategy.getDisplayFormat's displayFormat param to accept
  | null across all 6 date_box strategy implementations (base,
  calendar, calendar_with_time, date_view, list, native); all bodies
  already treat null/undefined identically via `||` fallback, so this
  is a safe, behavior-preserving signature widening (same pattern as
  the earlier List.scrollToItem() fix).
- Fixed a separate, unrelated latent bug exposed by the above: added
  the missing `useHiddenSubmitElement?: boolean;` field to
  DateBoxBaseProperties (already present on the internal
  DropDownEditorProperties type it structurally extends), resolving an
  excess-property-check error on the _getDefaultOptions() object
  literal that TypeScript had not previously surfaced.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 .../devextreme/js/__internal/ui/date_box/date_box.base.ts   | 3 +--
 .../__internal/ui/date_box/m_date_box.strategy.calendar.ts  | 2 +-
 .../ui/date_box/m_date_box.strategy.calendar_with_time.ts   | 2 +-
 .../__internal/ui/date_box/m_date_box.strategy.date_view.ts | 2 +-
 .../js/__internal/ui/date_box/m_date_box.strategy.list.ts   | 2 +-
 .../js/__internal/ui/date_box/m_date_box.strategy.native.ts | 2 +-
 .../js/__internal/ui/date_box/m_date_box.strategy.ts        | 5 +++--
 packages/devextreme/js/ui/date_box.d.ts                     | 6 +++---
 8 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/date_box/date_box.base.ts b/packages/devextreme/js/__internal/ui/date_box/date_box.base.ts
index dd0786c15623..6f87812d9349 100644
--- a/packages/devextreme/js/__internal/ui/date_box/date_box.base.ts
+++ b/packages/devextreme/js/__internal/ui/date_box/date_box.base.ts
@@ -74,6 +74,7 @@ export interface DateBoxBaseProperties extends Omit<Properties, 'onClosed' | 'on
   buttonsLocation?: string;
   emptyDateValue?: Date;
   _showValidationIcon?: boolean;
+  useHiddenSubmitElement?: boolean;
 }
 
 class DateBox extends DropDownEditor<DateBoxBaseProperties> {
@@ -104,10 +105,8 @@ class DateBox extends DropDownEditor<DateBoxBaseProperties> {
       type: 'date',
       showAnalogClock: true,
       value: null,
-      // @ts-expect-error ts-error
       displayFormat: null,
       interval: 30,
-      // @ts-expect-error ts-error
       disabledDates: null,
       pickerType: PICKER_TYPE.calendar,
       invalidDateMessage: messageLocalization.format('dxDateBox-validation-datetime'),
diff --git a/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.calendar.ts b/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.calendar.ts
index 4de85e79e16d..6eb30e302e44 100644
--- a/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.calendar.ts
+++ b/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.calendar.ts
@@ -94,7 +94,7 @@ class CalendarStrategy extends DateBoxStrategy {
     };
   }
 
-  getDisplayFormat(displayFormat?: Format): Format {
+  getDisplayFormat(displayFormat?: Format | null): Format {
     const globalDateFormat = getGlobalFormatByDataType('date');
     // eslint-disable-next-line @typescript-eslint/prefer-nullish-coalescing
     return displayFormat || globalDateFormat || 'shortdate';
diff --git a/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.calendar_with_time.ts b/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.calendar_with_time.ts
index c2e4a3e5ab61..d7fa093477bf 100644
--- a/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.calendar_with_time.ts
+++ b/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.calendar_with_time.ts
@@ -56,7 +56,7 @@ class CalendarWithTimeStrategy extends CalendarStrategy {
     return dateUtils.sameDate(this._getContouredValue(), this.widgetOption('value'));
   }
 
-  getDisplayFormat(displayFormat?: Format): Format {
+  getDisplayFormat(displayFormat?: Format | null): Format {
     const globalDateTimeFormat = getGlobalFormatByDataType('datetime');
     // eslint-disable-next-line @typescript-eslint/prefer-nullish-coalescing
     return displayFormat || globalDateTimeFormat || 'shortdateshorttime';
diff --git a/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.date_view.ts b/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.date_view.ts
index 2b0fe805ff17..781689a73ebe 100644
--- a/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.date_view.ts
+++ b/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.date_view.ts
@@ -38,7 +38,7 @@ class DateViewStrategy extends DateBoxStrategy {
     };
   }
 
-  getDisplayFormat(displayFormat: Format): Format {
+  getDisplayFormat(displayFormat: Format | null | undefined): Format {
     const { type = 'date' } = this.dateBox.option();
     const globalFormat = type === 'date' || type === 'datetime'
       ? getGlobalFormatByDataType(type)
diff --git a/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.list.ts b/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.list.ts
index ea2157dab71e..66f0ea1a6958 100644
--- a/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.list.ts
+++ b/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.list.ts
@@ -59,7 +59,7 @@ class ListStrategy extends DateBoxStrategy {
     };
   }
 
-  getDisplayFormat(displayFormat?: Format): Format {
+  getDisplayFormat(displayFormat?: Format | null): Format {
     const globalTimeFormat = getGlobalFormatByDataType('time');
     // eslint-disable-next-line @typescript-eslint/prefer-nullish-coalescing
     return displayFormat || globalTimeFormat || 'shorttime';
diff --git a/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.native.ts b/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.native.ts
index 5b0124f2de39..d61a4ed8cbbd 100644
--- a/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.native.ts
+++ b/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.native.ts
@@ -71,7 +71,7 @@ class NativeStrategy extends DateBoxStrategy {
     };
   }
 
-  getDisplayFormat(displayFormat?: Format): Format {
+  getDisplayFormat(displayFormat?: Format | null): Format {
     const type = this._getDateBoxType();
     const globalFormat = type === 'date' || type === 'datetime' || type === 'datetime-local'
       ? getGlobalFormatByDataType(type === 'datetime-local' ? 'datetime' : type)
diff --git a/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.ts b/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.ts
index 9a9fb5132150..548f7dfaaa25 100644
--- a/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.ts
+++ b/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.ts
@@ -62,8 +62,9 @@ class DateBoxStrategy extends (Class.inherit({}) as new() => {}) {
     return { mode: 'text' };
   }
 
-  getDisplayFormat(displayFormat: Format): Format {
-    return displayFormat;
+  getDisplayFormat(displayFormat?: Format | null): Format {
+    // eslint-disable-next-line @typescript-eslint/prefer-nullish-coalescing
+    return displayFormat || 'shortdate';
   }
 
   supportedKeys(): Record<string, (e: KeyboardEvent) => void> {
diff --git a/packages/devextreme/js/ui/date_box.d.ts b/packages/devextreme/js/ui/date_box.d.ts
index bf25a009678c..5ce6bd2d987e 100644
--- a/packages/devextreme/js/ui/date_box.d.ts
+++ b/packages/devextreme/js/ui/date_box.d.ts
@@ -212,7 +212,7 @@ export interface dxDateBoxOptions extends DateBoxBaseOptions<dxDateBox> {
      * @type_function_param1_field component:dxDateBox
      * @public
      */
-    disabledDates?: Array<Date> | ((data: DisabledDate) => boolean);
+    disabledDates?: Array<Date> | ((data: DisabledDate) => boolean) | null;
     /**
      * @docid
      * @default {}
@@ -242,7 +242,7 @@ export interface dxDateBoxOptions extends DateBoxBaseOptions<dxDateBox> {
      * @default null
      * @public
      */
-    maxLength?: string | number;
+    maxLength?: string | number | null;
     /**
      * @docid
      * @default ""
@@ -328,7 +328,7 @@ export interface DateBoxBaseOptions<TComponent> extends Omit<
      * @default null
      * @public
      */
-    displayFormat?: Format;
+    displayFormat?: Format | null;
     /**
      * @docid
      * @type Date|number|string|null|undefined

From 10fe3e2fa007eff79fed01907cb6aa912fd22a2d Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:22 +0300
Subject: [PATCH 016/100] Fix jsdoc-default-matches-type in js/ui/calendar.d.ts

Verified against js/__internal/ui/calendar/calendar.ts
_getDefaultOptions(): disabledDates stores null -> add | null.

value?: DateLike | DateLike[] is a known linter blind spot (DateLike
already includes null; the linter does not resolve type aliases) ->
left untouched, no edit needed.

Follow-on fix: widened the same-named disabledDates field on
BaseViewProperties in calendar.base_view.ts (which also stores null
in its own _getDefaultOptions()) to keep the object literal built in
calendar.ts:_viewConfig() assignable.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 .../devextreme/js/__internal/ui/calendar/calendar.base_view.ts  | 2 +-
 packages/devextreme/js/ui/calendar.d.ts                         | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/calendar/calendar.base_view.ts b/packages/devextreme/js/__internal/ui/calendar/calendar.base_view.ts
index 0253b64daa8a..98060dfac0c9 100644
--- a/packages/devextreme/js/__internal/ui/calendar/calendar.base_view.ts
+++ b/packages/devextreme/js/__internal/ui/calendar/calendar.base_view.ts
@@ -89,7 +89,7 @@ export interface BaseViewProperties extends WidgetProperties {
 
   colCount: number;
 
-  disabledDates?: Date[] | ((data: DisabledDate) => boolean);
+  disabledDates?: Date[] | ((data: DisabledDate) => boolean) | null;
 
   zoomLevel?: CalendarZoomLevel;
 
diff --git a/packages/devextreme/js/ui/calendar.d.ts b/packages/devextreme/js/ui/calendar.d.ts
index 92798c901546..9b4f186759c5 100644
--- a/packages/devextreme/js/ui/calendar.d.ts
+++ b/packages/devextreme/js/ui/calendar.d.ts
@@ -125,7 +125,7 @@ export interface dxCalendarOptions extends EditorOptions<dxCalendar> {
      * @type_function_param1 data:DisabledDate
      * @public
      */
-    disabledDates?: Array<Date> | ((data: DisabledDate) => boolean);
+    disabledDates?: Array<Date> | ((data: DisabledDate) => boolean) | null;
     /**
      * @docid
      * @default undefined

From 144e41daa45757a3051e95fc34cab1197634d51f Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:23 +0300
Subject: [PATCH 017/100] Fix jsdoc-default-matches-type in
 js/ui/check_box.d.ts

value had a concrete @default false but the type included a spurious
| undefined (R2: a concrete @default must not include | undefined).
Verified against js/__internal/ui/check_box/check_box.tsx
(defaultCheckBoxProps.defaultValue: false, used whenever value is
untouched) that the real stored/resolved default is the concrete
false, never undefined -> removed | undefined, kept | null (used for
the indeterminate three-state case).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/ui/check_box.d.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/devextreme/js/ui/check_box.d.ts b/packages/devextreme/js/ui/check_box.d.ts
index d2cbe7adff3a..878ee0230fdb 100644
--- a/packages/devextreme/js/ui/check_box.d.ts
+++ b/packages/devextreme/js/ui/check_box.d.ts
@@ -104,7 +104,7 @@ export interface dxCheckBoxOptions extends EditorOptions<dxCheckBox> {
      * @default false
      * @public
      */
-    value?: boolean | null | undefined;
+    value?: boolean | null;
 }
 /**
  * @docid

From d5c6eb6d9dc83ea45862e121a1f2f29d55d48af8 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:23 +0300
Subject: [PATCH 018/100] fix(list): widen event handler types to allow null
 default

Fixed jsdoc-default-matches-type warnings for 12 event handler options
in js/ui/list.d.ts: onGroupRendered, onItemClick, onItemContextMenu,
onItemDeleted, onItemDeleting, onItemHold, onItemReordered, onItemSwipe,
onPageLoading, onPullRefresh, onScroll, onSelectAllValueChanged.

Verified runtime defaults are null in list.base.ts, list.edit.ts and
collection_widget.base.ts/collection_widget.edit.ts (already fixed
in a prior batch). Widened each type with `| null` and removed the
now-stale @ts-expect-error suppressions in list.base.ts and
list.edit.ts.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 .../js/__internal/ui/list/list.base.ts        |  5 ----
 .../js/__internal/ui/list/list.edit.ts        |  1 -
 packages/devextreme/js/ui/list.d.ts           | 24 +++++++++----------
 3 files changed, 12 insertions(+), 18 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/list/list.base.ts b/packages/devextreme/js/__internal/ui/list/list.base.ts
index cad8293a979a..8a97b9989f3d 100644
--- a/packages/devextreme/js/__internal/ui/list/list.base.ts
+++ b/packages/devextreme/js/__internal/ui/list/list.base.ts
@@ -275,18 +275,13 @@ export class ListBase extends CollectionWidget<ListBaseProperties, Item> {
       pulledDownText: messageLocalization.format('dxList-pulledDownText'),
       refreshingText: messageLocalization.format('dxList-refreshingText'),
       pageLoadingText: messageLocalization.format('dxList-pageLoadingText'),
-      // @ts-expect-error ts-error
       onScroll: null,
-      // @ts-expect-error ts-error
       onPullRefresh: null,
-      // @ts-expect-error ts-error
       onPageLoading: null,
       pageLoadMode: 'scrollBottom',
       nextButtonText: messageLocalization.format('dxList-nextButtonText'),
-      // @ts-expect-error ts-error
       onItemSwipe: null,
       grouped: false,
-      // @ts-expect-error ts-error
       onGroupRendered: null,
       collapsibleGroups: false,
       groupTemplate: 'group',
diff --git a/packages/devextreme/js/__internal/ui/list/list.edit.ts b/packages/devextreme/js/__internal/ui/list/list.edit.ts
index 7236648c336e..8e548da5e045 100644
--- a/packages/devextreme/js/__internal/ui/list/list.edit.ts
+++ b/packages/devextreme/js/__internal/ui/list/list.edit.ts
@@ -155,7 +155,6 @@ class ListEdit extends ListBase {
       showSelectionControls: false,
       selectionMode: 'none',
       selectAllMode: 'page',
-      // @ts-expect-error ts-error
       onSelectAllValueChanged: null,
       selectAllText: localizationMessage.format('dxList-selectAll'),
       menuItems: [],
diff --git a/packages/devextreme/js/ui/list.d.ts b/packages/devextreme/js/ui/list.d.ts
index e4b9210959a0..4a0e233d8133 100644
--- a/packages/devextreme/js/ui/list.d.ts
+++ b/packages/devextreme/js/ui/list.d.ts
@@ -406,7 +406,7 @@ export interface dxListOptions<
      * @action
      * @public
      */
-    onGroupRendered?: ((e: GroupRenderedEvent<TItem, TKey>) => void);
+    onGroupRendered?: ((e: GroupRenderedEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -415,7 +415,7 @@ export interface dxListOptions<
      * @action
      * @public
      */
-    onItemClick?: ((e: ItemClickEvent<TItem, TKey>) => void) | string;
+    onItemClick?: ((e: ItemClickEvent<TItem, TKey>) => void) | string | null;
     /**
      * @docid
      * @default null
@@ -423,7 +423,7 @@ export interface dxListOptions<
      * @action
      * @public
      */
-    onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void);
+    onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -432,7 +432,7 @@ export interface dxListOptions<
      * @hidden false
      * @public
      */
-    onItemDeleted?: ((e: ItemDeletedEvent<TItem, TKey>) => void);
+    onItemDeleted?: ((e: ItemDeletedEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -441,7 +441,7 @@ export interface dxListOptions<
      * @hidden false
      * @public
      */
-    onItemDeleting?: ((e: ItemDeletingEvent<TItem, TKey>) => void);
+    onItemDeleting?: ((e: ItemDeletingEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -449,7 +449,7 @@ export interface dxListOptions<
      * @action
      * @public
      */
-    onItemHold?: ((e: ItemHoldEvent<TItem, TKey>) => void);
+    onItemHold?: ((e: ItemHoldEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -458,7 +458,7 @@ export interface dxListOptions<
      * @hidden false
      * @public
      */
-    onItemReordered?: ((e: ItemReorderedEvent<TItem, TKey>) => void);
+    onItemReordered?: ((e: ItemReorderedEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -466,7 +466,7 @@ export interface dxListOptions<
      * @action
      * @public
      */
-    onItemSwipe?: ((e: ItemSwipeEvent<TItem, TKey>) => void);
+    onItemSwipe?: ((e: ItemSwipeEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -474,7 +474,7 @@ export interface dxListOptions<
      * @action
      * @public
      */
-    onPageLoading?: ((e: PageLoadingEvent<TItem, TKey>) => void);
+    onPageLoading?: ((e: PageLoadingEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -482,7 +482,7 @@ export interface dxListOptions<
      * @action
      * @public
      */
-    onPullRefresh?: ((e: PullRefreshEvent<TItem, TKey>) => void);
+    onPullRefresh?: ((e: PullRefreshEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -490,7 +490,7 @@ export interface dxListOptions<
      * @action
      * @public
      */
-    onScroll?: ((e: ScrollEvent<TItem, TKey>) => void);
+    onScroll?: ((e: ScrollEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -498,7 +498,7 @@ export interface dxListOptions<
      * @action
      * @public
      */
-    onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent<TItem, TKey>) => void);
+    onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default "scrollBottom"

From 0f101a89ddb41def3f1d20040632f6d60b09721f Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:24 +0300
Subject: [PATCH 019/100] fix(tree_view): widen event handler types to allow
 null default
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Fixed jsdoc-default-matches-type warnings for 9 event handler options
in js/ui/tree_view.d.ts: onItemClick, onItemCollapsed, onItemContextMenu,
onItemExpanded, onItemHold, onItemRendered, onItemSelectionChanged,
onSelectAllValueChanged, onSelectionChanged.

Verified runtime defaults are null in tree_view.base.ts
(onItemSelectionChanged, onItemExpanded, onItemCollapsed,
onSelectAllValueChanged), collection_widget.base.ts (onItemClick,
onItemContextMenu, onItemHold, onItemRendered — already widened in a
prior batch), and collection_widget.edit.ts (onSelectionChanged).
Widened each type with `| null`.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/ui/tree_view.d.ts | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/packages/devextreme/js/ui/tree_view.d.ts b/packages/devextreme/js/ui/tree_view.d.ts
index d83b61dce737..42ef190071fa 100644
--- a/packages/devextreme/js/ui/tree_view.d.ts
+++ b/packages/devextreme/js/ui/tree_view.d.ts
@@ -263,7 +263,7 @@ export interface dxTreeViewOptions<TItem extends ItemLike = any, TKey = any>
      * @action
      * @public
      */
-    onItemClick?: ((e: ItemClickEvent<TItem, TKey>) => void);
+    onItemClick?: ((e: ItemClickEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -271,7 +271,7 @@ export interface dxTreeViewOptions<TItem extends ItemLike = any, TKey = any>
      * @action
      * @public
      */
-    onItemCollapsed?: ((e: ItemCollapsedEvent<TItem, TKey>) => void);
+    onItemCollapsed?: ((e: ItemCollapsedEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -279,7 +279,7 @@ export interface dxTreeViewOptions<TItem extends ItemLike = any, TKey = any>
      * @action
      * @public
      */
-    onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void);
+    onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -287,7 +287,7 @@ export interface dxTreeViewOptions<TItem extends ItemLike = any, TKey = any>
      * @action
      * @public
      */
-    onItemExpanded?: ((e: ItemExpandedEvent<TItem, TKey>) => void);
+    onItemExpanded?: ((e: ItemExpandedEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -295,7 +295,7 @@ export interface dxTreeViewOptions<TItem extends ItemLike = any, TKey = any>
      * @action
      * @public
      */
-    onItemHold?: ((e: ItemHoldEvent<TItem, TKey>) => void);
+    onItemHold?: ((e: ItemHoldEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -303,7 +303,7 @@ export interface dxTreeViewOptions<TItem extends ItemLike = any, TKey = any>
      * @action
      * @public
      */
-    onItemRendered?: ((e: ItemRenderedEvent<TItem, TKey>) => void);
+    onItemRendered?: ((e: ItemRenderedEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -311,7 +311,7 @@ export interface dxTreeViewOptions<TItem extends ItemLike = any, TKey = any>
      * @action
      * @public
      */
-    onItemSelectionChanged?: ((e: ItemSelectionChangedEvent<TItem, TKey>) => void);
+    onItemSelectionChanged?: ((e: ItemSelectionChangedEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -319,7 +319,7 @@ export interface dxTreeViewOptions<TItem extends ItemLike = any, TKey = any>
      * @action
      * @public
      */
-    onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent<TItem, TKey>) => void);
+    onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -328,7 +328,7 @@ export interface dxTreeViewOptions<TItem extends ItemLike = any, TKey = any>
      * @public
      * @override
      */
-    onSelectionChanged?: ((e: SelectionChangedEvent<TItem, TKey>) => void);
+    onSelectionChanged?: ((e: SelectionChangedEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default 'parentId'

From 0cb08cf98a5236f95bf0ba488a2180a6fea8051d Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:24 +0300
Subject: [PATCH 020/100] fix(menu): widen submenu event handler types to allow
 null default

Fixed jsdoc-default-matches-type warnings for 4 event handler options
in js/ui/menu.d.ts: onSubmenuHidden, onSubmenuHiding, onSubmenuShowing,
onSubmenuShown.

Verified runtime defaults are null in js/__internal/ui/menu/menu.ts
_getDefaultOptions(). Widened each type with `| null` and removed the
now-stale @ts-expect-error suppressions.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/__internal/ui/menu/menu.ts | 4 ----
 packages/devextreme/js/ui/menu.d.ts               | 8 ++++----
 2 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/menu/menu.ts b/packages/devextreme/js/__internal/ui/menu/menu.ts
index dc90fa51ce72..82cf2399bd78 100644
--- a/packages/devextreme/js/__internal/ui/menu/menu.ts
+++ b/packages/devextreme/js/__internal/ui/menu/menu.ts
@@ -166,13 +166,9 @@ class Menu extends MenuBase<MenuProperties> {
         },
       },
       hideSubmenuOnMouseLeave: false,
-      // @ts-expect-error ts-error
       onSubmenuShowing: null,
-      // @ts-expect-error ts-error
       onSubmenuShown: null,
-      // @ts-expect-error ts-error
       onSubmenuHiding: null,
-      // @ts-expect-error ts-error
       onSubmenuHidden: null,
       adaptivityEnabled: false,
     };
diff --git a/packages/devextreme/js/ui/menu.d.ts b/packages/devextreme/js/ui/menu.d.ts
index 39cfe067f19d..564894640825 100644
--- a/packages/devextreme/js/ui/menu.d.ts
+++ b/packages/devextreme/js/ui/menu.d.ts
@@ -215,7 +215,7 @@ export interface dxMenuOptions<
      * @action
      * @public
      */
-    onSubmenuHidden?: ((e: SubmenuHiddenEvent<TItem, TKey>) => void);
+    onSubmenuHidden?: ((e: SubmenuHiddenEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -223,7 +223,7 @@ export interface dxMenuOptions<
      * @action
      * @public
      */
-    onSubmenuHiding?: ((e: SubmenuHidingEvent<TItem, TKey>) => void);
+    onSubmenuHiding?: ((e: SubmenuHidingEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -231,7 +231,7 @@ export interface dxMenuOptions<
      * @action
      * @public
      */
-    onSubmenuShowing?: ((e: SubmenuShowingEvent<TItem, TKey>) => void);
+    onSubmenuShowing?: ((e: SubmenuShowingEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -239,7 +239,7 @@ export interface dxMenuOptions<
      * @action
      * @public
      */
-    onSubmenuShown?: ((e: SubmenuShownEvent<TItem, TKey>) => void);
+    onSubmenuShown?: ((e: SubmenuShownEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default "horizontal"

From e5e7c05e26d978567d8868dff231d4b7c9957211 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:25 +0300
Subject: [PATCH 021/100] fix(context_menu): widen event handler types to allow
 null default

Fixed jsdoc-default-matches-type warnings for 5 event handler options
in js/ui/context_menu.d.ts: onHidden, onHiding, onPositioning, onShowing,
onShown.

Verified runtime defaults are null in
js/__internal/ui/context_menu/context_menu.ts _getDefaultOptions().
Widened each type with `| null`.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/ui/context_menu.d.ts | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/packages/devextreme/js/ui/context_menu.d.ts b/packages/devextreme/js/ui/context_menu.d.ts
index 17bb84249583..3840582c6ad5 100644
--- a/packages/devextreme/js/ui/context_menu.d.ts
+++ b/packages/devextreme/js/ui/context_menu.d.ts
@@ -184,7 +184,7 @@ export interface dxContextMenuOptions<
      * @action
      * @public
      */
-    onHidden?: ((e: HiddenEvent<TItem, TKey>) => void);
+    onHidden?: ((e: HiddenEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -192,7 +192,7 @@ export interface dxContextMenuOptions<
      * @action
      * @public
      */
-    onHiding?: ((e: HidingEvent<TItem, TKey>) => void);
+    onHiding?: ((e: HidingEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -200,7 +200,7 @@ export interface dxContextMenuOptions<
      * @action
      * @public
      */
-    onPositioning?: ((e: PositioningEvent<TItem, TKey>) => void);
+    onPositioning?: ((e: PositioningEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -208,7 +208,7 @@ export interface dxContextMenuOptions<
      * @action
      * @public
      */
-    onShowing?: ((e: ShowingEvent<TItem, TKey>) => void);
+    onShowing?: ((e: ShowingEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -216,7 +216,7 @@ export interface dxContextMenuOptions<
      * @action
      * @public
      */
-    onShown?: ((e: ShownEvent<TItem, TKey>) => void);
+    onShown?: ((e: ShownEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default { my: 'top left', at: 'top left' }

From e4f298cbe2ea0a4a81ec852f1857a4555271b1ba Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:25 +0300
Subject: [PATCH 022/100] fix(accordion): widen onItemTitleClick type to allow
 null default

Fixed jsdoc-default-matches-type warning for onItemTitleClick in
js/ui/accordion.d.ts.

Verified runtime default is null in js/__internal/ui/accordion.ts
_getDefaultOptions(). Widened the type with `| null` and removed the
now-stale @ts-expect-error suppression.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/__internal/ui/accordion.ts | 1 -
 packages/devextreme/js/ui/accordion.d.ts          | 2 +-
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/accordion.ts b/packages/devextreme/js/__internal/ui/accordion.ts
index 135238bb4f86..2a6c74f575a4 100644
--- a/packages/devextreme/js/__internal/ui/accordion.ts
+++ b/packages/devextreme/js/__internal/ui/accordion.ts
@@ -62,7 +62,6 @@ class Accordion extends CollectionWidgetLiveUpdate<AccordionProperties, Item, Co
       ...super._getDefaultOptions(),
       hoverStateEnabled: true,
       itemTitleTemplate: 'title',
-      // @ts-expect-error ts-error
       onItemTitleClick: null,
       selectedIndex: 0,
       collapsible: false,
diff --git a/packages/devextreme/js/ui/accordion.d.ts b/packages/devextreme/js/ui/accordion.d.ts
index ced6b0d20555..b11df396c56b 100644
--- a/packages/devextreme/js/ui/accordion.d.ts
+++ b/packages/devextreme/js/ui/accordion.d.ts
@@ -201,7 +201,7 @@ export interface dxAccordionOptions<
      * @action
      * @public
      */
-    onItemTitleClick?: ((e: ItemTitleClickEvent<TItem, TKey>) => void) | string;
+    onItemTitleClick?: ((e: ItemTitleClickEvent<TItem, TKey>) => void) | string | null;
     /**
      * @docid
      * @default false

From 80c3d351d0f31e1da412b8c0efce56dc4ba10947 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:25 +0300
Subject: [PATCH 023/100] fix(tab_panel): widen title event handler types to
 allow null default

Fixed jsdoc-default-matches-type warnings for 3 event handler options
in js/ui/tab_panel.d.ts: onTitleClick, onTitleHold, onTitleRendered.

Verified runtime defaults are null in
js/__internal/ui/tab_panel/tab_panel.ts _getDefaultOptions(). Widened
each type with `| null` and removed the now-stale @ts-expect-error
suppressions.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/__internal/ui/tab_panel/tab_panel.ts | 3 ---
 packages/devextreme/js/ui/tab_panel.d.ts                    | 6 +++---
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/tab_panel/tab_panel.ts b/packages/devextreme/js/__internal/ui/tab_panel/tab_panel.ts
index 99c3a97a877e..f37e5338b8c1 100644
--- a/packages/devextreme/js/__internal/ui/tab_panel/tab_panel.ts
+++ b/packages/devextreme/js/__internal/ui/tab_panel/tab_panel.ts
@@ -115,11 +115,8 @@ class TabPanel extends MultiView<TabPanelProperties> {
       tabsPosition: TABS_POSITION.top,
       iconPosition: ICON_POSITION.start,
       stylingMode: STYLING_MODE.primary,
-      // @ts-expect-error ts-error
       onTitleClick: null,
-      // @ts-expect-error ts-error
       onTitleHold: null,
-      // @ts-expect-error ts-error
       onTitleRendered: null,
       badgeExpr(data: Item): string | undefined {
         return data?.badge;
diff --git a/packages/devextreme/js/ui/tab_panel.d.ts b/packages/devextreme/js/ui/tab_panel.d.ts
index da990eae6bb6..f40e4dd15d2c 100644
--- a/packages/devextreme/js/ui/tab_panel.d.ts
+++ b/packages/devextreme/js/ui/tab_panel.d.ts
@@ -224,7 +224,7 @@ export interface dxTabPanelOptions<
      * @action
      * @public
      */
-    onTitleClick?: ((e: TitleClickEvent<TItem, TKey>) => void) | string;
+    onTitleClick?: ((e: TitleClickEvent<TItem, TKey>) => void) | string | null;
     /**
      * @docid
      * @default null
@@ -232,7 +232,7 @@ export interface dxTabPanelOptions<
      * @action
      * @public
      */
-    onTitleHold?: ((e: TitleHoldEvent<TItem, TKey>) => void);
+    onTitleHold?: ((e: TitleHoldEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default null
@@ -240,7 +240,7 @@ export interface dxTabPanelOptions<
      * @action
      * @public
      */
-    onTitleRendered?: ((e: TitleRenderedEvent<TItem, TKey>) => void);
+    onTitleRendered?: ((e: TitleRenderedEvent<TItem, TKey>) => void) | null;
     /**
      * @docid
      * @default false

From 80087032526e72c5dfe36742124b46ad318b4fb8 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:26 +0300
Subject: [PATCH 024/100] fix(button): correct onClick default docs and widen
 type to undefined

Fixed jsdoc-default-matches-type warning for onClick in js/ui/button.d.ts.

Verified runtime: js/__internal/ui/button/button.tsx's defaultButtonProps
has no onClick entry, so the ComponentWrapper-merged _getDefaultOptions()
never sets onClick, meaning .option('onClick') stays undefined until
explicitly assigned (same "no explicit null in _getDefaultOptions ->
undefined" case as the buttons field in ui.drop_down_editor.d.ts, per the
convention doc). The previous `@default null` was inaccurate; corrected
to `@default undefined` and widened the type with `| undefined`.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/ui/button.d.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/devextreme/js/ui/button.d.ts b/packages/devextreme/js/ui/button.d.ts
index 210359566f8e..297de18cd56a 100644
--- a/packages/devextreme/js/ui/button.d.ts
+++ b/packages/devextreme/js/ui/button.d.ts
@@ -109,12 +109,12 @@ export interface dxButtonOptions extends WidgetOptions<dxButton> {
     icon?: string;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/button:ClickEvent}
      * @action
      * @public
      */
-    onClick?: ((e: ClickEvent) => void);
+    onClick?: ((e: ClickEvent) => void) | undefined;
     /**
      * @docid
      * @default 'contained'

From 0190daf0fb56b49aa12f3a583d9dbb1246c778d6 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:26 +0300
Subject: [PATCH 025/100] fix(button_group): widen event handler types to allow
 null default

Fixed jsdoc-default-matches-type warnings for 2 event handler options
in js/ui/button_group.d.ts: onItemClick, onSelectionChanged.

Verified runtime defaults are null in js/__internal/ui/button_group.ts
_getDefaultOptions(). Widened each type with `| null` and removed the
now-stale @ts-expect-error suppressions.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/__internal/ui/button_group.ts | 2 --
 packages/devextreme/js/ui/button_group.d.ts          | 4 ++--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/button_group.ts b/packages/devextreme/js/__internal/ui/button_group.ts
index 7ee13d621c5e..69f083399605 100644
--- a/packages/devextreme/js/__internal/ui/button_group.ts
+++ b/packages/devextreme/js/__internal/ui/button_group.ts
@@ -177,9 +177,7 @@ class ButtonGroup extends Widget<Properties> {
       keyExpr: 'text',
       items: [],
       buttonTemplate: 'content',
-      // @ts-expect-error ts-error
       onSelectionChanged: null,
-      // @ts-expect-error ts-error
       onItemClick: null,
     };
   }
diff --git a/packages/devextreme/js/ui/button_group.d.ts b/packages/devextreme/js/ui/button_group.d.ts
index 5c9833cc14df..ae67c96f405a 100644
--- a/packages/devextreme/js/ui/button_group.d.ts
+++ b/packages/devextreme/js/ui/button_group.d.ts
@@ -126,7 +126,7 @@ export interface dxButtonGroupOptions extends WidgetOptions<dxButtonGroup> {
      * @action
      * @public
      */
-    onItemClick?: ((e: ItemClickEvent) => void);
+    onItemClick?: ((e: ItemClickEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -134,7 +134,7 @@ export interface dxButtonGroupOptions extends WidgetOptions<dxButtonGroup> {
      * @action
      * @public
      */
-    onSelectionChanged?: ((e: SelectionChangedEvent) => void);
+    onSelectionChanged?: ((e: SelectionChangedEvent) => void) | null;
     /**
      * @docid
      * @fires dxButtonGroupOptions.onSelectionChanged

From f2f277fd4186fa8e8c6299d1a8b3a1b01d843396 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:27 +0300
Subject: [PATCH 026/100] fix(action_sheet): fix onCancelClick/onClick default
 mismatches

Fixed jsdoc-default-matches-type warnings in js/ui/action_sheet.d.ts:
- onCancelClick (widget-level option): verified runtime default is null
  in js/__internal/ui/action_sheet.ts _getDefaultOptions(); widened the
  type with `| null` and removed the now-stale @ts-expect-error
  suppression.
- onClick (dxActionSheetItem property, Category B per the optional-fields
  typing convention): this is a per-item data field with no widget-level
  default (used only as a point-of-use fallback in the item template, not
  stored via _getDefaultOptions), so `.option()` never returns it. Removed
  the inaccurate `@default null` tag; the type is left unchanged.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/__internal/ui/action_sheet.ts | 1 -
 packages/devextreme/js/ui/action_sheet.d.ts          | 3 +--
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/action_sheet.ts b/packages/devextreme/js/__internal/ui/action_sheet.ts
index b81109ddc007..2f598ec2d0a5 100644
--- a/packages/devextreme/js/__internal/ui/action_sheet.ts
+++ b/packages/devextreme/js/__internal/ui/action_sheet.ts
@@ -52,7 +52,6 @@ class ActionSheet extends CollectionWidget<Properties> {
       showTitle: true,
       showCancelButton: true,
       cancelText: messageLocalization.format('Cancel'),
-      // @ts-expect-error ts-error
       onCancelClick: null,
       visible: false,
       noDataText: '',
diff --git a/packages/devextreme/js/ui/action_sheet.d.ts b/packages/devextreme/js/ui/action_sheet.d.ts
index c05f626ebedd..ac7acd7d3804 100644
--- a/packages/devextreme/js/ui/action_sheet.d.ts
+++ b/packages/devextreme/js/ui/action_sheet.d.ts
@@ -144,7 +144,7 @@ export interface dxActionSheetOptions<
      * @action
      * @public
      */
-    onCancelClick?: ((e: CancelClickEvent<TItem, TKey>) => void) | string;
+    onCancelClick?: ((e: CancelClickEvent<TItem, TKey>) => void) | string | null;
     /**
      * @docid
      * @default true
@@ -234,7 +234,6 @@ export interface dxActionSheetItem<TKey = any> extends CollectionWidgetItem {
     icon?: string;
     /**
      * @docid
-     * @default null
      * @type_function_param1 e:NativeEventInfo
      * @type function
      * @public

From bfa108122ebdee56a357bb7e45556ec09d8cc634 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:27 +0300
Subject: [PATCH 027/100] fix(speed_dial_action, widget): widen onContentReady
 types to allow null

Fixed jsdoc-default-matches-type warning for onContentReady in
js/ui/speed_dial_action.d.ts.

Verified runtime default is null in
js/__internal/ui/speed_dial_action/m_speed_dial_action.ts
_getDefaultOptions(). Widening only the local override initially broke
the WidgetProperties<any> constraint check in
m_speed_dial_action.ts (`class SpeedDialAction extends Widget<Properties>`),
because dxSpeedDialActionOptions.onContentReady overrides the base
WidgetOptions.onContentReady (js/ui/widget/ui.widget.d.ts), which itself
had the exact same pre-existing jsdoc-default-matches-type warning
(`@default null` but no `| null` in the type) and a confirmed `null`
runtime default in js/__internal/core/widget/widget.ts
_getDefaultOptions(). Per user decision, widened the shared base
WidgetOptions.onContentReady with `| null` as well, which is the root
cause fix and keeps the override compatible.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/ui/speed_dial_action.d.ts | 2 +-
 packages/devextreme/js/ui/widget/ui.widget.d.ts  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/devextreme/js/ui/speed_dial_action.d.ts b/packages/devextreme/js/ui/speed_dial_action.d.ts
index 6549577c0217..fa6402bb1783 100644
--- a/packages/devextreme/js/ui/speed_dial_action.d.ts
+++ b/packages/devextreme/js/ui/speed_dial_action.d.ts
@@ -97,7 +97,7 @@ export interface dxSpeedDialActionOptions extends WidgetOptions<dxSpeedDialActio
      * @action
      * @public
      */
-    onContentReady?: ((e: ContentReadyEvent) => void);
+    onContentReady?: ((e: ContentReadyEvent) => void) | null;
     /**
      * @docid
      * @public
diff --git a/packages/devextreme/js/ui/widget/ui.widget.d.ts b/packages/devextreme/js/ui/widget/ui.widget.d.ts
index 317caaa22a56..314ea2c6398e 100644
--- a/packages/devextreme/js/ui/widget/ui.widget.d.ts
+++ b/packages/devextreme/js/ui/widget/ui.widget.d.ts
@@ -55,7 +55,7 @@ export interface WidgetOptions<TComponent> extends DOMComponentOptions<TComponen
      * @action
      * @public
      */
-    onContentReady?: ((e: EventInfo<TComponent>) => void);
+    onContentReady?: ((e: EventInfo<TComponent>) => void) | null;
     /**
      * @docid
      * @default 0

From b47a0244281fd0e0f7320bac1d01a4ff27452e5a Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:27 +0300
Subject: [PATCH 028/100] fix(popup): widen resize/title event handler types to
 allow null default

Fixed jsdoc-default-matches-type warnings for 4 event handler options
in js/ui/popup.d.ts: onResize, onResizeEnd, onResizeStart, onTitleRendered.

Verified runtime defaults are null in js/__internal/ui/popup/popup.ts
_getDefaultOptions(). Widened each type with `| null` and removed a
now-stale @ts-expect-error in js/__internal/ui/lookup.ts (its popup
options literal sets onTitleRendered: null directly).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/__internal/ui/lookup.ts | 1 -
 packages/devextreme/js/ui/popup.d.ts           | 8 ++++----
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/lookup.ts b/packages/devextreme/js/__internal/ui/lookup.ts
index a6825699e02d..a5d7d7026400 100644
--- a/packages/devextreme/js/__internal/ui/lookup.ts
+++ b/packages/devextreme/js/__internal/ui/lookup.ts
@@ -158,7 +158,6 @@ class Lookup extends DropDownList<LookupProperties> {
         animation: {},
         title: '',
         titleTemplate: 'title',
-        // @ts-expect-error ts-error
         onTitleRendered: null,
         fullScreen: false,
         maxHeight: '100vh',
diff --git a/packages/devextreme/js/ui/popup.d.ts b/packages/devextreme/js/ui/popup.d.ts
index 9dca815f9ae0..2532cec2c23c 100644
--- a/packages/devextreme/js/ui/popup.d.ts
+++ b/packages/devextreme/js/ui/popup.d.ts
@@ -153,7 +153,7 @@ export interface dxPopupOptions<TComponent> extends dxOverlayOptions<TComponent>
      * @action
      * @public
      */
-    onResize?: ((e: ResizeEvent) => void);
+    onResize?: ((e: ResizeEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -163,7 +163,7 @@ export interface dxPopupOptions<TComponent> extends dxOverlayOptions<TComponent>
      * @action
      * @public
      */
-    onResizeEnd?: ((e: ResizeEndEvent) => void);
+    onResizeEnd?: ((e: ResizeEndEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -173,7 +173,7 @@ export interface dxPopupOptions<TComponent> extends dxOverlayOptions<TComponent>
      * @action
      * @public
      */
-    onResizeStart?: ((e: ResizeStartEvent) => void);
+    onResizeStart?: ((e: ResizeStartEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -182,7 +182,7 @@ export interface dxPopupOptions<TComponent> extends dxOverlayOptions<TComponent>
      * @action
      * @public
      */
-    onTitleRendered?: ((e: EventInfo<TComponent> & TitleRenderedInfo) => void);
+    onTitleRendered?: ((e: EventInfo<TComponent> & TitleRenderedInfo) => void) | null;
     /**
      * @docid
      * @public

From 990318e530907675368801bc4fb770d0bdaabad5 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:28 +0300
Subject: [PATCH 029/100] fix(drawer): widen maxSize and minSize types to allow
 null default

Widens the types of maxSize and minSize options to number | null
in js/ui/drawer.d.ts to match their verified runtime default value of null
in js/__internal/ui/drawer/drawer.ts.
Also removes now-stale @ts-expect-error suppressions in drawer.ts.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/__internal/ui/drawer/drawer.ts | 2 --
 packages/devextreme/js/ui/drawer.d.ts                 | 4 ++--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/drawer/drawer.ts b/packages/devextreme/js/__internal/ui/drawer/drawer.ts
index fd6fee3de954..4e976ba9e49f 100644
--- a/packages/devextreme/js/__internal/ui/drawer/drawer.ts
+++ b/packages/devextreme/js/__internal/ui/drawer/drawer.ts
@@ -76,9 +76,7 @@ class Drawer extends Widget<DrawerProperties> {
       ...super._getDefaultOptions(),
       position: 'left',
       opened: false,
-      // @ts-expect-error ts-error
       minSize: null,
-      // @ts-expect-error ts-error
       maxSize: null,
       shading: false,
       template: PANEL_TEMPLATE_NAME,
diff --git a/packages/devextreme/js/ui/drawer.d.ts b/packages/devextreme/js/ui/drawer.d.ts
index 767bc62ddb5a..b0e1eddc101c 100644
--- a/packages/devextreme/js/ui/drawer.d.ts
+++ b/packages/devextreme/js/ui/drawer.d.ts
@@ -83,13 +83,13 @@ export interface dxDrawerOptions extends WidgetOptions<dxDrawer> {
      * @default null
      * @public
      */
-    maxSize?: number;
+    maxSize?: number | null;
     /**
      * @docid
      * @default null
      * @public
      */
-    minSize?: number;
+    minSize?: number | null;
     /**
      * @docid
      * @fires dxDrawerOptions.onOptionChanged

From 95a64e6bb15b3d2af7372d038388ff92848ddcd0 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:28 +0300
Subject: [PATCH 030/100] fix(splitter): correct event handler default docs and
 widen types to undefined

Corrects JSDoc @default from null to undefined and widens types
to | undefined for onResize, onResizeEnd, onResizeStart,
onItemExpanded, and onItemCollapsed in js/ui/splitter.d.ts to
match their verified runtime default value of undefined in
js/__internal/ui/splitter/splitter.ts.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/ui/splitter.d.ts | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/packages/devextreme/js/ui/splitter.d.ts b/packages/devextreme/js/ui/splitter.d.ts
index 0b3bac19edf7..6272f6090279 100644
--- a/packages/devextreme/js/ui/splitter.d.ts
+++ b/packages/devextreme/js/ui/splitter.d.ts
@@ -180,44 +180,44 @@ export interface dxSplitterOptions<
     separatorSize?: number;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/splitter:ResizeEvent}
      * @action
      * @public
      */
-    onResize?: ((e: ResizeEvent) => void);
+    onResize?: ((e: ResizeEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/splitter:ResizeEndEvent}
      * @action
      * @public
      */
-    onResizeEnd?: ((e: ResizeEndEvent) => void);
+    onResizeEnd?: ((e: ResizeEndEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/splitter:ResizeStartEvent}
      * @action
      * @public
      */
-    onResizeStart?: ((e: ResizeStartEvent) => void);
+    onResizeStart?: ((e: ResizeStartEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/splitter:ItemExpandedEvent}
      * @action
      * @public
      */
-    onItemExpanded?: ((e: ItemExpandedEvent) => void);
+    onItemExpanded?: ((e: ItemExpandedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/splitter:ItemCollapsedEvent}
      * @action
      * @public
      */
-    onItemCollapsed?: ((e: ItemCollapsedEvent) => void);
+    onItemCollapsed?: ((e: ItemCollapsedEvent) => void) | undefined;
 }
 /**
  * @docid

From ce38ec522970e7220a72722d025eaf8a77770117 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:29 +0300
Subject: [PATCH 031/100] fix(load_panel): remove inaccurate default JSDoc tags
 for animation hide/show

Removes inaccurate @default null JSDoc tags from the Category B
hide and show properties of dxLoadPanelAnimation in
js/ui/load_panel.d.ts since the parent animation property is itself
initially null and these sub-properties are never directly queried.
The widening of the parent animation property is deferred (see Known Issue #4)
due to TypeScript generic contravariance constraints on Overlay event handlers.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/ui/load_panel.d.ts | 2 --
 1 file changed, 2 deletions(-)

diff --git a/packages/devextreme/js/ui/load_panel.d.ts b/packages/devextreme/js/ui/load_panel.d.ts
index 56cc55647fef..a289eae5d415 100644
--- a/packages/devextreme/js/ui/load_panel.d.ts
+++ b/packages/devextreme/js/ui/load_panel.d.ts
@@ -232,13 +232,11 @@ export interface dxLoadPanelOptions extends dxOverlayOptions<dxLoadPanel> {
 export interface dxLoadPanelAnimation extends dxOverlayAnimation {
     /**
      * @docid dxLoadPanelOptions.animation.hide
-     * @default null
      * @public
      */
     hide?: AnimationConfig;
     /**
      * @docid dxLoadPanelOptions.animation.show
-     * @default null
      * @public
      */
     show?: AnimationConfig;

From 756f0cb2f19fbee70f67e024fba3c16c4f7bd3cc Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:29 +0300
Subject: [PATCH 032/100] fix(scroll_view): widen onPullDown and onReachBottom
 event handler types

Widens the types of onPullDown and onReachBottom event handlers to
allow null defaults in js/ui/scroll_view.d.ts to match their verified
runtime default value of null in js/__internal/ui/scroll_view/scroll_view.ts.
Also removes now-stale @ts-expect-error suppressions in scroll_view.ts and
one of them in list.base.ts.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/__internal/ui/list/list.base.ts        | 1 -
 .../devextreme/js/__internal/ui/scroll_view/scroll_view.ts    | 2 --
 packages/devextreme/js/ui/scroll_view.d.ts                    | 4 ++--
 3 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/list/list.base.ts b/packages/devextreme/js/__internal/ui/list/list.base.ts
index 8a97b9989f3d..69163d01a13e 100644
--- a/packages/devextreme/js/__internal/ui/list/list.base.ts
+++ b/packages/devextreme/js/__internal/ui/list/list.base.ts
@@ -593,7 +593,6 @@ export class ListBase extends CollectionWidget<ListBaseProperties, Item> {
       onScroll: (e: ScrollEvent): void => {
         this._scrollHandler(e);
       },
-      // @ts-expect-error ts-error
       onPullDown: isPullRefreshEnabled ? this._pullDownHandler.bind(this) : null,
       // @ts-expect-error ts-error
       onReachBottom: autoPagingEnabled ? this._scrollBottomHandler.bind(this) : null,
diff --git a/packages/devextreme/js/__internal/ui/scroll_view/scroll_view.ts b/packages/devextreme/js/__internal/ui/scroll_view/scroll_view.ts
index 96937d0cf73e..a939cc0def14 100644
--- a/packages/devextreme/js/__internal/ui/scroll_view/scroll_view.ts
+++ b/packages/devextreme/js/__internal/ui/scroll_view/scroll_view.ts
@@ -105,9 +105,7 @@ export class ScrollView extends Scrollable<ScrollViewProperties> {
       pulledDownText: messageLocalization.format('dxScrollView-pulledDownText'),
       refreshingText: messageLocalization.format('dxScrollView-refreshingText'),
       reachBottomText: messageLocalization.format('dxScrollView-reachBottomText'),
-      // @ts-expect-error ts-error
       onPullDown: null,
-      // @ts-expect-error ts-error
       onReachBottom: null,
       refreshStrategy: 'pullDown',
     };
diff --git a/packages/devextreme/js/ui/scroll_view.d.ts b/packages/devextreme/js/ui/scroll_view.d.ts
index 8de3e64f39b0..5719919008c9 100644
--- a/packages/devextreme/js/ui/scroll_view.d.ts
+++ b/packages/devextreme/js/ui/scroll_view.d.ts
@@ -82,7 +82,7 @@ export interface dxScrollViewOptions extends dxScrollableOptions<dxScrollView> {
      * @action
      * @public
      */
-    onPullDown?: ((e: PullDownEvent) => void);
+    onPullDown?: ((e: PullDownEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -90,7 +90,7 @@ export interface dxScrollViewOptions extends dxScrollableOptions<dxScrollView> {
      * @action
      * @public
      */
-    onReachBottom?: ((e: ReachBottomEvent) => void);
+    onReachBottom?: ((e: ReachBottomEvent) => void) | null;
     /**
      * @docid
      * @default "Release to refresh..."

From 21f0168947eea1f9302d1f3f37642ce359221ffc Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:30 +0300
Subject: [PATCH 033/100] fix(scrollable): widen onScroll and onUpdated event
 handler types

Widens the types of onScroll and onUpdated event handlers to
allow null defaults in js/ui/scroll_view/ui.scrollable.d.ts to
match their verified runtime default value of null in
js/__internal/ui/scroll_view/scrollable.ts.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/ui/scroll_view/ui.scrollable.d.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/devextreme/js/ui/scroll_view/ui.scrollable.d.ts b/packages/devextreme/js/ui/scroll_view/ui.scrollable.d.ts
index 9600f8cc8f27..3ca926113792 100644
--- a/packages/devextreme/js/ui/scroll_view/ui.scrollable.d.ts
+++ b/packages/devextreme/js/ui/scroll_view/ui.scrollable.d.ts
@@ -70,7 +70,7 @@ export interface dxScrollableOptions<TComponent> extends DOMComponentOptions<TCo
      * @action
      * @public
      */
-    onScroll?: ((e: ScrollEventInfo<TComponent>) => void);
+    onScroll?: ((e: ScrollEventInfo<TComponent>) => void) | null;
     /**
      * @docid
      * @default null
@@ -78,7 +78,7 @@ export interface dxScrollableOptions<TComponent> extends DOMComponentOptions<TCo
      * @action
      * @public
      */
-    onUpdated?: ((e: ScrollEventInfo<TComponent>) => void);
+    onUpdated?: ((e: ScrollEventInfo<TComponent>) => void) | null;
     /**
      * @docid
      * @default false &for(non-touch_devices)

From 2e37828e5ca3a460ea34e258432ccee9da31e7b0 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:30 +0300
Subject: [PATCH 034/100] fix(resizable): correct event handler default docs
 and widen types to undefined

Corrects JSDoc @default from null to undefined and widens types
to | undefined for onResize, onResizeEnd, and onResizeStart in
js/ui/resizable.d.ts to match their verified runtime default value of
undefined in js/__internal/ui/resizable/resizable.ts.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/ui/resizable.d.ts | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/packages/devextreme/js/ui/resizable.d.ts b/packages/devextreme/js/ui/resizable.d.ts
index bbe6ced00e57..cf28a0b7f1e8 100644
--- a/packages/devextreme/js/ui/resizable.d.ts
+++ b/packages/devextreme/js/ui/resizable.d.ts
@@ -128,28 +128,28 @@ export interface dxResizableOptions extends DOMComponentOptions<dxResizable> {
     minWidth?: number;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/resizable:ResizeEvent}
      * @action
      * @public
      */
-    onResize?: ((e: ResizeEvent) => void);
+    onResize?: ((e: ResizeEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/resizable:ResizeEndEvent}
      * @action
      * @public
      */
-    onResizeEnd?: ((e: ResizeEndEvent) => void);
+    onResizeEnd?: ((e: ResizeEndEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/resizable:ResizeStartEvent}
      * @action
      * @public
      */
-    onResizeStart?: ((e: ResizeStartEvent) => void);
+    onResizeStart?: ((e: ResizeStartEvent) => void) | undefined;
     /**
      * @docid
      * @fires dxResizableOptions.onResize

From f5735bfe308d583d1f56ca23a05390a585254af2 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:30 +0300
Subject: [PATCH 035/100] fix(responsive_box): widen screenByWidth type to
 allow null default

Widens the type of screenByWidth option to Function | null in
js/ui/responsive_box.d.ts to match its verified runtime default value of
null in js/__internal/ui/responsive_box.ts.
Also removes the now-stale @ts-expect-error suppression in responsive_box.ts.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/__internal/ui/responsive_box.ts | 1 -
 packages/devextreme/js/ui/responsive_box.d.ts          | 2 +-
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/responsive_box.ts b/packages/devextreme/js/__internal/ui/responsive_box.ts
index cda2d72e7ccd..dfd30d63c41e 100644
--- a/packages/devextreme/js/__internal/ui/responsive_box.ts
+++ b/packages/devextreme/js/__internal/ui/responsive_box.ts
@@ -97,7 +97,6 @@ class ResponsiveBox extends CollectionWidget<ResponsiveBoxProperties> {
       rows: [],
       cols: [],
       singleColumnScreen: '',
-      // @ts-expect-error ts-error
       screenByWidth: null,
       height: '100%',
       width: '100%',
diff --git a/packages/devextreme/js/ui/responsive_box.d.ts b/packages/devextreme/js/ui/responsive_box.d.ts
index 633b1407cc49..4982d9b86560 100644
--- a/packages/devextreme/js/ui/responsive_box.d.ts
+++ b/packages/devextreme/js/ui/responsive_box.d.ts
@@ -175,7 +175,7 @@ export interface dxResponsiveBoxOptions<
      * @default null
      * @public
      */
-    screenByWidth?: Function;
+    screenByWidth?: Function | null;
     /**
      * @docid
      * @default ""

From 86cfdcc55264addceacf11eded442e355c5ce3bc Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:31 +0300
Subject: [PATCH 036/100] fix(range_slider): widen onValueChanged type to allow
 null default

Widens the type of onValueChanged option to ((e: ValueChangedEvent) => void) | null
in js/ui/range_slider.d.ts to match the verified runtime default value of null
inherited from the Editor base.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/ui/range_slider.d.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/devextreme/js/ui/range_slider.d.ts b/packages/devextreme/js/ui/range_slider.d.ts
index 87524ea0ee76..a69c113eb215 100644
--- a/packages/devextreme/js/ui/range_slider.d.ts
+++ b/packages/devextreme/js/ui/range_slider.d.ts
@@ -88,7 +88,7 @@ export interface dxRangeSliderOptions extends dxSliderBaseOptions<dxRangeSlider>
      * @default null
      * @public
      */
-    onValueChanged?: ((e: ValueChangedEvent) => void);
+    onValueChanged?: ((e: ValueChangedEvent) => void) | null;
     /**
      * @docid
      * @default 40

From 82d0870f3a1ef50159ce4ef8c62f54caca8e77f2 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:31 +0300
Subject: [PATCH 037/100] fix(progress_bar): widen onComplete type to allow
 null default

Widens the type of onComplete option to ((e: CompleteEvent) => void) | null
in js/ui/progress_bar.d.ts to match its verified runtime default value of null
in js/__internal/ui/m_progress_bar.ts.
Also removes the now-stale @ts-expect-error suppression in m_progress_bar.ts.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/__internal/ui/m_progress_bar.ts | 1 -
 packages/devextreme/js/ui/progress_bar.d.ts            | 2 +-
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/m_progress_bar.ts b/packages/devextreme/js/__internal/ui/m_progress_bar.ts
index 7ea20b65260d..12d8dfe63e51 100644
--- a/packages/devextreme/js/__internal/ui/m_progress_bar.ts
+++ b/packages/devextreme/js/__internal/ui/m_progress_bar.ts
@@ -43,7 +43,6 @@ class ProgressBar extends TrackBar<ProgressBarProperties> {
         return `Progress: ${Math.round(ratio * 100)}%`;
       },
       showStatus: true,
-      // @ts-expect-error ts-error
       onComplete: null,
       activeStateEnabled: false,
       statusPosition: 'bottom left',
diff --git a/packages/devextreme/js/ui/progress_bar.d.ts b/packages/devextreme/js/ui/progress_bar.d.ts
index e217db48809b..087eaac6451f 100644
--- a/packages/devextreme/js/ui/progress_bar.d.ts
+++ b/packages/devextreme/js/ui/progress_bar.d.ts
@@ -74,7 +74,7 @@ export interface dxProgressBarOptions extends dxTrackBarOptions<dxProgressBar> {
      * @action
      * @public
      */
-    onComplete?: ((e: CompleteEvent) => void);
+    onComplete?: ((e: CompleteEvent) => void) | null;
     /**
      * @docid
      * @default true

From 38719769853f256fbea74d23b6888262d7789f6e Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:32 +0300
Subject: [PATCH 038/100] fix(file_uploader): widen event handler types to
 allow null default

Widens the types of 10 event handler options (onBeforeSend, onDropZoneEnter,
onDropZoneLeave, onFilesUploaded, onProgress, onUploadAborted,
onUploadError, onUploadStarted, onUploaded, onValueChanged) to allow null
defaults in js/ui/file_uploader.d.ts to match their verified runtime
default value of null in js/__internal/ui/file_uploader/file_uploader.ts.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/ui/file_uploader.d.ts | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/packages/devextreme/js/ui/file_uploader.d.ts b/packages/devextreme/js/ui/file_uploader.d.ts
index 72ab0bbbbcf7..45ba4bcc306b 100644
--- a/packages/devextreme/js/ui/file_uploader.d.ts
+++ b/packages/devextreme/js/ui/file_uploader.d.ts
@@ -307,7 +307,7 @@ export interface dxFileUploaderOptions extends EditorOptions<dxFileUploader> {
      * @action
      * @public
      */
-    onBeforeSend?: ((e: BeforeSendEvent) => void);
+    onBeforeSend?: ((e: BeforeSendEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -315,7 +315,7 @@ export interface dxFileUploaderOptions extends EditorOptions<dxFileUploader> {
      * @action
      * @public
      */
-    onDropZoneEnter?: ((e: DropZoneEnterEvent) => void);
+    onDropZoneEnter?: ((e: DropZoneEnterEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -323,7 +323,7 @@ export interface dxFileUploaderOptions extends EditorOptions<dxFileUploader> {
      * @action
      * @public
      */
-    onDropZoneLeave?: ((e: DropZoneLeaveEvent) => void);
+    onDropZoneLeave?: ((e: DropZoneLeaveEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -331,7 +331,7 @@ export interface dxFileUploaderOptions extends EditorOptions<dxFileUploader> {
      * @action
      * @public
      */
-    onFilesUploaded?: ((e: FilesUploadedEvent) => void);
+    onFilesUploaded?: ((e: FilesUploadedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -339,7 +339,7 @@ export interface dxFileUploaderOptions extends EditorOptions<dxFileUploader> {
      * @action
      * @public
      */
-    onProgress?: ((e: ProgressEvent) => void);
+    onProgress?: ((e: ProgressEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -347,7 +347,7 @@ export interface dxFileUploaderOptions extends EditorOptions<dxFileUploader> {
      * @action
      * @public
      */
-    onUploadAborted?: ((e: UploadAbortedEvent) => void);
+    onUploadAborted?: ((e: UploadAbortedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -355,7 +355,7 @@ export interface dxFileUploaderOptions extends EditorOptions<dxFileUploader> {
      * @action
      * @public
      */
-    onUploadError?: ((e: UploadErrorEvent) => void);
+    onUploadError?: ((e: UploadErrorEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -363,7 +363,7 @@ export interface dxFileUploaderOptions extends EditorOptions<dxFileUploader> {
      * @action
      * @public
      */
-    onUploadStarted?: ((e: UploadStartedEvent) => void);
+    onUploadStarted?: ((e: UploadStartedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -371,7 +371,7 @@ export interface dxFileUploaderOptions extends EditorOptions<dxFileUploader> {
      * @action
      * @public
      */
-    onUploaded?: ((e: UploadedEvent) => void);
+    onUploaded?: ((e: UploadedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -379,7 +379,7 @@ export interface dxFileUploaderOptions extends EditorOptions<dxFileUploader> {
      * @action
      * @public
      */
-    onValueChanged?: ((e: ValueChangedEvent) => void);
+    onValueChanged?: ((e: ValueChangedEvent) => void) | null;
     /**
      * @docid
      * @default 0

From 78e98bd35243d723ce93bfe371ed79607790dcd6 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:32 +0300
Subject: [PATCH 039/100] fix(html_editor): correct options default docs and
 widen types

Corrects options JSDoc defaults and widens types in js/ui/html_editor.d.ts
to match their verified runtime defaults in
js/__internal/ui/html_editor/html_editor.ts.
Specifically:
- Widens mediaResizing, tableResizing, mentions, tableContextMenu,
  toolbar, and variables to accept null.
- Widens onFocusIn and onFocusOut (undefined flavor) to accept
  undefined and corrects JSDoc default from @default null to @default undefined.
- Removes Category B JSDoc @default null from fileUploaderOptions and template
  nested options since their parent options default to null at runtime.
- Removes now-stale @ts-expect-error suppressions in html_editor.ts.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 .../__internal/ui/html_editor/html_editor.ts  |  6 -----
 packages/devextreme/js/ui/html_editor.d.ts    | 22 +++++++++----------
 2 files changed, 10 insertions(+), 18 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/html_editor/html_editor.ts b/packages/devextreme/js/__internal/ui/html_editor/html_editor.ts
index efaac05e9405..6c7f8443201f 100644
--- a/packages/devextreme/js/__internal/ui/html_editor/html_editor.ts
+++ b/packages/devextreme/js/__internal/ui/html_editor/html_editor.ts
@@ -123,19 +123,13 @@ class HtmlEditor extends Editor<Properties> {
       focusStateEnabled: true,
       // @ts-expect-error undefined is not allowed
       imageUpload: null,
-      // @ts-expect-error undefined is not allowed
       mediaResizing: null,
-      // @ts-expect-error undefined is not allowed
       mentions: null,
       placeholder: '',
       stylingMode,
-      // @ts-expect-error undefined is not allowed
       tableContextMenu: null,
-      // @ts-expect-error undefined is not allowed
       tableResizing: null,
-      // @ts-expect-error undefined is not allowed
       toolbar: null,
-      // @ts-expect-error undefined is not allowed
       variables: null,
     };
   }
diff --git a/packages/devextreme/js/ui/html_editor.d.ts b/packages/devextreme/js/ui/html_editor.d.ts
index 84c061d95b37..60525dc159ad 100644
--- a/packages/devextreme/js/ui/html_editor.d.ts
+++ b/packages/devextreme/js/ui/html_editor.d.ts
@@ -311,25 +311,25 @@ export interface dxHtmlEditorOptions extends EditorOptions<dxHtmlEditor> {
      * @default null
      * @public
      */
-    mediaResizing?: dxHtmlEditorMediaResizing;
+    mediaResizing?: dxHtmlEditorMediaResizing | null;
     /**
      * @docid
      * @default null
      * @public
      */
-    tableResizing?: dxHtmlEditorTableResizing;
+    tableResizing?: dxHtmlEditorTableResizing | null;
     /**
      * @docid
      * @default null
      * @public
      */
-    mentions?: Array<dxHtmlEditorMention>;
+    mentions?: Array<dxHtmlEditorMention> | null;
     /**
      * @docid
      * @default null
      * @public
      */
-    tableContextMenu?: dxHtmlEditorTableContextMenu;
+    tableContextMenu?: dxHtmlEditorTableContextMenu | null;
     /**
      * @docid
      * @default { tabs: ["url"], fileUploadMode: 'base64', uploadUrl: undefined, uploadDirectory: undefined }
@@ -344,20 +344,20 @@ export interface dxHtmlEditorOptions extends EditorOptions<dxHtmlEditor> {
     name?: string;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/html_editor:FocusInEvent}
      * @action
      * @public
      */
-    onFocusIn?: ((e: FocusInEvent) => void);
+    onFocusIn?: ((e: FocusInEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/html_editor:FocusOutEvent}
      * @action
      * @public
      */
-    onFocusOut?: ((e: FocusOutEvent) => void);
+    onFocusOut?: ((e: FocusOutEvent) => void) | undefined;
     /**
      * @docid
      * @default ""
@@ -369,13 +369,13 @@ export interface dxHtmlEditorOptions extends EditorOptions<dxHtmlEditor> {
      * @default null
      * @public
      */
-    toolbar?: dxHtmlEditorToolbar;
+    toolbar?: dxHtmlEditorToolbar | null;
     /**
      * @docid
      * @default null
      * @public
      */
-    variables?: dxHtmlEditorVariables;
+    variables?: dxHtmlEditorVariables | null;
     /**
      * @docid
      * @default 'outlined'
@@ -638,7 +638,6 @@ export interface dxHtmlEditorImageUpload {
     tabs?: Array<ImageUploadTab | HtmlEditorImageUploadTab>;
     /**
     * @docid
-    * @default null
     * @type dxFileUploaderOptions
     * @public
     */
@@ -764,7 +763,6 @@ export interface dxHtmlEditorMention {
     searchTimeout?: number;
     /**
      * @docid
-     * @default null
      * @type_function_param1 mentionData:object
      * @type_function_return string|Element|jQuery
      * @public

From 893c2548ee34bad54d244b1d1d624d70fd9c13be Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:33 +0300
Subject: [PATCH 040/100] fix(map): widen event handler types to allow null
 default

Widens the types of onClick, onMarkerAdded, onMarkerRemoved,
onReady, onRouteAdded, and onRouteRemoved event handlers to
allow null defaults in js/ui/map.d.ts to match their verified
runtime default value of null in js/__internal/ui/map/map.ts.
Also removes the now-stale @ts-expect-error suppressions in map.ts.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/__internal/ui/map/map.ts |  6 ------
 packages/devextreme/js/ui/map.d.ts              | 12 ++++++------
 2 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/map/map.ts b/packages/devextreme/js/__internal/ui/map/map.ts
index 8b987349f994..bc80c316c874 100644
--- a/packages/devextreme/js/__internal/ui/map/map.ts
+++ b/packages/devextreme/js/__internal/ui/map/map.ts
@@ -87,14 +87,10 @@ class Map extends Widget<MapProperties> {
       markers: [],
       // @ts-expect-error ts-error
       markerIconSrc: null,
-      // @ts-expect-error ts-error
       onMarkerAdded: null,
-      // @ts-expect-error ts-error
       onMarkerRemoved: null,
       routes: [],
-      // @ts-expect-error ts-error
       onRouteAdded: null,
-      // @ts-expect-error ts-error
       onRouteRemoved: null,
       apiKey: {
         bing: '',
@@ -106,12 +102,10 @@ class Map extends Widget<MapProperties> {
         useAdvancedMarkers: true,
       },
       controls: false,
-      // @ts-expect-error ts-error
       onReady: null,
       // for internal use only
       // @ts-expect-error ts-error
       onUpdated: null,
-      // @ts-expect-error ts-error
       onClick: null,
     };
   }
diff --git a/packages/devextreme/js/ui/map.d.ts b/packages/devextreme/js/ui/map.d.ts
index 547e62a96f0f..04342d12321a 100644
--- a/packages/devextreme/js/ui/map.d.ts
+++ b/packages/devextreme/js/ui/map.d.ts
@@ -270,7 +270,7 @@ export interface dxMapOptions extends WidgetOptions<dxMap> {
      * @action
      * @public
      */
-    onClick?: ((e: ClickEvent) => void) | string;
+    onClick?: ((e: ClickEvent) => void) | string | null;
     /**
      * @docid
      * @default null
@@ -278,7 +278,7 @@ export interface dxMapOptions extends WidgetOptions<dxMap> {
      * @action
      * @public
      */
-    onMarkerAdded?: ((e: MarkerAddedEvent) => void);
+    onMarkerAdded?: ((e: MarkerAddedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -286,7 +286,7 @@ export interface dxMapOptions extends WidgetOptions<dxMap> {
      * @action
      * @public
      */
-    onMarkerRemoved?: ((e: MarkerRemovedEvent) => void);
+    onMarkerRemoved?: ((e: MarkerRemovedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -294,7 +294,7 @@ export interface dxMapOptions extends WidgetOptions<dxMap> {
      * @action
      * @public
      */
-    onReady?: ((e: ReadyEvent) => void);
+    onReady?: ((e: ReadyEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -302,7 +302,7 @@ export interface dxMapOptions extends WidgetOptions<dxMap> {
      * @action
      * @public
      */
-    onRouteAdded?: ((e: RouteAddedEvent) => void);
+    onRouteAdded?: ((e: RouteAddedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -310,7 +310,7 @@ export interface dxMapOptions extends WidgetOptions<dxMap> {
      * @action
      * @public
      */
-    onRouteRemoved?: ((e: RouteRemovedEvent) => void);
+    onRouteRemoved?: ((e: RouteRemovedEvent) => void) | null;
     /**
      * @docid
      * @default "google"

From 02b63f3b39d399648f561f4746b51afc62a8a4f2 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:33 +0300
Subject: [PATCH 041/100] fix(viz): correct subtitle and title text defaults
 and widen types to undefined

Corrects JSDoc @default from null to undefined and widens types
to | undefined for subtitle.text and title.text in js/viz/common.d.ts
since their keys are not present in the generic theme title/subtitle default configurations.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/viz/common.d.ts | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/packages/devextreme/js/viz/common.d.ts b/packages/devextreme/js/viz/common.d.ts
index 9ace9ee1b3b0..abdd5fe9136e 100644
--- a/packages/devextreme/js/viz/common.d.ts
+++ b/packages/devextreme/js/viz/common.d.ts
@@ -245,15 +245,15 @@ export interface BaseLegend {
         offset?: number;
         /**
          * @docid
-         * @default null
+         * @default undefined
          */
-        text?: string;
+        text?: string | undefined;
       } | string;
       /**
        * @docid
-       * @default null
+       * @default undefined
        */
-      text?: string;
+      text?: string | undefined;
       /**
        * @docid
        * @default 'top'

From 7d03a50085051b4aa0f192a14e6b849227f8d7cb Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:33 +0300
Subject: [PATCH 042/100] fix(viz): correct base_chart event handler defaults
 and widen types to undefined

Corrects JSDoc @default from null to undefined and widens types
to | undefined for onDone, onPointClick, onTooltipHidden, and
onTooltipShown in js/viz/chart_components/base_chart.d.ts since
they are eventsMap-only options and default to undefined at runtime.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 .../js/viz/chart_components/base_chart.d.ts      | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/packages/devextreme/js/viz/chart_components/base_chart.d.ts b/packages/devextreme/js/viz/chart_components/base_chart.d.ts
index 9763c3d45f7a..986015bb5023 100644
--- a/packages/devextreme/js/viz/chart_components/base_chart.d.ts
+++ b/packages/devextreme/js/viz/chart_components/base_chart.d.ts
@@ -204,15 +204,15 @@ export interface BaseChartOptions<
     legend?: BaseChartLegend;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @notUsedInTheme
      * @action
      * @public
      */
-    onDone?: ((e: EventInfo<TComponent>) => void);
+    onDone?: ((e: EventInfo<TComponent>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type function
      * @type_function_param1 e:object
      * @type_function_param1_field component:this
@@ -222,7 +222,7 @@ export interface BaseChartOptions<
      * @action
      * @public
      */
-    onPointClick?: ((e: NativeEventInfo<TComponent, MouseEvent | PointerEvent> & PointInteractionInfo<TPoint>) => void) | string;
+    onPointClick?: ((e: NativeEventInfo<TComponent, MouseEvent | PointerEvent> & PointInteractionInfo<TPoint>) => void) | string | undefined;
     /**
      * @docid
      * @type_function_param1 e:object
@@ -247,7 +247,7 @@ export interface BaseChartOptions<
     onPointSelectionChanged?: ((e: EventInfo<TComponent> & PointInteractionInfo<TPoint>) => void);
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:object
      * @type_function_param1_field component:this
      * @type_function_param1_field target:object
@@ -255,10 +255,10 @@ export interface BaseChartOptions<
      * @action
      * @public
      */
-    onTooltipHidden?: ((e: EventInfo<TComponent> & TooltipInfo<TPoint>) => void);
+    onTooltipHidden?: ((e: EventInfo<TComponent> & TooltipInfo<TPoint>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:object
      * @type_function_param1_field component:this
      * @type_function_param1_field target:object
@@ -266,7 +266,7 @@ export interface BaseChartOptions<
      * @action
      * @public
      */
-    onTooltipShown?: ((e: EventInfo<TComponent> & TooltipInfo<TPoint>) => void);
+    onTooltipShown?: ((e: EventInfo<TComponent> & TooltipInfo<TPoint>) => void) | undefined;
     /**
      * @docid
      * @default "Material"

From 26c4cda4aa8de4aafccf7c50a31e69fd96695b42 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:34 +0300
Subject: [PATCH 043/100] fix(viz): correct chart options defaults and widen
 types

Corrects options defaults and widens types in js/viz/chart.d.ts:
- Widens event handlers (onArgumentAxisClick, onLegendClick, onSeriesClick, onSeriesHoverChanged, onSeriesSelectionChanged, onZoomEnd, onZoomStart) to accept | undefined and corrects JSDoc default to undefined.
- Widens seriesTemplate to | undefined.
- Widens axis properties (argumentAxis.breaks, holidays, minVisualRangeLength, singleWorkdays, valueAxis.breaks, minVisualRangeLength) to accept | undefined.
- Widens commonAxisSettings.placeholderSize to accept | null.
- Corrects CommonSeries.hoverStyle.border.dashStyle and selectionStyle.border.dashStyle default JSDoc to undefined.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/viz/chart.d.ts | 48 +++++++++++++--------------
 1 file changed, 24 insertions(+), 24 deletions(-)

diff --git a/packages/devextreme/js/viz/chart.d.ts b/packages/devextreme/js/viz/chart.d.ts
index d7b79f3f6adc..ab738994ae8a 100644
--- a/packages/devextreme/js/viz/chart.d.ts
+++ b/packages/devextreme/js/viz/chart.d.ts
@@ -1347,70 +1347,70 @@ export interface dxChartOptions extends BaseChartOptions<dxChart, chartPointObje
     negativesAsZeroes?: boolean;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type function
      * @type_function_param1 e:{viz/chart:ArgumentAxisClickEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onArgumentAxisClick?: ((e: ArgumentAxisClickEvent) => void) | string;
+    onArgumentAxisClick?: ((e: ArgumentAxisClickEvent) => void) | string | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type function
      * @type_function_param1 e:{viz/chart:LegendClickEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onLegendClick?: ((e: LegendClickEvent) => void) | string;
+    onLegendClick?: ((e: LegendClickEvent) => void) | string | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type function
      * @type_function_param1 e:{viz/chart:SeriesClickEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onSeriesClick?: ((e: SeriesClickEvent) => void) | string;
+    onSeriesClick?: ((e: SeriesClickEvent) => void) | string | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/chart:SeriesHoverChangedEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onSeriesHoverChanged?: ((e: SeriesHoverChangedEvent) => void);
+    onSeriesHoverChanged?: ((e: SeriesHoverChangedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/chart:SeriesSelectionChangedEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onSeriesSelectionChanged?: ((e: SeriesSelectionChangedEvent) => void);
+    onSeriesSelectionChanged?: ((e: SeriesSelectionChangedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/chart:ZoomEndEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onZoomEnd?: ((e: ZoomEndEvent) => void);
+    onZoomEnd?: ((e: ZoomEndEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/chart:ZoomStartEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onZoomStart?: ((e: ZoomStartEvent) => void);
+    onZoomStart?: ((e: ZoomStartEvent) => void) | undefined;
     /**
      * @docid
      * @type Object|Array<Object>
@@ -1504,7 +1504,7 @@ export interface dxChartOptions extends BaseChartOptions<dxChart, chartPointObje
        * @default 'series'
        */
       nameField?: string;
-    };
+    } | undefined;
     /**
      * @docid
      * @default true
@@ -1620,7 +1620,7 @@ export type ArgumentAxis = CommonAxisSettings & {
      * @notUsedInTheme
      * @public
      */
-    breaks?: Array<ScaleBreak>;
+    breaks?: Array<ScaleBreak> | undefined;
     /**
      * @docid dxChartOptions.argumentAxis.categories
      * @public
@@ -1652,7 +1652,7 @@ export type ArgumentAxis = CommonAxisSettings & {
      * @default undefined
      * @public
      */
-    holidays?: Array<Date | string> | Array<number>;
+    holidays?: Array<Date | string> | Array<number> | undefined;
     /**
      * @docid dxChartOptions.argumentAxis.hoverMode
      * @default 'none'
@@ -1685,7 +1685,7 @@ export type ArgumentAxis = CommonAxisSettings & {
      * @notUsedInTheme
      * @public
      */
-    minVisualRangeLength?: TimeIntervalConfig;
+    minVisualRangeLength?: TimeIntervalConfig | undefined;
     /**
      * @docid dxChartOptions.argumentAxis.minorTickCount
      * @default undefined
@@ -1728,7 +1728,7 @@ export type ArgumentAxis = CommonAxisSettings & {
      * @default undefined
      * @public
      */
-    singleWorkdays?: Array<Date | string> | Array<number>;
+    singleWorkdays?: Array<Date | string> | Array<number> | undefined;
     /**
      * @docid dxChartOptions.argumentAxis.strips
      * @type Array<Object>
@@ -2143,7 +2143,7 @@ export type CommonAxisSettings = {
      * @default null
      * @public
      */
-    placeholderSize?: number;
+    placeholderSize?: number | null;
     /**
      * @docid dxChartOptions.commonAxisSettings.stripStyle
      * @type object
@@ -2741,7 +2741,7 @@ export type ValueAxis = CommonAxisSettings & {
      * @notUsedInTheme
      * @public
      */
-    breaks?: Array<ScaleBreak>;
+    breaks?: Array<ScaleBreak> | undefined;
     /**
      * @docid dxChartOptions.valueAxis.categories
      * @public
@@ -2800,7 +2800,7 @@ export type ValueAxis = CommonAxisSettings & {
      * @notUsedInTheme
      * @public
      */
-    minVisualRangeLength?: TimeIntervalConfig;
+    minVisualRangeLength?: TimeIntervalConfig | undefined;
     /**
      * @docid dxChartOptions.valueAxis.minorTickCount
      * @default undefined
@@ -4019,7 +4019,7 @@ export interface dxChartSeriesTypesCommonSeriesHoverStyleBorder {
     color?: string | undefined;
     /**
      * @docid dxChartSeriesTypes.CommonSeries.hoverStyle.border.dashStyle
-     * @default 'solid'
+     * @default undefined
      * @public
      */
     dashStyle?: DashStyle | undefined;
@@ -4117,7 +4117,7 @@ export interface dxChartSeriesTypesCommonSeriesSelectionStyleBorder {
     color?: string | undefined;
     /**
      * @docid dxChartSeriesTypes.CommonSeries.selectionStyle.border.dashStyle
-     * @default 'solid'
+     * @default undefined
      * @public
      */
     dashStyle?: DashStyle | undefined;

From 5fbd73671816061ee5244099572ad44df39d3e44 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:34 +0300
Subject: [PATCH 044/100] fix(viz): correct pie_chart options defaults and
 widen/narrow types

Corrects options defaults and widens/narrows types in js/viz/pie_chart.d.ts:
- Widens onLegendClick to accept | undefined and corrects JSDoc default to undefined.
- Widens seriesTemplate to | undefined.
- Narrows label.border.color and label.border.dashStyle by removing | undefined since their default values are stored in the theme.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/viz/pie_chart.d.ts | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/packages/devextreme/js/viz/pie_chart.d.ts b/packages/devextreme/js/viz/pie_chart.d.ts
index 035119d3f49e..d6901916d436 100644
--- a/packages/devextreme/js/viz/pie_chart.d.ts
+++ b/packages/devextreme/js/viz/pie_chart.d.ts
@@ -349,14 +349,14 @@ export interface dxPieChartOptions extends BaseChartOptions<dxPieChart, piePoint
     minDiameter?: number;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type function
      * @type_function_param1 e:{viz/pie_chart:LegendClickEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onLegendClick?: ((e: LegendClickEvent) => void) | string;
+    onLegendClick?: ((e: LegendClickEvent) => void) | string | undefined;
     /**
      * @docid
      * @default "Material"
@@ -399,7 +399,7 @@ export interface dxPieChartOptions extends BaseChartOptions<dxPieChart, piePoint
        * @default 'series'
        */
       nameField?: string;
-    };
+    } | undefined;
     /**
      * @docid
      * @default undefined
@@ -739,12 +739,12 @@ export interface dxPieChartSeriesTypesCommonPieChartSeries {
            * @docid dxPieChartSeriesTypes.CommonPieChartSeries.label.border.color
            * @default  '#d3d3d3'
            */
-          color?: string | undefined;
+          color?: string;
           /**
            * @docid dxPieChartSeriesTypes.CommonPieChartSeries.label.border.dashStyle
            * @default 'solid'
            */
-          dashStyle?: DashStyle | undefined;
+          dashStyle?: DashStyle;
           /**
            * @docid dxPieChartSeriesTypes.CommonPieChartSeries.label.border.visible
            * @default false

From 803fc1f942d43967718af6bdeb9fec824dd117a2 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:35 +0300
Subject: [PATCH 045/100] fix(viz): correct polar_chart options defaults and
 widen/narrow types

Corrects options defaults and widens/narrows types in js/viz/polar_chart.d.ts:
- Widens event handlers (onArgumentAxisClick, onLegendClick, onSeriesClick, onSeriesHoverChanged, onSeriesSelectionChanged, onZoomEnd, onZoomStart) to accept | undefined and corrects JSDoc default to undefined.
- Widens seriesTemplate to | undefined.
- Widens valueAxis.minVisualRangeLength to accept | undefined.
- Corrects CommonPolarChartSeries.hoverStyle.border.dashStyle and selectionStyle.border.dashStyle default JSDoc to undefined.
- Narrows CommonPolarChartSeries.label.border.color and dashStyle by removing | undefined.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/viz/polar_chart.d.ts | 40 ++++++++++-----------
 1 file changed, 20 insertions(+), 20 deletions(-)

diff --git a/packages/devextreme/js/viz/polar_chart.d.ts b/packages/devextreme/js/viz/polar_chart.d.ts
index 002f56db7698..277e977789ae 100644
--- a/packages/devextreme/js/viz/polar_chart.d.ts
+++ b/packages/devextreme/js/viz/polar_chart.d.ts
@@ -437,70 +437,70 @@ export interface dxPolarChartOptions extends BaseChartOptions<dxPolarChart, pola
     negativesAsZeroes?: boolean;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type function
      * @type_function_param1 e:{viz/polar_chart:ArgumentAxisClickEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onArgumentAxisClick?: ((e: ArgumentAxisClickEvent) => void) | string;
+    onArgumentAxisClick?: ((e: ArgumentAxisClickEvent) => void) | string | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type function
      * @type_function_param1 e:{viz/polar_chart:LegendClickEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onLegendClick?: ((e: LegendClickEvent) => void) | string;
+    onLegendClick?: ((e: LegendClickEvent) => void) | string | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type function
      * @type_function_param1 e:{viz/polar_chart:SeriesClickEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onSeriesClick?: ((e: SeriesClickEvent) => void) | string;
+    onSeriesClick?: ((e: SeriesClickEvent) => void) | string | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/polar_chart:SeriesHoverChangedEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onSeriesHoverChanged?: ((e: SeriesHoverChangedEvent) => void);
+    onSeriesHoverChanged?: ((e: SeriesHoverChangedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/polar_chart:SeriesSelectionChangedEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onSeriesSelectionChanged?: ((e: SeriesSelectionChangedEvent) => void);
+    onSeriesSelectionChanged?: ((e: SeriesSelectionChangedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/polar_chart:ZoomEndEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onZoomEnd?: ((e: ZoomEndEvent) => void);
+    onZoomEnd?: ((e: ZoomEndEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/polar_chart:ZoomStartEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onZoomStart?: ((e: ZoomStartEvent) => void);
+    onZoomStart?: ((e: ZoomStartEvent) => void) | undefined;
     /**
      * @docid
      * @default "none"
@@ -538,7 +538,7 @@ export interface dxPolarChartOptions extends BaseChartOptions<dxPolarChart, pola
        * @default 'series'
        */
       nameField?: string;
-    };
+    } | undefined;
     /**
      * @docid
      * @type object
@@ -1324,7 +1324,7 @@ export type ValueAxis = CommonAxisSettings & {
      * @notUsedInTheme
      * @public
      */
-    minVisualRangeLength?: TimeIntervalConfig;
+    minVisualRangeLength?: TimeIntervalConfig | undefined;
     /**
      * @docid dxPolarChartOptions.valueAxis.minorTickCount
      * @default undefined
@@ -1758,7 +1758,7 @@ export interface dxPolarChartSeriesTypesCommonPolarChartSeries {
         color?: string | undefined;
         /**
          * @docid dxPolarChartSeriesTypes.CommonPolarChartSeries.hoverStyle.border.dashStyle
-         * @default 'solid'
+         * @default undefined
          */
         dashStyle?: DashStyle | undefined;
         /**
@@ -1885,7 +1885,7 @@ export interface dxPolarChartSeriesTypesCommonPolarChartSeries {
         color?: string | undefined;
         /**
          * @docid dxPolarChartSeriesTypes.CommonPolarChartSeries.selectionStyle.border.dashStyle
-         * @default 'solid'
+         * @default undefined
          */
         dashStyle?: DashStyle | undefined;
         /**
@@ -2065,12 +2065,12 @@ export interface dxPolarChartSeriesTypesCommonPolarChartSeriesLabel {
        * @docid dxPolarChartSeriesTypes.CommonPolarChartSeries.label.border.color
        * @default  '#d3d3d3'
        */
-      color?: string | undefined;
+      color?: string;
       /**
        * @docid dxPolarChartSeriesTypes.CommonPolarChartSeries.label.border.dashStyle
        * @default 'solid'
        */
-      dashStyle?: DashStyle | undefined;
+      dashStyle?: DashStyle;
       /**
        * @docid dxPolarChartSeriesTypes.CommonPolarChartSeries.label.border.visible
        * @default false

From 8cf15c99c68c298ff6edf3e030025ac9342d99ea Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:35 +0300
Subject: [PATCH 046/100] fix(viz): correct common/charts options defaults and
 widen/narrow types

Corrects options defaults and widens/narrows types in js/common/charts.d.ts:
- Widens VizTimeInterval.length type to accept | undefined.
- Narrows CommonSeries.label.border.color and dashStyle by removing | undefined.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/common/charts.d.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/devextreme/js/common/charts.d.ts b/packages/devextreme/js/common/charts.d.ts
index 9e8a2ca24e04..1e3776d59781 100644
--- a/packages/devextreme/js/common/charts.d.ts
+++ b/packages/devextreme/js/common/charts.d.ts
@@ -255,7 +255,7 @@ export type VisualRange = {
     * @default undefined
     * @public
     */
-    length?: TimeIntervalConfig;
+    length?: TimeIntervalConfig | undefined;
     /**
     * @docid
     * @default undefined
@@ -640,12 +640,12 @@ export interface SeriesLabel {
        * @docid dxChartSeriesTypes.CommonSeries.label.border.color
        * @default  '#d3d3d3'
        */
-      color?: string | undefined;
+      color?: string;
       /**
        * @docid dxChartSeriesTypes.CommonSeries.label.border.dashStyle
        * @default 'solid'
        */
-      dashStyle?: DashStyle | undefined;
+      dashStyle?: DashStyle;
       /**
        * @docid dxChartSeriesTypes.CommonSeries.label.border.visible
        * @default false

From c9c0cb4ca31fb09ec1cc0e244e626ef226f6e075 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:35 +0300
Subject: [PATCH 047/100] fix(viz): correct bar_gauge onTooltipHidden and
 onTooltipShown defaults

Corrects JSDoc @default from null to undefined and widens types
to | undefined for onTooltipHidden and onTooltipShown in
js/viz/bar_gauge.d.ts as they default to undefined at runtime.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/viz/bar_gauge.d.ts | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/packages/devextreme/js/viz/bar_gauge.d.ts b/packages/devextreme/js/viz/bar_gauge.d.ts
index 939b8d0f1d68..9b985db15941 100644
--- a/packages/devextreme/js/viz/bar_gauge.d.ts
+++ b/packages/devextreme/js/viz/bar_gauge.d.ts
@@ -299,22 +299,22 @@ export interface dxBarGaugeOptions extends BaseWidgetOptions<dxBarGauge> {
     loadingIndicator?: LoadingIndicator;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/bar_gauge:TooltipHiddenEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onTooltipHidden?: ((e: TooltipHiddenEvent) => void);
+    onTooltipHidden?: ((e: TooltipHiddenEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/bar_gauge:TooltipShownEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onTooltipShown?: ((e: TooltipShownEvent) => void);
+    onTooltipShown?: ((e: TooltipShownEvent) => void) | undefined;
     /**
      * @docid
      * @default "Material"

From 66cd45e30ad3425300ec520808f5964a69d47b0d Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:36 +0300
Subject: [PATCH 048/100] fix(viz): correct base_gauge options defaults and
 widen types

Corrects options defaults and widens types in js/viz/gauges/base_gauge.d.ts:
- Widens onTooltipHidden and onTooltipShown to accept | undefined and corrects JSDoc default to undefined.
- Widens subvalues, scale.customMinorTicks, and scale.customTicks to accept | undefined.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/viz/gauges/base_gauge.d.ts | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/packages/devextreme/js/viz/gauges/base_gauge.d.ts b/packages/devextreme/js/viz/gauges/base_gauge.d.ts
index 3d169ef86766..f2f69ae21d64 100644
--- a/packages/devextreme/js/viz/gauges/base_gauge.d.ts
+++ b/packages/devextreme/js/viz/gauges/base_gauge.d.ts
@@ -78,10 +78,10 @@ export interface BaseGaugeOptions<TComponent> extends BaseWidgetOptions<TCompone
      * @action
      * @public
      */
-    onTooltipHidden?: ((e: EventInfo<TComponent> & TooltipInfo) => void);
+    onTooltipHidden?: ((e: EventInfo<TComponent> & TooltipInfo) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:object
      * @type_function_param1_field component:this
      * @type_function_param1_field target:object
@@ -89,7 +89,7 @@ export interface BaseGaugeOptions<TComponent> extends BaseWidgetOptions<TCompone
      * @action
      * @public
      */
-    onTooltipShown?: ((e: EventInfo<TComponent> & TooltipInfo) => void);
+    onTooltipShown?: ((e: EventInfo<TComponent> & TooltipInfo) => void) | undefined;
     /**
      * @docid
      * @type object
@@ -109,7 +109,7 @@ export interface BaseGaugeOptions<TComponent> extends BaseWidgetOptions<TCompone
      * @fires BaseWidgetOptions.onOptionChanged
      * @public
      */
-    subvalues?: Array<number>;
+    subvalues?: Array<number> | undefined;
     /**
      * @docid
      * @type object
@@ -231,14 +231,14 @@ export interface BaseGaugeScale {
      * @notUsedInTheme
      * @public
      */
-    customMinorTicks?: Array<number>;
+    customMinorTicks?: Array<number> | undefined;
     /**
      * @docid BaseGaugeOptions.scale.customTicks
      * @default undefined
      * @notUsedInTheme
      * @public
      */
-    customTicks?: Array<number>;
+    customTicks?: Array<number> | undefined;
     /**
      * @docid BaseGaugeOptions.scale.endValue
      * @default 100

From d45538f5e5be781013e201dfd08235e5447743d8 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:36 +0300
Subject: [PATCH 049/100] fix(viz): correct base_sparkline onTooltipHidden and
 onTooltipShown defaults

Corrects JSDoc @default from null to undefined and widens types
to | undefined for onTooltipHidden and onTooltipShown in
js/viz/sparklines/base_sparkline.d.ts as they default to undefined at runtime.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/viz/sparklines/base_sparkline.d.ts | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/packages/devextreme/js/viz/sparklines/base_sparkline.d.ts b/packages/devextreme/js/viz/sparklines/base_sparkline.d.ts
index 70fe5a8d4cf3..2df6969d488d 100644
--- a/packages/devextreme/js/viz/sparklines/base_sparkline.d.ts
+++ b/packages/devextreme/js/viz/sparklines/base_sparkline.d.ts
@@ -39,20 +39,20 @@ export interface BaseSparklineOptions<TComponent> extends BaseWidgetOptions<TCom
     loadingIndicator?: BaseWidgetLoadingIndicator;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @notUsedInTheme
      * @action
      * @public
      */
-    onTooltipHidden?: ((e: EventInfo<TComponent>) => void);
+    onTooltipHidden?: ((e: EventInfo<TComponent>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @notUsedInTheme
      * @action
      * @public
      */
-    onTooltipShown?: ((e: EventInfo<TComponent>) => void);
+    onTooltipShown?: ((e: EventInfo<TComponent>) => void) | undefined;
     /**
      * @docid
      * @hidden

From cd2fb5d8f3b14ac2e470f406efd41253a7aea326 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:37 +0300
Subject: [PATCH 050/100] fix(viz): correct funnel options defaults and
 widen/narrow types

Corrects options defaults and widens/narrows types in js/viz/funnel.d.ts:
- Widens event handlers (onHoverChanged, onItemClick, onLegendClick, onSelectionChanged) to accept | undefined and corrects JSDoc default to undefined.
- Narrows item.border.color, visible, and width by removing | undefined as their default values are stored in the theme.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/viz/funnel.d.ts | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/packages/devextreme/js/viz/funnel.d.ts b/packages/devextreme/js/viz/funnel.d.ts
index 7f411d7f25d4..8314897c67b9 100644
--- a/packages/devextreme/js/viz/funnel.d.ts
+++ b/packages/devextreme/js/viz/funnel.d.ts
@@ -273,17 +273,17 @@ export interface dxFunnelOptions extends BaseWidgetOptions<dxFunnel> {
          * @docid
          * @default #ffffff
          */
-        color?: string | undefined;
+        color?: string;
         /**
          * @docid
          * @default false
          */
-        visible?: boolean | undefined;
+        visible?: boolean;
         /**
          * @docid
          * @default 2
          */
-        width?: number | undefined;
+        width?: number;
       };
       /**
        * @docid
@@ -518,42 +518,42 @@ export interface dxFunnelOptions extends BaseWidgetOptions<dxFunnel> {
     neckWidth?: number;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/funnel:HoverChangedEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onHoverChanged?: ((e: HoverChangedEvent) => void);
+    onHoverChanged?: ((e: HoverChangedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type function
      * @type_function_param1 e:{viz/funnel:ItemClickEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onItemClick?: ((e: ItemClickEvent) => void) | string;
+    onItemClick?: ((e: ItemClickEvent) => void) | string | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type function
      * @type_function_param1 e:{viz/funnel:LegendClickEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onLegendClick?: ((e: LegendClickEvent) => void) | string;
+    onLegendClick?: ((e: LegendClickEvent) => void) | string | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/funnel:SelectionChangedEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onSelectionChanged?: ((e: SelectionChangedEvent) => void);
+    onSelectionChanged?: ((e: SelectionChangedEvent) => void) | undefined;
     /**
      * @docid
      * @default "Material"

From 951e4173af1c48f27ce653a391e9237bd0616d3a Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:37 +0300
Subject: [PATCH 051/100] fix(viz): correct sankey options defaults and
 widen/narrow types

Corrects options defaults and widens/narrows types in js/viz/sankey.d.ts:
- Widens event handlers (onLinkClick, onLinkHoverChanged, onNodeClick, onNodeHoverChanged) to accept | undefined and corrects JSDoc default to undefined.
- Corrects node.label.border.color, link.border.color, and node.border.color JSDoc defaults to '#ffffff' and removes | undefined from their types.
- Corrects link.border.width JSDoc default to 1 and removes | undefined from its type.
- Corrects link.hoverStyle.border.opacity JSDoc default to undefined.
- Narrows node.label.border.visible/width, link.border.visible, and node.border.visible/width by removing | undefined.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/viz/sankey.d.ts | 44 +++++++++++++-------------
 1 file changed, 22 insertions(+), 22 deletions(-)

diff --git a/packages/devextreme/js/viz/sankey.d.ts b/packages/devextreme/js/viz/sankey.d.ts
index db5b69978e36..fc76d4435929 100644
--- a/packages/devextreme/js/viz/sankey.d.ts
+++ b/packages/devextreme/js/viz/sankey.d.ts
@@ -205,19 +205,19 @@ export interface dxSankeyOptions extends BaseWidgetOptions<dxSankey> {
       border?: {
         /**
          * @docid
-         * @default '#000000'
+         * @default '#ffffff'
          */
-        color?: string | undefined;
+        color?: string;
         /**
          * @docid
          * @default false
          */
-        visible?: boolean | undefined;
+        visible?: boolean;
         /**
          * @docid
          * @default 2
          */
-        width?: number | undefined;
+        width?: number;
       };
       /**
        * @docid
@@ -296,19 +296,19 @@ export interface dxSankeyOptions extends BaseWidgetOptions<dxSankey> {
       border?: {
         /**
          * @docid
-         * @default '#000000'
+         * @default '#ffffff'
          */
-        color?: string | undefined;
+        color?: string;
         /**
          * @docid
          * @default false
          */
-        visible?: boolean | undefined;
+        visible?: boolean;
         /**
          * @docid
-         * @default 2
+         * @default 1
          */
-        width?: number | undefined;
+        width?: number;
       };
       /**
        * @docid
@@ -376,7 +376,7 @@ export interface dxSankeyOptions extends BaseWidgetOptions<dxSankey> {
         };
         /**
          * @docid
-         * @default 0.5
+         * @default undefined
          */
         opacity?: number | undefined;
       };
@@ -397,19 +397,19 @@ export interface dxSankeyOptions extends BaseWidgetOptions<dxSankey> {
       border?: {
         /**
          * @docid
-         * @default '#000000'
+         * @default '#ffffff'
          */
-        color?: string | undefined;
+        color?: string;
         /**
          * @docid
          * @default false
          */
-        visible?: boolean | undefined;
+        visible?: boolean;
         /**
          * @docid
          * @default 1
          */
-        width?: number | undefined;
+        width?: number;
       };
       /**
        * @docid
@@ -494,42 +494,42 @@ export interface dxSankeyOptions extends BaseWidgetOptions<dxSankey> {
     };
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type function
      * @type_function_param1 e:{viz/sankey:LinkClickEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onLinkClick?: ((e: LinkClickEvent) => void) | string;
+    onLinkClick?: ((e: LinkClickEvent) => void) | string | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/sankey:LinkHoverEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onLinkHoverChanged?: ((e: LinkHoverEvent) => void);
+    onLinkHoverChanged?: ((e: LinkHoverEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type function
      * @type_function_param1 e:{viz/sankey:NodeClickEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onNodeClick?: ((e: NodeClickEvent) => void) | string;
+    onNodeClick?: ((e: NodeClickEvent) => void) | string | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/sankey:NodeHoverEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onNodeHoverChanged?: ((e: NodeHoverEvent) => void);
+    onNodeHoverChanged?: ((e: NodeHoverEvent) => void) | undefined;
     /**
      * @docid
      * @default "Material"

From 183dba27117215e7de342ccb98c87646dc1f7467 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:38 +0300
Subject: [PATCH 052/100] fix(viz): correct tree_map options defaults and
 widen/narrow types

Corrects options defaults and widens/narrows types in js/viz/tree_map.d.ts:
- Widens event handlers (onClick, onDrill, onHoverChanged, onNodesInitialized, onNodesRendering, onSelectionChanged) to accept | undefined and corrects JSDoc default to undefined.
- Widens colorizer.range to accept | undefined.
- Corrects group.border.color, group.selectionStyle.border.color, and tile.selectionStyle.border.color JSDoc defaults to undefined.
- Narrows group.border.width and tile.border.color/width by removing | undefined.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/viz/tree_map.d.ts | 38 ++++++++++++------------
 1 file changed, 19 insertions(+), 19 deletions(-)

diff --git a/packages/devextreme/js/viz/tree_map.d.ts b/packages/devextreme/js/viz/tree_map.d.ts
index dfe2f00fcb6c..aab54515e8bc 100644
--- a/packages/devextreme/js/viz/tree_map.d.ts
+++ b/packages/devextreme/js/viz/tree_map.d.ts
@@ -228,7 +228,7 @@ export interface dxTreeMapOptions extends BaseWidgetOptions<dxTreeMap> {
        * @docid
        * @default undefined
        */
-      range?: Array<number>;
+      range?: Array<number> | undefined;
       /**
        * @docid
        * @default undefined
@@ -253,14 +253,14 @@ export interface dxTreeMapOptions extends BaseWidgetOptions<dxTreeMap> {
       border?: {
         /**
          * @docid
-         * @default "#d3d3d3"
+         * @default undefined
          */
         color?: string | undefined;
         /**
          * @docid
          * @default 1
          */
-        width?: number | undefined;
+        width?: number;
       };
       /**
        * @docid
@@ -338,7 +338,7 @@ export interface dxTreeMapOptions extends BaseWidgetOptions<dxTreeMap> {
         border?: {
           /**
            * @docid
-           * @default "#232323"
+           * @default undefined
            */
           color?: string | undefined;
           /**
@@ -406,59 +406,59 @@ export interface dxTreeMapOptions extends BaseWidgetOptions<dxTreeMap> {
     maxDepth?: number | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type function
      * @type_function_param1 e:{viz/tree_map:ClickEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onClick?: ((e: ClickEvent) => void) | string;
+    onClick?: ((e: ClickEvent) => void) | string | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/tree_map:DrillEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onDrill?: ((e: DrillEvent) => void);
+    onDrill?: ((e: DrillEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/tree_map:HoverChangedEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onHoverChanged?: ((e: HoverChangedEvent) => void);
+    onHoverChanged?: ((e: HoverChangedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/tree_map:NodesInitializedEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onNodesInitialized?: ((e: NodesInitializedEvent) => void);
+    onNodesInitialized?: ((e: NodesInitializedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/tree_map:NodesRenderingEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onNodesRendering?: ((e: NodesRenderingEvent) => void);
+    onNodesRendering?: ((e: NodesRenderingEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/tree_map:SelectionChangedEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onSelectionChanged?: ((e: SelectionChangedEvent) => void);
+    onSelectionChanged?: ((e: SelectionChangedEvent) => void) | undefined;
     /**
      * @docid
      * @default undefined
@@ -484,12 +484,12 @@ export interface dxTreeMapOptions extends BaseWidgetOptions<dxTreeMap> {
          * @docid
          * @default "#000000"
          */
-        color?: string | undefined;
+        color?: string;
         /**
          * @docid
          * @default 1
          */
-        width?: number | undefined;
+        width?: number;
       };
       /**
        * @docid
@@ -557,7 +557,7 @@ export interface dxTreeMapOptions extends BaseWidgetOptions<dxTreeMap> {
         border?: {
           /**
            * @docid
-           * @default "#232323"
+           * @default undefined
            */
           color?: string | undefined;
           /**

From ad1a352f7d284cb00403a19bdf451bf6b1a111b5 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:38 +0300
Subject: [PATCH 053/100] regenerate ts

---
 packages/devextreme/ts/dx.all.d.ts | 1058 ++++++++++++++++------------
 1 file changed, 620 insertions(+), 438 deletions(-)

diff --git a/packages/devextreme/ts/dx.all.d.ts b/packages/devextreme/ts/dx.all.d.ts
index d915f281adee..5fa5f656ade9 100644
--- a/packages/devextreme/ts/dx.all.d.ts
+++ b/packages/devextreme/ts/dx.all.d.ts
@@ -2000,13 +2000,13 @@ declare module DevExpress.common.charts {
                 /**
                  * [descr:BaseLegend.title.subtitle.text]
                  */
-                text?: string;
+                text?: string | undefined;
               }
             | string;
           /**
            * [descr:BaseLegend.title.text]
            */
-          text?: string;
+          text?: string | undefined;
           /**
            * [descr:BaseLegend.title.verticalAlignment]
            */
@@ -2216,11 +2216,11 @@ declare module DevExpress.common.charts {
       /**
        * [descr:dxChartSeriesTypes.CommonSeries.label.border.color]
        */
-      color?: string | undefined;
+      color?: string;
       /**
        * [descr:dxChartSeriesTypes.CommonSeries.label.border.dashStyle]
        */
-      dashStyle?: DashStyle | undefined;
+      dashStyle?: DashStyle;
       /**
        * [descr:dxChartSeriesTypes.CommonSeries.label.border.visible]
        */
@@ -2566,7 +2566,7 @@ declare module DevExpress.common.charts {
     /**
      * [descr:VisualRange.length]
      */
-    length?: TimeIntervalConfig;
+    length?: TimeIntervalConfig | undefined;
     /**
      * [descr:VisualRange.startValue]
      */
@@ -9074,7 +9074,7 @@ declare module DevExpress.ui {
     /**
      * [descr:CollectionWidgetOptions.keyExpr]
      */
-    keyExpr?: string | ((item: TItem) => TKey);
+    keyExpr?: string | ((item: TItem) => TKey) | null;
     /**
      * [descr:CollectionWidgetOptions.noDataText]
      */
@@ -9090,47 +9090,58 @@ declare module DevExpress.ui {
           > &
             DevExpress.common.core.events.ItemInfo<TItem>
         ) => void)
-      | string;
+      | string
+      | null;
     /**
      * [descr:CollectionWidgetOptions.onItemContextMenu]
      */
-    onItemContextMenu?: (
-      e: DevExpress.common.core.events.NativeEventInfo<
-        TComponent,
-        DevExpress.events.PointerInteractionEvent
-      > &
-        DevExpress.common.core.events.ItemInfo<TItem>
-    ) => void;
+    onItemContextMenu?:
+      | ((
+          e: DevExpress.common.core.events.NativeEventInfo<
+            TComponent,
+            DevExpress.events.PointerInteractionEvent
+          > &
+            DevExpress.common.core.events.ItemInfo<TItem>
+        ) => void)
+      | null;
     /**
      * [descr:CollectionWidgetOptions.onItemHold]
      */
-    onItemHold?: (
-      e: DevExpress.common.core.events.NativeEventInfo<
-        TComponent,
-        DevExpress.events.PointerInteractionEvent
-      > &
-        DevExpress.common.core.events.ItemInfo<TItem>
-    ) => void;
+    onItemHold?:
+      | ((
+          e: DevExpress.common.core.events.NativeEventInfo<
+            TComponent,
+            DevExpress.events.PointerInteractionEvent
+          > &
+            DevExpress.common.core.events.ItemInfo<TItem>
+        ) => void)
+      | null;
     /**
      * [descr:CollectionWidgetOptions.onItemRendered]
      */
-    onItemRendered?: (
-      e: DevExpress.common.core.events.EventInfo<TComponent> &
-        DevExpress.common.core.events.ItemInfo<TItem>
-    ) => void;
+    onItemRendered?:
+      | ((
+          e: DevExpress.common.core.events.EventInfo<TComponent> &
+            DevExpress.common.core.events.ItemInfo<TItem>
+        ) => void)
+      | null;
     /**
      * [descr:CollectionWidgetOptions.onSelectionChanging]
      */
-    onSelectionChanging?: (
-      e: DevExpress.ui.CollectionWidget.SelectionChangingEventBase<TComponent>
-    ) => void;
+    onSelectionChanging?:
+      | ((
+          e: DevExpress.ui.CollectionWidget.SelectionChangingEventBase<TComponent>
+        ) => void)
+      | null;
     /**
      * [descr:CollectionWidgetOptions.onSelectionChanged]
      */
-    onSelectionChanged?: (
-      e: DevExpress.common.core.events.EventInfo<TComponent> &
-        DevExpress.ui.CollectionWidget.SelectionChangeInfo<TItem>
-    ) => void;
+    onSelectionChanged?:
+      | ((
+          e: DevExpress.common.core.events.EventInfo<TComponent> &
+            DevExpress.ui.CollectionWidget.SelectionChangeInfo<TItem>
+        ) => void)
+      | null;
     /**
      * [descr:CollectionWidgetOptions.selectedIndex]
      */
@@ -9138,7 +9149,7 @@ declare module DevExpress.ui {
     /**
      * [descr:CollectionWidgetOptions.selectedItem]
      */
-    selectedItem?: TItem;
+    selectedItem?: TItem | null;
     /**
      * [descr:CollectionWidgetOptions.selectedItemKeys]
      */
@@ -9196,7 +9207,7 @@ declare module DevExpress.ui {
     /**
      * [descr:DataExpressionMixinOptions.value]
      */
-    value?: any;
+    value?: any | null;
     /**
      * [descr:DataExpressionMixinOptions.valueExpr]
      */
@@ -9243,7 +9254,7 @@ declare module DevExpress.ui {
     /**
      * [descr:DateBoxBaseOptions.displayFormat]
      */
-    displayFormat?: DevExpress.common.core.localization.Format;
+    displayFormat?: DevExpress.common.core.localization.Format | null;
     /**
      * [descr:DateBoxBaseOptions.max]
      */
@@ -9564,7 +9575,8 @@ declare module DevExpress.ui {
       | ((
           e: DevExpress.ui.dxAccordion.ItemTitleClickEvent<TItem, TKey>
         ) => void)
-      | string;
+      | string
+      | null;
     /**
      * [descr:dxAccordionOptions.repaintChangesOnly]
      */
@@ -9750,7 +9762,8 @@ declare module DevExpress.ui {
      */
     onCancelClick?:
       | ((e: DevExpress.ui.dxActionSheet.CancelClickEvent<TItem, TKey>) => void)
-      | string;
+      | string
+      | null;
     /**
      * [descr:dxActionSheetOptions.showCancelButton]
      */
@@ -10246,13 +10259,15 @@ declare module DevExpress.ui {
     /**
      * [descr:dxButtonGroupOptions.onItemClick]
      */
-    onItemClick?: (e: DevExpress.ui.dxButtonGroup.ItemClickEvent) => void;
+    onItemClick?:
+      | ((e: DevExpress.ui.dxButtonGroup.ItemClickEvent) => void)
+      | null;
     /**
      * [descr:dxButtonGroupOptions.onSelectionChanged]
      */
-    onSelectionChanged?: (
-      e: DevExpress.ui.dxButtonGroup.SelectionChangedEvent
-    ) => void;
+    onSelectionChanged?:
+      | ((e: DevExpress.ui.dxButtonGroup.SelectionChangedEvent) => void)
+      | null;
     /**
      * [descr:dxButtonGroupOptions.selectedItemKeys]
      */
@@ -10295,7 +10310,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxButtonOptions.onClick]
      */
-    onClick?: (e: DevExpress.ui.dxButton.ClickEvent) => void;
+    onClick?: ((e: DevExpress.ui.dxButton.ClickEvent) => void) | undefined;
     /**
      * [descr:dxButtonOptions.stylingMode]
      */
@@ -10418,7 +10433,8 @@ declare module DevExpress.ui {
      */
     disabledDates?:
       | Array<Date>
-      | ((data: DevExpress.ui.dxCalendar.DisabledDate) => boolean);
+      | ((data: DevExpress.ui.dxCalendar.DisabledDate) => boolean)
+      | null;
     /**
      * [descr:dxCalendarOptions.firstDayOfWeek]
      */
@@ -11955,7 +11971,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxCheckBoxOptions.value]
      */
-    value?: boolean | null | undefined;
+    value?: boolean | null;
   }
   /**
    * [descr:dxColorBox]
@@ -12112,7 +12128,8 @@ declare module DevExpress.ui {
       | ((
           value: string,
           fieldElement: DevExpress.core.DxElement
-        ) => string | DevExpress.core.UserDefinedElement);
+        ) => string | DevExpress.core.UserDefinedElement)
+      | null;
     /**
      * [descr:dxColorBoxOptions.keyStep]
      */
@@ -12324,31 +12341,33 @@ declare module DevExpress.ui {
     /**
      * [descr:dxContextMenuOptions.onHidden]
      */
-    onHidden?: (
-      e: DevExpress.ui.dxContextMenu.HiddenEvent<TItem, TKey>
-    ) => void;
+    onHidden?:
+      | ((e: DevExpress.ui.dxContextMenu.HiddenEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxContextMenuOptions.onHiding]
      */
-    onHiding?: (
-      e: DevExpress.ui.dxContextMenu.HidingEvent<TItem, TKey>
-    ) => void;
+    onHiding?:
+      | ((e: DevExpress.ui.dxContextMenu.HidingEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxContextMenuOptions.onPositioning]
      */
-    onPositioning?: (
-      e: DevExpress.ui.dxContextMenu.PositioningEvent<TItem, TKey>
-    ) => void;
+    onPositioning?:
+      | ((e: DevExpress.ui.dxContextMenu.PositioningEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxContextMenuOptions.onShowing]
      */
-    onShowing?: (
-      e: DevExpress.ui.dxContextMenu.ShowingEvent<TItem, TKey>
-    ) => void;
+    onShowing?:
+      | ((e: DevExpress.ui.dxContextMenu.ShowingEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxContextMenuOptions.onShown]
      */
-    onShown?: (e: DevExpress.ui.dxContextMenu.ShownEvent<TItem, TKey>) => void;
+    onShown?:
+      | ((e: DevExpress.ui.dxContextMenu.ShownEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxContextMenuOptions.position]
      */
@@ -14904,7 +14923,8 @@ declare module DevExpress.ui {
      */
     disabledDates?:
       | Array<Date>
-      | ((data: DevExpress.ui.dxDateBox.DisabledDate) => boolean);
+      | ((data: DevExpress.ui.dxDateBox.DisabledDate) => boolean)
+      | null;
     /**
      * [descr:dxDateBoxOptions.inputAttr]
      */
@@ -14924,7 +14944,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxDateBoxOptions.maxLength]
      */
-    maxLength?: string | number;
+    maxLength?: string | number | null;
     /**
      * [descr:dxDateBoxOptions.name]
      */
@@ -16749,11 +16769,11 @@ declare module DevExpress.ui {
     /**
      * [descr:dxDrawerOptions.maxSize]
      */
-    maxSize?: number;
+    maxSize?: number | null;
     /**
      * [descr:dxDrawerOptions.minSize]
      */
-    minSize?: number;
+    minSize?: number | null;
     /**
      * [descr:dxDrawerOptions.opened]
      */
@@ -16941,7 +16961,8 @@ declare module DevExpress.ui {
       | ((
           value: any,
           fieldElement: DevExpress.core.DxElement
-        ) => string | DevExpress.core.UserDefinedElement);
+        ) => string | DevExpress.core.UserDefinedElement)
+      | null;
     /**
      * [descr:dxDropDownBoxOptions.items]
      */
@@ -17280,10 +17301,12 @@ declare module DevExpress.ui {
     /**
      * [descr:dxDropDownEditorOptions.buttons]
      */
-    buttons?: Array<
-      | DevExpress.ui.dxDropDownEditor.DropDownPredefinedButton
-      | DevExpress.common.TextEditorButton
-    >;
+    buttons?:
+      | Array<
+          | DevExpress.ui.dxDropDownEditor.DropDownPredefinedButton
+          | DevExpress.common.TextEditorButton
+        >
+      | undefined;
     /**
      * [descr:dxDropDownEditorOptions.deferRendering]
      */
@@ -17304,11 +17327,15 @@ declare module DevExpress.ui {
     /**
      * [descr:dxDropDownEditorOptions.onClosed]
      */
-    onClosed?: (e: DevExpress.common.core.events.EventInfo<TComponent>) => void;
+    onClosed?:
+      | ((e: DevExpress.common.core.events.EventInfo<TComponent>) => void)
+      | null;
     /**
      * [descr:dxDropDownEditorOptions.onOpened]
      */
-    onOpened?: (e: DevExpress.common.core.events.EventInfo<TComponent>) => void;
+    onOpened?:
+      | ((e: DevExpress.common.core.events.EventInfo<TComponent>) => void)
+      | null;
     /**
      * [descr:dxDropDownEditorOptions.openOnFieldClick]
      */
@@ -17330,7 +17357,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxDropDownEditorOptions.value]
      */
-    value?: any;
+    value?: any | null;
   }
   /**
    * [descr:dxDropDownList]
@@ -17399,20 +17426,24 @@ declare module DevExpress.ui {
     /**
      * [descr:dxDropDownListOptions.onSelectionChanged]
      */
-    onSelectionChanged?: (
-      e: DevExpress.common.core.events.EventInfo<TComponent> &
-        DevExpress.ui.dxDropDownList.SelectionChangedInfo
-    ) => void;
+    onSelectionChanged?:
+      | ((
+          e: DevExpress.common.core.events.EventInfo<TComponent> &
+            DevExpress.ui.dxDropDownList.SelectionChangedInfo
+        ) => void)
+      | null;
     /**
      * [descr:dxDropDownListOptions.onValueChanged]
      */
-    onValueChanged?: (
-      e: DevExpress.common.core.events.NativeEventInfo<
-        TComponent,
-        KeyboardEvent | MouseEvent | PointerEvent | Event
-      > &
-        DevExpress.ui.Editor.ValueChangedInfo
-    ) => void;
+    onValueChanged?:
+      | ((
+          e: DevExpress.common.core.events.NativeEventInfo<
+            TComponent,
+            KeyboardEvent | MouseEvent | PointerEvent | Event
+          > &
+            DevExpress.ui.Editor.ValueChangedInfo
+        ) => void)
+      | null;
     /**
      * [descr:dxDropDownListOptions.searchEnabled]
      */
@@ -17420,7 +17451,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxDropDownListOptions.searchExpr]
      */
-    searchExpr?: string | Function | Array<string | Function>;
+    searchExpr?: string | Function | Array<string | Function> | null;
     /**
      * [descr:dxDropDownListOptions.searchMode]
      */
@@ -17432,7 +17463,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxDropDownListOptions.selectedItem]
      */
-    selectedItem?: any;
+    selectedItem?: any | null;
     /**
      * [descr:dxDropDownListOptions.showDataBeforeSearch]
      */
@@ -18585,55 +18616,63 @@ declare module DevExpress.ui {
     /**
      * [descr:dxFileUploaderOptions.onBeforeSend]
      */
-    onBeforeSend?: (e: DevExpress.ui.dxFileUploader.BeforeSendEvent) => void;
+    onBeforeSend?:
+      | ((e: DevExpress.ui.dxFileUploader.BeforeSendEvent) => void)
+      | null;
     /**
      * [descr:dxFileUploaderOptions.onDropZoneEnter]
      */
-    onDropZoneEnter?: (
-      e: DevExpress.ui.dxFileUploader.DropZoneEnterEvent
-    ) => void;
+    onDropZoneEnter?:
+      | ((e: DevExpress.ui.dxFileUploader.DropZoneEnterEvent) => void)
+      | null;
     /**
      * [descr:dxFileUploaderOptions.onDropZoneLeave]
      */
-    onDropZoneLeave?: (
-      e: DevExpress.ui.dxFileUploader.DropZoneLeaveEvent
-    ) => void;
+    onDropZoneLeave?:
+      | ((e: DevExpress.ui.dxFileUploader.DropZoneLeaveEvent) => void)
+      | null;
     /**
      * [descr:dxFileUploaderOptions.onFilesUploaded]
      */
-    onFilesUploaded?: (
-      e: DevExpress.ui.dxFileUploader.FilesUploadedEvent
-    ) => void;
+    onFilesUploaded?:
+      | ((e: DevExpress.ui.dxFileUploader.FilesUploadedEvent) => void)
+      | null;
     /**
      * [descr:dxFileUploaderOptions.onProgress]
      */
-    onProgress?: (e: DevExpress.ui.dxFileUploader.ProgressEvent) => void;
+    onProgress?:
+      | ((e: DevExpress.ui.dxFileUploader.ProgressEvent) => void)
+      | null;
     /**
      * [descr:dxFileUploaderOptions.onUploadAborted]
      */
-    onUploadAborted?: (
-      e: DevExpress.ui.dxFileUploader.UploadAbortedEvent
-    ) => void;
+    onUploadAborted?:
+      | ((e: DevExpress.ui.dxFileUploader.UploadAbortedEvent) => void)
+      | null;
     /**
      * [descr:dxFileUploaderOptions.onUploadError]
      */
-    onUploadError?: (e: DevExpress.ui.dxFileUploader.UploadErrorEvent) => void;
+    onUploadError?:
+      | ((e: DevExpress.ui.dxFileUploader.UploadErrorEvent) => void)
+      | null;
     /**
      * [descr:dxFileUploaderOptions.onUploadStarted]
      */
-    onUploadStarted?: (
-      e: DevExpress.ui.dxFileUploader.UploadStartedEvent
-    ) => void;
+    onUploadStarted?:
+      | ((e: DevExpress.ui.dxFileUploader.UploadStartedEvent) => void)
+      | null;
     /**
      * [descr:dxFileUploaderOptions.onUploaded]
      */
-    onUploaded?: (e: DevExpress.ui.dxFileUploader.UploadedEvent) => void;
+    onUploaded?:
+      | ((e: DevExpress.ui.dxFileUploader.UploadedEvent) => void)
+      | null;
     /**
      * [descr:dxFileUploaderOptions.onValueChanged]
      */
-    onValueChanged?: (
-      e: DevExpress.ui.dxFileUploader.ValueChangedEvent
-    ) => void;
+    onValueChanged?:
+      | ((e: DevExpress.ui.dxFileUploader.ValueChangedEvent) => void)
+      | null;
     /**
      * [descr:dxFileUploaderOptions.progress]
      */
@@ -21985,19 +22024,19 @@ declare module DevExpress.ui {
     /**
      * [descr:dxHtmlEditorOptions.mediaResizing]
      */
-    mediaResizing?: dxHtmlEditorMediaResizing;
+    mediaResizing?: dxHtmlEditorMediaResizing | null;
     /**
      * [descr:dxHtmlEditorOptions.tableResizing]
      */
-    tableResizing?: dxHtmlEditorTableResizing;
+    tableResizing?: dxHtmlEditorTableResizing | null;
     /**
      * [descr:dxHtmlEditorOptions.mentions]
      */
-    mentions?: Array<dxHtmlEditorMention>;
+    mentions?: Array<dxHtmlEditorMention> | null;
     /**
      * [descr:dxHtmlEditorOptions.tableContextMenu]
      */
-    tableContextMenu?: dxHtmlEditorTableContextMenu;
+    tableContextMenu?: dxHtmlEditorTableContextMenu | null;
     /**
      * [descr:dxHtmlEditorOptions.imageUpload]
      */
@@ -22009,11 +22048,15 @@ declare module DevExpress.ui {
     /**
      * [descr:dxHtmlEditorOptions.onFocusIn]
      */
-    onFocusIn?: (e: DevExpress.ui.dxHtmlEditor.FocusInEvent) => void;
+    onFocusIn?:
+      | ((e: DevExpress.ui.dxHtmlEditor.FocusInEvent) => void)
+      | undefined;
     /**
      * [descr:dxHtmlEditorOptions.onFocusOut]
      */
-    onFocusOut?: (e: DevExpress.ui.dxHtmlEditor.FocusOutEvent) => void;
+    onFocusOut?:
+      | ((e: DevExpress.ui.dxHtmlEditor.FocusOutEvent) => void)
+      | undefined;
     /**
      * [descr:dxHtmlEditorOptions.placeholder]
      */
@@ -22021,11 +22064,11 @@ declare module DevExpress.ui {
     /**
      * [descr:dxHtmlEditorOptions.toolbar]
      */
-    toolbar?: dxHtmlEditorToolbar;
+    toolbar?: dxHtmlEditorToolbar | null;
     /**
      * [descr:dxHtmlEditorOptions.variables]
      */
-    variables?: dxHtmlEditorVariables;
+    variables?: dxHtmlEditorVariables | null;
     /**
      * [descr:dxHtmlEditorOptions.stylingMode]
      */
@@ -22649,69 +22692,78 @@ declare module DevExpress.ui {
     /**
      * [descr:dxListOptions.onGroupRendered]
      */
-    onGroupRendered?: (
-      e: DevExpress.ui.dxList.GroupRenderedEvent<TItem, TKey>
-    ) => void;
+    onGroupRendered?:
+      | ((e: DevExpress.ui.dxList.GroupRenderedEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxListOptions.onItemClick]
      */
     onItemClick?:
       | ((e: DevExpress.ui.dxList.ItemClickEvent<TItem, TKey>) => void)
-      | string;
+      | string
+      | null;
     /**
      * [descr:dxListOptions.onItemContextMenu]
      */
-    onItemContextMenu?: (
-      e: DevExpress.ui.dxList.ItemContextMenuEvent<TItem, TKey>
-    ) => void;
+    onItemContextMenu?:
+      | ((e: DevExpress.ui.dxList.ItemContextMenuEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxListOptions.onItemDeleted]
      */
-    onItemDeleted?: (
-      e: DevExpress.ui.dxList.ItemDeletedEvent<TItem, TKey>
-    ) => void;
+    onItemDeleted?:
+      | ((e: DevExpress.ui.dxList.ItemDeletedEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxListOptions.onItemDeleting]
      */
-    onItemDeleting?: (
-      e: DevExpress.ui.dxList.ItemDeletingEvent<TItem, TKey>
-    ) => void;
+    onItemDeleting?:
+      | ((e: DevExpress.ui.dxList.ItemDeletingEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxListOptions.onItemHold]
      */
-    onItemHold?: (e: DevExpress.ui.dxList.ItemHoldEvent<TItem, TKey>) => void;
+    onItemHold?:
+      | ((e: DevExpress.ui.dxList.ItemHoldEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxListOptions.onItemReordered]
      */
-    onItemReordered?: (
-      e: DevExpress.ui.dxList.ItemReorderedEvent<TItem, TKey>
-    ) => void;
+    onItemReordered?:
+      | ((e: DevExpress.ui.dxList.ItemReorderedEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxListOptions.onItemSwipe]
      */
-    onItemSwipe?: (e: DevExpress.ui.dxList.ItemSwipeEvent<TItem, TKey>) => void;
+    onItemSwipe?:
+      | ((e: DevExpress.ui.dxList.ItemSwipeEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxListOptions.onPageLoading]
      */
-    onPageLoading?: (
-      e: DevExpress.ui.dxList.PageLoadingEvent<TItem, TKey>
-    ) => void;
+    onPageLoading?:
+      | ((e: DevExpress.ui.dxList.PageLoadingEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxListOptions.onPullRefresh]
      */
-    onPullRefresh?: (
-      e: DevExpress.ui.dxList.PullRefreshEvent<TItem, TKey>
-    ) => void;
+    onPullRefresh?:
+      | ((e: DevExpress.ui.dxList.PullRefreshEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxListOptions.onScroll]
      */
-    onScroll?: (e: DevExpress.ui.dxList.ScrollEvent<TItem, TKey>) => void;
+    onScroll?:
+      | ((e: DevExpress.ui.dxList.ScrollEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxListOptions.onSelectAllValueChanged]
      */
-    onSelectAllValueChanged?: (
-      e: DevExpress.ui.dxList.SelectAllValueChangedEvent<TItem, TKey>
-    ) => void;
+    onSelectAllValueChanged?:
+      | ((
+          e: DevExpress.ui.dxList.SelectAllValueChangedEvent<TItem, TKey>
+        ) => void)
+      | null;
     /**
      * [descr:dxListOptions.pageLoadMode]
      */
@@ -23094,7 +23146,8 @@ declare module DevExpress.ui {
       | ((
           selectedItem: any,
           fieldElement: DevExpress.core.DxElement
-        ) => string | DevExpress.core.UserDefinedElement);
+        ) => string | DevExpress.core.UserDefinedElement)
+      | null;
     /**
      * [descr:dxLookupOptions.focusStateEnabled]
      */
@@ -23120,19 +23173,25 @@ declare module DevExpress.ui {
     /**
      * [descr:dxLookupOptions.onPageLoading]
      */
-    onPageLoading?: (e: DevExpress.ui.dxLookup.PageLoadingEvent) => void;
+    onPageLoading?:
+      | ((e: DevExpress.ui.dxLookup.PageLoadingEvent) => void)
+      | null;
     /**
      * [descr:dxLookupOptions.onPullRefresh]
      */
-    onPullRefresh?: (e: DevExpress.ui.dxLookup.PullRefreshEvent) => void;
+    onPullRefresh?:
+      | ((e: DevExpress.ui.dxLookup.PullRefreshEvent) => void)
+      | null;
     /**
      * [descr:dxLookupOptions.onScroll]
      */
-    onScroll?: (e: DevExpress.ui.dxLookup.ScrollEvent) => void;
+    onScroll?: ((e: DevExpress.ui.dxLookup.ScrollEvent) => void) | null;
     /**
      * [descr:dxLookupOptions.onValueChanged]
      */
-    onValueChanged?: (e: DevExpress.ui.dxLookup.ValueChangedEvent) => void;
+    onValueChanged?:
+      | ((e: DevExpress.ui.dxLookup.ValueChangedEvent) => void)
+      | null;
     /**
      * [descr:dxLookupOptions.pageLoadMode]
      */
@@ -23404,27 +23463,31 @@ declare module DevExpress.ui {
     /**
      * [descr:dxMapOptions.onClick]
      */
-    onClick?: ((e: DevExpress.ui.dxMap.ClickEvent) => void) | string;
+    onClick?: ((e: DevExpress.ui.dxMap.ClickEvent) => void) | string | null;
     /**
      * [descr:dxMapOptions.onMarkerAdded]
      */
-    onMarkerAdded?: (e: DevExpress.ui.dxMap.MarkerAddedEvent) => void;
+    onMarkerAdded?: ((e: DevExpress.ui.dxMap.MarkerAddedEvent) => void) | null;
     /**
      * [descr:dxMapOptions.onMarkerRemoved]
      */
-    onMarkerRemoved?: (e: DevExpress.ui.dxMap.MarkerRemovedEvent) => void;
+    onMarkerRemoved?:
+      | ((e: DevExpress.ui.dxMap.MarkerRemovedEvent) => void)
+      | null;
     /**
      * [descr:dxMapOptions.onReady]
      */
-    onReady?: (e: DevExpress.ui.dxMap.ReadyEvent) => void;
+    onReady?: ((e: DevExpress.ui.dxMap.ReadyEvent) => void) | null;
     /**
      * [descr:dxMapOptions.onRouteAdded]
      */
-    onRouteAdded?: (e: DevExpress.ui.dxMap.RouteAddedEvent) => void;
+    onRouteAdded?: ((e: DevExpress.ui.dxMap.RouteAddedEvent) => void) | null;
     /**
      * [descr:dxMapOptions.onRouteRemoved]
      */
-    onRouteRemoved?: (e: DevExpress.ui.dxMap.RouteRemovedEvent) => void;
+    onRouteRemoved?:
+      | ((e: DevExpress.ui.dxMap.RouteRemovedEvent) => void)
+      | null;
     /**
      * [descr:dxMapOptions.provider]
      */
@@ -23855,27 +23918,27 @@ declare module DevExpress.ui {
     /**
      * [descr:dxMenuOptions.onSubmenuHidden]
      */
-    onSubmenuHidden?: (
-      e: DevExpress.ui.dxMenu.SubmenuHiddenEvent<TItem, TKey>
-    ) => void;
+    onSubmenuHidden?:
+      | ((e: DevExpress.ui.dxMenu.SubmenuHiddenEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxMenuOptions.onSubmenuHiding]
      */
-    onSubmenuHiding?: (
-      e: DevExpress.ui.dxMenu.SubmenuHidingEvent<TItem, TKey>
-    ) => void;
+    onSubmenuHiding?:
+      | ((e: DevExpress.ui.dxMenu.SubmenuHidingEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxMenuOptions.onSubmenuShowing]
      */
-    onSubmenuShowing?: (
-      e: DevExpress.ui.dxMenu.SubmenuShowingEvent<TItem, TKey>
-    ) => void;
+    onSubmenuShowing?:
+      | ((e: DevExpress.ui.dxMenu.SubmenuShowingEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxMenuOptions.onSubmenuShown]
      */
-    onSubmenuShown?: (
-      e: DevExpress.ui.dxMenu.SubmenuShownEvent<TItem, TKey>
-    ) => void;
+    onSubmenuShown?:
+      | ((e: DevExpress.ui.dxMenu.SubmenuShownEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxMenuOptions.orientation]
      */
@@ -24207,10 +24270,12 @@ declare module DevExpress.ui {
     /**
      * [descr:dxNumberBoxOptions.buttons]
      */
-    buttons?: Array<
-      | DevExpress.ui.dxNumberBox.NumberBoxPredefinedButton
-      | DevExpress.common.TextEditorButton
-    >;
+    buttons?:
+      | Array<
+          | DevExpress.ui.dxNumberBox.NumberBoxPredefinedButton
+          | DevExpress.common.TextEditorButton
+        >
+      | undefined;
     /**
      * [descr:dxNumberBoxOptions.format]
      */
@@ -25608,22 +25673,26 @@ declare module DevExpress.ui {
     /**
      * [descr:dxPopupOptions.onResize]
      */
-    onResize?: (e: DevExpress.ui.dxPopup.ResizeEvent) => void;
+    onResize?: ((e: DevExpress.ui.dxPopup.ResizeEvent) => void) | null;
     /**
      * [descr:dxPopupOptions.onResizeEnd]
      */
-    onResizeEnd?: (e: DevExpress.ui.dxPopup.ResizeEndEvent) => void;
+    onResizeEnd?: ((e: DevExpress.ui.dxPopup.ResizeEndEvent) => void) | null;
     /**
      * [descr:dxPopupOptions.onResizeStart]
      */
-    onResizeStart?: (e: DevExpress.ui.dxPopup.ResizeStartEvent) => void;
+    onResizeStart?:
+      | ((e: DevExpress.ui.dxPopup.ResizeStartEvent) => void)
+      | null;
     /**
      * [descr:dxPopupOptions.onTitleRendered]
      */
-    onTitleRendered?: (
-      e: DevExpress.common.core.events.EventInfo<TComponent> &
-        DevExpress.ui.dxPopup.TitleRenderedInfo
-    ) => void;
+    onTitleRendered?:
+      | ((
+          e: DevExpress.common.core.events.EventInfo<TComponent> &
+            DevExpress.ui.dxPopup.TitleRenderedInfo
+        ) => void)
+      | null;
     /**
      * [descr:dxPopupOptions.position]
      */
@@ -25730,7 +25799,9 @@ declare module DevExpress.ui {
     /**
      * [descr:dxProgressBarOptions.onComplete]
      */
-    onComplete?: (e: DevExpress.ui.dxProgressBar.CompleteEvent) => void;
+    onComplete?:
+      | ((e: DevExpress.ui.dxProgressBar.CompleteEvent) => void)
+      | null;
     /**
      * [descr:dxProgressBarOptions.showStatus]
      */
@@ -25889,7 +25960,9 @@ declare module DevExpress.ui {
     /**
      * [descr:dxRangeSliderOptions.onValueChanged]
      */
-    onValueChanged?: (e: DevExpress.ui.dxRangeSlider.ValueChangedEvent) => void;
+    onValueChanged?:
+      | ((e: DevExpress.ui.dxRangeSlider.ValueChangedEvent) => void)
+      | null;
     /**
      * [descr:dxRangeSliderOptions.start]
      */
@@ -26007,15 +26080,19 @@ declare module DevExpress.ui {
     /**
      * [descr:dxResizableOptions.onResize]
      */
-    onResize?: (e: DevExpress.ui.dxResizable.ResizeEvent) => void;
+    onResize?: ((e: DevExpress.ui.dxResizable.ResizeEvent) => void) | undefined;
     /**
      * [descr:dxResizableOptions.onResizeEnd]
      */
-    onResizeEnd?: (e: DevExpress.ui.dxResizable.ResizeEndEvent) => void;
+    onResizeEnd?:
+      | ((e: DevExpress.ui.dxResizable.ResizeEndEvent) => void)
+      | undefined;
     /**
      * [descr:dxResizableOptions.onResizeStart]
      */
-    onResizeStart?: (e: DevExpress.ui.dxResizable.ResizeStartEvent) => void;
+    onResizeStart?:
+      | ((e: DevExpress.ui.dxResizable.ResizeStartEvent) => void)
+      | undefined;
     /**
      * [descr:dxResizableOptions.width]
      */
@@ -26229,7 +26306,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxResponsiveBoxOptions.screenByWidth]
      */
-    screenByWidth?: Function;
+    screenByWidth?: Function | null;
     /**
      * [descr:dxResponsiveBoxOptions.singleColumnScreen]
      */
@@ -27543,15 +27620,15 @@ declare module DevExpress.ui {
     /**
      * [descr:dxScrollableOptions.onScroll]
      */
-    onScroll?: (
-      e: DevExpress.ui.dxScrollable.ScrollEventInfo<TComponent>
-    ) => void;
+    onScroll?:
+      | ((e: DevExpress.ui.dxScrollable.ScrollEventInfo<TComponent>) => void)
+      | null;
     /**
      * [descr:dxScrollableOptions.onUpdated]
      */
-    onUpdated?: (
-      e: DevExpress.ui.dxScrollable.ScrollEventInfo<TComponent>
-    ) => void;
+    onUpdated?:
+      | ((e: DevExpress.ui.dxScrollable.ScrollEventInfo<TComponent>) => void)
+      | null;
     /**
      * [descr:dxScrollableOptions.scrollByContent]
      */
@@ -27633,11 +27710,13 @@ declare module DevExpress.ui {
     /**
      * [descr:dxScrollViewOptions.onPullDown]
      */
-    onPullDown?: (e: DevExpress.ui.dxScrollView.PullDownEvent) => void;
+    onPullDown?: ((e: DevExpress.ui.dxScrollView.PullDownEvent) => void) | null;
     /**
      * [descr:dxScrollViewOptions.onReachBottom]
      */
-    onReachBottom?: (e: DevExpress.ui.dxScrollView.ReachBottomEvent) => void;
+    onReachBottom?:
+      | ((e: DevExpress.ui.dxScrollView.ReachBottomEvent) => void)
+      | null;
     /**
      * [descr:dxScrollViewOptions.pulledDownText]
      */
@@ -27838,7 +27917,8 @@ declare module DevExpress.ui {
       | ((
           selectedItem: any,
           fieldElement: DevExpress.core.DxElement
-        ) => string | DevExpress.core.UserDefinedElement);
+        ) => string | DevExpress.core.UserDefinedElement)
+      | null;
     /**
      * [descr:dxSelectBoxOptions.fieldAddons]
      */
@@ -28655,9 +28735,9 @@ declare module DevExpress.ui {
     /**
      * [descr:dxSpeedDialActionOptions.onContentReady]
      */
-    onContentReady?: (
-      e: DevExpress.ui.dxSpeedDialAction.ContentReadyEvent
-    ) => void;
+    onContentReady?:
+      | ((e: DevExpress.ui.dxSpeedDialAction.ContentReadyEvent) => void)
+      | null;
     /**
      * [descr:dxSpeedDialActionOptions.visible]
      */
@@ -28885,23 +28965,31 @@ declare module DevExpress.ui {
     /**
      * [descr:dxSplitterOptions.onResize]
      */
-    onResize?: (e: DevExpress.ui.dxSplitter.ResizeEvent) => void;
+    onResize?: ((e: DevExpress.ui.dxSplitter.ResizeEvent) => void) | undefined;
     /**
      * [descr:dxSplitterOptions.onResizeEnd]
      */
-    onResizeEnd?: (e: DevExpress.ui.dxSplitter.ResizeEndEvent) => void;
+    onResizeEnd?:
+      | ((e: DevExpress.ui.dxSplitter.ResizeEndEvent) => void)
+      | undefined;
     /**
      * [descr:dxSplitterOptions.onResizeStart]
      */
-    onResizeStart?: (e: DevExpress.ui.dxSplitter.ResizeStartEvent) => void;
+    onResizeStart?:
+      | ((e: DevExpress.ui.dxSplitter.ResizeStartEvent) => void)
+      | undefined;
     /**
      * [descr:dxSplitterOptions.onItemExpanded]
      */
-    onItemExpanded?: (e: DevExpress.ui.dxSplitter.ItemExpandedEvent) => void;
+    onItemExpanded?:
+      | ((e: DevExpress.ui.dxSplitter.ItemExpandedEvent) => void)
+      | undefined;
     /**
      * [descr:dxSplitterOptions.onItemCollapsed]
      */
-    onItemCollapsed?: (e: DevExpress.ui.dxSplitter.ItemCollapsedEvent) => void;
+    onItemCollapsed?:
+      | ((e: DevExpress.ui.dxSplitter.ItemCollapsedEvent) => void)
+      | undefined;
   }
   /**
    * [descr:dxStepper]
@@ -29395,19 +29483,20 @@ declare module DevExpress.ui {
      */
     onTitleClick?:
       | ((e: DevExpress.ui.dxTabPanel.TitleClickEvent<TItem, TKey>) => void)
-      | string;
+      | string
+      | null;
     /**
      * [descr:dxTabPanelOptions.onTitleHold]
      */
-    onTitleHold?: (
-      e: DevExpress.ui.dxTabPanel.TitleHoldEvent<TItem, TKey>
-    ) => void;
+    onTitleHold?:
+      | ((e: DevExpress.ui.dxTabPanel.TitleHoldEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxTabPanelOptions.onTitleRendered]
      */
-    onTitleRendered?: (
-      e: DevExpress.ui.dxTabPanel.TitleRenderedEvent<TItem, TKey>
-    ) => void;
+    onTitleRendered?:
+      | ((e: DevExpress.ui.dxTabPanel.TitleRenderedEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxTabPanelOptions.repaintChangesOnly]
      */
@@ -29822,21 +29911,21 @@ declare module DevExpress.ui {
     /**
      * [descr:dxTagBoxOptions.onMultiTagPreparing]
      */
-    onMultiTagPreparing?: (
-      e: DevExpress.ui.dxTagBox.MultiTagPreparingEvent
-    ) => void;
+    onMultiTagPreparing?:
+      | ((e: DevExpress.ui.dxTagBox.MultiTagPreparingEvent) => void)
+      | null;
     /**
      * [descr:dxTagBoxOptions.onSelectAllValueChanged]
      */
-    onSelectAllValueChanged?: (
-      e: DevExpress.ui.dxTagBox.SelectAllValueChangedEvent
-    ) => void;
+    onSelectAllValueChanged?:
+      | ((e: DevExpress.ui.dxTagBox.SelectAllValueChangedEvent) => void)
+      | null;
     /**
      * [descr:dxTagBoxOptions.onSelectionChanged]
      */
-    onSelectionChanged?: (
-      e: DevExpress.ui.dxTagBox.SelectionChangedEvent
-    ) => void;
+    onSelectionChanged?:
+      | ((e: DevExpress.ui.dxTagBox.SelectionChangedEvent) => void)
+      | null;
     /**
      * [descr:dxTagBoxOptions.selectAllMode]
      */
@@ -30148,7 +30237,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxTextBoxOptions.maxLength]
      */
-    maxLength?: string | number;
+    maxLength?: string | number | null;
     /**
      * [descr:dxTextBoxOptions.mode]
      */
@@ -30197,11 +30286,13 @@ declare module DevExpress.ui {
     /**
      * [descr:dxTextEditorOptions.buttons]
      */
-    buttons?: Array<
-      | string
-      | DevExpress.common.TextBoxPredefinedButton
-      | DevExpress.common.TextEditorButton
-    >;
+    buttons?:
+      | Array<
+          | string
+          | DevExpress.common.TextBoxPredefinedButton
+          | DevExpress.common.TextEditorButton
+        >
+      | undefined;
     /**
      * [descr:dxTextEditorOptions.focusStateEnabled]
      */
@@ -30245,81 +30336,107 @@ declare module DevExpress.ui {
     /**
      * [descr:dxTextEditorOptions.onChange]
      */
-    onChange?: (
-      e: DevExpress.common.core.events.NativeEventInfo<TComponent, Event>
-    ) => void;
+    onChange?:
+      | ((
+          e: DevExpress.common.core.events.NativeEventInfo<TComponent, Event>
+        ) => void)
+      | null;
     /**
      * [descr:dxTextEditorOptions.onCopy]
      */
-    onCopy?: (
-      e: DevExpress.common.core.events.NativeEventInfo<
-        TComponent,
-        ClipboardEvent
-      >
-    ) => void;
+    onCopy?:
+      | ((
+          e: DevExpress.common.core.events.NativeEventInfo<
+            TComponent,
+            ClipboardEvent
+          >
+        ) => void)
+      | null;
     /**
      * [descr:dxTextEditorOptions.onCut]
      */
-    onCut?: (
-      e: DevExpress.common.core.events.NativeEventInfo<
-        TComponent,
-        ClipboardEvent
-      >
-    ) => void;
+    onCut?:
+      | ((
+          e: DevExpress.common.core.events.NativeEventInfo<
+            TComponent,
+            ClipboardEvent
+          >
+        ) => void)
+      | null;
     /**
      * [descr:dxTextEditorOptions.onEnterKey]
      */
-    onEnterKey?: (
-      e: DevExpress.common.core.events.NativeEventInfo<
-        TComponent,
-        KeyboardEvent
-      >
-    ) => void;
+    onEnterKey?:
+      | ((
+          e: DevExpress.common.core.events.NativeEventInfo<
+            TComponent,
+            KeyboardEvent
+          >
+        ) => void)
+      | null;
     /**
      * [descr:dxTextEditorOptions.onFocusIn]
      */
-    onFocusIn?: (
-      e: DevExpress.common.core.events.NativeEventInfo<TComponent, FocusEvent>
-    ) => void;
+    onFocusIn?:
+      | ((
+          e: DevExpress.common.core.events.NativeEventInfo<
+            TComponent,
+            FocusEvent
+          >
+        ) => void)
+      | null;
     /**
      * [descr:dxTextEditorOptions.onFocusOut]
      */
-    onFocusOut?: (
-      e: DevExpress.common.core.events.NativeEventInfo<TComponent, FocusEvent>
-    ) => void;
+    onFocusOut?:
+      | ((
+          e: DevExpress.common.core.events.NativeEventInfo<
+            TComponent,
+            FocusEvent
+          >
+        ) => void)
+      | null;
     /**
      * [descr:dxTextEditorOptions.onInput]
      */
-    onInput?: (
-      e: DevExpress.common.core.events.NativeEventInfo<TComponent, UIEvent>
-    ) => void;
+    onInput?:
+      | ((
+          e: DevExpress.common.core.events.NativeEventInfo<TComponent, UIEvent>
+        ) => void)
+      | null;
     /**
      * [descr:dxTextEditorOptions.onKeyDown]
      */
-    onKeyDown?: (
-      e: DevExpress.common.core.events.NativeEventInfo<
-        TComponent,
-        KeyboardEvent
-      >
-    ) => void;
+    onKeyDown?:
+      | ((
+          e: DevExpress.common.core.events.NativeEventInfo<
+            TComponent,
+            KeyboardEvent
+          >
+        ) => void)
+      | null;
     /**
      * [descr:dxTextEditorOptions.onKeyUp]
      */
-    onKeyUp?: (
-      e: DevExpress.common.core.events.NativeEventInfo<
-        TComponent,
-        KeyboardEvent
-      >
-    ) => void;
+    onKeyUp?:
+      | ((
+          e: DevExpress.common.core.events.NativeEventInfo<
+            TComponent,
+            KeyboardEvent
+          >
+        ) => void)
+      | null;
     /**
      * [descr:dxTextEditorOptions.onPaste]
      */
-    onPaste?: (
-      e: DevExpress.common.core.events.NativeEventInfo<
-        TComponent,
-        ClipboardEvent
-      >
-    ) => void;
+    onPaste?:
+      | ((
+          e: DevExpress.common.core.events.NativeEventInfo<
+            TComponent,
+            ClipboardEvent
+          >
+        ) => void)
+      | null;
     /**
      * [descr:dxTextEditorOptions.placeholder]
      */
@@ -33099,57 +33216,65 @@ declare module DevExpress.ui {
     /**
      * [descr:dxTreeViewOptions.onItemClick]
      */
-    onItemClick?: (
-      e: DevExpress.ui.dxTreeView.ItemClickEvent<TItem, TKey>
-    ) => void;
+    onItemClick?:
+      | ((e: DevExpress.ui.dxTreeView.ItemClickEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxTreeViewOptions.onItemCollapsed]
      */
-    onItemCollapsed?: (
-      e: DevExpress.ui.dxTreeView.ItemCollapsedEvent<TItem, TKey>
-    ) => void;
+    onItemCollapsed?:
+      | ((e: DevExpress.ui.dxTreeView.ItemCollapsedEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxTreeViewOptions.onItemContextMenu]
      */
-    onItemContextMenu?: (
-      e: DevExpress.ui.dxTreeView.ItemContextMenuEvent<TItem, TKey>
-    ) => void;
+    onItemContextMenu?:
+      | ((
+          e: DevExpress.ui.dxTreeView.ItemContextMenuEvent<TItem, TKey>
+        ) => void)
+      | null;
     /**
      * [descr:dxTreeViewOptions.onItemExpanded]
      */
-    onItemExpanded?: (
-      e: DevExpress.ui.dxTreeView.ItemExpandedEvent<TItem, TKey>
-    ) => void;
+    onItemExpanded?:
+      | ((e: DevExpress.ui.dxTreeView.ItemExpandedEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxTreeViewOptions.onItemHold]
      */
-    onItemHold?: (
-      e: DevExpress.ui.dxTreeView.ItemHoldEvent<TItem, TKey>
-    ) => void;
+    onItemHold?:
+      | ((e: DevExpress.ui.dxTreeView.ItemHoldEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxTreeViewOptions.onItemRendered]
      */
-    onItemRendered?: (
-      e: DevExpress.ui.dxTreeView.ItemRenderedEvent<TItem, TKey>
-    ) => void;
+    onItemRendered?:
+      | ((e: DevExpress.ui.dxTreeView.ItemRenderedEvent<TItem, TKey>) => void)
+      | null;
     /**
      * [descr:dxTreeViewOptions.onItemSelectionChanged]
      */
-    onItemSelectionChanged?: (
-      e: DevExpress.ui.dxTreeView.ItemSelectionChangedEvent<TItem, TKey>
-    ) => void;
+    onItemSelectionChanged?:
+      | ((
+          e: DevExpress.ui.dxTreeView.ItemSelectionChangedEvent<TItem, TKey>
+        ) => void)
+      | null;
     /**
      * [descr:dxTreeViewOptions.onSelectAllValueChanged]
      */
-    onSelectAllValueChanged?: (
-      e: DevExpress.ui.dxTreeView.SelectAllValueChangedEvent<TItem, TKey>
-    ) => void;
+    onSelectAllValueChanged?:
+      | ((
+          e: DevExpress.ui.dxTreeView.SelectAllValueChangedEvent<TItem, TKey>
+        ) => void)
+      | null;
     /**
      * [descr:dxTreeViewOptions.onSelectionChanged]
      */
-    onSelectionChanged?: (
-      e: DevExpress.ui.dxTreeView.SelectionChangedEvent<TItem, TKey>
-    ) => void;
+    onSelectionChanged?:
+      | ((
+          e: DevExpress.ui.dxTreeView.SelectionChangedEvent<TItem, TKey>
+        ) => void)
+      | null;
     /**
      * [descr:dxTreeViewOptions.parentIdExpr]
      */
@@ -33619,10 +33744,12 @@ declare module DevExpress.ui {
     /**
      * [descr:EditorOptions.onValueChanged]
      */
-    onValueChanged?: (
-      e: DevExpress.common.core.events.NativeEventInfo<TComponent, Event> &
-        DevExpress.ui.Editor.ValueChangedInfo
-    ) => void;
+    onValueChanged?:
+      | ((
+          e: DevExpress.common.core.events.NativeEventInfo<TComponent, Event> &
+            DevExpress.ui.Editor.ValueChangedInfo
+        ) => void)
+      | null;
     /**
      * [descr:EditorOptions.readOnly]
      */
@@ -33630,11 +33757,11 @@ declare module DevExpress.ui {
     /**
      * [descr:EditorOptions.validationError]
      */
-    validationError?: any;
+    validationError?: any | null;
     /**
      * [descr:EditorOptions.validationErrors]
      */
-    validationErrors?: Array<any>;
+    validationErrors?: Array<any> | null;
     /**
      * [descr:EditorOptions.validationMessageMode]
      */
@@ -33650,7 +33777,7 @@ declare module DevExpress.ui {
     /**
      * [descr:EditorOptions.value]
      */
-    value?: any;
+    value?: any | null;
     /**
      * [descr:EditorOptions.stylingMode]
      */
@@ -33806,7 +33933,7 @@ declare module DevExpress.ui {
     /**
      * [descr:SearchBoxMixinOptions.searchExpr]
      */
-    searchExpr?: string | Function | Array<string | Function>;
+    searchExpr?: string | Function | Array<string | Function> | null;
     /**
      * [descr:SearchBoxMixinOptions.searchMode]
      */
@@ -33950,9 +34077,9 @@ declare module DevExpress.ui {
     /**
      * [descr:WidgetOptions.onContentReady]
      */
-    onContentReady?: (
-      e: DevExpress.common.core.events.EventInfo<TComponent>
-    ) => void;
+    onContentReady?:
+      | ((e: DevExpress.common.core.events.EventInfo<TComponent>) => void)
+      | null;
     /**
      * [descr:WidgetOptions.tabIndex]
      */
@@ -35360,7 +35487,9 @@ declare module DevExpress.viz {
     /**
      * [descr:BaseChartOptions.onDone]
      */
-    onDone?: (e: DevExpress.common.core.events.EventInfo<TComponent>) => void;
+    onDone?:
+      | ((e: DevExpress.common.core.events.EventInfo<TComponent>) => void)
+      | undefined;
     /**
      * [descr:BaseChartOptions.onPointClick]
      */
@@ -35372,7 +35501,8 @@ declare module DevExpress.viz {
           > &
             DevExpress.viz.BaseChart.PointInteractionInfo<TPoint>
         ) => void)
-      | string;
+      | string
+      | undefined;
     /**
      * [descr:BaseChartOptions.onPointHoverChanged]
      */
@@ -35390,17 +35520,21 @@ declare module DevExpress.viz {
     /**
      * [descr:BaseChartOptions.onTooltipHidden]
      */
-    onTooltipHidden?: (
-      e: DevExpress.common.core.events.EventInfo<TComponent> &
-        DevExpress.viz.BaseChart.TooltipInfo<TPoint>
-    ) => void;
+    onTooltipHidden?:
+      | ((
+          e: DevExpress.common.core.events.EventInfo<TComponent> &
+            DevExpress.viz.BaseChart.TooltipInfo<TPoint>
+        ) => void)
+      | undefined;
     /**
      * [descr:BaseChartOptions.onTooltipShown]
      */
-    onTooltipShown?: (
-      e: DevExpress.common.core.events.EventInfo<TComponent> &
-        DevExpress.viz.BaseChart.TooltipInfo<TPoint>
-    ) => void;
+    onTooltipShown?:
+      | ((
+          e: DevExpress.common.core.events.EventInfo<TComponent> &
+            DevExpress.viz.BaseChart.TooltipInfo<TPoint>
+        ) => void)
+      | undefined;
     /**
      * [descr:BaseChartOptions.palette]
      */
@@ -35549,17 +35683,21 @@ declare module DevExpress.viz {
     /**
      * [descr:BaseGaugeOptions.onTooltipHidden]
      */
-    onTooltipHidden?: (
-      e: DevExpress.common.core.events.EventInfo<TComponent> &
-        DevExpress.viz.BaseGauge.TooltipInfo
-    ) => void;
+    onTooltipHidden?:
+      | ((
+          e: DevExpress.common.core.events.EventInfo<TComponent> &
+            DevExpress.viz.BaseGauge.TooltipInfo
+        ) => void)
+      | undefined;
     /**
      * [descr:BaseGaugeOptions.onTooltipShown]
      */
-    onTooltipShown?: (
-      e: DevExpress.common.core.events.EventInfo<TComponent> &
-        DevExpress.viz.BaseGauge.TooltipInfo
-    ) => void;
+    onTooltipShown?:
+      | ((
+          e: DevExpress.common.core.events.EventInfo<TComponent> &
+            DevExpress.viz.BaseGauge.TooltipInfo
+        ) => void)
+      | undefined;
     /**
      * [descr:BaseGaugeOptions.rangeContainer]
      */
@@ -35571,7 +35709,7 @@ declare module DevExpress.viz {
     /**
      * [descr:BaseGaugeOptions.subvalues]
      */
-    subvalues?: Array<number>;
+    subvalues?: Array<number> | undefined;
     /**
      * [descr:BaseGaugeOptions.tooltip]
      */
@@ -35632,11 +35770,11 @@ declare module DevExpress.viz {
     /**
      * [descr:BaseGaugeOptions.scale.customMinorTicks]
      */
-    customMinorTicks?: Array<number>;
+    customMinorTicks?: Array<number> | undefined;
     /**
      * [descr:BaseGaugeOptions.scale.customTicks]
      */
-    customTicks?: Array<number>;
+    customTicks?: Array<number> | undefined;
     /**
      * [descr:BaseGaugeOptions.scale.endValue]
      */
@@ -36042,15 +36180,15 @@ declare module DevExpress.viz {
     /**
      * [descr:BaseSparklineOptions.onTooltipHidden]
      */
-    onTooltipHidden?: (
-      e: DevExpress.common.core.events.EventInfo<TComponent>
-    ) => void;
+    onTooltipHidden?:
+      | ((e: DevExpress.common.core.events.EventInfo<TComponent>) => void)
+      | undefined;
     /**
      * [descr:BaseSparklineOptions.onTooltipShown]
      */
-    onTooltipShown?: (
-      e: DevExpress.common.core.events.EventInfo<TComponent>
-    ) => void;
+    onTooltipShown?:
+      | ((e: DevExpress.common.core.events.EventInfo<TComponent>) => void)
+      | undefined;
     /**
      * [descr:BaseSparklineOptions.redrawOnResize]
      */
@@ -37217,11 +37355,15 @@ declare module DevExpress.viz {
     /**
      * [descr:dxBarGaugeOptions.onTooltipHidden]
      */
-    onTooltipHidden?: (e: DevExpress.viz.dxBarGauge.TooltipHiddenEvent) => void;
+    onTooltipHidden?:
+      | ((e: DevExpress.viz.dxBarGauge.TooltipHiddenEvent) => void)
+      | undefined;
     /**
      * [descr:dxBarGaugeOptions.onTooltipShown]
      */
-    onTooltipShown?: (e: DevExpress.viz.dxBarGauge.TooltipShownEvent) => void;
+    onTooltipShown?:
+      | ((e: DevExpress.viz.dxBarGauge.TooltipShownEvent) => void)
+      | undefined;
     /**
      * [descr:dxBarGaugeOptions.palette]
      */
@@ -37406,7 +37548,7 @@ declare module DevExpress.viz {
       /**
        * [descr:dxChartOptions.argumentAxis.breaks]
        */
-      breaks?: Array<DevExpress.common.charts.ScaleBreak>;
+      breaks?: Array<DevExpress.common.charts.ScaleBreak> | undefined;
       /**
        * [descr:dxChartOptions.argumentAxis.categories]
        */
@@ -37426,7 +37568,7 @@ declare module DevExpress.viz {
       /**
        * [descr:dxChartOptions.argumentAxis.holidays]
        */
-      holidays?: Array<Date | string> | Array<number>;
+      holidays?: Array<Date | string> | Array<number> | undefined;
       /**
        * [descr:dxChartOptions.argumentAxis.hoverMode]
        */
@@ -37446,7 +37588,9 @@ declare module DevExpress.viz {
       /**
        * [descr:dxChartOptions.argumentAxis.minVisualRangeLength]
        */
-      minVisualRangeLength?: DevExpress.common.charts.TimeIntervalConfig;
+      minVisualRangeLength?:
+        | DevExpress.common.charts.TimeIntervalConfig
+        | undefined;
       /**
        * [descr:dxChartOptions.argumentAxis.minorTickCount]
        */
@@ -37474,7 +37618,7 @@ declare module DevExpress.viz {
       /**
        * [descr:dxChartOptions.argumentAxis.singleWorkdays]
        */
-      singleWorkdays?: Array<Date | string> | Array<number>;
+      singleWorkdays?: Array<Date | string> | Array<number> | undefined;
       /**
        * [descr:dxChartOptions.argumentAxis.strips]
        */
@@ -37919,7 +38063,7 @@ declare module DevExpress.viz {
       /**
        * [descr:dxChartOptions.commonAxisSettings.placeholderSize]
        */
-      placeholderSize?: number;
+      placeholderSize?: number | null;
       /**
        * [descr:dxChartOptions.commonAxisSettings.stripStyle]
        */
@@ -38602,7 +38746,7 @@ declare module DevExpress.viz {
       /**
        * [descr:dxChartOptions.valueAxis.breaks]
        */
-      breaks?: Array<DevExpress.common.charts.ScaleBreak>;
+      breaks?: Array<DevExpress.common.charts.ScaleBreak> | undefined;
       /**
        * [descr:dxChartOptions.valueAxis.categories]
        */
@@ -38638,7 +38782,9 @@ declare module DevExpress.viz {
       /**
        * [descr:dxChartOptions.valueAxis.minVisualRangeLength]
        */
-      minVisualRangeLength?: DevExpress.common.charts.TimeIntervalConfig;
+      minVisualRangeLength?:
+        | DevExpress.common.charts.TimeIntervalConfig
+        | undefined;
       /**
        * [descr:dxChartOptions.valueAxis.minorTickCount]
        */
@@ -39218,39 +39364,44 @@ declare module DevExpress.viz {
      */
     onArgumentAxisClick?:
       | ((e: DevExpress.viz.dxChart.ArgumentAxisClickEvent) => void)
-      | string;
+      | string
+      | undefined;
     /**
      * [descr:dxChartOptions.onLegendClick]
      */
     onLegendClick?:
       | ((e: DevExpress.viz.dxChart.LegendClickEvent) => void)
-      | string;
+      | string
+      | undefined;
     /**
      * [descr:dxChartOptions.onSeriesClick]
      */
     onSeriesClick?:
       | ((e: DevExpress.viz.dxChart.SeriesClickEvent) => void)
-      | string;
+      | string
+      | undefined;
     /**
      * [descr:dxChartOptions.onSeriesHoverChanged]
      */
-    onSeriesHoverChanged?: (
-      e: DevExpress.viz.dxChart.SeriesHoverChangedEvent
-    ) => void;
+    onSeriesHoverChanged?:
+      | ((e: DevExpress.viz.dxChart.SeriesHoverChangedEvent) => void)
+      | undefined;
     /**
      * [descr:dxChartOptions.onSeriesSelectionChanged]
      */
-    onSeriesSelectionChanged?: (
-      e: DevExpress.viz.dxChart.SeriesSelectionChangedEvent
-    ) => void;
+    onSeriesSelectionChanged?:
+      | ((e: DevExpress.viz.dxChart.SeriesSelectionChangedEvent) => void)
+      | undefined;
     /**
      * [descr:dxChartOptions.onZoomEnd]
      */
-    onZoomEnd?: (e: DevExpress.viz.dxChart.ZoomEndEvent) => void;
+    onZoomEnd?: ((e: DevExpress.viz.dxChart.ZoomEndEvent) => void) | undefined;
     /**
      * [descr:dxChartOptions.onZoomStart]
      */
-    onZoomStart?: (e: DevExpress.viz.dxChart.ZoomStartEvent) => void;
+    onZoomStart?:
+      | ((e: DevExpress.viz.dxChart.ZoomStartEvent) => void)
+      | undefined;
     /**
      * [descr:dxChartOptions.panes]
      */
@@ -39307,16 +39458,18 @@ declare module DevExpress.viz {
     /**
      * [descr:dxChartOptions.seriesTemplate]
      */
-    seriesTemplate?: {
-      /**
-       * [descr:dxChartOptions.seriesTemplate.customizeSeries]
-       */
-      customizeSeries?: (seriesName: any) => ChartSeries;
-      /**
-       * [descr:dxChartOptions.seriesTemplate.nameField]
-       */
-      nameField?: string;
-    };
+    seriesTemplate?:
+      | {
+          /**
+           * [descr:dxChartOptions.seriesTemplate.customizeSeries]
+           */
+          customizeSeries?: (seriesName: any) => ChartSeries;
+          /**
+           * [descr:dxChartOptions.seriesTemplate.nameField]
+           */
+          nameField?: string;
+        }
+      | undefined;
     /**
      * [descr:dxChartOptions.stickyHovering]
      */
@@ -41510,15 +41663,15 @@ declare module DevExpress.viz {
         /**
          * [descr:dxFunnelOptions.item.border.color]
          */
-        color?: string | undefined;
+        color?: string;
         /**
          * [descr:dxFunnelOptions.item.border.visible]
          */
-        visible?: boolean | undefined;
+        visible?: boolean;
         /**
          * [descr:dxFunnelOptions.item.border.width]
          */
-        width?: number | undefined;
+        width?: number;
       };
       /**
        * [descr:dxFunnelOptions.item.hoverStyle]
@@ -41719,25 +41872,29 @@ declare module DevExpress.viz {
     /**
      * [descr:dxFunnelOptions.onHoverChanged]
      */
-    onHoverChanged?: (e: DevExpress.viz.dxFunnel.HoverChangedEvent) => void;
+    onHoverChanged?:
+      | ((e: DevExpress.viz.dxFunnel.HoverChangedEvent) => void)
+      | undefined;
     /**
      * [descr:dxFunnelOptions.onItemClick]
      */
     onItemClick?:
       | ((e: DevExpress.viz.dxFunnel.ItemClickEvent) => void)
-      | string;
+      | string
+      | undefined;
     /**
      * [descr:dxFunnelOptions.onLegendClick]
      */
     onLegendClick?:
       | ((e: DevExpress.viz.dxFunnel.LegendClickEvent) => void)
-      | string;
+      | string
+      | undefined;
     /**
      * [descr:dxFunnelOptions.onSelectionChanged]
      */
-    onSelectionChanged?: (
-      e: DevExpress.viz.dxFunnel.SelectionChangedEvent
-    ) => void;
+    onSelectionChanged?:
+      | ((e: DevExpress.viz.dxFunnel.SelectionChangedEvent) => void)
+      | undefined;
     /**
      * [descr:dxFunnelOptions.palette]
      */
@@ -42226,7 +42383,8 @@ declare module DevExpress.viz {
      */
     onLegendClick?:
       | ((e: DevExpress.viz.dxPieChart.LegendClickEvent) => void)
-      | string;
+      | string
+      | undefined;
     /**
      * [descr:dxPieChartOptions.palette]
      */
@@ -42246,16 +42404,18 @@ declare module DevExpress.viz {
     /**
      * [descr:dxPieChartOptions.seriesTemplate]
      */
-    seriesTemplate?: {
-      /**
-       * [descr:dxPieChartOptions.seriesTemplate.customizeSeries]
-       */
-      customizeSeries?: (seriesName: any) => PieChartSeries;
-      /**
-       * [descr:dxPieChartOptions.seriesTemplate.nameField]
-       */
-      nameField?: string;
-    };
+    seriesTemplate?:
+      | {
+          /**
+           * [descr:dxPieChartOptions.seriesTemplate.customizeSeries]
+           */
+          customizeSeries?: (seriesName: any) => PieChartSeries;
+          /**
+           * [descr:dxPieChartOptions.seriesTemplate.nameField]
+           */
+          nameField?: string;
+        }
+      | undefined;
     /**
      * [descr:dxPieChartOptions.sizeGroup]
      */
@@ -42422,11 +42582,11 @@ declare module DevExpress.viz {
         /**
          * [descr:dxPieChartSeriesTypes.CommonPieChartSeries.label.border.color]
          */
-        color?: string | undefined;
+        color?: string;
         /**
          * [descr:dxPieChartSeriesTypes.CommonPieChartSeries.label.border.dashStyle]
          */
-        dashStyle?: DevExpress.common.charts.DashStyle | undefined;
+        dashStyle?: DevExpress.common.charts.DashStyle;
         /**
          * [descr:dxPieChartSeriesTypes.CommonPieChartSeries.label.border.visible]
          */
@@ -43301,7 +43461,9 @@ declare module DevExpress.viz {
       /**
        * [descr:dxPolarChartOptions.valueAxis.minVisualRangeLength]
        */
-      minVisualRangeLength?: DevExpress.common.charts.TimeIntervalConfig;
+      minVisualRangeLength?:
+        | DevExpress.common.charts.TimeIntervalConfig
+        | undefined;
       /**
        * [descr:dxPolarChartOptions.valueAxis.minorTickCount]
        */
@@ -43642,39 +43804,46 @@ declare module DevExpress.viz {
      */
     onArgumentAxisClick?:
       | ((e: DevExpress.viz.dxPolarChart.ArgumentAxisClickEvent) => void)
-      | string;
+      | string
+      | undefined;
     /**
      * [descr:dxPolarChartOptions.onLegendClick]
      */
     onLegendClick?:
       | ((e: DevExpress.viz.dxPolarChart.LegendClickEvent) => void)
-      | string;
+      | string
+      | undefined;
     /**
      * [descr:dxPolarChartOptions.onSeriesClick]
      */
     onSeriesClick?:
       | ((e: DevExpress.viz.dxPolarChart.SeriesClickEvent) => void)
-      | string;
+      | string
+      | undefined;
     /**
      * [descr:dxPolarChartOptions.onSeriesHoverChanged]
      */
-    onSeriesHoverChanged?: (
-      e: DevExpress.viz.dxPolarChart.SeriesHoverChangedEvent
-    ) => void;
+    onSeriesHoverChanged?:
+      | ((e: DevExpress.viz.dxPolarChart.SeriesHoverChangedEvent) => void)
+      | undefined;
     /**
      * [descr:dxPolarChartOptions.onSeriesSelectionChanged]
      */
-    onSeriesSelectionChanged?: (
-      e: DevExpress.viz.dxPolarChart.SeriesSelectionChangedEvent
-    ) => void;
+    onSeriesSelectionChanged?:
+      | ((e: DevExpress.viz.dxPolarChart.SeriesSelectionChangedEvent) => void)
+      | undefined;
     /**
      * [descr:dxPolarChartOptions.onZoomEnd]
      */
-    onZoomEnd?: (e: DevExpress.viz.dxPolarChart.ZoomEndEvent) => void;
+    onZoomEnd?:
+      | ((e: DevExpress.viz.dxPolarChart.ZoomEndEvent) => void)
+      | undefined;
     /**
      * [descr:dxPolarChartOptions.onZoomStart]
      */
-    onZoomStart?: (e: DevExpress.viz.dxPolarChart.ZoomStartEvent) => void;
+    onZoomStart?:
+      | ((e: DevExpress.viz.dxPolarChart.ZoomStartEvent) => void)
+      | undefined;
     /**
      * [descr:dxPolarChartOptions.resolveLabelOverlapping]
      */
@@ -43690,16 +43859,18 @@ declare module DevExpress.viz {
     /**
      * [descr:dxPolarChartOptions.seriesTemplate]
      */
-    seriesTemplate?: {
-      /**
-       * [descr:dxPolarChartOptions.seriesTemplate.customizeSeries]
-       */
-      customizeSeries?: (seriesName: any) => PolarChartSeries;
-      /**
-       * [descr:dxPolarChartOptions.seriesTemplate.nameField]
-       */
-      nameField?: string;
-    };
+    seriesTemplate?:
+      | {
+          /**
+           * [descr:dxPolarChartOptions.seriesTemplate.customizeSeries]
+           */
+          customizeSeries?: (seriesName: any) => PolarChartSeries;
+          /**
+           * [descr:dxPolarChartOptions.seriesTemplate.nameField]
+           */
+          nameField?: string;
+        }
+      | undefined;
     /**
      * [descr:dxPolarChartOptions.tooltip]
      */
@@ -44081,11 +44252,11 @@ declare module DevExpress.viz {
       /**
        * [descr:dxPolarChartSeriesTypes.CommonPolarChartSeries.label.border.color]
        */
-      color?: string | undefined;
+      color?: string;
       /**
        * [descr:dxPolarChartSeriesTypes.CommonPolarChartSeries.label.border.dashStyle]
        */
-      dashStyle?: DevExpress.common.charts.DashStyle | undefined;
+      dashStyle?: DevExpress.common.charts.DashStyle;
       /**
        * [descr:dxPolarChartSeriesTypes.CommonPolarChartSeries.label.border.visible]
        */
@@ -45228,15 +45399,15 @@ declare module DevExpress.viz {
         /**
          * [descr:dxSankeyOptions.label.border.color]
          */
-        color?: string | undefined;
+        color?: string;
         /**
          * [descr:dxSankeyOptions.label.border.visible]
          */
-        visible?: boolean | undefined;
+        visible?: boolean;
         /**
          * [descr:dxSankeyOptions.label.border.width]
          */
-        width?: number | undefined;
+        width?: number;
       };
       /**
        * [descr:dxSankeyOptions.label.customizeText]
@@ -45303,15 +45474,15 @@ declare module DevExpress.viz {
         /**
          * [descr:dxSankeyOptions.link.border.color]
          */
-        color?: string | undefined;
+        color?: string;
         /**
          * [descr:dxSankeyOptions.link.border.visible]
          */
-        visible?: boolean | undefined;
+        visible?: boolean;
         /**
          * [descr:dxSankeyOptions.link.border.width]
          */
-        width?: number | undefined;
+        width?: number;
       };
       /**
        * [descr:dxSankeyOptions.link.color]
@@ -45388,15 +45559,15 @@ declare module DevExpress.viz {
         /**
          * [descr:dxSankeyOptions.node.border.color]
          */
-        color?: string | undefined;
+        color?: string;
         /**
          * [descr:dxSankeyOptions.node.border.visible]
          */
-        visible?: boolean | undefined;
+        visible?: boolean;
         /**
          * [descr:dxSankeyOptions.node.border.width]
          */
-        width?: number | undefined;
+        width?: number;
       };
       /**
        * [descr:dxSankeyOptions.node.color]
@@ -45471,21 +45642,27 @@ declare module DevExpress.viz {
      */
     onLinkClick?:
       | ((e: DevExpress.viz.dxSankey.LinkClickEvent) => void)
-      | string;
+      | string
+      | undefined;
     /**
      * [descr:dxSankeyOptions.onLinkHoverChanged]
      */
-    onLinkHoverChanged?: (e: DevExpress.viz.dxSankey.LinkHoverEvent) => void;
+    onLinkHoverChanged?:
+      | ((e: DevExpress.viz.dxSankey.LinkHoverEvent) => void)
+      | undefined;
     /**
      * [descr:dxSankeyOptions.onNodeClick]
      */
     onNodeClick?:
       | ((e: DevExpress.viz.dxSankey.NodeClickEvent) => void)
-      | string;
+      | string
+      | undefined;
     /**
      * [descr:dxSankeyOptions.onNodeHoverChanged]
      */
-    onNodeHoverChanged?: (e: DevExpress.viz.dxSankey.NodeHoverEvent) => void;
+    onNodeHoverChanged?:
+      | ((e: DevExpress.viz.dxSankey.NodeHoverEvent) => void)
+      | undefined;
     /**
      * [descr:dxSankeyOptions.palette]
      */
@@ -45981,7 +46158,7 @@ declare module DevExpress.viz {
       /**
        * [descr:dxTreeMapOptions.colorizer.range]
        */
-      range?: Array<number>;
+      range?: Array<number> | undefined;
       /**
        * [descr:dxTreeMapOptions.colorizer.type]
        */
@@ -46006,7 +46183,7 @@ declare module DevExpress.viz {
         /**
          * [descr:dxTreeMapOptions.group.border.width]
          */
-        width?: number | undefined;
+        width?: number;
       };
       /**
        * [descr:dxTreeMapOptions.group.color]
@@ -46127,33 +46304,38 @@ declare module DevExpress.viz {
     /**
      * [descr:dxTreeMapOptions.onClick]
      */
-    onClick?: ((e: DevExpress.viz.dxTreeMap.ClickEvent) => void) | string;
+    onClick?:
+      | ((e: DevExpress.viz.dxTreeMap.ClickEvent) => void)
+      | string
+      | undefined;
     /**
      * [descr:dxTreeMapOptions.onDrill]
      */
-    onDrill?: (e: DevExpress.viz.dxTreeMap.DrillEvent) => void;
+    onDrill?: ((e: DevExpress.viz.dxTreeMap.DrillEvent) => void) | undefined;
     /**
      * [descr:dxTreeMapOptions.onHoverChanged]
      */
-    onHoverChanged?: (e: DevExpress.viz.dxTreeMap.HoverChangedEvent) => void;
+    onHoverChanged?:
+      | ((e: DevExpress.viz.dxTreeMap.HoverChangedEvent) => void)
+      | undefined;
     /**
      * [descr:dxTreeMapOptions.onNodesInitialized]
      */
-    onNodesInitialized?: (
-      e: DevExpress.viz.dxTreeMap.NodesInitializedEvent
-    ) => void;
+    onNodesInitialized?:
+      | ((e: DevExpress.viz.dxTreeMap.NodesInitializedEvent) => void)
+      | undefined;
     /**
      * [descr:dxTreeMapOptions.onNodesRendering]
      */
-    onNodesRendering?: (
-      e: DevExpress.viz.dxTreeMap.NodesRenderingEvent
-    ) => void;
+    onNodesRendering?:
+      | ((e: DevExpress.viz.dxTreeMap.NodesRenderingEvent) => void)
+      | undefined;
     /**
      * [descr:dxTreeMapOptions.onSelectionChanged]
      */
-    onSelectionChanged?: (
-      e: DevExpress.viz.dxTreeMap.SelectionChangedEvent
-    ) => void;
+    onSelectionChanged?:
+      | ((e: DevExpress.viz.dxTreeMap.SelectionChangedEvent) => void)
+      | undefined;
     /**
      * [descr:dxTreeMapOptions.parentField]
      */
@@ -46173,11 +46355,11 @@ declare module DevExpress.viz {
         /**
          * [descr:dxTreeMapOptions.tile.border.color]
          */
-        color?: string | undefined;
+        color?: string;
         /**
          * [descr:dxTreeMapOptions.tile.border.width]
          */
-        width?: number | undefined;
+        width?: number;
       };
       /**
        * [descr:dxTreeMapOptions.tile.color]

From 86c7e29b556d474064d4bef3bcc43798c65c96ea Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:38 +0300
Subject: [PATCH 054/100] fix(viz): correct vector_map options defaults and
 widen types

Corrects options defaults and widens types in js/viz/vector_map.d.ts:
- Widens bounds, layers, layers[].colorGroups, layers[].sizeGroups, and annotation.coordinates to accept | undefined.
- Widens event handlers (onCenterChanged, onClick, onSelectionChanged, onTooltipHidden, onTooltipShown, onZoomFactorChanged) to accept | undefined and corrects JSDoc default to undefined.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/viz/vector_map.d.ts | 34 +++++++++++-----------
 1 file changed, 17 insertions(+), 17 deletions(-)

diff --git a/packages/devextreme/js/viz/vector_map.d.ts b/packages/devextreme/js/viz/vector_map.d.ts
index d9c75a2457b6..0d6de8dca3a4 100644
--- a/packages/devextreme/js/viz/vector_map.d.ts
+++ b/packages/devextreme/js/viz/vector_map.d.ts
@@ -360,7 +360,7 @@ export interface dxVectorMapOptions extends BaseWidgetOptions<dxVectorMap> {
      * @notUsedInTheme
      * @public
      */
-    bounds?: Array<number>;
+    bounds?: Array<number> | undefined;
     /**
      * @docid
      * @default [0, 0]
@@ -450,7 +450,7 @@ export interface dxVectorMapOptions extends BaseWidgetOptions<dxVectorMap> {
        * @docid
        * @default undefined
        */
-      colorGroups?: Array<number>;
+      colorGroups?: Array<number> | undefined;
       /**
        * @docid
        * @notUsedInTheme
@@ -579,13 +579,13 @@ export interface dxVectorMapOptions extends BaseWidgetOptions<dxVectorMap> {
        * @docid
        * @default undefined
        */
-      sizeGroups?: Array<number>;
+      sizeGroups?: Array<number> | undefined;
       /**
        * @docid
        * @notUsedInTheme
        */
       type?: VectorMapLayerType;
-    }> | { borderColor?: string; borderWidth?: number; color?: string; colorGroupingField?: string; colorGroups?: Array<number>; customize?: ((elements: Array<MapLayerElement>) => any); dataField?: string; dataSource?: object | DataSourceLike<any> | null; elementType?: 'bubble' | 'dot' | 'image' | 'pie'; hoverEnabled?: boolean; hoveredBorderColor?: string; hoveredBorderWidth?: number; hoveredColor?: string; label?: { dataField?: string; enabled?: boolean; font?: Font }; maxSize?: number; minSize?: number; name?: string; opacity?: number; palette?: Array<string> | Palette; paletteSize?: number; selectedBorderColor?: string; selectedBorderWidth?: number; selectedColor?: string; selectionMode?: SingleMultipleOrNone; size?: number; sizeGroupingField?: string; sizeGroups?: Array<number>; type?: 'area' | 'line' | 'marker' };
+    }> | { borderColor?: string; borderWidth?: number; color?: string; colorGroupingField?: string; colorGroups?: Array<number>; customize?: ((elements: Array<MapLayerElement>) => any); dataField?: string; dataSource?: object | DataSourceLike<any> | null; elementType?: 'bubble' | 'dot' | 'image' | 'pie'; hoverEnabled?: boolean; hoveredBorderColor?: string; hoveredBorderWidth?: number; hoveredColor?: string; label?: { dataField?: string; enabled?: boolean; font?: Font }; maxSize?: number; minSize?: number; name?: string; opacity?: number; palette?: Array<string> | Palette; paletteSize?: number; selectedBorderColor?: string; selectedBorderWidth?: number; selectedColor?: string; selectionMode?: SingleMultipleOrNone; size?: number; sizeGroupingField?: string; sizeGroups?: Array<number>; type?: 'area' | 'line' | 'marker' } | undefined;
     /**
      * @docid
      * @type Array<Object>
@@ -609,59 +609,59 @@ export interface dxVectorMapOptions extends BaseWidgetOptions<dxVectorMap> {
     maxZoomFactor?: number;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/vector_map:CenterChangedEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onCenterChanged?: ((e: CenterChangedEvent) => void);
+    onCenterChanged?: ((e: CenterChangedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type function
      * @type_function_param1 e:{viz/vector_map:ClickEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onClick?: ((e: ClickEvent) => void) | string;
+    onClick?: ((e: ClickEvent) => void) | string | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/vector_map:SelectionChangedEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onSelectionChanged?: ((e: SelectionChangedEvent) => void);
+    onSelectionChanged?: ((e: SelectionChangedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/vector_map:TooltipHiddenEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onTooltipHidden?: ((e: TooltipHiddenEvent) => void);
+    onTooltipHidden?: ((e: TooltipHiddenEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/vector_map:TooltipShownEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onTooltipShown?: ((e: TooltipShownEvent) => void);
+    onTooltipShown?: ((e: TooltipShownEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/vector_map:ZoomFactorChangedEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onZoomFactorChanged?: ((e: ZoomFactorChangedEvent) => void);
+    onZoomFactorChanged?: ((e: ZoomFactorChangedEvent) => void) | undefined;
     /**
      * @docid
      * @default true
@@ -754,7 +754,7 @@ export interface dxVectorMapCommonAnnotationConfig extends BaseWidgetAnnotationC
      * @default undefined
      * @public
      */
-    coordinates?: Array<number>;
+    coordinates?: Array<number> | undefined;
     /**
      * @docid
      * @type_function_return object

From a32d3db5f0d82d574443831e9aabc02b4dcba1c9 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:39 +0300
Subject: [PATCH 055/100] fix(viz): correct range_selector options defaults and
 widen types

Corrects options defaults and widens types in js/viz/range_selector.d.ts:
- Widens seriesTemplate to accept | undefined.
- Widens onValueChanged to accept | undefined and corrects JSDoc default to undefined.
- Widens scale.breaks, scale.holidays, and scale.singleWorkdays to accept | undefined.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/viz/range_selector.d.ts | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/packages/devextreme/js/viz/range_selector.d.ts b/packages/devextreme/js/viz/range_selector.d.ts
index 3a7b3d6a76cd..456490abc790 100644
--- a/packages/devextreme/js/viz/range_selector.d.ts
+++ b/packages/devextreme/js/viz/range_selector.d.ts
@@ -304,7 +304,7 @@ export interface dxRangeSelectorOptions extends BaseWidgetOptions<dxRangeSelecto
          * @default 'series'
          */
         nameField?: string;
-      };
+      } | undefined;
       /**
        * @docid
        * @default 0.1
@@ -385,13 +385,13 @@ export interface dxRangeSelectorOptions extends BaseWidgetOptions<dxRangeSelecto
     };
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{viz/range_selector:ValueChangedEvent}
      * @notUsedInTheme
      * @action
      * @public
      */
-    onValueChanged?: ((e: ValueChangedEvent) => void);
+    onValueChanged?: ((e: ValueChangedEvent) => void) | undefined;
     /**
      * @docid
      * @public
@@ -445,7 +445,7 @@ export interface dxRangeSelectorOptions extends BaseWidgetOptions<dxRangeSelecto
        * @default undefined
        * @notUsedInTheme
        */
-      breaks?: Array<ScaleBreak>;
+      breaks?: Array<ScaleBreak> | undefined;
       /**
        * @docid
        */
@@ -465,7 +465,7 @@ export interface dxRangeSelectorOptions extends BaseWidgetOptions<dxRangeSelecto
        * @docid
        * @default undefined
        */
-      holidays?: Array<Date | string> | Array<number>;
+      holidays?: Array<Date | string> | Array<number> | undefined;
       /**
        * @docid
        */
@@ -619,7 +619,7 @@ export interface dxRangeSelectorOptions extends BaseWidgetOptions<dxRangeSelecto
        * @docid
        * @default undefined
        */
-      singleWorkdays?: Array<Date | string> | Array<number>;
+      singleWorkdays?: Array<Date | string> | Array<number> | undefined;
       /**
        * @docid
        * @default undefined

From 8de6b0aefdc341fb4edc7979c9784ab88185b6a3 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:39 +0300
Subject: [PATCH 056/100] fix(ui): correct diagram options defaults and widen
 types

Corrects options in js/ui/diagram.d.ts:
- Removes @default null from edges and nodes (A-obj: runtime stores a config object).
- Removes @default undefined from contextMenu.commands, propertiesPanel.tabs,
  mainToolbar.commands, historyToolbar.commands, viewToolbar.commands,
  toolbox.groups, zoomLevel.items (Category B sub-properties).
- Widens onItemClick, onItemDblClick, onSelectionChanged, onRequestEditOperation,
  and onRequestLayoutUpdate to accept | null (runtime stores null).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/ui/diagram.d.ts | 19 +++++--------------
 1 file changed, 5 insertions(+), 14 deletions(-)

diff --git a/packages/devextreme/js/ui/diagram.d.ts b/packages/devextreme/js/ui/diagram.d.ts
index 15061e8f32e0..90a87a50ce96 100644
--- a/packages/devextreme/js/ui/diagram.d.ts
+++ b/packages/devextreme/js/ui/diagram.d.ts
@@ -251,7 +251,6 @@ export interface dxDiagramOptions extends WidgetOptions<dxDiagram> {
     contextMenu?: {
       /**
        * @docid
-       * @default undefined
        */
       commands?: Array<CustomCommand | Command>;
       /**
@@ -595,7 +594,6 @@ export interface dxDiagramOptions extends WidgetOptions<dxDiagram> {
     };
     /**
      * @docid
-     * @default null
      * @public
      */
     edges?: {
@@ -715,7 +713,6 @@ export interface dxDiagramOptions extends WidgetOptions<dxDiagram> {
     };
     /**
      * @docid
-     * @default null
      * @public
      */
     nodes?: {
@@ -843,7 +840,7 @@ export interface dxDiagramOptions extends WidgetOptions<dxDiagram> {
      * @action
      * @public
      */
-    onItemClick?: ((e: ItemClickEvent) => void);
+    onItemClick?: ((e: ItemClickEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -851,7 +848,7 @@ export interface dxDiagramOptions extends WidgetOptions<dxDiagram> {
      * @action
      * @public
      */
-    onItemDblClick?: ((e: ItemDblClickEvent) => void);
+    onItemDblClick?: ((e: ItemDblClickEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -859,7 +856,7 @@ export interface dxDiagramOptions extends WidgetOptions<dxDiagram> {
      * @action
      * @public
      */
-    onSelectionChanged?: ((e: SelectionChangedEvent) => void);
+    onSelectionChanged?: ((e: SelectionChangedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -867,7 +864,7 @@ export interface dxDiagramOptions extends WidgetOptions<dxDiagram> {
      * @action
      * @public
      */
-    onRequestEditOperation?: ((e: RequestEditOperationEvent) => void);
+    onRequestEditOperation?: ((e: RequestEditOperationEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -875,7 +872,7 @@ export interface dxDiagramOptions extends WidgetOptions<dxDiagram> {
      * @action
      * @public
      */
-    onRequestLayoutUpdate?: ((e: RequestLayoutUpdateEvent) => void);
+    onRequestLayoutUpdate?: ((e: RequestLayoutUpdateEvent) => void) | null;
     /**
      * @docid
      * @default "white"
@@ -929,7 +926,6 @@ export interface dxDiagramOptions extends WidgetOptions<dxDiagram> {
     propertiesPanel?: {
       /**
        * @docid
-       * @default undefined
        */
       tabs?: Array<{
         /**
@@ -999,7 +995,6 @@ export interface dxDiagramOptions extends WidgetOptions<dxDiagram> {
     mainToolbar?: {
       /**
        * @docid
-       * @default undefined
        */
       commands?: Array<CustomCommand | Command>;
       /**
@@ -1016,7 +1011,6 @@ export interface dxDiagramOptions extends WidgetOptions<dxDiagram> {
     historyToolbar?: {
       /**
        * @docid
-       * @default undefined
        */
       commands?: Array<CustomCommand | Command>;
       /**
@@ -1033,7 +1027,6 @@ export interface dxDiagramOptions extends WidgetOptions<dxDiagram> {
     viewToolbar?: {
       /**
        * @docid
-       * @default undefined
        */
       commands?: Array<CustomCommand | Command>;
       /**
@@ -1050,7 +1043,6 @@ export interface dxDiagramOptions extends WidgetOptions<dxDiagram> {
     toolbox?: {
       /**
        * @docid
-       * @default undefined
        */
       groups?: Array<{
         /**
@@ -1115,7 +1107,6 @@ export interface dxDiagramOptions extends WidgetOptions<dxDiagram> {
     zoomLevel?: number | {
       /**
        * @docid
-       * @default undefined
        */
       items?: Array<number>;
       /**

From ee8dcf03e87d90eef3a95d5c9b054caa0edeae06 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:40 +0300
Subject: [PATCH 057/100] fix(ui): correct file_manager options defaults and
 widen types
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Corrects options in js/ui/file_manager.d.ts:
- Widens fileSystemProvider to accept | null (runtime stores null).
- Removes @default null from itemView (A-obj: runtime stores a config object).
- Corrects @default null → undefined and widens 20 event handlers to | undefined
  (runtime stores undefined via _createActionByOption pattern).
- Corrects focusedItemKey @default null → undefined and widens to | undefined.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/ui/file_manager.d.ts | 87 ++++++++++-----------
 1 file changed, 43 insertions(+), 44 deletions(-)

diff --git a/packages/devextreme/js/ui/file_manager.d.ts b/packages/devextreme/js/ui/file_manager.d.ts
index d6f59ffef9ff..8d1a28f1f476 100644
--- a/packages/devextreme/js/ui/file_manager.d.ts
+++ b/packages/devextreme/js/ui/file_manager.d.ts
@@ -456,10 +456,9 @@ export interface dxFileManagerOptions extends WidgetOptions<dxFileManager> {
      * @default null
      * @public
      */
-    fileSystemProvider?: any;
+    fileSystemProvider?: any | null;
     /**
      * @docid
-     * @default null
      * @public
      */
     itemView?: {
@@ -507,44 +506,44 @@ export interface dxFileManagerOptions extends WidgetOptions<dxFileManager> {
     };
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/file_manager:ContextMenuItemClickEvent}
      * @action
      * @public
      */
-    onContextMenuItemClick?: ((e: ContextMenuItemClickEvent) => void);
+    onContextMenuItemClick?: ((e: ContextMenuItemClickEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/file_manager:ContextMenuShowingEvent}
      * @action
      * @public
      */
-    onContextMenuShowing?: ((e: ContextMenuShowingEvent) => void);
+    onContextMenuShowing?: ((e: ContextMenuShowingEvent) => void) | undefined;
     /**
      * @docid
      * @type_function_param1 e:{ui/file_manager:CurrentDirectoryChangedEvent}
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onCurrentDirectoryChanged?: ((e: CurrentDirectoryChangedEvent) => void);
+    onCurrentDirectoryChanged?: ((e: CurrentDirectoryChangedEvent) => void) | undefined;
     /**
      * @docid
      * @type_function_param1 e:{ui/file_manager:SelectedFileOpenedEvent}
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onSelectedFileOpened?: ((e: SelectedFileOpenedEvent) => void);
+    onSelectedFileOpened?: ((e: SelectedFileOpenedEvent) => void) | undefined;
     /**
      * @docid
      * @type_function_param1 e:{ui/file_manager:SelectionChangedEvent}
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onSelectionChanged?: ((e: SelectionChangedEvent) => void);
+    onSelectionChanged?: ((e: SelectionChangedEvent) => void) | undefined;
     /**
      * @docid
      * @type_function_param1 e:{ui/file_manager:ToolbarItemClickEvent}
@@ -555,123 +554,123 @@ export interface dxFileManagerOptions extends WidgetOptions<dxFileManager> {
     /**
      * @docid
      * @type_function_param1 e:{ui/file_manager:FocusedItemChangedEvent}
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onFocusedItemChanged?: ((e: FocusedItemChangedEvent) => void);
+    onFocusedItemChanged?: ((e: FocusedItemChangedEvent) => void) | undefined;
     /**
      * @docid
      * @type_function_param1 e:{ui/file_manager:ErrorOccurredEvent}
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onErrorOccurred?: ((e: ErrorOccurredEvent) => void);
+    onErrorOccurred?: ((e: ErrorOccurredEvent) => void) | undefined;
     /**
      * @docid
      * @type_function_param1 e:{ui/file_manager:DirectoryCreatingEvent}
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onDirectoryCreating?: ((e: DirectoryCreatingEvent) => void);
+    onDirectoryCreating?: ((e: DirectoryCreatingEvent) => void) | undefined;
     /**
      * @docid
      * @type_function_param1 e:{ui/file_manager:DirectoryCreatedEvent}
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onDirectoryCreated?: ((e: DirectoryCreatedEvent) => void);
+    onDirectoryCreated?: ((e: DirectoryCreatedEvent) => void) | undefined;
     /**
      * @docid
      * @type_function_param1 e:{ui/file_manager:ItemRenamingEvent}
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onItemRenaming?: ((e: ItemRenamingEvent) => void);
+    onItemRenaming?: ((e: ItemRenamingEvent) => void) | undefined;
     /**
      * @docid
      * @type_function_param1 e:{ui/file_manager:ItemRenamedEvent}
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onItemRenamed?: ((e: ItemRenamedEvent) => void);
+    onItemRenamed?: ((e: ItemRenamedEvent) => void) | undefined;
     /**
      * @docid
      * @type_function_param1 e:{ui/file_manager:ItemMovingEvent}
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onItemMoving?: ((e: ItemMovingEvent) => void);
+    onItemMoving?: ((e: ItemMovingEvent) => void) | undefined;
     /**
      * @docid
      * @type_function_param1 e:{ui/file_manager:ItemMovedEvent}
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onItemMoved?: ((e: ItemMovedEvent) => void);
+    onItemMoved?: ((e: ItemMovedEvent) => void) | undefined;
     /**
      * @docid
      * @type_function_param1 e:{ui/file_manager:ItemCopyingEvent}
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onItemCopying?: ((e: ItemCopyingEvent) => void);
+    onItemCopying?: ((e: ItemCopyingEvent) => void) | undefined;
     /**
      * @docid
      * @type_function_param1 e:{ui/file_manager:ItemCopiedEvent}
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onItemCopied?: ((e: ItemCopiedEvent) => void);
+    onItemCopied?: ((e: ItemCopiedEvent) => void) | undefined;
     /**
      * @docid
      * @type_function_param1 e:{ui/file_manager:ItemDeletingEvent}
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onItemDeleting?: ((e: ItemDeletingEvent) => void);
+    onItemDeleting?: ((e: ItemDeletingEvent) => void) | undefined;
     /**
      * @docid
      * @type_function_param1 e:{ui/file_manager:ItemDeletedEvent}
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onItemDeleted?: ((e: ItemDeletedEvent) => void);
+    onItemDeleted?: ((e: ItemDeletedEvent) => void) | undefined;
     /**
      * @docid
      * @type_function_param1 e:{ui/file_manager:FileUploadingEvent}
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onFileUploading?: ((e: FileUploadingEvent) => void);
+    onFileUploading?: ((e: FileUploadingEvent) => void) | undefined;
     /**
      * @docid
      * @type_function_param1 e:{ui/file_manager:FileUploadedEvent}
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onFileUploaded?: ((e: FileUploadedEvent) => void);
+    onFileUploaded?: ((e: FileUploadedEvent) => void) | undefined;
     /**
      * @docid
      * @type_function_param1 e:{ui/file_manager:ItemDownloadingEvent}
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onItemDownloading?: ((e: ItemDownloadingEvent) => void);
+    onItemDownloading?: ((e: ItemDownloadingEvent) => void) | undefined;
     /**
      * @docid
      * @public
@@ -733,10 +732,10 @@ export interface dxFileManagerOptions extends WidgetOptions<dxFileManager> {
     selectedItemKeys?: Array<string>;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @public
      */
-    focusedItemKey?: string;
+    focusedItemKey?: string | undefined;
     /**
      * @docid
      * @public

From 9dd957db76263e828f172f8042c5b69883ce0291 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:40 +0300
Subject: [PATCH 058/100] fix(ui): correct gantt options defaults and widen
 types
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Corrects options in js/ui/gantt.d.ts:
- Removes @default null from dependencies, resourceAssignments, resources, tasks
  (A-obj: runtime stores config objects, not null).
- Widens 24 event handlers to | null (runtime stores null via getDefaultOptions).
- Corrects onResourceManagerDialogShowing and onScaleCellPrepared:
  @default null → @default undefined, widened to | undefined (createAction-only).
- Widens toolbar to | null (runtime stores null).
- Widens stripLines to | undefined (runtime stores undefined).
- Corrects startDateRange and endDateRange @default null → @default undefined,
  widened to | undefined (not in getDefaultOptions).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 packages/devextreme/js/ui/gantt.d.ts | 74 +++++++++++++---------------
 1 file changed, 35 insertions(+), 39 deletions(-)

diff --git a/packages/devextreme/js/ui/gantt.d.ts b/packages/devextreme/js/ui/gantt.d.ts
index 45d5faed6310..5e5892b32abe 100644
--- a/packages/devextreme/js/ui/gantt.d.ts
+++ b/packages/devextreme/js/ui/gantt.d.ts
@@ -519,7 +519,6 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
     columns?: Array<Column | string> | undefined;
     /**
      * @docid
-     * @default null
      * @public
      */
     dependencies?: {
@@ -649,7 +648,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onSelectionChanged?: ((e: SelectionChangedEvent) => void);
+    onSelectionChanged?: ((e: SelectionChangedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -657,7 +656,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onCustomCommand?: ((e: CustomCommandEvent) => void);
+    onCustomCommand?: ((e: CustomCommandEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -665,7 +664,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onContextMenuPreparing?: ((e: ContextMenuPreparingEvent) => void);
+    onContextMenuPreparing?: ((e: ContextMenuPreparingEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -673,7 +672,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onTaskInserting?: ((e: TaskInsertingEvent) => void);
+    onTaskInserting?: ((e: TaskInsertingEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -681,7 +680,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onTaskInserted?: ((e: TaskInsertedEvent) => void);
+    onTaskInserted?: ((e: TaskInsertedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -689,7 +688,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onTaskDeleting?: ((e: TaskDeletingEvent) => void);
+    onTaskDeleting?: ((e: TaskDeletingEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -697,7 +696,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onTaskDeleted?: ((e: TaskDeletedEvent) => void);
+    onTaskDeleted?: ((e: TaskDeletedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -705,7 +704,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onTaskUpdating?: ((e: TaskUpdatingEvent) => void);
+    onTaskUpdating?: ((e: TaskUpdatingEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -713,7 +712,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onTaskUpdated?: ((e: TaskUpdatedEvent) => void);
+    onTaskUpdated?: ((e: TaskUpdatedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -721,7 +720,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onTaskMoving?: ((e: TaskMovingEvent) => void);
+    onTaskMoving?: ((e: TaskMovingEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -729,15 +728,15 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onTaskEditDialogShowing?: ((e: TaskEditDialogShowingEvent) => void);
+    onTaskEditDialogShowing?: ((e: TaskEditDialogShowingEvent) => void) | null;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:ResourceManagerDialogShowingEvent}
      * @action
      * @public
      */
-    onResourceManagerDialogShowing?: ((e: ResourceManagerDialogShowingEvent) => void);
+    onResourceManagerDialogShowing?: ((e: ResourceManagerDialogShowingEvent) => void) | undefined;
     /**
      * @docid
      * @default null
@@ -745,7 +744,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onDependencyInserting?: ((e: DependencyInsertingEvent) => void);
+    onDependencyInserting?: ((e: DependencyInsertingEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -753,7 +752,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onDependencyInserted?: ((e: DependencyInsertedEvent) => void);
+    onDependencyInserted?: ((e: DependencyInsertedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -761,7 +760,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onDependencyDeleting?: ((e: DependencyDeletingEvent) => void);
+    onDependencyDeleting?: ((e: DependencyDeletingEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -769,7 +768,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onDependencyDeleted?: ((e: DependencyDeletedEvent) => void);
+    onDependencyDeleted?: ((e: DependencyDeletedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -777,7 +776,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onResourceInserting?: ((e: ResourceInsertingEvent) => void);
+    onResourceInserting?: ((e: ResourceInsertingEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -785,7 +784,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onResourceInserted?: ((e: ResourceInsertedEvent) => void);
+    onResourceInserted?: ((e: ResourceInsertedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -793,7 +792,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onResourceDeleting?: ((e: ResourceDeletingEvent) => void);
+    onResourceDeleting?: ((e: ResourceDeletingEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -801,7 +800,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onResourceDeleted?: ((e: ResourceDeletedEvent) => void);
+    onResourceDeleted?: ((e: ResourceDeletedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -809,7 +808,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onResourceAssigning?: ((e: ResourceAssigningEvent) => void);
+    onResourceAssigning?: ((e: ResourceAssigningEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -817,7 +816,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onResourceAssigned?: ((e: ResourceAssignedEvent) => void);
+    onResourceAssigned?: ((e: ResourceAssignedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -825,7 +824,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onResourceUnassigning?: ((e: ResourceUnassigningEvent) => void);
+    onResourceUnassigning?: ((e: ResourceUnassigningEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -833,7 +832,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onResourceUnassigned?: ((e: ResourceUnassignedEvent) => void);
+    onResourceUnassigned?: ((e: ResourceUnassignedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -841,7 +840,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onTaskClick?: ((e: TaskClickEvent) => void);
+    onTaskClick?: ((e: TaskClickEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -849,19 +848,18 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @action
      * @public
      */
-    onTaskDblClick?: ((e: TaskDblClickEvent) => void);
+    onTaskDblClick?: ((e: TaskDblClickEvent) => void) | null;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:ScaleCellPreparedEvent}
      * @action
      * @public
      */
-    onScaleCellPrepared?: ((e: ScaleCellPreparedEvent) => void);
+    onScaleCellPrepared?: ((e: ScaleCellPreparedEvent) => void) | undefined;
 
     /**
      * @docid
-     * @default null
      * @public
      */
     resourceAssignments?: {
@@ -889,7 +887,6 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
     };
     /**
      * @docid
-     * @default null
      * @public
      */
     resources?: {
@@ -981,7 +978,6 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
     firstDayOfWeek?: DayOfWeek | undefined;
     /**
      * @docid
-     * @default null
      * @public
      */
     tasks?: {
@@ -1032,7 +1028,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @default null
      * @public
      */
-    toolbar?: dxGanttToolbar;
+    toolbar?: dxGanttToolbar | null;
     /**
      * @docid
      * @public
@@ -1043,7 +1039,7 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      * @default undefined
      * @public
      */
-    stripLines?: Array<dxGanttStripLine>;
+    stripLines?: Array<dxGanttStripLine> | undefined;
     /**
      * @docid
      * @type_function_return string|Element|jQuery
@@ -1085,16 +1081,16 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
     rootValue?: any;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @public
      */
-    startDateRange?: Date;
+    startDateRange?: Date | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @public
      */
-    endDateRange?: Date;
+    endDateRange?: Date | undefined;
 }
 /**
  * @docid

From 8c43a739ccb9fd026e0edd93c4b4b1b2321c3f4d Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:41 +0300
Subject: [PATCH 059/100] fix(viz/ui): resolve metadata generator name
 collisions

Fixes 'Complex option name collisions are not allowed' when running regenerate-all:
- Reverts union undefined/null on complex options (seriesTemplate in chart options, layers in vector_map, toolbar/stripLines in gantt).
- Widens properties inside sub-border configurations (in common/charts, pie_chart, polar_chart, funnel, sankey, tree_map) to | undefined to ensure consistent types across all properties mapping to the same forced component names (seriesBorder, itemBorder, sankeyborder, treeMapborder) and prevent component merging collisions.
---
 packages/devextreme/js/common/charts.d.ts     |   4 +-
 packages/devextreme/js/ui/gantt.d.ts          |   6 +-
 packages/devextreme/js/viz/chart.d.ts         |   2 +-
 packages/devextreme/js/viz/funnel.d.ts        |   6 +-
 packages/devextreme/js/viz/pie_chart.d.ts     |   6 +-
 packages/devextreme/js/viz/polar_chart.d.ts   |   6 +-
 .../devextreme/js/viz/range_selector.d.ts     |   3 +-
 packages/devextreme/js/viz/sankey.d.ts        |  18 +-
 packages/devextreme/js/viz/tree_map.d.ts      |   6 +-
 packages/devextreme/js/viz/vector_map.d.ts    |   3 +-
 packages/devextreme/ts/dx.all.d.ts            | 352 ++++++++++--------
 11 files changed, 227 insertions(+), 185 deletions(-)

diff --git a/packages/devextreme/js/common/charts.d.ts b/packages/devextreme/js/common/charts.d.ts
index 1e3776d59781..8907a07b402e 100644
--- a/packages/devextreme/js/common/charts.d.ts
+++ b/packages/devextreme/js/common/charts.d.ts
@@ -640,12 +640,12 @@ export interface SeriesLabel {
        * @docid dxChartSeriesTypes.CommonSeries.label.border.color
        * @default  '#d3d3d3'
        */
-      color?: string;
+      color?: string | undefined;
       /**
        * @docid dxChartSeriesTypes.CommonSeries.label.border.dashStyle
        * @default 'solid'
        */
-      dashStyle?: DashStyle;
+      dashStyle?: DashStyle | undefined;
       /**
        * @docid dxChartSeriesTypes.CommonSeries.label.border.visible
        * @default false
diff --git a/packages/devextreme/js/ui/gantt.d.ts b/packages/devextreme/js/ui/gantt.d.ts
index 5e5892b32abe..7c605450ae67 100644
--- a/packages/devextreme/js/ui/gantt.d.ts
+++ b/packages/devextreme/js/ui/gantt.d.ts
@@ -1025,10 +1025,9 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
     };
     /**
      * @docid
-     * @default null
      * @public
      */
-    toolbar?: dxGanttToolbar | null;
+    toolbar?: dxGanttToolbar;
     /**
      * @docid
      * @public
@@ -1036,10 +1035,9 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
     contextMenu?: dxGanttContextMenu;
     /**
      * @docid
-     * @default undefined
      * @public
      */
-    stripLines?: Array<dxGanttStripLine> | undefined;
+    stripLines?: Array<dxGanttStripLine>;
     /**
      * @docid
      * @type_function_return string|Element|jQuery
diff --git a/packages/devextreme/js/viz/chart.d.ts b/packages/devextreme/js/viz/chart.d.ts
index ab738994ae8a..dc849d55b362 100644
--- a/packages/devextreme/js/viz/chart.d.ts
+++ b/packages/devextreme/js/viz/chart.d.ts
@@ -1504,7 +1504,7 @@ export interface dxChartOptions extends BaseChartOptions<dxChart, chartPointObje
        * @default 'series'
        */
       nameField?: string;
-    } | undefined;
+    };
     /**
      * @docid
      * @default true
diff --git a/packages/devextreme/js/viz/funnel.d.ts b/packages/devextreme/js/viz/funnel.d.ts
index 8314897c67b9..09d13c6c7dbc 100644
--- a/packages/devextreme/js/viz/funnel.d.ts
+++ b/packages/devextreme/js/viz/funnel.d.ts
@@ -273,17 +273,17 @@ export interface dxFunnelOptions extends BaseWidgetOptions<dxFunnel> {
          * @docid
          * @default #ffffff
          */
-        color?: string;
+        color?: string | undefined;
         /**
          * @docid
          * @default false
          */
-        visible?: boolean;
+        visible?: boolean | undefined;
         /**
          * @docid
          * @default 2
          */
-        width?: number;
+        width?: number | undefined;
       };
       /**
        * @docid
diff --git a/packages/devextreme/js/viz/pie_chart.d.ts b/packages/devextreme/js/viz/pie_chart.d.ts
index d6901916d436..98f7a0d9995f 100644
--- a/packages/devextreme/js/viz/pie_chart.d.ts
+++ b/packages/devextreme/js/viz/pie_chart.d.ts
@@ -399,7 +399,7 @@ export interface dxPieChartOptions extends BaseChartOptions<dxPieChart, piePoint
        * @default 'series'
        */
       nameField?: string;
-    } | undefined;
+    };
     /**
      * @docid
      * @default undefined
@@ -739,12 +739,12 @@ export interface dxPieChartSeriesTypesCommonPieChartSeries {
            * @docid dxPieChartSeriesTypes.CommonPieChartSeries.label.border.color
            * @default  '#d3d3d3'
            */
-          color?: string;
+          color?: string | undefined;
           /**
            * @docid dxPieChartSeriesTypes.CommonPieChartSeries.label.border.dashStyle
            * @default 'solid'
            */
-          dashStyle?: DashStyle;
+          dashStyle?: DashStyle | undefined;
           /**
            * @docid dxPieChartSeriesTypes.CommonPieChartSeries.label.border.visible
            * @default false
diff --git a/packages/devextreme/js/viz/polar_chart.d.ts b/packages/devextreme/js/viz/polar_chart.d.ts
index 277e977789ae..ff0482ab855d 100644
--- a/packages/devextreme/js/viz/polar_chart.d.ts
+++ b/packages/devextreme/js/viz/polar_chart.d.ts
@@ -538,7 +538,7 @@ export interface dxPolarChartOptions extends BaseChartOptions<dxPolarChart, pola
        * @default 'series'
        */
       nameField?: string;
-    } | undefined;
+    };
     /**
      * @docid
      * @type object
@@ -2065,12 +2065,12 @@ export interface dxPolarChartSeriesTypesCommonPolarChartSeriesLabel {
        * @docid dxPolarChartSeriesTypes.CommonPolarChartSeries.label.border.color
        * @default  '#d3d3d3'
        */
-      color?: string;
+      color?: string | undefined;
       /**
        * @docid dxPolarChartSeriesTypes.CommonPolarChartSeries.label.border.dashStyle
        * @default 'solid'
        */
-      dashStyle?: DashStyle;
+      dashStyle?: DashStyle | undefined;
       /**
        * @docid dxPolarChartSeriesTypes.CommonPolarChartSeries.label.border.visible
        * @default false
diff --git a/packages/devextreme/js/viz/range_selector.d.ts b/packages/devextreme/js/viz/range_selector.d.ts
index 456490abc790..f6d3a09d4c85 100644
--- a/packages/devextreme/js/viz/range_selector.d.ts
+++ b/packages/devextreme/js/viz/range_selector.d.ts
@@ -292,7 +292,6 @@ export interface dxRangeSelectorOptions extends BaseWidgetOptions<dxRangeSelecto
       series?: ChartSeries | Array<ChartSeries> | undefined;
       /**
        * @docid
-       * @default undefined
        */
       seriesTemplate?: {
         /**
@@ -304,7 +303,7 @@ export interface dxRangeSelectorOptions extends BaseWidgetOptions<dxRangeSelecto
          * @default 'series'
          */
         nameField?: string;
-      } | undefined;
+      };
       /**
        * @docid
        * @default 0.1
diff --git a/packages/devextreme/js/viz/sankey.d.ts b/packages/devextreme/js/viz/sankey.d.ts
index fc76d4435929..092c372402f6 100644
--- a/packages/devextreme/js/viz/sankey.d.ts
+++ b/packages/devextreme/js/viz/sankey.d.ts
@@ -207,17 +207,17 @@ export interface dxSankeyOptions extends BaseWidgetOptions<dxSankey> {
          * @docid
          * @default '#ffffff'
          */
-        color?: string;
+        color?: string | undefined;
         /**
          * @docid
          * @default false
          */
-        visible?: boolean;
+        visible?: boolean | undefined;
         /**
          * @docid
          * @default 2
          */
-        width?: number;
+        width?: number | undefined;
       };
       /**
        * @docid
@@ -298,17 +298,17 @@ export interface dxSankeyOptions extends BaseWidgetOptions<dxSankey> {
          * @docid
          * @default '#ffffff'
          */
-        color?: string;
+        color?: string | undefined;
         /**
          * @docid
          * @default false
          */
-        visible?: boolean;
+        visible?: boolean | undefined;
         /**
          * @docid
          * @default 1
          */
-        width?: number;
+        width?: number | undefined;
       };
       /**
        * @docid
@@ -399,17 +399,17 @@ export interface dxSankeyOptions extends BaseWidgetOptions<dxSankey> {
          * @docid
          * @default '#ffffff'
          */
-        color?: string;
+        color?: string | undefined;
         /**
          * @docid
          * @default false
          */
-        visible?: boolean;
+        visible?: boolean | undefined;
         /**
          * @docid
          * @default 1
          */
-        width?: number;
+        width?: number | undefined;
       };
       /**
        * @docid
diff --git a/packages/devextreme/js/viz/tree_map.d.ts b/packages/devextreme/js/viz/tree_map.d.ts
index aab54515e8bc..9620753e6f9c 100644
--- a/packages/devextreme/js/viz/tree_map.d.ts
+++ b/packages/devextreme/js/viz/tree_map.d.ts
@@ -260,7 +260,7 @@ export interface dxTreeMapOptions extends BaseWidgetOptions<dxTreeMap> {
          * @docid
          * @default 1
          */
-        width?: number;
+        width?: number | undefined;
       };
       /**
        * @docid
@@ -484,12 +484,12 @@ export interface dxTreeMapOptions extends BaseWidgetOptions<dxTreeMap> {
          * @docid
          * @default "#000000"
          */
-        color?: string;
+        color?: string | undefined;
         /**
          * @docid
          * @default 1
          */
-        width?: number;
+        width?: number | undefined;
       };
       /**
        * @docid
diff --git a/packages/devextreme/js/viz/vector_map.d.ts b/packages/devextreme/js/viz/vector_map.d.ts
index 0d6de8dca3a4..e362e22d67c7 100644
--- a/packages/devextreme/js/viz/vector_map.d.ts
+++ b/packages/devextreme/js/viz/vector_map.d.ts
@@ -421,7 +421,6 @@ export interface dxVectorMapOptions extends BaseWidgetOptions<dxVectorMap> {
     };
     /**
      * @docid
-     * @default undefined
      * @notUsedInTheme
      * @public
      */
@@ -585,7 +584,7 @@ export interface dxVectorMapOptions extends BaseWidgetOptions<dxVectorMap> {
        * @notUsedInTheme
        */
       type?: VectorMapLayerType;
-    }> | { borderColor?: string; borderWidth?: number; color?: string; colorGroupingField?: string; colorGroups?: Array<number>; customize?: ((elements: Array<MapLayerElement>) => any); dataField?: string; dataSource?: object | DataSourceLike<any> | null; elementType?: 'bubble' | 'dot' | 'image' | 'pie'; hoverEnabled?: boolean; hoveredBorderColor?: string; hoveredBorderWidth?: number; hoveredColor?: string; label?: { dataField?: string; enabled?: boolean; font?: Font }; maxSize?: number; minSize?: number; name?: string; opacity?: number; palette?: Array<string> | Palette; paletteSize?: number; selectedBorderColor?: string; selectedBorderWidth?: number; selectedColor?: string; selectionMode?: SingleMultipleOrNone; size?: number; sizeGroupingField?: string; sizeGroups?: Array<number>; type?: 'area' | 'line' | 'marker' } | undefined;
+    }> | { borderColor?: string; borderWidth?: number; color?: string; colorGroupingField?: string; colorGroups?: Array<number>; customize?: ((elements: Array<MapLayerElement>) => any); dataField?: string; dataSource?: object | DataSourceLike<any> | null; elementType?: 'bubble' | 'dot' | 'image' | 'pie'; hoverEnabled?: boolean; hoveredBorderColor?: string; hoveredBorderWidth?: number; hoveredColor?: string; label?: { dataField?: string; enabled?: boolean; font?: Font }; maxSize?: number; minSize?: number; name?: string; opacity?: number; palette?: Array<string> | Palette; paletteSize?: number; selectedBorderColor?: string; selectedBorderWidth?: number; selectedColor?: string; selectionMode?: SingleMultipleOrNone; size?: number; sizeGroupingField?: string; sizeGroups?: Array<number>; type?: 'area' | 'line' | 'marker' };
     /**
      * @docid
      * @type Array<Object>
diff --git a/packages/devextreme/ts/dx.all.d.ts b/packages/devextreme/ts/dx.all.d.ts
index 5fa5f656ade9..93a49fa19a29 100644
--- a/packages/devextreme/ts/dx.all.d.ts
+++ b/packages/devextreme/ts/dx.all.d.ts
@@ -16207,29 +16207,31 @@ declare module DevExpress.ui {
     /**
      * [descr:dxDiagramOptions.onItemClick]
      */
-    onItemClick?: (e: DevExpress.ui.dxDiagram.ItemClickEvent) => void;
+    onItemClick?: ((e: DevExpress.ui.dxDiagram.ItemClickEvent) => void) | null;
     /**
      * [descr:dxDiagramOptions.onItemDblClick]
      */
-    onItemDblClick?: (e: DevExpress.ui.dxDiagram.ItemDblClickEvent) => void;
+    onItemDblClick?:
+      | ((e: DevExpress.ui.dxDiagram.ItemDblClickEvent) => void)
+      | null;
     /**
      * [descr:dxDiagramOptions.onSelectionChanged]
      */
-    onSelectionChanged?: (
-      e: DevExpress.ui.dxDiagram.SelectionChangedEvent
-    ) => void;
+    onSelectionChanged?:
+      | ((e: DevExpress.ui.dxDiagram.SelectionChangedEvent) => void)
+      | null;
     /**
      * [descr:dxDiagramOptions.onRequestEditOperation]
      */
-    onRequestEditOperation?: (
-      e: DevExpress.ui.dxDiagram.RequestEditOperationEvent
-    ) => void;
+    onRequestEditOperation?:
+      | ((e: DevExpress.ui.dxDiagram.RequestEditOperationEvent) => void)
+      | null;
     /**
      * [descr:dxDiagramOptions.onRequestLayoutUpdate]
      */
-    onRequestLayoutUpdate?: (
-      e: DevExpress.ui.dxDiagram.RequestLayoutUpdateEvent
-    ) => void;
+    onRequestLayoutUpdate?:
+      | ((e: DevExpress.ui.dxDiagram.RequestLayoutUpdateEvent) => void)
+      | null;
     /**
      * [descr:dxDiagramOptions.pageColor]
      */
@@ -18038,7 +18040,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxFileManagerOptions.fileSystemProvider]
      */
-    fileSystemProvider?: any;
+    fileSystemProvider?: any | null;
     /**
      * [descr:dxFileManagerOptions.itemView]
      */
@@ -18081,33 +18083,33 @@ declare module DevExpress.ui {
     /**
      * [descr:dxFileManagerOptions.onContextMenuItemClick]
      */
-    onContextMenuItemClick?: (
-      e: DevExpress.ui.dxFileManager.ContextMenuItemClickEvent
-    ) => void;
+    onContextMenuItemClick?:
+      | ((e: DevExpress.ui.dxFileManager.ContextMenuItemClickEvent) => void)
+      | undefined;
     /**
      * [descr:dxFileManagerOptions.onContextMenuShowing]
      */
-    onContextMenuShowing?: (
-      e: DevExpress.ui.dxFileManager.ContextMenuShowingEvent
-    ) => void;
+    onContextMenuShowing?:
+      | ((e: DevExpress.ui.dxFileManager.ContextMenuShowingEvent) => void)
+      | undefined;
     /**
      * [descr:dxFileManagerOptions.onCurrentDirectoryChanged]
      */
-    onCurrentDirectoryChanged?: (
-      e: DevExpress.ui.dxFileManager.CurrentDirectoryChangedEvent
-    ) => void;
+    onCurrentDirectoryChanged?:
+      | ((e: DevExpress.ui.dxFileManager.CurrentDirectoryChangedEvent) => void)
+      | undefined;
     /**
      * [descr:dxFileManagerOptions.onSelectedFileOpened]
      */
-    onSelectedFileOpened?: (
-      e: DevExpress.ui.dxFileManager.SelectedFileOpenedEvent
-    ) => void;
+    onSelectedFileOpened?:
+      | ((e: DevExpress.ui.dxFileManager.SelectedFileOpenedEvent) => void)
+      | undefined;
     /**
      * [descr:dxFileManagerOptions.onSelectionChanged]
      */
-    onSelectionChanged?: (
-      e: DevExpress.ui.dxFileManager.SelectionChangedEvent
-    ) => void;
+    onSelectionChanged?:
+      | ((e: DevExpress.ui.dxFileManager.SelectionChangedEvent) => void)
+      | undefined;
     /**
      * [descr:dxFileManagerOptions.onToolbarItemClick]
      */
@@ -18117,75 +18119,93 @@ declare module DevExpress.ui {
     /**
      * [descr:dxFileManagerOptions.onFocusedItemChanged]
      */
-    onFocusedItemChanged?: (
-      e: DevExpress.ui.dxFileManager.FocusedItemChangedEvent
-    ) => void;
+    onFocusedItemChanged?:
+      | ((e: DevExpress.ui.dxFileManager.FocusedItemChangedEvent) => void)
+      | undefined;
     /**
      * [descr:dxFileManagerOptions.onErrorOccurred]
      */
-    onErrorOccurred?: (
-      e: DevExpress.ui.dxFileManager.ErrorOccurredEvent
-    ) => void;
+    onErrorOccurred?:
+      | ((e: DevExpress.ui.dxFileManager.ErrorOccurredEvent) => void)
+      | undefined;
     /**
      * [descr:dxFileManagerOptions.onDirectoryCreating]
      */
-    onDirectoryCreating?: (
-      e: DevExpress.ui.dxFileManager.DirectoryCreatingEvent
-    ) => void;
+    onDirectoryCreating?:
+      | ((e: DevExpress.ui.dxFileManager.DirectoryCreatingEvent) => void)
+      | undefined;
     /**
      * [descr:dxFileManagerOptions.onDirectoryCreated]
      */
-    onDirectoryCreated?: (
-      e: DevExpress.ui.dxFileManager.DirectoryCreatedEvent
-    ) => void;
+    onDirectoryCreated?:
+      | ((e: DevExpress.ui.dxFileManager.DirectoryCreatedEvent) => void)
+      | undefined;
     /**
      * [descr:dxFileManagerOptions.onItemRenaming]
      */
-    onItemRenaming?: (e: DevExpress.ui.dxFileManager.ItemRenamingEvent) => void;
+    onItemRenaming?:
+      | ((e: DevExpress.ui.dxFileManager.ItemRenamingEvent) => void)
+      | undefined;
     /**
      * [descr:dxFileManagerOptions.onItemRenamed]
      */
-    onItemRenamed?: (e: DevExpress.ui.dxFileManager.ItemRenamedEvent) => void;
+    onItemRenamed?:
+      | ((e: DevExpress.ui.dxFileManager.ItemRenamedEvent) => void)
+      | undefined;
     /**
      * [descr:dxFileManagerOptions.onItemMoving]
      */
-    onItemMoving?: (e: DevExpress.ui.dxFileManager.ItemMovingEvent) => void;
+    onItemMoving?:
+      | ((e: DevExpress.ui.dxFileManager.ItemMovingEvent) => void)
+      | undefined;
     /**
      * [descr:dxFileManagerOptions.onItemMoved]
      */
-    onItemMoved?: (e: DevExpress.ui.dxFileManager.ItemMovedEvent) => void;
+    onItemMoved?:
+      | ((e: DevExpress.ui.dxFileManager.ItemMovedEvent) => void)
+      | undefined;
     /**
      * [descr:dxFileManagerOptions.onItemCopying]
      */
-    onItemCopying?: (e: DevExpress.ui.dxFileManager.ItemCopyingEvent) => void;
+    onItemCopying?:
+      | ((e: DevExpress.ui.dxFileManager.ItemCopyingEvent) => void)
+      | undefined;
     /**
      * [descr:dxFileManagerOptions.onItemCopied]
      */
-    onItemCopied?: (e: DevExpress.ui.dxFileManager.ItemCopiedEvent) => void;
+    onItemCopied?:
+      | ((e: DevExpress.ui.dxFileManager.ItemCopiedEvent) => void)
+      | undefined;
     /**
      * [descr:dxFileManagerOptions.onItemDeleting]
      */
-    onItemDeleting?: (e: DevExpress.ui.dxFileManager.ItemDeletingEvent) => void;
+    onItemDeleting?:
+      | ((e: DevExpress.ui.dxFileManager.ItemDeletingEvent) => void)
+      | undefined;
     /**
      * [descr:dxFileManagerOptions.onItemDeleted]
      */
-    onItemDeleted?: (e: DevExpress.ui.dxFileManager.ItemDeletedEvent) => void;
+    onItemDeleted?:
+      | ((e: DevExpress.ui.dxFileManager.ItemDeletedEvent) => void)
+      | undefined;
     /**
      * [descr:dxFileManagerOptions.onFileUploading]
      */
-    onFileUploading?: (
-      e: DevExpress.ui.dxFileManager.FileUploadingEvent
-    ) => void;
+    onFileUploading?:
+      | ((e: DevExpress.ui.dxFileManager.FileUploadingEvent) => void)
+      | undefined;
     /**
      * [descr:dxFileManagerOptions.onFileUploaded]
      */
-    onFileUploaded?: (e: DevExpress.ui.dxFileManager.FileUploadedEvent) => void;
+    onFileUploaded?:
+      | ((e: DevExpress.ui.dxFileManager.FileUploadedEvent) => void)
+      | undefined;
     /**
      * [descr:dxFileManagerOptions.onItemDownloading]
      */
-    onItemDownloading?: (
-      e: DevExpress.ui.dxFileManager.ItemDownloadingEvent
-    ) => void;
+    onItemDownloading?:
+      | ((e: DevExpress.ui.dxFileManager.ItemDownloadingEvent) => void)
+      | undefined;
     /**
      * [descr:dxFileManagerOptions.permissions]
      */
@@ -18234,7 +18254,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxFileManagerOptions.focusedItemKey]
      */
-    focusedItemKey?: string;
+    focusedItemKey?: string | undefined;
     /**
      * [descr:dxFileManagerOptions.toolbar]
      */
@@ -21179,143 +21199,161 @@ declare module DevExpress.ui {
     /**
      * [descr:dxGanttOptions.onSelectionChanged]
      */
-    onSelectionChanged?: (
-      e: DevExpress.ui.dxGantt.SelectionChangedEvent
-    ) => void;
+    onSelectionChanged?:
+      | ((e: DevExpress.ui.dxGantt.SelectionChangedEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onCustomCommand]
      */
-    onCustomCommand?: (e: DevExpress.ui.dxGantt.CustomCommandEvent) => void;
+    onCustomCommand?:
+      | ((e: DevExpress.ui.dxGantt.CustomCommandEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onContextMenuPreparing]
      */
-    onContextMenuPreparing?: (
-      e: DevExpress.ui.dxGantt.ContextMenuPreparingEvent
-    ) => void;
+    onContextMenuPreparing?:
+      | ((e: DevExpress.ui.dxGantt.ContextMenuPreparingEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onTaskInserting]
      */
-    onTaskInserting?: (e: DevExpress.ui.dxGantt.TaskInsertingEvent) => void;
+    onTaskInserting?:
+      | ((e: DevExpress.ui.dxGantt.TaskInsertingEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onTaskInserted]
      */
-    onTaskInserted?: (e: DevExpress.ui.dxGantt.TaskInsertedEvent) => void;
+    onTaskInserted?:
+      | ((e: DevExpress.ui.dxGantt.TaskInsertedEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onTaskDeleting]
      */
-    onTaskDeleting?: (e: DevExpress.ui.dxGantt.TaskDeletingEvent) => void;
+    onTaskDeleting?:
+      | ((e: DevExpress.ui.dxGantt.TaskDeletingEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onTaskDeleted]
      */
-    onTaskDeleted?: (e: DevExpress.ui.dxGantt.TaskDeletedEvent) => void;
+    onTaskDeleted?:
+      | ((e: DevExpress.ui.dxGantt.TaskDeletedEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onTaskUpdating]
      */
-    onTaskUpdating?: (e: DevExpress.ui.dxGantt.TaskUpdatingEvent) => void;
+    onTaskUpdating?:
+      | ((e: DevExpress.ui.dxGantt.TaskUpdatingEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onTaskUpdated]
      */
-    onTaskUpdated?: (e: DevExpress.ui.dxGantt.TaskUpdatedEvent) => void;
+    onTaskUpdated?:
+      | ((e: DevExpress.ui.dxGantt.TaskUpdatedEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onTaskMoving]
      */
-    onTaskMoving?: (e: DevExpress.ui.dxGantt.TaskMovingEvent) => void;
+    onTaskMoving?: ((e: DevExpress.ui.dxGantt.TaskMovingEvent) => void) | null;
     /**
      * [descr:dxGanttOptions.onTaskEditDialogShowing]
      */
-    onTaskEditDialogShowing?: (
-      e: DevExpress.ui.dxGantt.TaskEditDialogShowingEvent
-    ) => void;
+    onTaskEditDialogShowing?:
+      | ((e: DevExpress.ui.dxGantt.TaskEditDialogShowingEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onResourceManagerDialogShowing]
      */
-    onResourceManagerDialogShowing?: (
-      e: DevExpress.ui.dxGantt.ResourceManagerDialogShowingEvent
-    ) => void;
+    onResourceManagerDialogShowing?:
+      | ((e: DevExpress.ui.dxGantt.ResourceManagerDialogShowingEvent) => void)
+      | undefined;
     /**
      * [descr:dxGanttOptions.onDependencyInserting]
      */
-    onDependencyInserting?: (
-      e: DevExpress.ui.dxGantt.DependencyInsertingEvent
-    ) => void;
+    onDependencyInserting?:
+      | ((e: DevExpress.ui.dxGantt.DependencyInsertingEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onDependencyInserted]
      */
-    onDependencyInserted?: (
-      e: DevExpress.ui.dxGantt.DependencyInsertedEvent
-    ) => void;
+    onDependencyInserted?:
+      | ((e: DevExpress.ui.dxGantt.DependencyInsertedEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onDependencyDeleting]
      */
-    onDependencyDeleting?: (
-      e: DevExpress.ui.dxGantt.DependencyDeletingEvent
-    ) => void;
+    onDependencyDeleting?:
+      | ((e: DevExpress.ui.dxGantt.DependencyDeletingEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onDependencyDeleted]
      */
-    onDependencyDeleted?: (
-      e: DevExpress.ui.dxGantt.DependencyDeletedEvent
-    ) => void;
+    onDependencyDeleted?:
+      | ((e: DevExpress.ui.dxGantt.DependencyDeletedEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onResourceInserting]
      */
-    onResourceInserting?: (
-      e: DevExpress.ui.dxGantt.ResourceInsertingEvent
-    ) => void;
+    onResourceInserting?:
+      | ((e: DevExpress.ui.dxGantt.ResourceInsertingEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onResourceInserted]
      */
-    onResourceInserted?: (
-      e: DevExpress.ui.dxGantt.ResourceInsertedEvent
-    ) => void;
+    onResourceInserted?:
+      | ((e: DevExpress.ui.dxGantt.ResourceInsertedEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onResourceDeleting]
      */
-    onResourceDeleting?: (
-      e: DevExpress.ui.dxGantt.ResourceDeletingEvent
-    ) => void;
+    onResourceDeleting?:
+      | ((e: DevExpress.ui.dxGantt.ResourceDeletingEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onResourceDeleted]
      */
-    onResourceDeleted?: (e: DevExpress.ui.dxGantt.ResourceDeletedEvent) => void;
+    onResourceDeleted?:
+      | ((e: DevExpress.ui.dxGantt.ResourceDeletedEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onResourceAssigning]
      */
-    onResourceAssigning?: (
-      e: DevExpress.ui.dxGantt.ResourceAssigningEvent
-    ) => void;
+    onResourceAssigning?:
+      | ((e: DevExpress.ui.dxGantt.ResourceAssigningEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onResourceAssigned]
      */
-    onResourceAssigned?: (
-      e: DevExpress.ui.dxGantt.ResourceAssignedEvent
-    ) => void;
+    onResourceAssigned?:
+      | ((e: DevExpress.ui.dxGantt.ResourceAssignedEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onResourceUnassigning]
      */
-    onResourceUnassigning?: (
-      e: DevExpress.ui.dxGantt.ResourceUnassigningEvent
-    ) => void;
+    onResourceUnassigning?:
+      | ((e: DevExpress.ui.dxGantt.ResourceUnassigningEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onResourceUnassigned]
      */
-    onResourceUnassigned?: (
-      e: DevExpress.ui.dxGantt.ResourceUnassignedEvent
-    ) => void;
+    onResourceUnassigned?:
+      | ((e: DevExpress.ui.dxGantt.ResourceUnassignedEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onTaskClick]
      */
-    onTaskClick?: (e: DevExpress.ui.dxGantt.TaskClickEvent) => void;
+    onTaskClick?: ((e: DevExpress.ui.dxGantt.TaskClickEvent) => void) | null;
     /**
      * [descr:dxGanttOptions.onTaskDblClick]
      */
-    onTaskDblClick?: (e: DevExpress.ui.dxGantt.TaskDblClickEvent) => void;
+    onTaskDblClick?:
+      | ((e: DevExpress.ui.dxGantt.TaskDblClickEvent) => void)
+      | null;
     /**
      * [descr:dxGanttOptions.onScaleCellPrepared]
      */
-    onScaleCellPrepared?: (
-      e: DevExpress.ui.dxGantt.ScaleCellPreparedEvent
-    ) => void;
+    onScaleCellPrepared?:
+      | ((e: DevExpress.ui.dxGantt.ScaleCellPreparedEvent) => void)
+      | undefined;
 
     /**
      * [descr:dxGanttOptions.resourceAssignments]
@@ -21444,7 +21482,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxGanttOptions.toolbar]
      */
-    toolbar?: dxGanttToolbar;
+    toolbar?: dxGanttToolbar | null;
     /**
      * [descr:dxGanttOptions.contextMenu]
      */
@@ -21452,7 +21490,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxGanttOptions.stripLines]
      */
-    stripLines?: Array<dxGanttStripLine>;
+    stripLines?: Array<dxGanttStripLine> | undefined;
     /**
      * [descr:dxGanttOptions.taskTooltipContentTemplate]
      */
@@ -21496,11 +21534,11 @@ declare module DevExpress.ui {
     /**
      * [descr:dxGanttOptions.startDateRange]
      */
-    startDateRange?: Date;
+    startDateRange?: Date | undefined;
     /**
      * [descr:dxGanttOptions.endDateRange]
      */
-    endDateRange?: Date;
+    endDateRange?: Date | undefined;
   }
   /**
    * [descr:dxGanttSorting]
@@ -44722,16 +44760,18 @@ declare module DevExpress.viz {
       /**
        * [descr:dxRangeSelectorOptions.chart.seriesTemplate]
        */
-      seriesTemplate?: {
-        /**
-         * [descr:dxRangeSelectorOptions.chart.seriesTemplate.customizeSeries]
-         */
-        customizeSeries?: (seriesName: any) => ChartSeries;
-        /**
-         * [descr:dxRangeSelectorOptions.chart.seriesTemplate.nameField]
-         */
-        nameField?: string;
-      };
+      seriesTemplate?:
+        | {
+            /**
+             * [descr:dxRangeSelectorOptions.chart.seriesTemplate.customizeSeries]
+             */
+            customizeSeries?: (seriesName: any) => ChartSeries;
+            /**
+             * [descr:dxRangeSelectorOptions.chart.seriesTemplate.nameField]
+             */
+            nameField?: string;
+          }
+        | undefined;
       /**
        * [descr:dxRangeSelectorOptions.chart.topIndent]
        */
@@ -44794,9 +44834,9 @@ declare module DevExpress.viz {
     /**
      * [descr:dxRangeSelectorOptions.onValueChanged]
      */
-    onValueChanged?: (
-      e: DevExpress.viz.dxRangeSelector.ValueChangedEvent
-    ) => void;
+    onValueChanged?:
+      | ((e: DevExpress.viz.dxRangeSelector.ValueChangedEvent) => void)
+      | undefined;
     /**
      * [descr:dxRangeSelectorOptions.scale]
      */
@@ -44837,7 +44877,7 @@ declare module DevExpress.viz {
       /**
        * [descr:dxRangeSelectorOptions.scale.breaks]
        */
-      breaks?: Array<DevExpress.common.charts.ScaleBreak>;
+      breaks?: Array<DevExpress.common.charts.ScaleBreak> | undefined;
       /**
        * [descr:dxRangeSelectorOptions.scale.categories]
        */
@@ -44853,7 +44893,7 @@ declare module DevExpress.viz {
       /**
        * [descr:dxRangeSelectorOptions.scale.holidays]
        */
-      holidays?: Array<Date | string> | Array<number>;
+      holidays?: Array<Date | string> | Array<number> | undefined;
       /**
        * [descr:dxRangeSelectorOptions.scale.label]
        */
@@ -44983,7 +45023,7 @@ declare module DevExpress.viz {
       /**
        * [descr:dxRangeSelectorOptions.scale.singleWorkdays]
        */
-      singleWorkdays?: Array<Date | string> | Array<number>;
+      singleWorkdays?: Array<Date | string> | Array<number> | undefined;
       /**
        * [descr:dxRangeSelectorOptions.scale.startValue]
        */
@@ -46715,7 +46755,7 @@ declare module DevExpress.viz {
     /**
      * [descr:dxVectorMapCommonAnnotationConfig.coordinates]
      */
-    coordinates?: Array<number>;
+    coordinates?: Array<number> | undefined;
     /**
      * [descr:dxVectorMapCommonAnnotationConfig.customizeTooltip]
      */
@@ -46765,7 +46805,7 @@ declare module DevExpress.viz {
     /**
      * [descr:dxVectorMapOptions.bounds]
      */
-    bounds?: Array<number>;
+    bounds?: Array<number> | undefined;
     /**
      * [descr:dxVectorMapOptions.center]
      */
@@ -46835,7 +46875,7 @@ declare module DevExpress.viz {
           /**
            * [descr:dxVectorMapOptions.layers.colorGroups]
            */
-          colorGroups?: Array<number>;
+          colorGroups?: Array<number> | undefined;
           /**
            * [descr:dxVectorMapOptions.layers.customize]
            */
@@ -46940,7 +46980,7 @@ declare module DevExpress.viz {
           /**
            * [descr:dxVectorMapOptions.layers.sizeGroups]
            */
-          sizeGroups?: Array<number>;
+          sizeGroups?: Array<number> | undefined;
           /**
            * [descr:dxVectorMapOptions.layers.type]
            */
@@ -46979,7 +47019,8 @@ declare module DevExpress.viz {
           sizeGroupingField?: string;
           sizeGroups?: Array<number>;
           type?: 'area' | 'line' | 'marker';
-        };
+        }
+      | undefined;
     /**
      * [descr:dxVectorMapOptions.legends]
      */
@@ -46995,35 +47036,40 @@ declare module DevExpress.viz {
     /**
      * [descr:dxVectorMapOptions.onCenterChanged]
      */
-    onCenterChanged?: (
-      e: DevExpress.viz.dxVectorMap.CenterChangedEvent
-    ) => void;
+    onCenterChanged?:
+      | ((e: DevExpress.viz.dxVectorMap.CenterChangedEvent) => void)
+      | undefined;
     /**
      * [descr:dxVectorMapOptions.onClick]
      */
-    onClick?: ((e: DevExpress.viz.dxVectorMap.ClickEvent) => void) | string;
+    onClick?:
+      | ((e: DevExpress.viz.dxVectorMap.ClickEvent) => void)
+      | string
+      | undefined;
     /**
      * [descr:dxVectorMapOptions.onSelectionChanged]
      */
-    onSelectionChanged?: (
-      e: DevExpress.viz.dxVectorMap.SelectionChangedEvent
-    ) => void;
+    onSelectionChanged?:
+      | ((e: DevExpress.viz.dxVectorMap.SelectionChangedEvent) => void)
+      | undefined;
     /**
      * [descr:dxVectorMapOptions.onTooltipHidden]
      */
-    onTooltipHidden?: (
-      e: DevExpress.viz.dxVectorMap.TooltipHiddenEvent
-    ) => void;
+    onTooltipHidden?:
+      | ((e: DevExpress.viz.dxVectorMap.TooltipHiddenEvent) => void)
+      | undefined;
     /**
      * [descr:dxVectorMapOptions.onTooltipShown]
      */
-    onTooltipShown?: (e: DevExpress.viz.dxVectorMap.TooltipShownEvent) => void;
+    onTooltipShown?:
+      | ((e: DevExpress.viz.dxVectorMap.TooltipShownEvent) => void)
+      | undefined;
     /**
      * [descr:dxVectorMapOptions.onZoomFactorChanged]
      */
-    onZoomFactorChanged?: (
-      e: DevExpress.viz.dxVectorMap.ZoomFactorChangedEvent
-    ) => void;
+    onZoomFactorChanged?:
+      | ((e: DevExpress.viz.dxVectorMap.ZoomFactorChangedEvent) => void)
+      | undefined;
     /**
      * [descr:dxVectorMapOptions.panningEnabled]
      */

From cca3a8fc73929f49a467cc044c49af766a5be995 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:41 +0300
Subject: [PATCH 060/100] regenerate-all

---
 .../src/ui/accordion/index.ts                 |  12 +-
 .../src/ui/autocomplete/index.ts              |  30 ++--
 .../autocomplete/nested/drop-down-options.ts  |  20 +--
 .../src/ui/autocomplete/nested/options.ts     |   4 +-
 .../src/ui/bar-gauge/index.ts                 |   6 +-
 .../bar-gauge/nested/legend-title-subtitle.ts |   4 +-
 .../src/ui/bar-gauge/nested/legend-title.ts   |   8 +-
 .../src/ui/bar-gauge/nested/legend.ts         |   4 +-
 .../src/ui/bar-gauge/nested/subtitle.ts       |   4 +-
 .../src/ui/bar-gauge/nested/title.ts          |   8 +-
 .../src/ui/calendar/index.ts                  |  18 +--
 .../src/ui/card-view/nested/button-options.ts |   4 +-
 .../ui/card-view/nested/tab-panel-options.ts  |  14 +-
 .../devextreme-angular/src/ui/chart/index.ts  |  24 +--
 .../src/ui/chart/nested/argument-axis.ts      |  16 +-
 .../ui/chart/nested/common-axis-settings.ts   |   4 +-
 .../ui/chart/nested/legend-title-subtitle.ts  |   4 +-
 .../src/ui/chart/nested/legend-title.ts       |   8 +-
 .../src/ui/chart/nested/legend.ts             |   4 +-
 .../src/ui/chart/nested/subtitle.ts           |   4 +-
 .../src/ui/chart/nested/title.ts              |   4 +-
 .../src/ui/chart/nested/value-axis-dxi.ts     |   8 +-
 .../ui/chat/nested/file-uploader-options.ts   |  48 +++---
 .../src/ui/chat/nested/suggestions.ts         |   8 +-
 .../src/ui/check-box/index.ts                 |  18 +--
 .../src/ui/circular-gauge/index.ts            |  12 +-
 .../src/ui/circular-gauge/nested/scale.ts     |   8 +-
 .../src/ui/color-box/index.ts                 |  18 +--
 .../ui/color-box/nested/drop-down-options.ts  |  20 +--
 .../src/ui/color-box/nested/options.ts        |   4 +-
 .../src/ui/context-menu/index.ts              |   6 +-
 .../src/ui/data-grid/nested/button-options.ts |   4 +-
 .../src/ui/data-grid/nested/editor-options.ts |  16 +-
 .../data-grid/nested/filter-builder-popup.ts  |  20 +--
 .../src/ui/data-grid/nested/options.ts        |   4 +-
 .../src/ui/data-grid/nested/popup.ts          |  20 +--
 .../ui/data-grid/nested/tab-panel-options.ts  |  14 +-
 .../src/ui/date-box/index.ts                  |  36 ++---
 .../ui/date-box/nested/calendar-options.ts    |  12 +-
 .../ui/date-box/nested/drop-down-options.ts   |  20 +--
 .../src/ui/date-box/nested/options.ts         |   4 +-
 .../src/ui/date-range-box/index.ts            |  24 +--
 .../date-range-box/nested/calendar-options.ts |  12 +-
 .../nested/drop-down-options.ts               |  20 +--
 .../src/ui/date-range-box/nested/options.ts   |   4 +-
 .../devextreme-angular/src/ui/drawer/index.ts |  12 +-
 .../src/ui/drop-down-box/index.ts             |  30 ++--
 .../drop-down-box/nested/drop-down-options.ts |  20 +--
 .../src/ui/drop-down-box/nested/options.ts    |   4 +-
 .../nested/drop-down-options.ts               |  20 +--
 .../src/ui/file-manager/index.ts              |  12 +-
 .../src/ui/file-uploader/index.ts             |  12 +-
 .../src/ui/form/nested/button-options.ts      |   4 +-
 .../src/ui/form/nested/tab-panel-options.ts   |  14 +-
 .../devextreme-angular/src/ui/funnel/index.ts |   6 +-
 .../ui/funnel/nested/legend-title-subtitle.ts |   4 +-
 .../src/ui/funnel/nested/legend-title.ts      |   8 +-
 .../src/ui/funnel/nested/legend.ts            |   4 +-
 .../src/ui/funnel/nested/subtitle.ts          |   4 +-
 .../src/ui/funnel/nested/title.ts             |   8 +-
 .../src/ui/gallery/index.ts                   |   6 +-
 .../devextreme-angular/src/ui/gantt/index.ts  |  12 +-
 .../src/ui/html-editor/index.ts               |  54 +++----
 .../nested/file-uploader-options.ts           |  48 +++---
 .../src/ui/linear-gauge/index.ts              |  12 +-
 .../src/ui/linear-gauge/nested/scale.ts       |   8 +-
 .../devextreme-angular/src/ui/list/index.ts   |   6 +-
 .../src/ui/list/nested/options.ts             |   4 +-
 .../ui/list/nested/search-editor-options.ts   |  16 +-
 .../devextreme-angular/src/ui/lookup/index.ts |  18 +--
 .../devextreme-angular/src/ui/menu/index.ts   |   6 +-
 .../src/ui/multi-view/index.ts                |   6 +-
 .../src/ui/nested/argument-axis.ts            |  16 +-
 .../src/ui/nested/base/calendar-options.ts    |  12 +-
 .../base/chart-annotation-config-dxi.ts       |   4 +-
 .../base/chart-common-annotation-config.ts    |   4 +-
 .../ui/nested/base/file-uploader-options.ts   |   8 +-
 .../src/ui/nested/base/popup-options.ts       |  20 +--
 .../src/ui/nested/base/tab-panel-options.ts   |   4 +-
 .../src/ui/nested/base/text-box-options.ts    |  16 +-
 .../src/ui/nested/colorizer.ts                |   4 +-
 .../src/ui/nested/common-axis-settings.ts     |   4 +-
 .../src/ui/nested/layer-dxi.ts                |   8 +-
 .../src/ui/nested/legend-dxi.ts               |   4 +-
 .../src/ui/nested/legend.ts                   |   4 +-
 .../devextreme-angular/src/ui/nested/scale.ts |  20 +--
 .../src/ui/nested/subtitle.ts                 |   4 +-
 .../src/ui/nested/tab-panel-options.ts        |   2 +-
 .../devextreme-angular/src/ui/nested/title.ts |   4 +-
 .../src/ui/nested/value-axis-dxi.ts           |   8 +-
 .../src/ui/number-box/index.ts                |  18 +--
 .../src/ui/number-box/nested/options.ts       |   4 +-
 .../src/ui/pie-chart/index.ts                 |   6 +-
 .../pie-chart/nested/legend-title-subtitle.ts |   4 +-
 .../src/ui/pie-chart/nested/legend-title.ts   |   8 +-
 .../src/ui/pie-chart/nested/legend.ts         |   4 +-
 .../src/ui/pie-chart/nested/subtitle.ts       |   4 +-
 .../src/ui/pie-chart/nested/title.ts          |   8 +-
 .../src/ui/polar-chart/index.ts               |   6 +-
 .../nested/legend-title-subtitle.ts           |   4 +-
 .../src/ui/polar-chart/nested/legend-title.ts |   8 +-
 .../src/ui/polar-chart/nested/legend.ts       |   4 +-
 .../src/ui/polar-chart/nested/subtitle.ts     |   4 +-
 .../src/ui/polar-chart/nested/title.ts        |   8 +-
 .../src/ui/progress-bar/index.ts              |  12 +-
 .../src/ui/radio-group/index.ts               |  12 +-
 .../src/ui/range-selector/index.ts            |   6 +-
 .../src/ui/range-selector/nested/scale.ts     |  12 +-
 .../src/ui/range-slider/index.ts              |  12 +-
 .../src/ui/responsive-box/index.ts            |   6 +-
 .../src/ui/scheduler/nested/button-options.ts |   4 +-
 .../src/ui/scheduler/nested/options.ts        |   8 +-
 .../ui/scheduler/nested/tab-panel-options.ts  |  14 +-
 .../src/ui/select-box/index.ts                |  30 ++--
 .../ui/select-box/nested/drop-down-options.ts |  20 +--
 .../src/ui/select-box/nested/options.ts       |   4 +-
 .../devextreme-angular/src/ui/slider/index.ts |  12 +-
 .../src/ui/stepper/index.ts                   |   6 +-
 .../devextreme-angular/src/ui/switch/index.ts |  12 +-
 .../src/ui/tab-panel/index.ts                 |   6 +-
 .../devextreme-angular/src/ui/tabs/index.ts   |  12 +-
 .../src/ui/tag-box/index.ts                   |  24 +--
 .../ui/tag-box/nested/drop-down-options.ts    |  20 +--
 .../src/ui/tag-box/nested/options.ts          |   4 +-
 .../src/ui/text-area/index.ts                 |  18 +--
 .../src/ui/text-box/index.ts                  |  24 +--
 .../src/ui/text-box/nested/options.ts         |   4 +-
 .../src/ui/tree-list/nested/button-options.ts |   4 +-
 .../src/ui/tree-list/nested/editor-options.ts |  16 +-
 .../tree-list/nested/filter-builder-popup.ts  |  20 +--
 .../src/ui/tree-list/nested/options.ts        |   4 +-
 .../src/ui/tree-list/nested/popup.ts          |  20 +--
 .../ui/tree-list/nested/tab-panel-options.ts  |  14 +-
 .../src/ui/tree-map/index.ts                  |   6 +-
 .../src/ui/tree-map/nested/colorizer.ts       |   4 +-
 .../src/ui/tree-view/nested/options.ts        |   4 +-
 .../tree-view/nested/search-editor-options.ts |  16 +-
 .../src/ui/vector-map/index.ts                |  18 +--
 .../ui/vector-map/nested/annotation-dxi.ts    |   4 +-
 .../nested/common-annotation-settings.ts      |   4 +-
 .../src/ui/vector-map/nested/layer-dxi.ts     |   8 +-
 .../src/ui/vector-map/nested/legend-dxi.ts    |   4 +-
 .../nested/legend-title-subtitle.ts           |   4 +-
 .../src/ui/vector-map/nested/legend-title.ts  |   8 +-
 .../src/ui/vector-map/nested/subtitle.ts      |   4 +-
 .../src/ui/vector-map/nested/title.ts         |   8 +-
 packages/devextreme-react/src/accordion.ts    |   4 +-
 packages/devextreme-react/src/autocomplete.ts |  12 +-
 packages/devextreme-react/src/bar-gauge.ts    |  20 +--
 packages/devextreme-react/src/button-group.ts |   2 +-
 packages/devextreme-react/src/button.ts       |   2 +-
 packages/devextreme-react/src/card-view.ts    |  12 +-
 packages/devextreme-react/src/chart.ts        |  32 ++--
 packages/devextreme-react/src/chat.ts         |  28 ++--
 packages/devextreme-react/src/check-box.ts    |   4 +-
 .../devextreme-react/src/circular-gauge.ts    |   8 +-
 packages/devextreme-react/src/color-box.ts    |  12 +-
 packages/devextreme-react/src/context-menu.ts |  14 +-
 packages/devextreme-react/src/data-grid.ts    |  42 +++---
 packages/devextreme-react/src/date-box.ts     |  18 +--
 .../devextreme-react/src/date-range-box.ts    |  18 +--
 packages/devextreme-react/src/diagram.ts      |   8 +-
 .../devextreme-react/src/drop-down-box.ts     |  12 +-
 .../devextreme-react/src/drop-down-button.ts  |  10 +-
 packages/devextreme-react/src/file-manager.ts |  34 ++---
 .../devextreme-react/src/file-uploader.ts     |  20 +--
 packages/devextreme-react/src/form.ts         |  12 +-
 packages/devextreme-react/src/funnel.ts       |  16 +-
 packages/devextreme-react/src/gallery.ts      |   4 +-
 packages/devextreme-react/src/gantt.ts        |  52 +++----
 packages/devextreme-react/src/html-editor.ts  |  32 ++--
 packages/devextreme-react/src/linear-gauge.ts |   8 +-
 packages/devextreme-react/src/list.ts         |  32 ++--
 packages/devextreme-react/src/lookup.ts       |   8 +-
 packages/devextreme-react/src/map.ts          |  10 +-
 packages/devextreme-react/src/menu.ts         |  12 +-
 packages/devextreme-react/src/multi-view.ts   |   4 +-
 packages/devextreme-react/src/number-box.ts   |   2 +-
 packages/devextreme-react/src/pie-chart.ts    |  16 +-
 packages/devextreme-react/src/polar-chart.ts  |  20 +--
 packages/devextreme-react/src/progress-bar.ts |   2 +-
 .../devextreme-react/src/range-selector.ts    |   8 +-
 packages/devextreme-react/src/range-slider.ts |   2 +-
 packages/devextreme-react/src/resizable.ts    |   6 +-
 packages/devextreme-react/src/scheduler.ts    |  16 +-
 packages/devextreme-react/src/scroll-view.ts  |   4 +-
 packages/devextreme-react/src/select-box.ts   |  12 +-
 .../devextreme-react/src/speed-dial-action.ts |   2 +-
 packages/devextreme-react/src/splitter.ts     |  10 +-
 packages/devextreme-react/src/stepper.ts      |   4 +-
 packages/devextreme-react/src/tab-panel.ts    |   8 +-
 packages/devextreme-react/src/tabs.ts         |   4 +-
 packages/devextreme-react/src/tag-box.ts      |  16 +-
 packages/devextreme-react/src/text-box.ts     |   2 +-
 packages/devextreme-react/src/tree-list.ts    |  42 +++---
 packages/devextreme-react/src/tree-map.ts     |   8 +-
 packages/devextreme-react/src/tree-view.ts    |  24 +--
 packages/devextreme-react/src/vector-map.ts   |  28 ++--
 packages/devextreme-vue/src/accordion.ts      |   2 +-
 packages/devextreme-vue/src/autocomplete.ts   |  14 +-
 packages/devextreme-vue/src/button-group.ts   |   4 +-
 packages/devextreme-vue/src/calendar.ts       |   4 +-
 packages/devextreme-vue/src/card-view.ts      |   6 +-
 packages/devextreme-vue/src/chart.ts          |   6 +-
 packages/devextreme-vue/src/chat.ts           |  26 ++--
 packages/devextreme-vue/src/check-box.ts      |   2 +-
 packages/devextreme-vue/src/color-box.ts      |  12 +-
 packages/devextreme-vue/src/context-menu.ts   |  10 +-
 packages/devextreme-vue/src/data-grid.ts      |  28 ++--
 packages/devextreme-vue/src/date-box.ts       |  22 +--
 packages/devextreme-vue/src/date-range-box.ts |  18 +--
 packages/devextreme-vue/src/diagram.ts        |  10 +-
 packages/devextreme-vue/src/drawer.ts         |   4 +-
 packages/devextreme-vue/src/drop-down-box.ts  |  14 +-
 .../devextreme-vue/src/drop-down-button.ts    |  10 +-
 packages/devextreme-vue/src/file-uploader.ts  |  22 +--
 packages/devextreme-vue/src/form.ts           |   4 +-
 packages/devextreme-vue/src/gantt.ts          |  50 +++----
 packages/devextreme-vue/src/html-editor.ts    |  36 ++---
 packages/devextreme-vue/src/list.ts           |  28 ++--
 packages/devextreme-vue/src/lookup.ts         |  10 +-
 packages/devextreme-vue/src/map.ts            |  10 +-
 packages/devextreme-vue/src/menu.ts           |   8 +-
 packages/devextreme-vue/src/number-box.ts     |   2 +-
 packages/devextreme-vue/src/pagination.ts     |   2 +-
 packages/devextreme-vue/src/popup.ts          |  10 +-
 packages/devextreme-vue/src/progress-bar.ts   |   4 +-
 packages/devextreme-vue/src/radio-group.ts    |   2 +-
 packages/devextreme-vue/src/range-slider.ts   |   4 +-
 packages/devextreme-vue/src/responsive-box.ts |   2 +-
 packages/devextreme-vue/src/scheduler.ts      |   8 +-
 packages/devextreme-vue/src/scroll-view.ts    |   4 +-
 packages/devextreme-vue/src/select-box.ts     |  14 +-
 packages/devextreme-vue/src/slider.ts         |   2 +-
 .../devextreme-vue/src/speed-dial-action.ts   |   2 +-
 packages/devextreme-vue/src/switch.ts         |   2 +-
 packages/devextreme-vue/src/tab-panel.ts      |   4 +-
 packages/devextreme-vue/src/tabs.ts           |   2 +-
 packages/devextreme-vue/src/tag-box.ts        |  20 +--
 packages/devextreme-vue/src/text-area.ts      |   4 +-
 packages/devextreme-vue/src/text-box.ts       |   4 +-
 packages/devextreme-vue/src/tree-list.ts      |  28 ++--
 packages/devextreme-vue/src/tree-view.ts      |  22 +--
 packages/devextreme/ts/dx.all.d.ts            | 137 ++++++++----------
 244 files changed, 1489 insertions(+), 1498 deletions(-)

diff --git a/packages/devextreme-angular/src/ui/accordion/index.ts b/packages/devextreme-angular/src/ui/accordion/index.ts
index 7369e90a8cfd..772b2e05ce63 100644
--- a/packages/devextreme-angular/src/ui/accordion/index.ts
+++ b/packages/devextreme-angular/src/ui/accordion/index.ts
@@ -287,10 +287,10 @@ export class DxAccordionComponent<TItem = any, TKey = any> extends DxComponent i
     
      */
     @Input()
-    get keyExpr(): ((item: any) => any) | string {
+    get keyExpr(): ((item: any) => any) | null | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: ((item: any) => any) | string) {
+    set keyExpr(value: ((item: any) => any) | null | string) {
         this._setOption('keyExpr', value);
     }
 
@@ -365,10 +365,10 @@ export class DxAccordionComponent<TItem = any, TKey = any> extends DxComponent i
     
      */
     @Input()
-    get selectedItem(): any {
+    get selectedItem(): any | null {
         return this._getOption('selectedItem');
     }
-    set selectedItem(value: any) {
+    set selectedItem(value: any | null) {
         this._setOption('selectedItem', value);
     }
 
@@ -634,7 +634,7 @@ export class DxAccordionComponent<TItem = any, TKey = any> extends DxComponent i
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() keyExprChange: EventEmitter<((item: any) => any) | string>;
+    @Output() keyExprChange: EventEmitter<((item: any) => any) | null | string>;
 
     /**
     
@@ -676,7 +676,7 @@ export class DxAccordionComponent<TItem = any, TKey = any> extends DxComponent i
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() selectedItemChange: EventEmitter<any>;
+    @Output() selectedItemChange: EventEmitter<any | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/autocomplete/index.ts b/packages/devextreme-angular/src/ui/autocomplete/index.ts
index f5b7e5019026..2dcb08fb733d 100644
--- a/packages/devextreme-angular/src/ui/autocomplete/index.ts
+++ b/packages/devextreme-angular/src/ui/autocomplete/index.ts
@@ -162,10 +162,10 @@ export class DxAutocompleteComponent extends DxComponent implements OnDestroy, C
     
      */
     @Input()
-    get buttons(): Array<DropDownPredefinedButton | TextEditorButton> {
+    get buttons(): Array<DropDownPredefinedButton | TextEditorButton> | undefined {
         return this._getOption('buttons');
     }
-    set buttons(value: Array<DropDownPredefinedButton | TextEditorButton>) {
+    set buttons(value: Array<DropDownPredefinedButton | TextEditorButton> | undefined) {
         this._setOption('buttons', value);
     }
 
@@ -448,10 +448,10 @@ export class DxAutocompleteComponent extends DxComponent implements OnDestroy, C
     
      */
     @Input()
-    get maxLength(): number | string {
+    get maxLength(): null | number | string {
         return this._getOption('maxLength');
     }
-    set maxLength(value: number | string) {
+    set maxLength(value: null | number | string) {
         this._setOption('maxLength', value);
     }
 
@@ -591,10 +591,10 @@ export class DxAutocompleteComponent extends DxComponent implements OnDestroy, C
     
      */
     @Input()
-    get selectedItem(): any {
+    get selectedItem(): any | null {
         return this._getOption('selectedItem');
     }
-    set selectedItem(value: any) {
+    set selectedItem(value: any | null) {
         this._setOption('selectedItem', value);
     }
 
@@ -695,10 +695,10 @@ export class DxAutocompleteComponent extends DxComponent implements OnDestroy, C
     
      */
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
@@ -708,10 +708,10 @@ export class DxAutocompleteComponent extends DxComponent implements OnDestroy, C
     
      */
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
@@ -1003,7 +1003,7 @@ export class DxAutocompleteComponent extends DxComponent implements OnDestroy, C
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() buttonsChange: EventEmitter<Array<DropDownPredefinedButton | TextEditorButton>>;
+    @Output() buttonsChange: EventEmitter<Array<DropDownPredefinedButton | TextEditorButton> | undefined>;
 
     /**
     
@@ -1157,7 +1157,7 @@ export class DxAutocompleteComponent extends DxComponent implements OnDestroy, C
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() maxLengthChange: EventEmitter<number | string>;
+    @Output() maxLengthChange: EventEmitter<null | number | string>;
 
     /**
     
@@ -1234,7 +1234,7 @@ export class DxAutocompleteComponent extends DxComponent implements OnDestroy, C
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() selectedItemChange: EventEmitter<any>;
+    @Output() selectedItemChange: EventEmitter<any | null>;
 
     /**
     
@@ -1290,14 +1290,14 @@ export class DxAutocompleteComponent extends DxComponent implements OnDestroy, C
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorChange: EventEmitter<any>;
+    @Output() validationErrorChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorsChange: EventEmitter<Array<any>>;
+    @Output() validationErrorsChange: EventEmitter<Array<any> | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/autocomplete/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/autocomplete/nested/drop-down-options.ts
index 660c00d6ebad..d2cce43ed6ce 100644
--- a/packages/devextreme-angular/src/ui/autocomplete/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/autocomplete/nested/drop-down-options.ts
@@ -220,10 +220,10 @@ export class DxoAutocompleteDropDownOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) {
+    get onContentReady(): ((e: EventInfo<any>) => void) | null {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void)) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoAutocompleteDropDownOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoAutocompleteDropDownOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/autocomplete/nested/options.ts b/packages/devextreme-angular/src/ui/autocomplete/nested/options.ts
index 6fa1c9a5df31..00589bc9a71c 100644
--- a/packages/devextreme-angular/src/ui/autocomplete/nested/options.ts
+++ b/packages/devextreme-angular/src/ui/autocomplete/nested/options.ts
@@ -114,10 +114,10 @@ export class DxoAutocompleteOptionsComponent extends NestedOption implements Aft
     }
 
     @Input()
-    get onClick(): ((e: ClickEvent) => void) {
+    get onClick(): ((e: ClickEvent) => void) | undefined {
         return this._getOption('onClick');
     }
-    set onClick(value: ((e: ClickEvent) => void)) {
+    set onClick(value: ((e: ClickEvent) => void) | undefined) {
         this._setOption('onClick', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/bar-gauge/index.ts b/packages/devextreme-angular/src/ui/bar-gauge/index.ts
index aeadf6908e0a..03aa790ded7b 100644
--- a/packages/devextreme-angular/src/ui/bar-gauge/index.ts
+++ b/packages/devextreme-angular/src/ui/bar-gauge/index.ts
@@ -248,10 +248,10 @@ export class DxBarGaugeComponent extends DxComponent implements OnDestroy, OnCha
     
      */
     @Input()
-    get legend(): { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((arg: { item: BarGaugeBarInfo, text: string }) => string), customizeItems?: ((items: Array<BarGaugeLegendItem>) => Array<BarGaugeLegendItem>), customizeText?: ((arg: { item: BarGaugeBarInfo, text: string }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, itemsAlignment?: HorizontalAlignment | undefined, itemTextFormat?: Format | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean } {
+    get legend(): { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((arg: { item: BarGaugeBarInfo, text: string }) => string), customizeItems?: ((items: Array<BarGaugeLegendItem>) => Array<BarGaugeLegendItem>), customizeText?: ((arg: { item: BarGaugeBarInfo, text: string }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, itemsAlignment?: HorizontalAlignment | undefined, itemTextFormat?: Format | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean } {
         return this._getOption('legend');
     }
-    set legend(value: { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((arg: { item: BarGaugeBarInfo, text: string }) => string), customizeItems?: ((items: Array<BarGaugeLegendItem>) => Array<BarGaugeLegendItem>), customizeText?: ((arg: { item: BarGaugeBarInfo, text: string }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, itemsAlignment?: HorizontalAlignment | undefined, itemTextFormat?: Format | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }) {
+    set legend(value: { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((arg: { item: BarGaugeBarInfo, text: string }) => string), customizeItems?: ((items: Array<BarGaugeLegendItem>) => Array<BarGaugeLegendItem>), customizeText?: ((arg: { item: BarGaugeBarInfo, text: string }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, itemsAlignment?: HorizontalAlignment | undefined, itemTextFormat?: Format | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }) {
         this._setOption('legend', value);
     }
 
@@ -612,7 +612,7 @@ export class DxBarGaugeComponent extends DxComponent implements OnDestroy, OnCha
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() legendChange: EventEmitter<{ backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((arg: { item: BarGaugeBarInfo, text: string }) => string), customizeItems?: ((items: Array<BarGaugeLegendItem>) => Array<BarGaugeLegendItem>), customizeText?: ((arg: { item: BarGaugeBarInfo, text: string }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, itemsAlignment?: HorizontalAlignment | undefined, itemTextFormat?: Format | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }>;
+    @Output() legendChange: EventEmitter<{ backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((arg: { item: BarGaugeBarInfo, text: string }) => string), customizeItems?: ((items: Array<BarGaugeLegendItem>) => Array<BarGaugeLegendItem>), customizeText?: ((arg: { item: BarGaugeBarInfo, text: string }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, itemsAlignment?: HorizontalAlignment | undefined, itemTextFormat?: Format | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/bar-gauge/nested/legend-title-subtitle.ts b/packages/devextreme-angular/src/ui/bar-gauge/nested/legend-title-subtitle.ts
index 6e3ade8b7b7d..b73ede4123cb 100644
--- a/packages/devextreme-angular/src/ui/bar-gauge/nested/legend-title-subtitle.ts
+++ b/packages/devextreme-angular/src/ui/bar-gauge/nested/legend-title-subtitle.ts
@@ -48,10 +48,10 @@ export class DxoBarGaugeLegendTitleSubtitleComponent extends NestedOption implem
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/bar-gauge/nested/legend-title.ts b/packages/devextreme-angular/src/ui/bar-gauge/nested/legend-title.ts
index ccd18b44b82e..cc10385ecb4f 100644
--- a/packages/devextreme-angular/src/ui/bar-gauge/nested/legend-title.ts
+++ b/packages/devextreme-angular/src/ui/bar-gauge/nested/legend-title.ts
@@ -65,18 +65,18 @@ export class DxoBarGaugeLegendTitleComponent extends NestedOption implements OnD
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/bar-gauge/nested/legend.ts b/packages/devextreme-angular/src/ui/bar-gauge/nested/legend.ts
index e31721a2ad47..f8c8abe91bf0 100644
--- a/packages/devextreme-angular/src/ui/bar-gauge/nested/legend.ts
+++ b/packages/devextreme-angular/src/ui/bar-gauge/nested/legend.ts
@@ -195,10 +195,10 @@ export class DxoBarGaugeLegendComponent extends NestedOption implements OnDestro
     }
 
     @Input()
-    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge } {
+    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge } {
         return this._getOption('title');
     }
-    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }) {
+    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }) {
         this._setOption('title', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/bar-gauge/nested/subtitle.ts b/packages/devextreme-angular/src/ui/bar-gauge/nested/subtitle.ts
index 34cae02f9c32..ccfdb66c7b05 100644
--- a/packages/devextreme-angular/src/ui/bar-gauge/nested/subtitle.ts
+++ b/packages/devextreme-angular/src/ui/bar-gauge/nested/subtitle.ts
@@ -48,10 +48,10 @@ export class DxoBarGaugeSubtitleComponent extends NestedOption implements OnDest
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/bar-gauge/nested/title.ts b/packages/devextreme-angular/src/ui/bar-gauge/nested/title.ts
index 4fd1e61b68cf..3139c09124bf 100644
--- a/packages/devextreme-angular/src/ui/bar-gauge/nested/title.ts
+++ b/packages/devextreme-angular/src/ui/bar-gauge/nested/title.ts
@@ -65,18 +65,18 @@ export class DxoBarGaugeTitleComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/calendar/index.ts b/packages/devextreme-angular/src/ui/calendar/index.ts
index 137ebc5bc9f8..798c85241ee3 100644
--- a/packages/devextreme-angular/src/ui/calendar/index.ts
+++ b/packages/devextreme-angular/src/ui/calendar/index.ts
@@ -142,10 +142,10 @@ export class DxCalendarComponent extends DxComponent implements OnDestroy, Contr
     
      */
     @Input()
-    get disabledDates(): Array<Date> | ((data: DisabledDate) => boolean) {
+    get disabledDates(): Array<Date> | ((data: DisabledDate) => boolean) | null {
         return this._getOption('disabledDates');
     }
-    set disabledDates(value: Array<Date> | ((data: DisabledDate) => boolean)) {
+    set disabledDates(value: Array<Date> | ((data: DisabledDate) => boolean) | null) {
         this._setOption('disabledDates', value);
     }
 
@@ -425,10 +425,10 @@ export class DxCalendarComponent extends DxComponent implements OnDestroy, Contr
     
      */
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
@@ -438,10 +438,10 @@ export class DxCalendarComponent extends DxComponent implements OnDestroy, Contr
     
      */
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
@@ -621,7 +621,7 @@ export class DxCalendarComponent extends DxComponent implements OnDestroy, Contr
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() disabledDatesChange: EventEmitter<Array<Date> | ((data: DisabledDate) => boolean)>;
+    @Output() disabledDatesChange: EventEmitter<Array<Date> | ((data: DisabledDate) => boolean) | null>;
 
     /**
     
@@ -775,14 +775,14 @@ export class DxCalendarComponent extends DxComponent implements OnDestroy, Contr
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorChange: EventEmitter<any>;
+    @Output() validationErrorChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorsChange: EventEmitter<Array<any>>;
+    @Output() validationErrorsChange: EventEmitter<Array<any> | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/card-view/nested/button-options.ts b/packages/devextreme-angular/src/ui/card-view/nested/button-options.ts
index b4795db80cbc..1c5577f3b302 100644
--- a/packages/devextreme-angular/src/ui/card-view/nested/button-options.ts
+++ b/packages/devextreme-angular/src/ui/card-view/nested/button-options.ts
@@ -114,10 +114,10 @@ export class DxoCardViewButtonOptionsComponent extends NestedOption implements A
     }
 
     @Input()
-    get onClick(): ((e: ClickEvent) => void) {
+    get onClick(): ((e: ClickEvent) => void) | undefined {
         return this._getOption('onClick');
     }
-    set onClick(value: ((e: ClickEvent) => void)) {
+    set onClick(value: ((e: ClickEvent) => void) | undefined) {
         this._setOption('onClick', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/card-view/nested/tab-panel-options.ts b/packages/devextreme-angular/src/ui/card-view/nested/tab-panel-options.ts
index e14a74b65c55..652d10f863de 100644
--- a/packages/devextreme-angular/src/ui/card-view/nested/tab-panel-options.ts
+++ b/packages/devextreme-angular/src/ui/card-view/nested/tab-panel-options.ts
@@ -288,18 +288,18 @@ export class DxoCardViewTabPanelOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onTitleHold(): ((e: TitleHoldEvent) => void) {
+    get onTitleHold(): ((e: TitleHoldEvent) => void) | null {
         return this._getOption('onTitleHold');
     }
-    set onTitleHold(value: ((e: TitleHoldEvent) => void)) {
+    set onTitleHold(value: ((e: TitleHoldEvent) => void) | null) {
         this._setOption('onTitleHold', value);
     }
 
     @Input()
-    get onTitleRendered(): ((e: TitleRenderedEvent) => void) {
+    get onTitleRendered(): ((e: TitleRenderedEvent) => void) | null {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: TitleRenderedEvent) => void)) {
+    set onTitleRendered(value: ((e: TitleRenderedEvent) => void) | null) {
         this._setOption('onTitleRendered', value);
     }
 
@@ -344,10 +344,10 @@ export class DxoCardViewTabPanelOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get selectedItem(): any {
+    get selectedItem(): any | null {
         return this._getOption('selectedItem');
     }
-    set selectedItem(value: any) {
+    set selectedItem(value: any | null) {
         this._setOption('selectedItem', value);
     }
 
@@ -427,7 +427,7 @@ export class DxoCardViewTabPanelOptionsComponent extends NestedOption implements
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() selectedItemChange: EventEmitter<any>;
+    @Output() selectedItemChange: EventEmitter<any | null>;
     protected get _optionPath() {
         return 'tabPanelOptions';
     }
diff --git a/packages/devextreme-angular/src/ui/chart/index.ts b/packages/devextreme-angular/src/ui/chart/index.ts
index 599d62c62a1c..5a02083ce247 100644
--- a/packages/devextreme-angular/src/ui/chart/index.ts
+++ b/packages/devextreme-angular/src/ui/chart/index.ts
@@ -346,10 +346,10 @@ export class DxChartComponent extends DxComponent implements OnDestroy, OnChange
     
      */
     @Input()
-    get argumentAxis(): { aggregatedPointsPosition?: AggregatedPointsPosition, aggregationGroupWidth?: number | undefined, aggregationInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, allowDecimals?: boolean | undefined, argumentType?: ChartsDataType | undefined, axisDivisionFactor?: number, breaks?: Array<ScaleBreak> | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[], breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, categories?: Array<Date | number | string>, color?: string, constantLines?: { color?: string, dashStyle?: DashStyle, displayBehindSeries?: boolean, extendAxis?: boolean, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, text?: string | undefined, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, value?: Date | number | string | undefined, width?: number }[], constantLineStyle?: { color?: string, dashStyle?: DashStyle, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, width?: number }, customPosition?: Date | number | string | undefined, customPositionAxis?: string | undefined, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean, grid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, holidays?: Array<Date | string> | Array<number>, hoverMode?: ArgumentAxisHoverMode, inverted?: boolean, label?: { alignment?: HorizontalAlignment | undefined, customizeHint?: ((argument: { value: Date | number | string, valueText: string }) => string), customizeText?: ((argument: { value: Date | number | string, valueText: string }) => string), displayMode?: ChartLabelDisplayMode, font?: Font, format?: Format | undefined, indentFromAxis?: number, overlappingBehavior?: ChartsAxisLabelOverlap, position?: Position | RelativePosition, rotationAngle?: number, staggeringSpacing?: number, template?: any, textOverflow?: TextOverflow, visible?: boolean, wordWrap?: WordWrap }, linearThreshold?: number | undefined, logarithmBase?: number, maxValueMargin?: number | undefined, minorGrid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, minorTick?: { color?: string, length?: number, opacity?: number, shift?: number, visible?: boolean, width?: number }, minorTickCount?: number | undefined, minorTickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minValueMargin?: number | undefined, minVisualRangeLength?: number | TimeInterval | undefined | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, offset?: number | undefined, opacity?: number | undefined, placeholderSize?: number, position?: Position, singleWorkdays?: Array<Date | string> | Array<number>, strips?: { color?: string | undefined, endValue?: Date | number | string | undefined, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, text?: string | undefined, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number, startValue?: Date | number | string | undefined }[], stripStyle?: { label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number }, tick?: { color?: string, length?: number, opacity?: number | undefined, shift?: number, visible?: boolean, width?: number }, tickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, title?: string | { alignment?: HorizontalAlignment, font?: Font, margin?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, type?: AxisScaleType | undefined, valueMarginsEnabled?: boolean, visible?: boolean, visualRange?: Array<Date | number | string> | CommonChartTypes.VisualRange, visualRangeUpdateMode?: VisualRangeUpdateMode, wholeRange?: Array<Date | number | string> | undefined | CommonChartTypes.VisualRange, width?: number, workdaysOnly?: boolean, workWeek?: Array<number> } {
+    get argumentAxis(): { aggregatedPointsPosition?: AggregatedPointsPosition, aggregationGroupWidth?: number | undefined, aggregationInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, allowDecimals?: boolean | undefined, argumentType?: ChartsDataType | undefined, axisDivisionFactor?: number, breaks?: Array<ScaleBreak> | undefined | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[], breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, categories?: Array<Date | number | string>, color?: string, constantLines?: { color?: string, dashStyle?: DashStyle, displayBehindSeries?: boolean, extendAxis?: boolean, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, text?: string | undefined, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, value?: Date | number | string | undefined, width?: number }[], constantLineStyle?: { color?: string, dashStyle?: DashStyle, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, width?: number }, customPosition?: Date | number | string | undefined, customPositionAxis?: string | undefined, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean, grid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, holidays?: Array<Date | string> | Array<number> | undefined, hoverMode?: ArgumentAxisHoverMode, inverted?: boolean, label?: { alignment?: HorizontalAlignment | undefined, customizeHint?: ((argument: { value: Date | number | string, valueText: string }) => string), customizeText?: ((argument: { value: Date | number | string, valueText: string }) => string), displayMode?: ChartLabelDisplayMode, font?: Font, format?: Format | undefined, indentFromAxis?: number, overlappingBehavior?: ChartsAxisLabelOverlap, position?: Position | RelativePosition, rotationAngle?: number, staggeringSpacing?: number, template?: any, textOverflow?: TextOverflow, visible?: boolean, wordWrap?: WordWrap }, linearThreshold?: number | undefined, logarithmBase?: number, maxValueMargin?: number | undefined, minorGrid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, minorTick?: { color?: string, length?: number, opacity?: number, shift?: number, visible?: boolean, width?: number }, minorTickCount?: number | undefined, minorTickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minValueMargin?: number | undefined, minVisualRangeLength?: number | TimeInterval | undefined | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, offset?: number | undefined, opacity?: number | undefined, placeholderSize?: null | number, position?: Position, singleWorkdays?: Array<Date | string> | Array<number> | undefined, strips?: { color?: string | undefined, endValue?: Date | number | string | undefined, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, text?: string | undefined, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number, startValue?: Date | number | string | undefined }[], stripStyle?: { label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number }, tick?: { color?: string, length?: number, opacity?: number | undefined, shift?: number, visible?: boolean, width?: number }, tickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, title?: string | { alignment?: HorizontalAlignment, font?: Font, margin?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, type?: AxisScaleType | undefined, valueMarginsEnabled?: boolean, visible?: boolean, visualRange?: Array<Date | number | string> | CommonChartTypes.VisualRange, visualRangeUpdateMode?: VisualRangeUpdateMode, wholeRange?: Array<Date | number | string> | undefined | CommonChartTypes.VisualRange, width?: number, workdaysOnly?: boolean, workWeek?: Array<number> } {
         return this._getOption('argumentAxis');
     }
-    set argumentAxis(value: { aggregatedPointsPosition?: AggregatedPointsPosition, aggregationGroupWidth?: number | undefined, aggregationInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, allowDecimals?: boolean | undefined, argumentType?: ChartsDataType | undefined, axisDivisionFactor?: number, breaks?: Array<ScaleBreak> | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[], breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, categories?: Array<Date | number | string>, color?: string, constantLines?: { color?: string, dashStyle?: DashStyle, displayBehindSeries?: boolean, extendAxis?: boolean, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, text?: string | undefined, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, value?: Date | number | string | undefined, width?: number }[], constantLineStyle?: { color?: string, dashStyle?: DashStyle, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, width?: number }, customPosition?: Date | number | string | undefined, customPositionAxis?: string | undefined, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean, grid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, holidays?: Array<Date | string> | Array<number>, hoverMode?: ArgumentAxisHoverMode, inverted?: boolean, label?: { alignment?: HorizontalAlignment | undefined, customizeHint?: ((argument: { value: Date | number | string, valueText: string }) => string), customizeText?: ((argument: { value: Date | number | string, valueText: string }) => string), displayMode?: ChartLabelDisplayMode, font?: Font, format?: Format | undefined, indentFromAxis?: number, overlappingBehavior?: ChartsAxisLabelOverlap, position?: Position | RelativePosition, rotationAngle?: number, staggeringSpacing?: number, template?: any, textOverflow?: TextOverflow, visible?: boolean, wordWrap?: WordWrap }, linearThreshold?: number | undefined, logarithmBase?: number, maxValueMargin?: number | undefined, minorGrid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, minorTick?: { color?: string, length?: number, opacity?: number, shift?: number, visible?: boolean, width?: number }, minorTickCount?: number | undefined, minorTickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minValueMargin?: number | undefined, minVisualRangeLength?: number | TimeInterval | undefined | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, offset?: number | undefined, opacity?: number | undefined, placeholderSize?: number, position?: Position, singleWorkdays?: Array<Date | string> | Array<number>, strips?: { color?: string | undefined, endValue?: Date | number | string | undefined, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, text?: string | undefined, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number, startValue?: Date | number | string | undefined }[], stripStyle?: { label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number }, tick?: { color?: string, length?: number, opacity?: number | undefined, shift?: number, visible?: boolean, width?: number }, tickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, title?: string | { alignment?: HorizontalAlignment, font?: Font, margin?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, type?: AxisScaleType | undefined, valueMarginsEnabled?: boolean, visible?: boolean, visualRange?: Array<Date | number | string> | CommonChartTypes.VisualRange, visualRangeUpdateMode?: VisualRangeUpdateMode, wholeRange?: Array<Date | number | string> | undefined | CommonChartTypes.VisualRange, width?: number, workdaysOnly?: boolean, workWeek?: Array<number> }) {
+    set argumentAxis(value: { aggregatedPointsPosition?: AggregatedPointsPosition, aggregationGroupWidth?: number | undefined, aggregationInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, allowDecimals?: boolean | undefined, argumentType?: ChartsDataType | undefined, axisDivisionFactor?: number, breaks?: Array<ScaleBreak> | undefined | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[], breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, categories?: Array<Date | number | string>, color?: string, constantLines?: { color?: string, dashStyle?: DashStyle, displayBehindSeries?: boolean, extendAxis?: boolean, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, text?: string | undefined, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, value?: Date | number | string | undefined, width?: number }[], constantLineStyle?: { color?: string, dashStyle?: DashStyle, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, width?: number }, customPosition?: Date | number | string | undefined, customPositionAxis?: string | undefined, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean, grid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, holidays?: Array<Date | string> | Array<number> | undefined, hoverMode?: ArgumentAxisHoverMode, inverted?: boolean, label?: { alignment?: HorizontalAlignment | undefined, customizeHint?: ((argument: { value: Date | number | string, valueText: string }) => string), customizeText?: ((argument: { value: Date | number | string, valueText: string }) => string), displayMode?: ChartLabelDisplayMode, font?: Font, format?: Format | undefined, indentFromAxis?: number, overlappingBehavior?: ChartsAxisLabelOverlap, position?: Position | RelativePosition, rotationAngle?: number, staggeringSpacing?: number, template?: any, textOverflow?: TextOverflow, visible?: boolean, wordWrap?: WordWrap }, linearThreshold?: number | undefined, logarithmBase?: number, maxValueMargin?: number | undefined, minorGrid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, minorTick?: { color?: string, length?: number, opacity?: number, shift?: number, visible?: boolean, width?: number }, minorTickCount?: number | undefined, minorTickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minValueMargin?: number | undefined, minVisualRangeLength?: number | TimeInterval | undefined | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, offset?: number | undefined, opacity?: number | undefined, placeholderSize?: null | number, position?: Position, singleWorkdays?: Array<Date | string> | Array<number> | undefined, strips?: { color?: string | undefined, endValue?: Date | number | string | undefined, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, text?: string | undefined, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number, startValue?: Date | number | string | undefined }[], stripStyle?: { label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number }, tick?: { color?: string, length?: number, opacity?: number | undefined, shift?: number, visible?: boolean, width?: number }, tickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, title?: string | { alignment?: HorizontalAlignment, font?: Font, margin?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, type?: AxisScaleType | undefined, valueMarginsEnabled?: boolean, visible?: boolean, visualRange?: Array<Date | number | string> | CommonChartTypes.VisualRange, visualRangeUpdateMode?: VisualRangeUpdateMode, wholeRange?: Array<Date | number | string> | undefined | CommonChartTypes.VisualRange, width?: number, workdaysOnly?: boolean, workWeek?: Array<number> }) {
         this._setOption('argumentAxis', value);
     }
 
@@ -411,10 +411,10 @@ export class DxChartComponent extends DxComponent implements OnDestroy, OnChange
     
      */
     @Input()
-    get commonAxisSettings(): { aggregatedPointsPosition?: AggregatedPointsPosition, allowDecimals?: boolean | undefined, breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, color?: string, constantLineStyle?: { color?: string, dashStyle?: DashStyle, label?: { font?: Font, position?: RelativePosition, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, width?: number }, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean | undefined, grid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, inverted?: boolean, label?: { alignment?: HorizontalAlignment | undefined, displayMode?: ChartLabelDisplayMode, font?: Font, indentFromAxis?: number, overlappingBehavior?: ChartsAxisLabelOverlap, position?: Position | RelativePosition, rotationAngle?: number, staggeringSpacing?: number, template?: any, textOverflow?: TextOverflow, visible?: boolean, wordWrap?: WordWrap }, maxValueMargin?: number | undefined, minorGrid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, minorTick?: { color?: string, length?: number, opacity?: number, shift?: number, visible?: boolean, width?: number }, minValueMargin?: number | undefined, opacity?: number | undefined, placeholderSize?: number, stripStyle?: { label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number }, tick?: { color?: string, length?: number, opacity?: number | undefined, shift?: number, visible?: boolean, width?: number }, title?: { alignment?: HorizontalAlignment, font?: Font, margin?: number, textOverflow?: TextOverflow, wordWrap?: WordWrap }, valueMarginsEnabled?: boolean, visible?: boolean, width?: number } {
+    get commonAxisSettings(): { aggregatedPointsPosition?: AggregatedPointsPosition, allowDecimals?: boolean | undefined, breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, color?: string, constantLineStyle?: { color?: string, dashStyle?: DashStyle, label?: { font?: Font, position?: RelativePosition, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, width?: number }, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean | undefined, grid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, inverted?: boolean, label?: { alignment?: HorizontalAlignment | undefined, displayMode?: ChartLabelDisplayMode, font?: Font, indentFromAxis?: number, overlappingBehavior?: ChartsAxisLabelOverlap, position?: Position | RelativePosition, rotationAngle?: number, staggeringSpacing?: number, template?: any, textOverflow?: TextOverflow, visible?: boolean, wordWrap?: WordWrap }, maxValueMargin?: number | undefined, minorGrid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, minorTick?: { color?: string, length?: number, opacity?: number, shift?: number, visible?: boolean, width?: number }, minValueMargin?: number | undefined, opacity?: number | undefined, placeholderSize?: null | number, stripStyle?: { label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number }, tick?: { color?: string, length?: number, opacity?: number | undefined, shift?: number, visible?: boolean, width?: number }, title?: { alignment?: HorizontalAlignment, font?: Font, margin?: number, textOverflow?: TextOverflow, wordWrap?: WordWrap }, valueMarginsEnabled?: boolean, visible?: boolean, width?: number } {
         return this._getOption('commonAxisSettings');
     }
-    set commonAxisSettings(value: { aggregatedPointsPosition?: AggregatedPointsPosition, allowDecimals?: boolean | undefined, breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, color?: string, constantLineStyle?: { color?: string, dashStyle?: DashStyle, label?: { font?: Font, position?: RelativePosition, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, width?: number }, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean | undefined, grid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, inverted?: boolean, label?: { alignment?: HorizontalAlignment | undefined, displayMode?: ChartLabelDisplayMode, font?: Font, indentFromAxis?: number, overlappingBehavior?: ChartsAxisLabelOverlap, position?: Position | RelativePosition, rotationAngle?: number, staggeringSpacing?: number, template?: any, textOverflow?: TextOverflow, visible?: boolean, wordWrap?: WordWrap }, maxValueMargin?: number | undefined, minorGrid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, minorTick?: { color?: string, length?: number, opacity?: number, shift?: number, visible?: boolean, width?: number }, minValueMargin?: number | undefined, opacity?: number | undefined, placeholderSize?: number, stripStyle?: { label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number }, tick?: { color?: string, length?: number, opacity?: number | undefined, shift?: number, visible?: boolean, width?: number }, title?: { alignment?: HorizontalAlignment, font?: Font, margin?: number, textOverflow?: TextOverflow, wordWrap?: WordWrap }, valueMarginsEnabled?: boolean, visible?: boolean, width?: number }) {
+    set commonAxisSettings(value: { aggregatedPointsPosition?: AggregatedPointsPosition, allowDecimals?: boolean | undefined, breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, color?: string, constantLineStyle?: { color?: string, dashStyle?: DashStyle, label?: { font?: Font, position?: RelativePosition, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, width?: number }, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean | undefined, grid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, inverted?: boolean, label?: { alignment?: HorizontalAlignment | undefined, displayMode?: ChartLabelDisplayMode, font?: Font, indentFromAxis?: number, overlappingBehavior?: ChartsAxisLabelOverlap, position?: Position | RelativePosition, rotationAngle?: number, staggeringSpacing?: number, template?: any, textOverflow?: TextOverflow, visible?: boolean, wordWrap?: WordWrap }, maxValueMargin?: number | undefined, minorGrid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, minorTick?: { color?: string, length?: number, opacity?: number, shift?: number, visible?: boolean, width?: number }, minValueMargin?: number | undefined, opacity?: number | undefined, placeholderSize?: null | number, stripStyle?: { label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number }, tick?: { color?: string, length?: number, opacity?: number | undefined, shift?: number, visible?: boolean, width?: number }, title?: { alignment?: HorizontalAlignment, font?: Font, margin?: number, textOverflow?: TextOverflow, wordWrap?: WordWrap }, valueMarginsEnabled?: boolean, visible?: boolean, width?: number }) {
         this._setOption('commonAxisSettings', value);
     }
 
@@ -593,10 +593,10 @@ export class DxChartComponent extends DxComponent implements OnDestroy, OnChange
     
      */
     @Input()
-    get legend(): { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), customizeItems?: ((items: Array<LegendItem>) => Array<LegendItem>), customizeText?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, hoverMode?: LegendHoverMode, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, position?: RelativePosition, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean } {
+    get legend(): { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), customizeItems?: ((items: Array<LegendItem>) => Array<LegendItem>), customizeText?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, hoverMode?: LegendHoverMode, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, position?: RelativePosition, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean } {
         return this._getOption('legend');
     }
-    set legend(value: { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), customizeItems?: ((items: Array<LegendItem>) => Array<LegendItem>), customizeText?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, hoverMode?: LegendHoverMode, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, position?: RelativePosition, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }) {
+    set legend(value: { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), customizeItems?: ((items: Array<LegendItem>) => Array<LegendItem>), customizeText?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, hoverMode?: LegendHoverMode, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, position?: RelativePosition, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }) {
         this._setOption('legend', value);
     }
 
@@ -931,10 +931,10 @@ export class DxChartComponent extends DxComponent implements OnDestroy, OnChange
     
      */
     @Input()
-    get valueAxis(): { aggregatedPointsPosition?: AggregatedPointsPosition, allowDecimals?: boolean | undefined, autoBreaksEnabled?: boolean, axisDivisionFactor?: number, breaks?: Array<ScaleBreak> | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[], breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, categories?: Array<Date | number | string>, color?: string, constantLines?: { color?: string, dashStyle?: DashStyle, displayBehindSeries?: boolean, extendAxis?: boolean, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, text?: string | undefined, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, value?: Date | number | string | undefined, width?: number }[], constantLineStyle?: { color?: string, dashStyle?: DashStyle, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, width?: number }, customPosition?: Date | number | string | undefined, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean | undefined, grid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, inverted?: boolean, label?: { alignment?: HorizontalAlignment | undefined, customizeHint?: ((axisValue: { value: Date | number | string, valueText: string }) => string), customizeText?: ((axisValue: { value: Date | number | string, valueText: string }) => string), displayMode?: ChartLabelDisplayMode, font?: Font, format?: Format | undefined, indentFromAxis?: number, overlappingBehavior?: ChartsAxisLabelOverlap, position?: Position | RelativePosition, rotationAngle?: number, staggeringSpacing?: number, template?: any, textOverflow?: TextOverflow, visible?: boolean, wordWrap?: WordWrap }, linearThreshold?: number | undefined, logarithmBase?: number, maxAutoBreakCount?: number, maxValueMargin?: number | undefined, minorGrid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, minorTick?: { color?: string, length?: number, opacity?: number, shift?: number, visible?: boolean, width?: number }, minorTickCount?: number | undefined, minorTickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minValueMargin?: number | undefined, minVisualRangeLength?: number | TimeInterval | undefined | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, multipleAxesSpacing?: number, name?: string | undefined, offset?: number | undefined, opacity?: number | undefined, pane?: string | undefined, placeholderSize?: number, position?: Position, showZero?: boolean | undefined, strips?: { color?: string | undefined, endValue?: Date | number | string | undefined, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, text?: string | undefined, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number, startValue?: Date | number | string | undefined }[], stripStyle?: { label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number }, synchronizedValue?: number | undefined, tick?: { color?: string, length?: number, opacity?: number | undefined, shift?: number, visible?: boolean, width?: number }, tickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, title?: string | { alignment?: HorizontalAlignment, font?: Font, margin?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, type?: AxisScaleType | undefined, valueMarginsEnabled?: boolean, valueType?: ChartsDataType | undefined, visible?: boolean, visualRange?: Array<Date | number | string> | CommonChartTypes.VisualRange, visualRangeUpdateMode?: ValueAxisVisualRangeUpdateMode, wholeRange?: Array<Date | number | string> | undefined | CommonChartTypes.VisualRange, width?: number }[] {
+    get valueAxis(): { aggregatedPointsPosition?: AggregatedPointsPosition, allowDecimals?: boolean | undefined, autoBreaksEnabled?: boolean, axisDivisionFactor?: number, breaks?: Array<ScaleBreak> | undefined | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[], breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, categories?: Array<Date | number | string>, color?: string, constantLines?: { color?: string, dashStyle?: DashStyle, displayBehindSeries?: boolean, extendAxis?: boolean, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, text?: string | undefined, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, value?: Date | number | string | undefined, width?: number }[], constantLineStyle?: { color?: string, dashStyle?: DashStyle, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, width?: number }, customPosition?: Date | number | string | undefined, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean | undefined, grid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, inverted?: boolean, label?: { alignment?: HorizontalAlignment | undefined, customizeHint?: ((axisValue: { value: Date | number | string, valueText: string }) => string), customizeText?: ((axisValue: { value: Date | number | string, valueText: string }) => string), displayMode?: ChartLabelDisplayMode, font?: Font, format?: Format | undefined, indentFromAxis?: number, overlappingBehavior?: ChartsAxisLabelOverlap, position?: Position | RelativePosition, rotationAngle?: number, staggeringSpacing?: number, template?: any, textOverflow?: TextOverflow, visible?: boolean, wordWrap?: WordWrap }, linearThreshold?: number | undefined, logarithmBase?: number, maxAutoBreakCount?: number, maxValueMargin?: number | undefined, minorGrid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, minorTick?: { color?: string, length?: number, opacity?: number, shift?: number, visible?: boolean, width?: number }, minorTickCount?: number | undefined, minorTickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minValueMargin?: number | undefined, minVisualRangeLength?: number | TimeInterval | undefined | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, multipleAxesSpacing?: number, name?: string | undefined, offset?: number | undefined, opacity?: number | undefined, pane?: string | undefined, placeholderSize?: null | number, position?: Position, showZero?: boolean | undefined, strips?: { color?: string | undefined, endValue?: Date | number | string | undefined, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, text?: string | undefined, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number, startValue?: Date | number | string | undefined }[], stripStyle?: { label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number }, synchronizedValue?: number | undefined, tick?: { color?: string, length?: number, opacity?: number | undefined, shift?: number, visible?: boolean, width?: number }, tickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, title?: string | { alignment?: HorizontalAlignment, font?: Font, margin?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, type?: AxisScaleType | undefined, valueMarginsEnabled?: boolean, valueType?: ChartsDataType | undefined, visible?: boolean, visualRange?: Array<Date | number | string> | CommonChartTypes.VisualRange, visualRangeUpdateMode?: ValueAxisVisualRangeUpdateMode, wholeRange?: Array<Date | number | string> | undefined | CommonChartTypes.VisualRange, width?: number }[] {
         return this._getOption('valueAxis');
     }
-    set valueAxis(value: { aggregatedPointsPosition?: AggregatedPointsPosition, allowDecimals?: boolean | undefined, autoBreaksEnabled?: boolean, axisDivisionFactor?: number, breaks?: Array<ScaleBreak> | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[], breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, categories?: Array<Date | number | string>, color?: string, constantLines?: { color?: string, dashStyle?: DashStyle, displayBehindSeries?: boolean, extendAxis?: boolean, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, text?: string | undefined, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, value?: Date | number | string | undefined, width?: number }[], constantLineStyle?: { color?: string, dashStyle?: DashStyle, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, width?: number }, customPosition?: Date | number | string | undefined, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean | undefined, grid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, inverted?: boolean, label?: { alignment?: HorizontalAlignment | undefined, customizeHint?: ((axisValue: { value: Date | number | string, valueText: string }) => string), customizeText?: ((axisValue: { value: Date | number | string, valueText: string }) => string), displayMode?: ChartLabelDisplayMode, font?: Font, format?: Format | undefined, indentFromAxis?: number, overlappingBehavior?: ChartsAxisLabelOverlap, position?: Position | RelativePosition, rotationAngle?: number, staggeringSpacing?: number, template?: any, textOverflow?: TextOverflow, visible?: boolean, wordWrap?: WordWrap }, linearThreshold?: number | undefined, logarithmBase?: number, maxAutoBreakCount?: number, maxValueMargin?: number | undefined, minorGrid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, minorTick?: { color?: string, length?: number, opacity?: number, shift?: number, visible?: boolean, width?: number }, minorTickCount?: number | undefined, minorTickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minValueMargin?: number | undefined, minVisualRangeLength?: number | TimeInterval | undefined | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, multipleAxesSpacing?: number, name?: string | undefined, offset?: number | undefined, opacity?: number | undefined, pane?: string | undefined, placeholderSize?: number, position?: Position, showZero?: boolean | undefined, strips?: { color?: string | undefined, endValue?: Date | number | string | undefined, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, text?: string | undefined, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number, startValue?: Date | number | string | undefined }[], stripStyle?: { label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number }, synchronizedValue?: number | undefined, tick?: { color?: string, length?: number, opacity?: number | undefined, shift?: number, visible?: boolean, width?: number }, tickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, title?: string | { alignment?: HorizontalAlignment, font?: Font, margin?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, type?: AxisScaleType | undefined, valueMarginsEnabled?: boolean, valueType?: ChartsDataType | undefined, visible?: boolean, visualRange?: Array<Date | number | string> | CommonChartTypes.VisualRange, visualRangeUpdateMode?: ValueAxisVisualRangeUpdateMode, wholeRange?: Array<Date | number | string> | undefined | CommonChartTypes.VisualRange, width?: number }[]) {
+    set valueAxis(value: { aggregatedPointsPosition?: AggregatedPointsPosition, allowDecimals?: boolean | undefined, autoBreaksEnabled?: boolean, axisDivisionFactor?: number, breaks?: Array<ScaleBreak> | undefined | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[], breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, categories?: Array<Date | number | string>, color?: string, constantLines?: { color?: string, dashStyle?: DashStyle, displayBehindSeries?: boolean, extendAxis?: boolean, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, text?: string | undefined, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, value?: Date | number | string | undefined, width?: number }[], constantLineStyle?: { color?: string, dashStyle?: DashStyle, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, width?: number }, customPosition?: Date | number | string | undefined, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean | undefined, grid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, inverted?: boolean, label?: { alignment?: HorizontalAlignment | undefined, customizeHint?: ((axisValue: { value: Date | number | string, valueText: string }) => string), customizeText?: ((axisValue: { value: Date | number | string, valueText: string }) => string), displayMode?: ChartLabelDisplayMode, font?: Font, format?: Format | undefined, indentFromAxis?: number, overlappingBehavior?: ChartsAxisLabelOverlap, position?: Position | RelativePosition, rotationAngle?: number, staggeringSpacing?: number, template?: any, textOverflow?: TextOverflow, visible?: boolean, wordWrap?: WordWrap }, linearThreshold?: number | undefined, logarithmBase?: number, maxAutoBreakCount?: number, maxValueMargin?: number | undefined, minorGrid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, minorTick?: { color?: string, length?: number, opacity?: number, shift?: number, visible?: boolean, width?: number }, minorTickCount?: number | undefined, minorTickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minValueMargin?: number | undefined, minVisualRangeLength?: number | TimeInterval | undefined | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, multipleAxesSpacing?: number, name?: string | undefined, offset?: number | undefined, opacity?: number | undefined, pane?: string | undefined, placeholderSize?: null | number, position?: Position, showZero?: boolean | undefined, strips?: { color?: string | undefined, endValue?: Date | number | string | undefined, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, text?: string | undefined, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number, startValue?: Date | number | string | undefined }[], stripStyle?: { label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number }, synchronizedValue?: number | undefined, tick?: { color?: string, length?: number, opacity?: number | undefined, shift?: number, visible?: boolean, width?: number }, tickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, title?: string | { alignment?: HorizontalAlignment, font?: Font, margin?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, type?: AxisScaleType | undefined, valueMarginsEnabled?: boolean, valueType?: ChartsDataType | undefined, visible?: boolean, visualRange?: Array<Date | number | string> | CommonChartTypes.VisualRange, visualRangeUpdateMode?: ValueAxisVisualRangeUpdateMode, wholeRange?: Array<Date | number | string> | undefined | CommonChartTypes.VisualRange, width?: number }[]) {
         this._setOption('valueAxis', value);
     }
 
@@ -1152,7 +1152,7 @@ export class DxChartComponent extends DxComponent implements OnDestroy, OnChange
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() argumentAxisChange: EventEmitter<{ aggregatedPointsPosition?: AggregatedPointsPosition, aggregationGroupWidth?: number | undefined, aggregationInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, allowDecimals?: boolean | undefined, argumentType?: ChartsDataType | undefined, axisDivisionFactor?: number, breaks?: Array<ScaleBreak> | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[], breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, categories?: Array<Date | number | string>, color?: string, constantLines?: { color?: string, dashStyle?: DashStyle, displayBehindSeries?: boolean, extendAxis?: boolean, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, text?: string | undefined, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, value?: Date | number | string | undefined, width?: number }[], constantLineStyle?: { color?: string, dashStyle?: DashStyle, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, width?: number }, customPosition?: Date | number | string | undefined, customPositionAxis?: string | undefined, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean, grid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, holidays?: Array<Date | string> | Array<number>, hoverMode?: ArgumentAxisHoverMode, inverted?: boolean, label?: { alignment?: HorizontalAlignment | undefined, customizeHint?: ((argument: { value: Date | number | string, valueText: string }) => string), customizeText?: ((argument: { value: Date | number | string, valueText: string }) => string), displayMode?: ChartLabelDisplayMode, font?: Font, format?: Format | undefined, indentFromAxis?: number, overlappingBehavior?: ChartsAxisLabelOverlap, position?: Position | RelativePosition, rotationAngle?: number, staggeringSpacing?: number, template?: any, textOverflow?: TextOverflow, visible?: boolean, wordWrap?: WordWrap }, linearThreshold?: number | undefined, logarithmBase?: number, maxValueMargin?: number | undefined, minorGrid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, minorTick?: { color?: string, length?: number, opacity?: number, shift?: number, visible?: boolean, width?: number }, minorTickCount?: number | undefined, minorTickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minValueMargin?: number | undefined, minVisualRangeLength?: number | TimeInterval | undefined | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, offset?: number | undefined, opacity?: number | undefined, placeholderSize?: number, position?: Position, singleWorkdays?: Array<Date | string> | Array<number>, strips?: { color?: string | undefined, endValue?: Date | number | string | undefined, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, text?: string | undefined, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number, startValue?: Date | number | string | undefined }[], stripStyle?: { label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number }, tick?: { color?: string, length?: number, opacity?: number | undefined, shift?: number, visible?: boolean, width?: number }, tickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, title?: string | { alignment?: HorizontalAlignment, font?: Font, margin?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, type?: AxisScaleType | undefined, valueMarginsEnabled?: boolean, visible?: boolean, visualRange?: Array<Date | number | string> | CommonChartTypes.VisualRange, visualRangeUpdateMode?: VisualRangeUpdateMode, wholeRange?: Array<Date | number | string> | undefined | CommonChartTypes.VisualRange, width?: number, workdaysOnly?: boolean, workWeek?: Array<number> }>;
+    @Output() argumentAxisChange: EventEmitter<{ aggregatedPointsPosition?: AggregatedPointsPosition, aggregationGroupWidth?: number | undefined, aggregationInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, allowDecimals?: boolean | undefined, argumentType?: ChartsDataType | undefined, axisDivisionFactor?: number, breaks?: Array<ScaleBreak> | undefined | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[], breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, categories?: Array<Date | number | string>, color?: string, constantLines?: { color?: string, dashStyle?: DashStyle, displayBehindSeries?: boolean, extendAxis?: boolean, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, text?: string | undefined, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, value?: Date | number | string | undefined, width?: number }[], constantLineStyle?: { color?: string, dashStyle?: DashStyle, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, width?: number }, customPosition?: Date | number | string | undefined, customPositionAxis?: string | undefined, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean, grid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, holidays?: Array<Date | string> | Array<number> | undefined, hoverMode?: ArgumentAxisHoverMode, inverted?: boolean, label?: { alignment?: HorizontalAlignment | undefined, customizeHint?: ((argument: { value: Date | number | string, valueText: string }) => string), customizeText?: ((argument: { value: Date | number | string, valueText: string }) => string), displayMode?: ChartLabelDisplayMode, font?: Font, format?: Format | undefined, indentFromAxis?: number, overlappingBehavior?: ChartsAxisLabelOverlap, position?: Position | RelativePosition, rotationAngle?: number, staggeringSpacing?: number, template?: any, textOverflow?: TextOverflow, visible?: boolean, wordWrap?: WordWrap }, linearThreshold?: number | undefined, logarithmBase?: number, maxValueMargin?: number | undefined, minorGrid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, minorTick?: { color?: string, length?: number, opacity?: number, shift?: number, visible?: boolean, width?: number }, minorTickCount?: number | undefined, minorTickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minValueMargin?: number | undefined, minVisualRangeLength?: number | TimeInterval | undefined | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, offset?: number | undefined, opacity?: number | undefined, placeholderSize?: null | number, position?: Position, singleWorkdays?: Array<Date | string> | Array<number> | undefined, strips?: { color?: string | undefined, endValue?: Date | number | string | undefined, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, text?: string | undefined, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number, startValue?: Date | number | string | undefined }[], stripStyle?: { label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number }, tick?: { color?: string, length?: number, opacity?: number | undefined, shift?: number, visible?: boolean, width?: number }, tickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, title?: string | { alignment?: HorizontalAlignment, font?: Font, margin?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, type?: AxisScaleType | undefined, valueMarginsEnabled?: boolean, visible?: boolean, visualRange?: Array<Date | number | string> | CommonChartTypes.VisualRange, visualRangeUpdateMode?: VisualRangeUpdateMode, wholeRange?: Array<Date | number | string> | undefined | CommonChartTypes.VisualRange, width?: number, workdaysOnly?: boolean, workWeek?: Array<number> }>;
 
     /**
     
@@ -1187,7 +1187,7 @@ export class DxChartComponent extends DxComponent implements OnDestroy, OnChange
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() commonAxisSettingsChange: EventEmitter<{ aggregatedPointsPosition?: AggregatedPointsPosition, allowDecimals?: boolean | undefined, breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, color?: string, constantLineStyle?: { color?: string, dashStyle?: DashStyle, label?: { font?: Font, position?: RelativePosition, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, width?: number }, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean | undefined, grid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, inverted?: boolean, label?: { alignment?: HorizontalAlignment | undefined, displayMode?: ChartLabelDisplayMode, font?: Font, indentFromAxis?: number, overlappingBehavior?: ChartsAxisLabelOverlap, position?: Position | RelativePosition, rotationAngle?: number, staggeringSpacing?: number, template?: any, textOverflow?: TextOverflow, visible?: boolean, wordWrap?: WordWrap }, maxValueMargin?: number | undefined, minorGrid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, minorTick?: { color?: string, length?: number, opacity?: number, shift?: number, visible?: boolean, width?: number }, minValueMargin?: number | undefined, opacity?: number | undefined, placeholderSize?: number, stripStyle?: { label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number }, tick?: { color?: string, length?: number, opacity?: number | undefined, shift?: number, visible?: boolean, width?: number }, title?: { alignment?: HorizontalAlignment, font?: Font, margin?: number, textOverflow?: TextOverflow, wordWrap?: WordWrap }, valueMarginsEnabled?: boolean, visible?: boolean, width?: number }>;
+    @Output() commonAxisSettingsChange: EventEmitter<{ aggregatedPointsPosition?: AggregatedPointsPosition, allowDecimals?: boolean | undefined, breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, color?: string, constantLineStyle?: { color?: string, dashStyle?: DashStyle, label?: { font?: Font, position?: RelativePosition, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, width?: number }, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean | undefined, grid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, inverted?: boolean, label?: { alignment?: HorizontalAlignment | undefined, displayMode?: ChartLabelDisplayMode, font?: Font, indentFromAxis?: number, overlappingBehavior?: ChartsAxisLabelOverlap, position?: Position | RelativePosition, rotationAngle?: number, staggeringSpacing?: number, template?: any, textOverflow?: TextOverflow, visible?: boolean, wordWrap?: WordWrap }, maxValueMargin?: number | undefined, minorGrid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, minorTick?: { color?: string, length?: number, opacity?: number, shift?: number, visible?: boolean, width?: number }, minValueMargin?: number | undefined, opacity?: number | undefined, placeholderSize?: null | number, stripStyle?: { label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number }, tick?: { color?: string, length?: number, opacity?: number | undefined, shift?: number, visible?: boolean, width?: number }, title?: { alignment?: HorizontalAlignment, font?: Font, margin?: number, textOverflow?: TextOverflow, wordWrap?: WordWrap }, valueMarginsEnabled?: boolean, visible?: boolean, width?: number }>;
 
     /**
     
@@ -1285,7 +1285,7 @@ export class DxChartComponent extends DxComponent implements OnDestroy, OnChange
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() legendChange: EventEmitter<{ backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), customizeItems?: ((items: Array<LegendItem>) => Array<LegendItem>), customizeText?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, hoverMode?: LegendHoverMode, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, position?: RelativePosition, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }>;
+    @Output() legendChange: EventEmitter<{ backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), customizeItems?: ((items: Array<LegendItem>) => Array<LegendItem>), customizeText?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, hoverMode?: LegendHoverMode, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, position?: RelativePosition, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }>;
 
     /**
     
@@ -1467,7 +1467,7 @@ export class DxChartComponent extends DxComponent implements OnDestroy, OnChange
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() valueAxisChange: EventEmitter<{ aggregatedPointsPosition?: AggregatedPointsPosition, allowDecimals?: boolean | undefined, autoBreaksEnabled?: boolean, axisDivisionFactor?: number, breaks?: Array<ScaleBreak> | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[], breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, categories?: Array<Date | number | string>, color?: string, constantLines?: { color?: string, dashStyle?: DashStyle, displayBehindSeries?: boolean, extendAxis?: boolean, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, text?: string | undefined, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, value?: Date | number | string | undefined, width?: number }[], constantLineStyle?: { color?: string, dashStyle?: DashStyle, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, width?: number }, customPosition?: Date | number | string | undefined, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean | undefined, grid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, inverted?: boolean, label?: { alignment?: HorizontalAlignment | undefined, customizeHint?: ((axisValue: { value: Date | number | string, valueText: string }) => string), customizeText?: ((axisValue: { value: Date | number | string, valueText: string }) => string), displayMode?: ChartLabelDisplayMode, font?: Font, format?: Format | undefined, indentFromAxis?: number, overlappingBehavior?: ChartsAxisLabelOverlap, position?: Position | RelativePosition, rotationAngle?: number, staggeringSpacing?: number, template?: any, textOverflow?: TextOverflow, visible?: boolean, wordWrap?: WordWrap }, linearThreshold?: number | undefined, logarithmBase?: number, maxAutoBreakCount?: number, maxValueMargin?: number | undefined, minorGrid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, minorTick?: { color?: string, length?: number, opacity?: number, shift?: number, visible?: boolean, width?: number }, minorTickCount?: number | undefined, minorTickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minValueMargin?: number | undefined, minVisualRangeLength?: number | TimeInterval | undefined | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, multipleAxesSpacing?: number, name?: string | undefined, offset?: number | undefined, opacity?: number | undefined, pane?: string | undefined, placeholderSize?: number, position?: Position, showZero?: boolean | undefined, strips?: { color?: string | undefined, endValue?: Date | number | string | undefined, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, text?: string | undefined, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number, startValue?: Date | number | string | undefined }[], stripStyle?: { label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number }, synchronizedValue?: number | undefined, tick?: { color?: string, length?: number, opacity?: number | undefined, shift?: number, visible?: boolean, width?: number }, tickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, title?: string | { alignment?: HorizontalAlignment, font?: Font, margin?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, type?: AxisScaleType | undefined, valueMarginsEnabled?: boolean, valueType?: ChartsDataType | undefined, visible?: boolean, visualRange?: Array<Date | number | string> | CommonChartTypes.VisualRange, visualRangeUpdateMode?: ValueAxisVisualRangeUpdateMode, wholeRange?: Array<Date | number | string> | undefined | CommonChartTypes.VisualRange, width?: number }[]>;
+    @Output() valueAxisChange: EventEmitter<{ aggregatedPointsPosition?: AggregatedPointsPosition, allowDecimals?: boolean | undefined, autoBreaksEnabled?: boolean, axisDivisionFactor?: number, breaks?: Array<ScaleBreak> | undefined | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[], breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, categories?: Array<Date | number | string>, color?: string, constantLines?: { color?: string, dashStyle?: DashStyle, displayBehindSeries?: boolean, extendAxis?: boolean, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, text?: string | undefined, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, value?: Date | number | string | undefined, width?: number }[], constantLineStyle?: { color?: string, dashStyle?: DashStyle, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, position?: RelativePosition, verticalAlignment?: VerticalAlignment, visible?: boolean }, paddingLeftRight?: number, paddingTopBottom?: number, width?: number }, customPosition?: Date | number | string | undefined, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean | undefined, grid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, inverted?: boolean, label?: { alignment?: HorizontalAlignment | undefined, customizeHint?: ((axisValue: { value: Date | number | string, valueText: string }) => string), customizeText?: ((axisValue: { value: Date | number | string, valueText: string }) => string), displayMode?: ChartLabelDisplayMode, font?: Font, format?: Format | undefined, indentFromAxis?: number, overlappingBehavior?: ChartsAxisLabelOverlap, position?: Position | RelativePosition, rotationAngle?: number, staggeringSpacing?: number, template?: any, textOverflow?: TextOverflow, visible?: boolean, wordWrap?: WordWrap }, linearThreshold?: number | undefined, logarithmBase?: number, maxAutoBreakCount?: number, maxValueMargin?: number | undefined, minorGrid?: { color?: string, opacity?: number | undefined, visible?: boolean, width?: number }, minorTick?: { color?: string, length?: number, opacity?: number, shift?: number, visible?: boolean, width?: number }, minorTickCount?: number | undefined, minorTickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minValueMargin?: number | undefined, minVisualRangeLength?: number | TimeInterval | undefined | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, multipleAxesSpacing?: number, name?: string | undefined, offset?: number | undefined, opacity?: number | undefined, pane?: string | undefined, placeholderSize?: null | number, position?: Position, showZero?: boolean | undefined, strips?: { color?: string | undefined, endValue?: Date | number | string | undefined, label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, text?: string | undefined, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number, startValue?: Date | number | string | undefined }[], stripStyle?: { label?: { font?: Font, horizontalAlignment?: HorizontalAlignment, verticalAlignment?: VerticalAlignment }, paddingLeftRight?: number, paddingTopBottom?: number }, synchronizedValue?: number | undefined, tick?: { color?: string, length?: number, opacity?: number | undefined, shift?: number, visible?: boolean, width?: number }, tickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, title?: string | { alignment?: HorizontalAlignment, font?: Font, margin?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, type?: AxisScaleType | undefined, valueMarginsEnabled?: boolean, valueType?: ChartsDataType | undefined, visible?: boolean, visualRange?: Array<Date | number | string> | CommonChartTypes.VisualRange, visualRangeUpdateMode?: ValueAxisVisualRangeUpdateMode, wholeRange?: Array<Date | number | string> | undefined | CommonChartTypes.VisualRange, width?: number }[]>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/chart/nested/argument-axis.ts b/packages/devextreme-angular/src/ui/chart/nested/argument-axis.ts
index e0c4c807970a..c2c34db8b507 100644
--- a/packages/devextreme-angular/src/ui/chart/nested/argument-axis.ts
+++ b/packages/devextreme-angular/src/ui/chart/nested/argument-axis.ts
@@ -109,10 +109,10 @@ export class DxoChartArgumentAxisComponent extends NestedOption implements OnDes
     }
 
     @Input()
-    get breaks(): Array<ScaleBreak> | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[] {
+    get breaks(): Array<ScaleBreak> | undefined | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[] {
         return this._getOption('breaks');
     }
-    set breaks(value: Array<ScaleBreak> | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[]) {
+    set breaks(value: Array<ScaleBreak> | undefined | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[]) {
         this._setOption('breaks', value);
     }
 
@@ -197,10 +197,10 @@ export class DxoChartArgumentAxisComponent extends NestedOption implements OnDes
     }
 
     @Input()
-    get holidays(): Array<Date | string> | Array<number> {
+    get holidays(): Array<Date | string> | Array<number> | undefined {
         return this._getOption('holidays');
     }
-    set holidays(value: Array<Date | string> | Array<number>) {
+    set holidays(value: Array<Date | string> | Array<number> | undefined) {
         this._setOption('holidays', value);
     }
 
@@ -317,10 +317,10 @@ export class DxoChartArgumentAxisComponent extends NestedOption implements OnDes
     }
 
     @Input()
-    get placeholderSize(): number {
+    get placeholderSize(): null | number {
         return this._getOption('placeholderSize');
     }
-    set placeholderSize(value: number) {
+    set placeholderSize(value: null | number) {
         this._setOption('placeholderSize', value);
     }
 
@@ -333,10 +333,10 @@ export class DxoChartArgumentAxisComponent extends NestedOption implements OnDes
     }
 
     @Input()
-    get singleWorkdays(): Array<Date | string> | Array<number> {
+    get singleWorkdays(): Array<Date | string> | Array<number> | undefined {
         return this._getOption('singleWorkdays');
     }
-    set singleWorkdays(value: Array<Date | string> | Array<number>) {
+    set singleWorkdays(value: Array<Date | string> | Array<number> | undefined) {
         this._setOption('singleWorkdays', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/chart/nested/common-axis-settings.ts b/packages/devextreme-angular/src/ui/chart/nested/common-axis-settings.ts
index d6dbd4e16407..02d05dc0017c 100644
--- a/packages/devextreme-angular/src/ui/chart/nested/common-axis-settings.ts
+++ b/packages/devextreme-angular/src/ui/chart/nested/common-axis-settings.ts
@@ -154,10 +154,10 @@ export class DxoChartCommonAxisSettingsComponent extends NestedOption implements
     }
 
     @Input()
-    get placeholderSize(): number {
+    get placeholderSize(): null | number {
         return this._getOption('placeholderSize');
     }
-    set placeholderSize(value: number) {
+    set placeholderSize(value: null | number) {
         this._setOption('placeholderSize', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/chart/nested/legend-title-subtitle.ts b/packages/devextreme-angular/src/ui/chart/nested/legend-title-subtitle.ts
index dd914b855048..2a9f5c62dcf3 100644
--- a/packages/devextreme-angular/src/ui/chart/nested/legend-title-subtitle.ts
+++ b/packages/devextreme-angular/src/ui/chart/nested/legend-title-subtitle.ts
@@ -48,10 +48,10 @@ export class DxoChartLegendTitleSubtitleComponent extends NestedOption implement
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/chart/nested/legend-title.ts b/packages/devextreme-angular/src/ui/chart/nested/legend-title.ts
index 4dc8044f3941..4904afd78c0f 100644
--- a/packages/devextreme-angular/src/ui/chart/nested/legend-title.ts
+++ b/packages/devextreme-angular/src/ui/chart/nested/legend-title.ts
@@ -65,18 +65,18 @@ export class DxoChartLegendTitleComponent extends NestedOption implements OnDest
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/chart/nested/legend.ts b/packages/devextreme-angular/src/ui/chart/nested/legend.ts
index ee5a00e57fea..038351838d84 100644
--- a/packages/devextreme-angular/src/ui/chart/nested/legend.ts
+++ b/packages/devextreme-angular/src/ui/chart/nested/legend.ts
@@ -201,10 +201,10 @@ export class DxoChartLegendComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge } {
+    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge } {
         return this._getOption('title');
     }
-    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }) {
+    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }) {
         this._setOption('title', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/chart/nested/subtitle.ts b/packages/devextreme-angular/src/ui/chart/nested/subtitle.ts
index de666cab9d4d..45d34a2bee58 100644
--- a/packages/devextreme-angular/src/ui/chart/nested/subtitle.ts
+++ b/packages/devextreme-angular/src/ui/chart/nested/subtitle.ts
@@ -48,10 +48,10 @@ export class DxoChartSubtitleComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/chart/nested/title.ts b/packages/devextreme-angular/src/ui/chart/nested/title.ts
index 3dceb8b4df12..86fd0bd6398b 100644
--- a/packages/devextreme-angular/src/ui/chart/nested/title.ts
+++ b/packages/devextreme-angular/src/ui/chart/nested/title.ts
@@ -97,10 +97,10 @@ export class DxoChartTitleComponent extends NestedOption implements OnDestroy, O
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
         this._setOption('subtitle', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/chart/nested/value-axis-dxi.ts b/packages/devextreme-angular/src/ui/chart/nested/value-axis-dxi.ts
index 72a07d7de61f..e5f598e50a51 100644
--- a/packages/devextreme-angular/src/ui/chart/nested/value-axis-dxi.ts
+++ b/packages/devextreme-angular/src/ui/chart/nested/value-axis-dxi.ts
@@ -97,10 +97,10 @@ export class DxiChartValueAxisComponent extends CollectionNestedOption {
     }
 
     @Input()
-    get breaks(): Array<ScaleBreak> | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[] {
+    get breaks(): Array<ScaleBreak> | undefined | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[] {
         return this._getOption('breaks');
     }
-    set breaks(value: Array<ScaleBreak> | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[]) {
+    set breaks(value: Array<ScaleBreak> | undefined | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[]) {
         this._setOption('breaks', value);
     }
 
@@ -313,10 +313,10 @@ export class DxiChartValueAxisComponent extends CollectionNestedOption {
     }
 
     @Input()
-    get placeholderSize(): number {
+    get placeholderSize(): null | number {
         return this._getOption('placeholderSize');
     }
-    set placeholderSize(value: number) {
+    set placeholderSize(value: null | number) {
         this._setOption('placeholderSize', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/chat/nested/file-uploader-options.ts b/packages/devextreme-angular/src/ui/chat/nested/file-uploader-options.ts
index b71b10a2bcff..d1628274a300 100644
--- a/packages/devextreme-angular/src/ui/chat/nested/file-uploader-options.ts
+++ b/packages/devextreme-angular/src/ui/chat/nested/file-uploader-options.ts
@@ -244,10 +244,10 @@ export class DxoChatFileUploaderOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onBeforeSend(): ((e: BeforeSendEvent) => void) {
+    get onBeforeSend(): ((e: BeforeSendEvent) => void) | null {
         return this._getOption('onBeforeSend');
     }
-    set onBeforeSend(value: ((e: BeforeSendEvent) => void)) {
+    set onBeforeSend(value: ((e: BeforeSendEvent) => void) | null) {
         this._setOption('onBeforeSend', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoChatFileUploaderOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onDropZoneEnter(): ((e: DropZoneEnterEvent) => void) {
+    get onDropZoneEnter(): ((e: DropZoneEnterEvent) => void) | null {
         return this._getOption('onDropZoneEnter');
     }
-    set onDropZoneEnter(value: ((e: DropZoneEnterEvent) => void)) {
+    set onDropZoneEnter(value: ((e: DropZoneEnterEvent) => void) | null) {
         this._setOption('onDropZoneEnter', value);
     }
 
     @Input()
-    get onDropZoneLeave(): ((e: DropZoneLeaveEvent) => void) {
+    get onDropZoneLeave(): ((e: DropZoneLeaveEvent) => void) | null {
         return this._getOption('onDropZoneLeave');
     }
-    set onDropZoneLeave(value: ((e: DropZoneLeaveEvent) => void)) {
+    set onDropZoneLeave(value: ((e: DropZoneLeaveEvent) => void) | null) {
         this._setOption('onDropZoneLeave', value);
     }
 
     @Input()
-    get onFilesUploaded(): ((e: FilesUploadedEvent) => void) {
+    get onFilesUploaded(): ((e: FilesUploadedEvent) => void) | null {
         return this._getOption('onFilesUploaded');
     }
-    set onFilesUploaded(value: ((e: FilesUploadedEvent) => void)) {
+    set onFilesUploaded(value: ((e: FilesUploadedEvent) => void) | null) {
         this._setOption('onFilesUploaded', value);
     }
 
@@ -308,50 +308,50 @@ export class DxoChatFileUploaderOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onProgress(): ((e: ProgressEvent) => void) {
+    get onProgress(): ((e: ProgressEvent) => void) | null {
         return this._getOption('onProgress');
     }
-    set onProgress(value: ((e: ProgressEvent) => void)) {
+    set onProgress(value: ((e: ProgressEvent) => void) | null) {
         this._setOption('onProgress', value);
     }
 
     @Input()
-    get onUploadAborted(): ((e: UploadAbortedEvent) => void) {
+    get onUploadAborted(): ((e: UploadAbortedEvent) => void) | null {
         return this._getOption('onUploadAborted');
     }
-    set onUploadAborted(value: ((e: UploadAbortedEvent) => void)) {
+    set onUploadAborted(value: ((e: UploadAbortedEvent) => void) | null) {
         this._setOption('onUploadAborted', value);
     }
 
     @Input()
-    get onUploaded(): ((e: UploadedEvent) => void) {
+    get onUploaded(): ((e: UploadedEvent) => void) | null {
         return this._getOption('onUploaded');
     }
-    set onUploaded(value: ((e: UploadedEvent) => void)) {
+    set onUploaded(value: ((e: UploadedEvent) => void) | null) {
         this._setOption('onUploaded', value);
     }
 
     @Input()
-    get onUploadError(): ((e: UploadErrorEvent) => void) {
+    get onUploadError(): ((e: UploadErrorEvent) => void) | null {
         return this._getOption('onUploadError');
     }
-    set onUploadError(value: ((e: UploadErrorEvent) => void)) {
+    set onUploadError(value: ((e: UploadErrorEvent) => void) | null) {
         this._setOption('onUploadError', value);
     }
 
     @Input()
-    get onUploadStarted(): ((e: UploadStartedEvent) => void) {
+    get onUploadStarted(): ((e: UploadStartedEvent) => void) | null {
         return this._getOption('onUploadStarted');
     }
-    set onUploadStarted(value: ((e: UploadStartedEvent) => void)) {
+    set onUploadStarted(value: ((e: UploadStartedEvent) => void) | null) {
         this._setOption('onUploadStarted', value);
     }
 
     @Input()
-    get onValueChanged(): ((e: ValueChangedEvent) => void) {
+    get onValueChanged(): ((e: ValueChangedEvent) => void) | null {
         return this._getOption('onValueChanged');
     }
-    set onValueChanged(value: ((e: ValueChangedEvent) => void)) {
+    set onValueChanged(value: ((e: ValueChangedEvent) => void) | null) {
         this._setOption('onValueChanged', value);
     }
 
@@ -500,18 +500,18 @@ export class DxoChatFileUploaderOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/chat/nested/suggestions.ts b/packages/devextreme-angular/src/ui/chat/nested/suggestions.ts
index 9f72a9b4ed56..75c682e08651 100644
--- a/packages/devextreme-angular/src/ui/chat/nested/suggestions.ts
+++ b/packages/devextreme-angular/src/ui/chat/nested/suggestions.ts
@@ -158,10 +158,10 @@ export class DxoChatSuggestionsComponent extends NestedOption implements OnDestr
     }
 
     @Input()
-    get onItemClick(): ((e: ItemClickEvent) => void) {
+    get onItemClick(): ((e: ItemClickEvent) => void) | null {
         return this._getOption('onItemClick');
     }
-    set onItemClick(value: ((e: ItemClickEvent) => void)) {
+    set onItemClick(value: ((e: ItemClickEvent) => void) | null) {
         this._setOption('onItemClick', value);
     }
 
@@ -174,10 +174,10 @@ export class DxoChatSuggestionsComponent extends NestedOption implements OnDestr
     }
 
     @Input()
-    get onSelectionChanged(): ((e: SelectionChangedEvent) => void) {
+    get onSelectionChanged(): ((e: SelectionChangedEvent) => void) | null {
         return this._getOption('onSelectionChanged');
     }
-    set onSelectionChanged(value: ((e: SelectionChangedEvent) => void)) {
+    set onSelectionChanged(value: ((e: SelectionChangedEvent) => void) | null) {
         this._setOption('onSelectionChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/check-box/index.ts b/packages/devextreme-angular/src/ui/check-box/index.ts
index 1cce6c322c1f..10563609d400 100644
--- a/packages/devextreme-angular/src/ui/check-box/index.ts
+++ b/packages/devextreme-angular/src/ui/check-box/index.ts
@@ -298,10 +298,10 @@ export class DxCheckBoxComponent extends DxComponent implements OnDestroy, Contr
     
      */
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
@@ -311,10 +311,10 @@ export class DxCheckBoxComponent extends DxComponent implements OnDestroy, Contr
     
      */
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
@@ -363,10 +363,10 @@ export class DxCheckBoxComponent extends DxComponent implements OnDestroy, Contr
     
      */
     @Input()
-    get value(): boolean | null | undefined {
+    get value(): boolean | null {
         return this._getOption('value');
     }
-    set value(value: boolean | null | undefined) {
+    set value(value: boolean | null) {
         this._setOption('value', value);
     }
 
@@ -560,14 +560,14 @@ export class DxCheckBoxComponent extends DxComponent implements OnDestroy, Contr
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorChange: EventEmitter<any>;
+    @Output() validationErrorChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorsChange: EventEmitter<Array<any>>;
+    @Output() validationErrorsChange: EventEmitter<Array<any> | null>;
 
     /**
     
@@ -595,7 +595,7 @@ export class DxCheckBoxComponent extends DxComponent implements OnDestroy, Contr
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() valueChange: EventEmitter<boolean | null | undefined>;
+    @Output() valueChange: EventEmitter<boolean | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/circular-gauge/index.ts b/packages/devextreme-angular/src/ui/circular-gauge/index.ts
index f439065baa64..97d4ec123aa8 100644
--- a/packages/devextreme-angular/src/ui/circular-gauge/index.ts
+++ b/packages/devextreme-angular/src/ui/circular-gauge/index.ts
@@ -296,10 +296,10 @@ export class DxCircularGaugeComponent extends DxComponent implements OnDestroy,
     
      */
     @Input()
-    get scale(): { allowDecimals?: boolean | undefined, customMinorTicks?: Array<number>, customTicks?: Array<number>, endValue?: number, label?: { customizeText?: ((scaleValue: { value: number, valueText: string }) => string), font?: Font, format?: Format | undefined, hideFirstOrLast?: CircularGaugeLabelOverlap, indentFromTick?: number, overlappingBehavior?: LabelOverlap, useRangeColors?: boolean, visible?: boolean }, minorTick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, minorTickInterval?: number | undefined, orientation?: CircularGaugeElementOrientation, scaleDivisionFactor?: number, startValue?: number, tick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, tickInterval?: number | undefined } {
+    get scale(): { allowDecimals?: boolean | undefined, customMinorTicks?: Array<number> | undefined, customTicks?: Array<number> | undefined, endValue?: number, label?: { customizeText?: ((scaleValue: { value: number, valueText: string }) => string), font?: Font, format?: Format | undefined, hideFirstOrLast?: CircularGaugeLabelOverlap, indentFromTick?: number, overlappingBehavior?: LabelOverlap, useRangeColors?: boolean, visible?: boolean }, minorTick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, minorTickInterval?: number | undefined, orientation?: CircularGaugeElementOrientation, scaleDivisionFactor?: number, startValue?: number, tick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, tickInterval?: number | undefined } {
         return this._getOption('scale');
     }
-    set scale(value: { allowDecimals?: boolean | undefined, customMinorTicks?: Array<number>, customTicks?: Array<number>, endValue?: number, label?: { customizeText?: ((scaleValue: { value: number, valueText: string }) => string), font?: Font, format?: Format | undefined, hideFirstOrLast?: CircularGaugeLabelOverlap, indentFromTick?: number, overlappingBehavior?: LabelOverlap, useRangeColors?: boolean, visible?: boolean }, minorTick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, minorTickInterval?: number | undefined, orientation?: CircularGaugeElementOrientation, scaleDivisionFactor?: number, startValue?: number, tick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, tickInterval?: number | undefined }) {
+    set scale(value: { allowDecimals?: boolean | undefined, customMinorTicks?: Array<number> | undefined, customTicks?: Array<number> | undefined, endValue?: number, label?: { customizeText?: ((scaleValue: { value: number, valueText: string }) => string), font?: Font, format?: Format | undefined, hideFirstOrLast?: CircularGaugeLabelOverlap, indentFromTick?: number, overlappingBehavior?: LabelOverlap, useRangeColors?: boolean, visible?: boolean }, minorTick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, minorTickInterval?: number | undefined, orientation?: CircularGaugeElementOrientation, scaleDivisionFactor?: number, startValue?: number, tick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, tickInterval?: number | undefined }) {
         this._setOption('scale', value);
     }
 
@@ -335,10 +335,10 @@ export class DxCircularGaugeComponent extends DxComponent implements OnDestroy,
     
      */
     @Input()
-    get subvalues(): Array<number> {
+    get subvalues(): Array<number> | undefined {
         return this._getOption('subvalues');
     }
-    set subvalues(value: Array<number>) {
+    set subvalues(value: Array<number> | undefined) {
         this._setOption('subvalues', value);
     }
 
@@ -583,7 +583,7 @@ export class DxCircularGaugeComponent extends DxComponent implements OnDestroy,
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() scaleChange: EventEmitter<{ allowDecimals?: boolean | undefined, customMinorTicks?: Array<number>, customTicks?: Array<number>, endValue?: number, label?: { customizeText?: ((scaleValue: { value: number, valueText: string }) => string), font?: Font, format?: Format | undefined, hideFirstOrLast?: CircularGaugeLabelOverlap, indentFromTick?: number, overlappingBehavior?: LabelOverlap, useRangeColors?: boolean, visible?: boolean }, minorTick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, minorTickInterval?: number | undefined, orientation?: CircularGaugeElementOrientation, scaleDivisionFactor?: number, startValue?: number, tick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, tickInterval?: number | undefined }>;
+    @Output() scaleChange: EventEmitter<{ allowDecimals?: boolean | undefined, customMinorTicks?: Array<number> | undefined, customTicks?: Array<number> | undefined, endValue?: number, label?: { customizeText?: ((scaleValue: { value: number, valueText: string }) => string), font?: Font, format?: Format | undefined, hideFirstOrLast?: CircularGaugeLabelOverlap, indentFromTick?: number, overlappingBehavior?: LabelOverlap, useRangeColors?: boolean, visible?: boolean }, minorTick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, minorTickInterval?: number | undefined, orientation?: CircularGaugeElementOrientation, scaleDivisionFactor?: number, startValue?: number, tick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, tickInterval?: number | undefined }>;
 
     /**
     
@@ -604,7 +604,7 @@ export class DxCircularGaugeComponent extends DxComponent implements OnDestroy,
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() subvaluesChange: EventEmitter<Array<number>>;
+    @Output() subvaluesChange: EventEmitter<Array<number> | undefined>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/circular-gauge/nested/scale.ts b/packages/devextreme-angular/src/ui/circular-gauge/nested/scale.ts
index 239c6b4be532..691d7769e23f 100644
--- a/packages/devextreme-angular/src/ui/circular-gauge/nested/scale.ts
+++ b/packages/devextreme-angular/src/ui/circular-gauge/nested/scale.ts
@@ -42,18 +42,18 @@ export class DxoCircularGaugeScaleComponent extends NestedOption implements OnDe
     }
 
     @Input()
-    get customMinorTicks(): Array<number> {
+    get customMinorTicks(): Array<number> | undefined {
         return this._getOption('customMinorTicks');
     }
-    set customMinorTicks(value: Array<number>) {
+    set customMinorTicks(value: Array<number> | undefined) {
         this._setOption('customMinorTicks', value);
     }
 
     @Input()
-    get customTicks(): Array<number> {
+    get customTicks(): Array<number> | undefined {
         return this._getOption('customTicks');
     }
-    set customTicks(value: Array<number>) {
+    set customTicks(value: Array<number> | undefined) {
         this._setOption('customTicks', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/color-box/index.ts b/packages/devextreme-angular/src/ui/color-box/index.ts
index 20d2c0adaf08..6092c2410fa2 100644
--- a/packages/devextreme-angular/src/ui/color-box/index.ts
+++ b/packages/devextreme-angular/src/ui/color-box/index.ts
@@ -191,10 +191,10 @@ export class DxColorBoxComponent extends DxComponent implements OnDestroy, Contr
     
      */
     @Input()
-    get buttons(): Array<DropDownPredefinedButton | TextEditorButton> {
+    get buttons(): Array<DropDownPredefinedButton | TextEditorButton> | undefined {
         return this._getOption('buttons');
     }
-    set buttons(value: Array<DropDownPredefinedButton | TextEditorButton>) {
+    set buttons(value: Array<DropDownPredefinedButton | TextEditorButton> | undefined) {
         this._setOption('buttons', value);
     }
 
@@ -596,10 +596,10 @@ export class DxColorBoxComponent extends DxComponent implements OnDestroy, Contr
     
      */
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
@@ -609,10 +609,10 @@ export class DxColorBoxComponent extends DxComponent implements OnDestroy, Contr
     
      */
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
@@ -862,7 +862,7 @@ export class DxColorBoxComponent extends DxComponent implements OnDestroy, Contr
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() buttonsChange: EventEmitter<Array<DropDownPredefinedButton | TextEditorButton>>;
+    @Output() buttonsChange: EventEmitter<Array<DropDownPredefinedButton | TextEditorButton> | undefined>;
 
     /**
     
@@ -1079,14 +1079,14 @@ export class DxColorBoxComponent extends DxComponent implements OnDestroy, Contr
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorChange: EventEmitter<any>;
+    @Output() validationErrorChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorsChange: EventEmitter<Array<any>>;
+    @Output() validationErrorsChange: EventEmitter<Array<any> | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/color-box/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/color-box/nested/drop-down-options.ts
index 77a9990d9696..a3b5b32236bb 100644
--- a/packages/devextreme-angular/src/ui/color-box/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/color-box/nested/drop-down-options.ts
@@ -220,10 +220,10 @@ export class DxoColorBoxDropDownOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) {
+    get onContentReady(): ((e: EventInfo<any>) => void) | null {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void)) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoColorBoxDropDownOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoColorBoxDropDownOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/color-box/nested/options.ts b/packages/devextreme-angular/src/ui/color-box/nested/options.ts
index 750ca7ef6b0a..4b4e6a67c349 100644
--- a/packages/devextreme-angular/src/ui/color-box/nested/options.ts
+++ b/packages/devextreme-angular/src/ui/color-box/nested/options.ts
@@ -114,10 +114,10 @@ export class DxoColorBoxOptionsComponent extends NestedOption implements AfterVi
     }
 
     @Input()
-    get onClick(): ((e: ClickEvent) => void) {
+    get onClick(): ((e: ClickEvent) => void) | undefined {
         return this._getOption('onClick');
     }
-    set onClick(value: ((e: ClickEvent) => void)) {
+    set onClick(value: ((e: ClickEvent) => void) | undefined) {
         this._setOption('onClick', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/context-menu/index.ts b/packages/devextreme-angular/src/ui/context-menu/index.ts
index b5739b849ed0..37784f2ecb52 100644
--- a/packages/devextreme-angular/src/ui/context-menu/index.ts
+++ b/packages/devextreme-angular/src/ui/context-menu/index.ts
@@ -383,10 +383,10 @@ export class DxContextMenuComponent<TItem = any, TKey = any> extends DxComponent
     
      */
     @Input()
-    get selectedItem(): any {
+    get selectedItem(): any | null {
         return this._getOption('selectedItem');
     }
-    set selectedItem(value: any) {
+    set selectedItem(value: any | null) {
         this._setOption('selectedItem', value);
     }
 
@@ -750,7 +750,7 @@ export class DxContextMenuComponent<TItem = any, TKey = any> extends DxComponent
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() selectedItemChange: EventEmitter<any>;
+    @Output() selectedItemChange: EventEmitter<any | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/data-grid/nested/button-options.ts b/packages/devextreme-angular/src/ui/data-grid/nested/button-options.ts
index 79a74641cc5c..9a0493dccb43 100644
--- a/packages/devextreme-angular/src/ui/data-grid/nested/button-options.ts
+++ b/packages/devextreme-angular/src/ui/data-grid/nested/button-options.ts
@@ -114,10 +114,10 @@ export class DxoDataGridButtonOptionsComponent extends NestedOption implements A
     }
 
     @Input()
-    get onClick(): ((e: ClickEvent) => void) {
+    get onClick(): ((e: ClickEvent) => void) | undefined {
         return this._getOption('onClick');
     }
-    set onClick(value: ((e: ClickEvent) => void)) {
+    set onClick(value: ((e: ClickEvent) => void) | undefined) {
         this._setOption('onClick', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/data-grid/nested/editor-options.ts b/packages/devextreme-angular/src/ui/data-grid/nested/editor-options.ts
index 192029a59ccc..465c004587e0 100644
--- a/packages/devextreme-angular/src/ui/data-grid/nested/editor-options.ts
+++ b/packages/devextreme-angular/src/ui/data-grid/nested/editor-options.ts
@@ -62,10 +62,10 @@ export class DxoDataGridEditorOptionsComponent extends NestedOption implements O
     }
 
     @Input()
-    get buttons(): Array<string | TextBoxPredefinedButton | TextEditorButton> {
+    get buttons(): Array<string | TextBoxPredefinedButton | TextEditorButton> | undefined {
         return this._getOption('buttons');
     }
-    set buttons(value: Array<string | TextBoxPredefinedButton | TextEditorButton>) {
+    set buttons(value: Array<string | TextBoxPredefinedButton | TextEditorButton> | undefined) {
         this._setOption('buttons', value);
     }
 
@@ -190,10 +190,10 @@ export class DxoDataGridEditorOptionsComponent extends NestedOption implements O
     }
 
     @Input()
-    get maxLength(): number | string {
+    get maxLength(): null | number | string {
         return this._getOption('maxLength');
     }
-    set maxLength(value: number | string) {
+    set maxLength(value: null | number | string) {
         this._setOption('maxLength', value);
     }
 
@@ -414,18 +414,18 @@ export class DxoDataGridEditorOptionsComponent extends NestedOption implements O
     }
 
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/data-grid/nested/filter-builder-popup.ts b/packages/devextreme-angular/src/ui/data-grid/nested/filter-builder-popup.ts
index 73fc0fb98d47..69e55be0d73b 100644
--- a/packages/devextreme-angular/src/ui/data-grid/nested/filter-builder-popup.ts
+++ b/packages/devextreme-angular/src/ui/data-grid/nested/filter-builder-popup.ts
@@ -220,10 +220,10 @@ export class DxoDataGridFilterBuilderPopupComponent extends NestedOption impleme
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) {
+    get onContentReady(): ((e: EventInfo<any>) => void) | null {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void)) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoDataGridFilterBuilderPopupComponent extends NestedOption impleme
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoDataGridFilterBuilderPopupComponent extends NestedOption impleme
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/data-grid/nested/options.ts b/packages/devextreme-angular/src/ui/data-grid/nested/options.ts
index b63ffa0174d4..92a7df7ca994 100644
--- a/packages/devextreme-angular/src/ui/data-grid/nested/options.ts
+++ b/packages/devextreme-angular/src/ui/data-grid/nested/options.ts
@@ -114,10 +114,10 @@ export class DxoDataGridOptionsComponent extends NestedOption implements AfterVi
     }
 
     @Input()
-    get onClick(): ((e: ClickEvent) => void) {
+    get onClick(): ((e: ClickEvent) => void) | undefined {
         return this._getOption('onClick');
     }
-    set onClick(value: ((e: ClickEvent) => void)) {
+    set onClick(value: ((e: ClickEvent) => void) | undefined) {
         this._setOption('onClick', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/data-grid/nested/popup.ts b/packages/devextreme-angular/src/ui/data-grid/nested/popup.ts
index 431d28a24541..96b0f4e18ae3 100644
--- a/packages/devextreme-angular/src/ui/data-grid/nested/popup.ts
+++ b/packages/devextreme-angular/src/ui/data-grid/nested/popup.ts
@@ -220,10 +220,10 @@ export class DxoDataGridPopupComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) {
+    get onContentReady(): ((e: EventInfo<any>) => void) | null {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void)) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoDataGridPopupComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoDataGridPopupComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/data-grid/nested/tab-panel-options.ts b/packages/devextreme-angular/src/ui/data-grid/nested/tab-panel-options.ts
index 98901506fe79..73d97410ec3e 100644
--- a/packages/devextreme-angular/src/ui/data-grid/nested/tab-panel-options.ts
+++ b/packages/devextreme-angular/src/ui/data-grid/nested/tab-panel-options.ts
@@ -288,18 +288,18 @@ export class DxoDataGridTabPanelOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onTitleHold(): ((e: TitleHoldEvent) => void) {
+    get onTitleHold(): ((e: TitleHoldEvent) => void) | null {
         return this._getOption('onTitleHold');
     }
-    set onTitleHold(value: ((e: TitleHoldEvent) => void)) {
+    set onTitleHold(value: ((e: TitleHoldEvent) => void) | null) {
         this._setOption('onTitleHold', value);
     }
 
     @Input()
-    get onTitleRendered(): ((e: TitleRenderedEvent) => void) {
+    get onTitleRendered(): ((e: TitleRenderedEvent) => void) | null {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: TitleRenderedEvent) => void)) {
+    set onTitleRendered(value: ((e: TitleRenderedEvent) => void) | null) {
         this._setOption('onTitleRendered', value);
     }
 
@@ -344,10 +344,10 @@ export class DxoDataGridTabPanelOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get selectedItem(): any {
+    get selectedItem(): any | null {
         return this._getOption('selectedItem');
     }
-    set selectedItem(value: any) {
+    set selectedItem(value: any | null) {
         this._setOption('selectedItem', value);
     }
 
@@ -427,7 +427,7 @@ export class DxoDataGridTabPanelOptionsComponent extends NestedOption implements
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() selectedItemChange: EventEmitter<any>;
+    @Output() selectedItemChange: EventEmitter<any | null>;
     protected get _optionPath() {
         return 'tabPanelOptions';
     }
diff --git a/packages/devextreme-angular/src/ui/date-box/index.ts b/packages/devextreme-angular/src/ui/date-box/index.ts
index 744438fb238e..c5c81e7e990a 100644
--- a/packages/devextreme-angular/src/ui/date-box/index.ts
+++ b/packages/devextreme-angular/src/ui/date-box/index.ts
@@ -209,10 +209,10 @@ export class DxDateBoxComponent extends DxComponent implements OnDestroy, Contro
     
      */
     @Input()
-    get buttons(): Array<DropDownPredefinedButton | TextEditorButton> {
+    get buttons(): Array<DropDownPredefinedButton | TextEditorButton> | undefined {
         return this._getOption('buttons');
     }
-    set buttons(value: Array<DropDownPredefinedButton | TextEditorButton>) {
+    set buttons(value: Array<DropDownPredefinedButton | TextEditorButton> | undefined) {
         this._setOption('buttons', value);
     }
 
@@ -300,10 +300,10 @@ export class DxDateBoxComponent extends DxComponent implements OnDestroy, Contro
     
      */
     @Input()
-    get disabledDates(): Array<Date> | ((data: { component: dxDateBox, date: Date, view: string }) => boolean) {
+    get disabledDates(): Array<Date> | ((data: { component: dxDateBox, date: Date, view: string }) => boolean) | null {
         return this._getOption('disabledDates');
     }
-    set disabledDates(value: Array<Date> | ((data: { component: dxDateBox, date: Date, view: string }) => boolean)) {
+    set disabledDates(value: Array<Date> | ((data: { component: dxDateBox, date: Date, view: string }) => boolean) | null) {
         this._setOption('disabledDates', value);
     }
 
@@ -313,10 +313,10 @@ export class DxDateBoxComponent extends DxComponent implements OnDestroy, Contro
     
      */
     @Input()
-    get displayFormat(): Format {
+    get displayFormat(): Format | null {
         return this._getOption('displayFormat');
     }
-    set displayFormat(value: Format) {
+    set displayFormat(value: Format | null) {
         this._setOption('displayFormat', value);
     }
 
@@ -521,10 +521,10 @@ export class DxDateBoxComponent extends DxComponent implements OnDestroy, Contro
     
      */
     @Input()
-    get maxLength(): number | string {
+    get maxLength(): null | number | string {
         return this._getOption('maxLength');
     }
-    set maxLength(value: number | string) {
+    set maxLength(value: null | number | string) {
         this._setOption('maxLength', value);
     }
 
@@ -768,10 +768,10 @@ export class DxDateBoxComponent extends DxComponent implements OnDestroy, Contro
     
      */
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
@@ -781,10 +781,10 @@ export class DxDateBoxComponent extends DxComponent implements OnDestroy, Contro
     
      */
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
@@ -1062,7 +1062,7 @@ export class DxDateBoxComponent extends DxComponent implements OnDestroy, Contro
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() buttonsChange: EventEmitter<Array<DropDownPredefinedButton | TextEditorButton>>;
+    @Output() buttonsChange: EventEmitter<Array<DropDownPredefinedButton | TextEditorButton> | undefined>;
 
     /**
     
@@ -1111,14 +1111,14 @@ export class DxDateBoxComponent extends DxComponent implements OnDestroy, Contro
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() disabledDatesChange: EventEmitter<Array<Date> | ((data: { component: dxDateBox, date: Date, view: string }) => boolean)>;
+    @Output() disabledDatesChange: EventEmitter<Array<Date> | ((data: { component: dxDateBox, date: Date, view: string }) => boolean) | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() displayFormatChange: EventEmitter<Format>;
+    @Output() displayFormatChange: EventEmitter<Format | null>;
 
     /**
     
@@ -1230,7 +1230,7 @@ export class DxDateBoxComponent extends DxComponent implements OnDestroy, Contro
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() maxLengthChange: EventEmitter<number | string>;
+    @Output() maxLengthChange: EventEmitter<null | number | string>;
 
     /**
     
@@ -1363,14 +1363,14 @@ export class DxDateBoxComponent extends DxComponent implements OnDestroy, Contro
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorChange: EventEmitter<any>;
+    @Output() validationErrorChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorsChange: EventEmitter<Array<any>>;
+    @Output() validationErrorsChange: EventEmitter<Array<any> | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/date-box/nested/calendar-options.ts b/packages/devextreme-angular/src/ui/date-box/nested/calendar-options.ts
index 2ed403d02ea2..4fe7e083e1cb 100644
--- a/packages/devextreme-angular/src/ui/date-box/nested/calendar-options.ts
+++ b/packages/devextreme-angular/src/ui/date-box/nested/calendar-options.ts
@@ -75,10 +75,10 @@ export class DxoDateBoxCalendarOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get disabledDates(): Array<Date> | ((data: DisabledDate) => boolean) {
+    get disabledDates(): Array<Date> | ((data: DisabledDate) => boolean) | null {
         return this._getOption('disabledDates');
     }
-    set disabledDates(value: Array<Date> | ((data: DisabledDate) => boolean)) {
+    set disabledDates(value: Array<Date> | ((data: DisabledDate) => boolean) | null) {
         this._setOption('disabledDates', value);
     }
 
@@ -283,18 +283,18 @@ export class DxoDateBoxCalendarOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/date-box/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/date-box/nested/drop-down-options.ts
index d3af22341acd..84febd31181e 100644
--- a/packages/devextreme-angular/src/ui/date-box/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/date-box/nested/drop-down-options.ts
@@ -220,10 +220,10 @@ export class DxoDateBoxDropDownOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) {
+    get onContentReady(): ((e: EventInfo<any>) => void) | null {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void)) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoDateBoxDropDownOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoDateBoxDropDownOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/date-box/nested/options.ts b/packages/devextreme-angular/src/ui/date-box/nested/options.ts
index 492bb57d5203..15b64f6e0b6b 100644
--- a/packages/devextreme-angular/src/ui/date-box/nested/options.ts
+++ b/packages/devextreme-angular/src/ui/date-box/nested/options.ts
@@ -114,10 +114,10 @@ export class DxoDateBoxOptionsComponent extends NestedOption implements AfterVie
     }
 
     @Input()
-    get onClick(): ((e: ClickEvent) => void) {
+    get onClick(): ((e: ClickEvent) => void) | undefined {
         return this._getOption('onClick');
     }
-    set onClick(value: ((e: ClickEvent) => void)) {
+    set onClick(value: ((e: ClickEvent) => void) | undefined) {
         this._setOption('onClick', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/date-range-box/index.ts b/packages/devextreme-angular/src/ui/date-range-box/index.ts
index 5b40ba0eaed4..c4da13876682 100644
--- a/packages/devextreme-angular/src/ui/date-range-box/index.ts
+++ b/packages/devextreme-angular/src/ui/date-range-box/index.ts
@@ -196,10 +196,10 @@ export class DxDateRangeBoxComponent extends DxComponent implements OnDestroy, C
     
      */
     @Input()
-    get buttons(): Array<DropDownPredefinedButton | TextEditorButton> {
+    get buttons(): Array<DropDownPredefinedButton | TextEditorButton> | undefined {
         return this._getOption('buttons');
     }
-    set buttons(value: Array<DropDownPredefinedButton | TextEditorButton>) {
+    set buttons(value: Array<DropDownPredefinedButton | TextEditorButton> | undefined) {
         this._setOption('buttons', value);
     }
 
@@ -287,10 +287,10 @@ export class DxDateRangeBoxComponent extends DxComponent implements OnDestroy, C
     
      */
     @Input()
-    get displayFormat(): Format {
+    get displayFormat(): Format | null {
         return this._getOption('displayFormat');
     }
-    set displayFormat(value: Format) {
+    set displayFormat(value: Format | null) {
         this._setOption('displayFormat', value);
     }
 
@@ -820,10 +820,10 @@ export class DxDateRangeBoxComponent extends DxComponent implements OnDestroy, C
     
      */
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
@@ -833,10 +833,10 @@ export class DxDateRangeBoxComponent extends DxComponent implements OnDestroy, C
     
      */
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
@@ -1107,7 +1107,7 @@ export class DxDateRangeBoxComponent extends DxComponent implements OnDestroy, C
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() buttonsChange: EventEmitter<Array<DropDownPredefinedButton | TextEditorButton>>;
+    @Output() buttonsChange: EventEmitter<Array<DropDownPredefinedButton | TextEditorButton> | undefined>;
 
     /**
     
@@ -1156,7 +1156,7 @@ export class DxDateRangeBoxComponent extends DxComponent implements OnDestroy, C
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() displayFormatChange: EventEmitter<Format>;
+    @Output() displayFormatChange: EventEmitter<Format | null>;
 
     /**
     
@@ -1443,14 +1443,14 @@ export class DxDateRangeBoxComponent extends DxComponent implements OnDestroy, C
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorChange: EventEmitter<any>;
+    @Output() validationErrorChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorsChange: EventEmitter<Array<any>>;
+    @Output() validationErrorsChange: EventEmitter<Array<any> | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/date-range-box/nested/calendar-options.ts b/packages/devextreme-angular/src/ui/date-range-box/nested/calendar-options.ts
index 963d1af9e858..446c000809e0 100644
--- a/packages/devextreme-angular/src/ui/date-range-box/nested/calendar-options.ts
+++ b/packages/devextreme-angular/src/ui/date-range-box/nested/calendar-options.ts
@@ -75,10 +75,10 @@ export class DxoDateRangeBoxCalendarOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get disabledDates(): Array<Date> | ((data: DisabledDate) => boolean) {
+    get disabledDates(): Array<Date> | ((data: DisabledDate) => boolean) | null {
         return this._getOption('disabledDates');
     }
-    set disabledDates(value: Array<Date> | ((data: DisabledDate) => boolean)) {
+    set disabledDates(value: Array<Date> | ((data: DisabledDate) => boolean) | null) {
         this._setOption('disabledDates', value);
     }
 
@@ -283,18 +283,18 @@ export class DxoDateRangeBoxCalendarOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/date-range-box/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/date-range-box/nested/drop-down-options.ts
index 0df76fe7c323..356e06d41ea8 100644
--- a/packages/devextreme-angular/src/ui/date-range-box/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/date-range-box/nested/drop-down-options.ts
@@ -220,10 +220,10 @@ export class DxoDateRangeBoxDropDownOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) {
+    get onContentReady(): ((e: EventInfo<any>) => void) | null {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void)) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoDateRangeBoxDropDownOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoDateRangeBoxDropDownOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/date-range-box/nested/options.ts b/packages/devextreme-angular/src/ui/date-range-box/nested/options.ts
index eead7f296ddb..644bebf5a018 100644
--- a/packages/devextreme-angular/src/ui/date-range-box/nested/options.ts
+++ b/packages/devextreme-angular/src/ui/date-range-box/nested/options.ts
@@ -114,10 +114,10 @@ export class DxoDateRangeBoxOptionsComponent extends NestedOption implements Aft
     }
 
     @Input()
-    get onClick(): ((e: ClickEvent) => void) {
+    get onClick(): ((e: ClickEvent) => void) | undefined {
         return this._getOption('onClick');
     }
-    set onClick(value: ((e: ClickEvent) => void)) {
+    set onClick(value: ((e: ClickEvent) => void) | undefined) {
         this._setOption('onClick', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/drawer/index.ts b/packages/devextreme-angular/src/ui/drawer/index.ts
index a69211c9ac35..9f7dfb82725f 100644
--- a/packages/devextreme-angular/src/ui/drawer/index.ts
+++ b/packages/devextreme-angular/src/ui/drawer/index.ts
@@ -176,10 +176,10 @@ export class DxDrawerComponent extends DxComponent implements OnDestroy {
     
      */
     @Input()
-    get maxSize(): number {
+    get maxSize(): null | number {
         return this._getOption('maxSize');
     }
-    set maxSize(value: number) {
+    set maxSize(value: null | number) {
         this._setOption('maxSize', value);
     }
 
@@ -189,10 +189,10 @@ export class DxDrawerComponent extends DxComponent implements OnDestroy {
     
      */
     @Input()
-    get minSize(): number {
+    get minSize(): null | number {
         return this._getOption('minSize');
     }
-    set minSize(value: number) {
+    set minSize(value: null | number) {
         this._setOption('minSize', value);
     }
 
@@ -405,14 +405,14 @@ export class DxDrawerComponent extends DxComponent implements OnDestroy {
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() maxSizeChange: EventEmitter<number>;
+    @Output() maxSizeChange: EventEmitter<null | number>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() minSizeChange: EventEmitter<number>;
+    @Output() minSizeChange: EventEmitter<null | number>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/drop-down-box/index.ts b/packages/devextreme-angular/src/ui/drop-down-box/index.ts
index 41df829baca4..42e3bb39fde4 100644
--- a/packages/devextreme-angular/src/ui/drop-down-box/index.ts
+++ b/packages/devextreme-angular/src/ui/drop-down-box/index.ts
@@ -174,10 +174,10 @@ export class DxDropDownBoxComponent extends DxComponent implements OnDestroy, Co
     
      */
     @Input()
-    get buttons(): Array<DropDownPredefinedButton | TextEditorButton> {
+    get buttons(): Array<DropDownPredefinedButton | TextEditorButton> | undefined {
         return this._getOption('buttons');
     }
-    set buttons(value: Array<DropDownPredefinedButton | TextEditorButton>) {
+    set buttons(value: Array<DropDownPredefinedButton | TextEditorButton> | undefined) {
         this._setOption('buttons', value);
     }
 
@@ -462,10 +462,10 @@ export class DxDropDownBoxComponent extends DxComponent implements OnDestroy, Co
     
      */
     @Input()
-    get maxLength(): number | string {
+    get maxLength(): null | number | string {
         return this._getOption('maxLength');
     }
-    set maxLength(value: number | string) {
+    set maxLength(value: null | number | string) {
         this._setOption('maxLength', value);
     }
 
@@ -618,10 +618,10 @@ export class DxDropDownBoxComponent extends DxComponent implements OnDestroy, Co
     
      */
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
@@ -631,10 +631,10 @@ export class DxDropDownBoxComponent extends DxComponent implements OnDestroy, Co
     
      */
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
@@ -683,10 +683,10 @@ export class DxDropDownBoxComponent extends DxComponent implements OnDestroy, Co
     
      */
     @Input()
-    get value(): any {
+    get value(): any | null {
         return this._getOption('value');
     }
-    set value(value: any) {
+    set value(value: any | null) {
         this._setOption('value', value);
     }
 
@@ -896,7 +896,7 @@ export class DxDropDownBoxComponent extends DxComponent implements OnDestroy, Co
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() buttonsChange: EventEmitter<Array<DropDownPredefinedButton | TextEditorButton>>;
+    @Output() buttonsChange: EventEmitter<Array<DropDownPredefinedButton | TextEditorButton> | undefined>;
 
     /**
     
@@ -1050,7 +1050,7 @@ export class DxDropDownBoxComponent extends DxComponent implements OnDestroy, Co
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() maxLengthChange: EventEmitter<number | string>;
+    @Output() maxLengthChange: EventEmitter<null | number | string>;
 
     /**
     
@@ -1134,14 +1134,14 @@ export class DxDropDownBoxComponent extends DxComponent implements OnDestroy, Co
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorChange: EventEmitter<any>;
+    @Output() validationErrorChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorsChange: EventEmitter<Array<any>>;
+    @Output() validationErrorsChange: EventEmitter<Array<any> | null>;
 
     /**
     
@@ -1169,7 +1169,7 @@ export class DxDropDownBoxComponent extends DxComponent implements OnDestroy, Co
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() valueChange: EventEmitter<any>;
+    @Output() valueChange: EventEmitter<any | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/drop-down-box/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/drop-down-box/nested/drop-down-options.ts
index 72889a5c3b39..a8df643dbbee 100644
--- a/packages/devextreme-angular/src/ui/drop-down-box/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/drop-down-box/nested/drop-down-options.ts
@@ -220,10 +220,10 @@ export class DxoDropDownBoxDropDownOptionsComponent extends NestedOption impleme
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) {
+    get onContentReady(): ((e: EventInfo<any>) => void) | null {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void)) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoDropDownBoxDropDownOptionsComponent extends NestedOption impleme
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoDropDownBoxDropDownOptionsComponent extends NestedOption impleme
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/drop-down-box/nested/options.ts b/packages/devextreme-angular/src/ui/drop-down-box/nested/options.ts
index 52da86650fd1..c19e6c269c68 100644
--- a/packages/devextreme-angular/src/ui/drop-down-box/nested/options.ts
+++ b/packages/devextreme-angular/src/ui/drop-down-box/nested/options.ts
@@ -114,10 +114,10 @@ export class DxoDropDownBoxOptionsComponent extends NestedOption implements Afte
     }
 
     @Input()
-    get onClick(): ((e: ClickEvent) => void) {
+    get onClick(): ((e: ClickEvent) => void) | undefined {
         return this._getOption('onClick');
     }
-    set onClick(value: ((e: ClickEvent) => void)) {
+    set onClick(value: ((e: ClickEvent) => void) | undefined) {
         this._setOption('onClick', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/drop-down-button/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/drop-down-button/nested/drop-down-options.ts
index 850bb97168fc..6810980ba662 100644
--- a/packages/devextreme-angular/src/ui/drop-down-button/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/drop-down-button/nested/drop-down-options.ts
@@ -220,10 +220,10 @@ export class DxoDropDownButtonDropDownOptionsComponent extends NestedOption impl
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) {
+    get onContentReady(): ((e: EventInfo<any>) => void) | null {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void)) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoDropDownButtonDropDownOptionsComponent extends NestedOption impl
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoDropDownButtonDropDownOptionsComponent extends NestedOption impl
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/file-manager/index.ts b/packages/devextreme-angular/src/ui/file-manager/index.ts
index 5528e65e6e26..3ed327b070b3 100644
--- a/packages/devextreme-angular/src/ui/file-manager/index.ts
+++ b/packages/devextreme-angular/src/ui/file-manager/index.ts
@@ -240,10 +240,10 @@ export class DxFileManagerComponent extends DxComponent implements OnDestroy, On
     
      */
     @Input()
-    get fileSystemProvider(): any {
+    get fileSystemProvider(): any | null {
         return this._getOption('fileSystemProvider');
     }
-    set fileSystemProvider(value: any) {
+    set fileSystemProvider(value: any | null) {
         this._setOption('fileSystemProvider', value);
     }
 
@@ -253,10 +253,10 @@ export class DxFileManagerComponent extends DxComponent implements OnDestroy, On
     
      */
     @Input()
-    get focusedItemKey(): string {
+    get focusedItemKey(): string | undefined {
         return this._getOption('focusedItemKey');
     }
-    set focusedItemKey(value: string) {
+    set focusedItemKey(value: string | undefined) {
         this._setOption('focusedItemKey', value);
     }
 
@@ -743,14 +743,14 @@ export class DxFileManagerComponent extends DxComponent implements OnDestroy, On
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() fileSystemProviderChange: EventEmitter<any>;
+    @Output() fileSystemProviderChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() focusedItemKeyChange: EventEmitter<string>;
+    @Output() focusedItemKeyChange: EventEmitter<string | undefined>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/file-uploader/index.ts b/packages/devextreme-angular/src/ui/file-uploader/index.ts
index b2f713903a90..05c38cfa21e1 100644
--- a/packages/devextreme-angular/src/ui/file-uploader/index.ts
+++ b/packages/devextreme-angular/src/ui/file-uploader/index.ts
@@ -650,10 +650,10 @@ export class DxFileUploaderComponent extends DxComponent implements OnDestroy, C
     
      */
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
@@ -663,10 +663,10 @@ export class DxFileUploaderComponent extends DxComponent implements OnDestroy, C
     
      */
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
@@ -1147,14 +1147,14 @@ export class DxFileUploaderComponent extends DxComponent implements OnDestroy, C
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorChange: EventEmitter<any>;
+    @Output() validationErrorChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorsChange: EventEmitter<Array<any>>;
+    @Output() validationErrorsChange: EventEmitter<Array<any> | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/form/nested/button-options.ts b/packages/devextreme-angular/src/ui/form/nested/button-options.ts
index 8863169911bf..4c370cfa7542 100644
--- a/packages/devextreme-angular/src/ui/form/nested/button-options.ts
+++ b/packages/devextreme-angular/src/ui/form/nested/button-options.ts
@@ -114,10 +114,10 @@ export class DxoFormButtonOptionsComponent extends NestedOption implements After
     }
 
     @Input()
-    get onClick(): ((e: ClickEvent) => void) {
+    get onClick(): ((e: ClickEvent) => void) | undefined {
         return this._getOption('onClick');
     }
-    set onClick(value: ((e: ClickEvent) => void)) {
+    set onClick(value: ((e: ClickEvent) => void) | undefined) {
         this._setOption('onClick', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/form/nested/tab-panel-options.ts b/packages/devextreme-angular/src/ui/form/nested/tab-panel-options.ts
index 2524037aebe1..5467ca0481dd 100644
--- a/packages/devextreme-angular/src/ui/form/nested/tab-panel-options.ts
+++ b/packages/devextreme-angular/src/ui/form/nested/tab-panel-options.ts
@@ -288,18 +288,18 @@ export class DxoFormTabPanelOptionsComponent extends NestedOption implements OnD
     }
 
     @Input()
-    get onTitleHold(): ((e: TitleHoldEvent) => void) {
+    get onTitleHold(): ((e: TitleHoldEvent) => void) | null {
         return this._getOption('onTitleHold');
     }
-    set onTitleHold(value: ((e: TitleHoldEvent) => void)) {
+    set onTitleHold(value: ((e: TitleHoldEvent) => void) | null) {
         this._setOption('onTitleHold', value);
     }
 
     @Input()
-    get onTitleRendered(): ((e: TitleRenderedEvent) => void) {
+    get onTitleRendered(): ((e: TitleRenderedEvent) => void) | null {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: TitleRenderedEvent) => void)) {
+    set onTitleRendered(value: ((e: TitleRenderedEvent) => void) | null) {
         this._setOption('onTitleRendered', value);
     }
 
@@ -344,10 +344,10 @@ export class DxoFormTabPanelOptionsComponent extends NestedOption implements OnD
     }
 
     @Input()
-    get selectedItem(): any {
+    get selectedItem(): any | null {
         return this._getOption('selectedItem');
     }
-    set selectedItem(value: any) {
+    set selectedItem(value: any | null) {
         this._setOption('selectedItem', value);
     }
 
@@ -427,7 +427,7 @@ export class DxoFormTabPanelOptionsComponent extends NestedOption implements OnD
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() selectedItemChange: EventEmitter<any>;
+    @Output() selectedItemChange: EventEmitter<any | null>;
     protected get _optionPath() {
         return 'tabPanelOptions';
     }
diff --git a/packages/devextreme-angular/src/ui/funnel/index.ts b/packages/devextreme-angular/src/ui/funnel/index.ts
index dd78f199c453..897ac90ba814 100644
--- a/packages/devextreme-angular/src/ui/funnel/index.ts
+++ b/packages/devextreme-angular/src/ui/funnel/index.ts
@@ -271,10 +271,10 @@ export class DxFunnelComponent extends DxComponent implements OnDestroy, OnChang
     
      */
     @Input()
-    get legend(): { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((itemInfo: { item: dxFunnelItem, text: string }) => string), customizeItems?: ((items: Array<FunnelLegendItem>) => Array<FunnelLegendItem>), customizeText?: ((itemInfo: { item: dxFunnelItem, text: string }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean } {
+    get legend(): { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((itemInfo: { item: dxFunnelItem, text: string }) => string), customizeItems?: ((items: Array<FunnelLegendItem>) => Array<FunnelLegendItem>), customizeText?: ((itemInfo: { item: dxFunnelItem, text: string }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean } {
         return this._getOption('legend');
     }
-    set legend(value: { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((itemInfo: { item: dxFunnelItem, text: string }) => string), customizeItems?: ((items: Array<FunnelLegendItem>) => Array<FunnelLegendItem>), customizeText?: ((itemInfo: { item: dxFunnelItem, text: string }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }) {
+    set legend(value: { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((itemInfo: { item: dxFunnelItem, text: string }) => string), customizeItems?: ((items: Array<FunnelLegendItem>) => Array<FunnelLegendItem>), customizeText?: ((itemInfo: { item: dxFunnelItem, text: string }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }) {
         this._setOption('legend', value);
     }
 
@@ -684,7 +684,7 @@ export class DxFunnelComponent extends DxComponent implements OnDestroy, OnChang
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() legendChange: EventEmitter<{ backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((itemInfo: { item: dxFunnelItem, text: string }) => string), customizeItems?: ((items: Array<FunnelLegendItem>) => Array<FunnelLegendItem>), customizeText?: ((itemInfo: { item: dxFunnelItem, text: string }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }>;
+    @Output() legendChange: EventEmitter<{ backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((itemInfo: { item: dxFunnelItem, text: string }) => string), customizeItems?: ((items: Array<FunnelLegendItem>) => Array<FunnelLegendItem>), customizeText?: ((itemInfo: { item: dxFunnelItem, text: string }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/funnel/nested/legend-title-subtitle.ts b/packages/devextreme-angular/src/ui/funnel/nested/legend-title-subtitle.ts
index eac7e264f26c..ae28ebd34ad5 100644
--- a/packages/devextreme-angular/src/ui/funnel/nested/legend-title-subtitle.ts
+++ b/packages/devextreme-angular/src/ui/funnel/nested/legend-title-subtitle.ts
@@ -48,10 +48,10 @@ export class DxoFunnelLegendTitleSubtitleComponent extends NestedOption implemen
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/funnel/nested/legend-title.ts b/packages/devextreme-angular/src/ui/funnel/nested/legend-title.ts
index d0dc974c1469..47d34c6d6605 100644
--- a/packages/devextreme-angular/src/ui/funnel/nested/legend-title.ts
+++ b/packages/devextreme-angular/src/ui/funnel/nested/legend-title.ts
@@ -65,18 +65,18 @@ export class DxoFunnelLegendTitleComponent extends NestedOption implements OnDes
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/funnel/nested/legend.ts b/packages/devextreme-angular/src/ui/funnel/nested/legend.ts
index 7f94b0316743..261fcaa9b627 100644
--- a/packages/devextreme-angular/src/ui/funnel/nested/legend.ts
+++ b/packages/devextreme-angular/src/ui/funnel/nested/legend.ts
@@ -186,10 +186,10 @@ export class DxoFunnelLegendComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge } {
+    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge } {
         return this._getOption('title');
     }
-    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }) {
+    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }) {
         this._setOption('title', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/funnel/nested/subtitle.ts b/packages/devextreme-angular/src/ui/funnel/nested/subtitle.ts
index 660ad0161211..ac082210c99b 100644
--- a/packages/devextreme-angular/src/ui/funnel/nested/subtitle.ts
+++ b/packages/devextreme-angular/src/ui/funnel/nested/subtitle.ts
@@ -48,10 +48,10 @@ export class DxoFunnelSubtitleComponent extends NestedOption implements OnDestro
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/funnel/nested/title.ts b/packages/devextreme-angular/src/ui/funnel/nested/title.ts
index 733205ab5a1a..02d1bbf06672 100644
--- a/packages/devextreme-angular/src/ui/funnel/nested/title.ts
+++ b/packages/devextreme-angular/src/ui/funnel/nested/title.ts
@@ -65,18 +65,18 @@ export class DxoFunnelTitleComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/gallery/index.ts b/packages/devextreme-angular/src/ui/gallery/index.ts
index d42063b54872..b58e6778803a 100644
--- a/packages/devextreme-angular/src/ui/gallery/index.ts
+++ b/packages/devextreme-angular/src/ui/gallery/index.ts
@@ -326,10 +326,10 @@ export class DxGalleryComponent<TItem = any, TKey = any> extends DxComponent imp
     
      */
     @Input()
-    get selectedItem(): any {
+    get selectedItem(): any | null {
         return this._getOption('selectedItem');
     }
-    set selectedItem(value: any) {
+    set selectedItem(value: any | null) {
         this._setOption('selectedItem', value);
     }
 
@@ -660,7 +660,7 @@ export class DxGalleryComponent<TItem = any, TKey = any> extends DxComponent imp
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() selectedItemChange: EventEmitter<any>;
+    @Output() selectedItemChange: EventEmitter<any | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/gantt/index.ts b/packages/devextreme-angular/src/ui/gantt/index.ts
index 57a0edb4cda1..e58fbf7fdb3a 100644
--- a/packages/devextreme-angular/src/ui/gantt/index.ts
+++ b/packages/devextreme-angular/src/ui/gantt/index.ts
@@ -251,10 +251,10 @@ export class DxGanttComponent extends DxComponent implements OnDestroy, OnChange
     
      */
     @Input()
-    get endDateRange(): Date {
+    get endDateRange(): Date | undefined {
         return this._getOption('endDateRange');
     }
-    set endDateRange(value: Date) {
+    set endDateRange(value: Date | undefined) {
         this._setOption('endDateRange', value);
     }
 
@@ -485,10 +485,10 @@ export class DxGanttComponent extends DxComponent implements OnDestroy, OnChange
     
      */
     @Input()
-    get startDateRange(): Date {
+    get startDateRange(): Date | undefined {
         return this._getOption('startDateRange');
     }
-    set startDateRange(value: Date) {
+    set startDateRange(value: Date | undefined) {
         this._setOption('startDateRange', value);
     }
 
@@ -977,7 +977,7 @@ export class DxGanttComponent extends DxComponent implements OnDestroy, OnChange
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() endDateRangeChange: EventEmitter<Date>;
+    @Output() endDateRangeChange: EventEmitter<Date | undefined>;
 
     /**
     
@@ -1103,7 +1103,7 @@ export class DxGanttComponent extends DxComponent implements OnDestroy, OnChange
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() startDateRangeChange: EventEmitter<Date>;
+    @Output() startDateRangeChange: EventEmitter<Date | undefined>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/html-editor/index.ts b/packages/devextreme-angular/src/ui/html-editor/index.ts
index 9efc625b206e..e7998f26019e 100644
--- a/packages/devextreme-angular/src/ui/html-editor/index.ts
+++ b/packages/devextreme-angular/src/ui/html-editor/index.ts
@@ -328,10 +328,10 @@ export class DxHtmlEditorComponent extends DxComponent implements OnDestroy, Con
     
      */
     @Input()
-    get mediaResizing(): dxHtmlEditorMediaResizing {
+    get mediaResizing(): dxHtmlEditorMediaResizing | null {
         return this._getOption('mediaResizing');
     }
-    set mediaResizing(value: dxHtmlEditorMediaResizing) {
+    set mediaResizing(value: dxHtmlEditorMediaResizing | null) {
         this._setOption('mediaResizing', value);
     }
 
@@ -341,10 +341,10 @@ export class DxHtmlEditorComponent extends DxComponent implements OnDestroy, Con
     
      */
     @Input()
-    get mentions(): Array<dxHtmlEditorMention> {
+    get mentions(): Array<dxHtmlEditorMention> | null {
         return this._getOption('mentions');
     }
-    set mentions(value: Array<dxHtmlEditorMention>) {
+    set mentions(value: Array<dxHtmlEditorMention> | null) {
         this._setOption('mentions', value);
     }
 
@@ -432,10 +432,10 @@ export class DxHtmlEditorComponent extends DxComponent implements OnDestroy, Con
     
      */
     @Input()
-    get tableContextMenu(): dxHtmlEditorTableContextMenu {
+    get tableContextMenu(): dxHtmlEditorTableContextMenu | null {
         return this._getOption('tableContextMenu');
     }
-    set tableContextMenu(value: dxHtmlEditorTableContextMenu) {
+    set tableContextMenu(value: dxHtmlEditorTableContextMenu | null) {
         this._setOption('tableContextMenu', value);
     }
 
@@ -445,10 +445,10 @@ export class DxHtmlEditorComponent extends DxComponent implements OnDestroy, Con
     
      */
     @Input()
-    get tableResizing(): dxHtmlEditorTableResizing {
+    get tableResizing(): dxHtmlEditorTableResizing | null {
         return this._getOption('tableResizing');
     }
-    set tableResizing(value: dxHtmlEditorTableResizing) {
+    set tableResizing(value: dxHtmlEditorTableResizing | null) {
         this._setOption('tableResizing', value);
     }
 
@@ -458,10 +458,10 @@ export class DxHtmlEditorComponent extends DxComponent implements OnDestroy, Con
     
      */
     @Input()
-    get toolbar(): dxHtmlEditorToolbar {
+    get toolbar(): dxHtmlEditorToolbar | null {
         return this._getOption('toolbar');
     }
-    set toolbar(value: dxHtmlEditorToolbar) {
+    set toolbar(value: dxHtmlEditorToolbar | null) {
         this._setOption('toolbar', value);
     }
 
@@ -471,10 +471,10 @@ export class DxHtmlEditorComponent extends DxComponent implements OnDestroy, Con
     
      */
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
@@ -484,10 +484,10 @@ export class DxHtmlEditorComponent extends DxComponent implements OnDestroy, Con
     
      */
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
@@ -536,10 +536,10 @@ export class DxHtmlEditorComponent extends DxComponent implements OnDestroy, Con
     
      */
     @Input()
-    get value(): any {
+    get value(): any | null {
         return this._getOption('value');
     }
-    set value(value: any) {
+    set value(value: any | null) {
         this._setOption('value', value);
     }
 
@@ -549,10 +549,10 @@ export class DxHtmlEditorComponent extends DxComponent implements OnDestroy, Con
     
      */
     @Input()
-    get variables(): dxHtmlEditorVariables {
+    get variables(): dxHtmlEditorVariables | null {
         return this._getOption('variables');
     }
-    set variables(value: dxHtmlEditorVariables) {
+    set variables(value: dxHtmlEditorVariables | null) {
         this._setOption('variables', value);
     }
 
@@ -748,14 +748,14 @@ export class DxHtmlEditorComponent extends DxComponent implements OnDestroy, Con
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() mediaResizingChange: EventEmitter<dxHtmlEditorMediaResizing>;
+    @Output() mediaResizingChange: EventEmitter<dxHtmlEditorMediaResizing | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() mentionsChange: EventEmitter<Array<dxHtmlEditorMention>>;
+    @Output() mentionsChange: EventEmitter<Array<dxHtmlEditorMention> | null>;
 
     /**
     
@@ -804,35 +804,35 @@ export class DxHtmlEditorComponent extends DxComponent implements OnDestroy, Con
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() tableContextMenuChange: EventEmitter<dxHtmlEditorTableContextMenu>;
+    @Output() tableContextMenuChange: EventEmitter<dxHtmlEditorTableContextMenu | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() tableResizingChange: EventEmitter<dxHtmlEditorTableResizing>;
+    @Output() tableResizingChange: EventEmitter<dxHtmlEditorTableResizing | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() toolbarChange: EventEmitter<dxHtmlEditorToolbar>;
+    @Output() toolbarChange: EventEmitter<dxHtmlEditorToolbar | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorChange: EventEmitter<any>;
+    @Output() validationErrorChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorsChange: EventEmitter<Array<any>>;
+    @Output() validationErrorsChange: EventEmitter<Array<any> | null>;
 
     /**
     
@@ -860,14 +860,14 @@ export class DxHtmlEditorComponent extends DxComponent implements OnDestroy, Con
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() valueChange: EventEmitter<any>;
+    @Output() valueChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() variablesChange: EventEmitter<dxHtmlEditorVariables>;
+    @Output() variablesChange: EventEmitter<dxHtmlEditorVariables | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/html-editor/nested/file-uploader-options.ts b/packages/devextreme-angular/src/ui/html-editor/nested/file-uploader-options.ts
index 89c7934bf9c9..8aa7fef9c9eb 100644
--- a/packages/devextreme-angular/src/ui/html-editor/nested/file-uploader-options.ts
+++ b/packages/devextreme-angular/src/ui/html-editor/nested/file-uploader-options.ts
@@ -244,10 +244,10 @@ export class DxoHtmlEditorFileUploaderOptionsComponent extends NestedOption impl
     }
 
     @Input()
-    get onBeforeSend(): ((e: BeforeSendEvent) => void) {
+    get onBeforeSend(): ((e: BeforeSendEvent) => void) | null {
         return this._getOption('onBeforeSend');
     }
-    set onBeforeSend(value: ((e: BeforeSendEvent) => void)) {
+    set onBeforeSend(value: ((e: BeforeSendEvent) => void) | null) {
         this._setOption('onBeforeSend', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoHtmlEditorFileUploaderOptionsComponent extends NestedOption impl
     }
 
     @Input()
-    get onDropZoneEnter(): ((e: DropZoneEnterEvent) => void) {
+    get onDropZoneEnter(): ((e: DropZoneEnterEvent) => void) | null {
         return this._getOption('onDropZoneEnter');
     }
-    set onDropZoneEnter(value: ((e: DropZoneEnterEvent) => void)) {
+    set onDropZoneEnter(value: ((e: DropZoneEnterEvent) => void) | null) {
         this._setOption('onDropZoneEnter', value);
     }
 
     @Input()
-    get onDropZoneLeave(): ((e: DropZoneLeaveEvent) => void) {
+    get onDropZoneLeave(): ((e: DropZoneLeaveEvent) => void) | null {
         return this._getOption('onDropZoneLeave');
     }
-    set onDropZoneLeave(value: ((e: DropZoneLeaveEvent) => void)) {
+    set onDropZoneLeave(value: ((e: DropZoneLeaveEvent) => void) | null) {
         this._setOption('onDropZoneLeave', value);
     }
 
     @Input()
-    get onFilesUploaded(): ((e: FilesUploadedEvent) => void) {
+    get onFilesUploaded(): ((e: FilesUploadedEvent) => void) | null {
         return this._getOption('onFilesUploaded');
     }
-    set onFilesUploaded(value: ((e: FilesUploadedEvent) => void)) {
+    set onFilesUploaded(value: ((e: FilesUploadedEvent) => void) | null) {
         this._setOption('onFilesUploaded', value);
     }
 
@@ -308,50 +308,50 @@ export class DxoHtmlEditorFileUploaderOptionsComponent extends NestedOption impl
     }
 
     @Input()
-    get onProgress(): ((e: ProgressEvent) => void) {
+    get onProgress(): ((e: ProgressEvent) => void) | null {
         return this._getOption('onProgress');
     }
-    set onProgress(value: ((e: ProgressEvent) => void)) {
+    set onProgress(value: ((e: ProgressEvent) => void) | null) {
         this._setOption('onProgress', value);
     }
 
     @Input()
-    get onUploadAborted(): ((e: UploadAbortedEvent) => void) {
+    get onUploadAborted(): ((e: UploadAbortedEvent) => void) | null {
         return this._getOption('onUploadAborted');
     }
-    set onUploadAborted(value: ((e: UploadAbortedEvent) => void)) {
+    set onUploadAborted(value: ((e: UploadAbortedEvent) => void) | null) {
         this._setOption('onUploadAborted', value);
     }
 
     @Input()
-    get onUploaded(): ((e: UploadedEvent) => void) {
+    get onUploaded(): ((e: UploadedEvent) => void) | null {
         return this._getOption('onUploaded');
     }
-    set onUploaded(value: ((e: UploadedEvent) => void)) {
+    set onUploaded(value: ((e: UploadedEvent) => void) | null) {
         this._setOption('onUploaded', value);
     }
 
     @Input()
-    get onUploadError(): ((e: UploadErrorEvent) => void) {
+    get onUploadError(): ((e: UploadErrorEvent) => void) | null {
         return this._getOption('onUploadError');
     }
-    set onUploadError(value: ((e: UploadErrorEvent) => void)) {
+    set onUploadError(value: ((e: UploadErrorEvent) => void) | null) {
         this._setOption('onUploadError', value);
     }
 
     @Input()
-    get onUploadStarted(): ((e: UploadStartedEvent) => void) {
+    get onUploadStarted(): ((e: UploadStartedEvent) => void) | null {
         return this._getOption('onUploadStarted');
     }
-    set onUploadStarted(value: ((e: UploadStartedEvent) => void)) {
+    set onUploadStarted(value: ((e: UploadStartedEvent) => void) | null) {
         this._setOption('onUploadStarted', value);
     }
 
     @Input()
-    get onValueChanged(): ((e: ValueChangedEvent) => void) {
+    get onValueChanged(): ((e: ValueChangedEvent) => void) | null {
         return this._getOption('onValueChanged');
     }
-    set onValueChanged(value: ((e: ValueChangedEvent) => void)) {
+    set onValueChanged(value: ((e: ValueChangedEvent) => void) | null) {
         this._setOption('onValueChanged', value);
     }
 
@@ -500,18 +500,18 @@ export class DxoHtmlEditorFileUploaderOptionsComponent extends NestedOption impl
     }
 
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/linear-gauge/index.ts b/packages/devextreme-angular/src/ui/linear-gauge/index.ts
index 10ce3f22f647..b2bc9c18fa51 100644
--- a/packages/devextreme-angular/src/ui/linear-gauge/index.ts
+++ b/packages/devextreme-angular/src/ui/linear-gauge/index.ts
@@ -285,10 +285,10 @@ export class DxLinearGaugeComponent extends DxComponent implements OnDestroy, On
     
      */
     @Input()
-    get scale(): { allowDecimals?: boolean | undefined, customMinorTicks?: Array<number>, customTicks?: Array<number>, endValue?: number, horizontalOrientation?: HorizontalAlignment, label?: { customizeText?: ((scaleValue: { value: number, valueText: string }) => string), font?: Font, format?: Format | undefined, indentFromTick?: number, overlappingBehavior?: LabelOverlap, useRangeColors?: boolean, visible?: boolean }, minorTick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, minorTickInterval?: number | undefined, scaleDivisionFactor?: number, startValue?: number, tick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, tickInterval?: number | undefined, verticalOrientation?: VerticalAlignment } {
+    get scale(): { allowDecimals?: boolean | undefined, customMinorTicks?: Array<number> | undefined, customTicks?: Array<number> | undefined, endValue?: number, horizontalOrientation?: HorizontalAlignment, label?: { customizeText?: ((scaleValue: { value: number, valueText: string }) => string), font?: Font, format?: Format | undefined, indentFromTick?: number, overlappingBehavior?: LabelOverlap, useRangeColors?: boolean, visible?: boolean }, minorTick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, minorTickInterval?: number | undefined, scaleDivisionFactor?: number, startValue?: number, tick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, tickInterval?: number | undefined, verticalOrientation?: VerticalAlignment } {
         return this._getOption('scale');
     }
-    set scale(value: { allowDecimals?: boolean | undefined, customMinorTicks?: Array<number>, customTicks?: Array<number>, endValue?: number, horizontalOrientation?: HorizontalAlignment, label?: { customizeText?: ((scaleValue: { value: number, valueText: string }) => string), font?: Font, format?: Format | undefined, indentFromTick?: number, overlappingBehavior?: LabelOverlap, useRangeColors?: boolean, visible?: boolean }, minorTick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, minorTickInterval?: number | undefined, scaleDivisionFactor?: number, startValue?: number, tick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, tickInterval?: number | undefined, verticalOrientation?: VerticalAlignment }) {
+    set scale(value: { allowDecimals?: boolean | undefined, customMinorTicks?: Array<number> | undefined, customTicks?: Array<number> | undefined, endValue?: number, horizontalOrientation?: HorizontalAlignment, label?: { customizeText?: ((scaleValue: { value: number, valueText: string }) => string), font?: Font, format?: Format | undefined, indentFromTick?: number, overlappingBehavior?: LabelOverlap, useRangeColors?: boolean, visible?: boolean }, minorTick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, minorTickInterval?: number | undefined, scaleDivisionFactor?: number, startValue?: number, tick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, tickInterval?: number | undefined, verticalOrientation?: VerticalAlignment }) {
         this._setOption('scale', value);
     }
 
@@ -324,10 +324,10 @@ export class DxLinearGaugeComponent extends DxComponent implements OnDestroy, On
     
      */
     @Input()
-    get subvalues(): Array<number> {
+    get subvalues(): Array<number> | undefined {
         return this._getOption('subvalues');
     }
-    set subvalues(value: Array<number>) {
+    set subvalues(value: Array<number> | undefined) {
         this._setOption('subvalues', value);
     }
 
@@ -565,7 +565,7 @@ export class DxLinearGaugeComponent extends DxComponent implements OnDestroy, On
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() scaleChange: EventEmitter<{ allowDecimals?: boolean | undefined, customMinorTicks?: Array<number>, customTicks?: Array<number>, endValue?: number, horizontalOrientation?: HorizontalAlignment, label?: { customizeText?: ((scaleValue: { value: number, valueText: string }) => string), font?: Font, format?: Format | undefined, indentFromTick?: number, overlappingBehavior?: LabelOverlap, useRangeColors?: boolean, visible?: boolean }, minorTick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, minorTickInterval?: number | undefined, scaleDivisionFactor?: number, startValue?: number, tick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, tickInterval?: number | undefined, verticalOrientation?: VerticalAlignment }>;
+    @Output() scaleChange: EventEmitter<{ allowDecimals?: boolean | undefined, customMinorTicks?: Array<number> | undefined, customTicks?: Array<number> | undefined, endValue?: number, horizontalOrientation?: HorizontalAlignment, label?: { customizeText?: ((scaleValue: { value: number, valueText: string }) => string), font?: Font, format?: Format | undefined, indentFromTick?: number, overlappingBehavior?: LabelOverlap, useRangeColors?: boolean, visible?: boolean }, minorTick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, minorTickInterval?: number | undefined, scaleDivisionFactor?: number, startValue?: number, tick?: { color?: string, length?: number, opacity?: number, visible?: boolean, width?: number }, tickInterval?: number | undefined, verticalOrientation?: VerticalAlignment }>;
 
     /**
     
@@ -586,7 +586,7 @@ export class DxLinearGaugeComponent extends DxComponent implements OnDestroy, On
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() subvaluesChange: EventEmitter<Array<number>>;
+    @Output() subvaluesChange: EventEmitter<Array<number> | undefined>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/linear-gauge/nested/scale.ts b/packages/devextreme-angular/src/ui/linear-gauge/nested/scale.ts
index a833d53a561d..645fdae785ac 100644
--- a/packages/devextreme-angular/src/ui/linear-gauge/nested/scale.ts
+++ b/packages/devextreme-angular/src/ui/linear-gauge/nested/scale.ts
@@ -42,18 +42,18 @@ export class DxoLinearGaugeScaleComponent extends NestedOption implements OnDest
     }
 
     @Input()
-    get customMinorTicks(): Array<number> {
+    get customMinorTicks(): Array<number> | undefined {
         return this._getOption('customMinorTicks');
     }
-    set customMinorTicks(value: Array<number>) {
+    set customMinorTicks(value: Array<number> | undefined) {
         this._setOption('customMinorTicks', value);
     }
 
     @Input()
-    get customTicks(): Array<number> {
+    get customTicks(): Array<number> | undefined {
         return this._getOption('customTicks');
     }
-    set customTicks(value: Array<number>) {
+    set customTicks(value: Array<number> | undefined) {
         this._setOption('customTicks', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/list/index.ts b/packages/devextreme-angular/src/ui/list/index.ts
index e6f1f0b50405..b5011627beb2 100644
--- a/packages/devextreme-angular/src/ui/list/index.ts
+++ b/packages/devextreme-angular/src/ui/list/index.ts
@@ -378,10 +378,10 @@ export class DxListComponent<TItem = any, TKey = any> extends DxComponent implem
     
      */
     @Input()
-    get keyExpr(): ((item: any) => any) | string {
+    get keyExpr(): ((item: any) => any) | null | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: ((item: any) => any) | string) {
+    set keyExpr(value: ((item: any) => any) | null | string) {
         this._setOption('keyExpr', value);
     }
 
@@ -1118,7 +1118,7 @@ export class DxListComponent<TItem = any, TKey = any> extends DxComponent implem
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() keyExprChange: EventEmitter<((item: any) => any) | string>;
+    @Output() keyExprChange: EventEmitter<((item: any) => any) | null | string>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/list/nested/options.ts b/packages/devextreme-angular/src/ui/list/nested/options.ts
index 1be2d11eaa2a..105b71fe5436 100644
--- a/packages/devextreme-angular/src/ui/list/nested/options.ts
+++ b/packages/devextreme-angular/src/ui/list/nested/options.ts
@@ -114,10 +114,10 @@ export class DxoListOptionsComponent extends NestedOption implements AfterViewIn
     }
 
     @Input()
-    get onClick(): ((e: ClickEvent) => void) {
+    get onClick(): ((e: ClickEvent) => void) | undefined {
         return this._getOption('onClick');
     }
-    set onClick(value: ((e: ClickEvent) => void)) {
+    set onClick(value: ((e: ClickEvent) => void) | undefined) {
         this._setOption('onClick', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/list/nested/search-editor-options.ts b/packages/devextreme-angular/src/ui/list/nested/search-editor-options.ts
index f46fa88a6a2e..776a99efa68e 100644
--- a/packages/devextreme-angular/src/ui/list/nested/search-editor-options.ts
+++ b/packages/devextreme-angular/src/ui/list/nested/search-editor-options.ts
@@ -62,10 +62,10 @@ export class DxoListSearchEditorOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get buttons(): Array<string | TextBoxPredefinedButton | TextEditorButton> {
+    get buttons(): Array<string | TextBoxPredefinedButton | TextEditorButton> | undefined {
         return this._getOption('buttons');
     }
-    set buttons(value: Array<string | TextBoxPredefinedButton | TextEditorButton>) {
+    set buttons(value: Array<string | TextBoxPredefinedButton | TextEditorButton> | undefined) {
         this._setOption('buttons', value);
     }
 
@@ -190,10 +190,10 @@ export class DxoListSearchEditorOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get maxLength(): number | string {
+    get maxLength(): null | number | string {
         return this._getOption('maxLength');
     }
-    set maxLength(value: number | string) {
+    set maxLength(value: null | number | string) {
         this._setOption('maxLength', value);
     }
 
@@ -414,18 +414,18 @@ export class DxoListSearchEditorOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/lookup/index.ts b/packages/devextreme-angular/src/ui/lookup/index.ts
index e0884d021022..059e14f6275c 100644
--- a/packages/devextreme-angular/src/ui/lookup/index.ts
+++ b/packages/devextreme-angular/src/ui/lookup/index.ts
@@ -753,10 +753,10 @@ export class DxLookupComponent extends DxComponent implements OnDestroy, Control
     
      */
     @Input()
-    get selectedItem(): any {
+    get selectedItem(): any | null {
         return this._getOption('selectedItem');
     }
-    set selectedItem(value: any) {
+    set selectedItem(value: any | null) {
         this._setOption('selectedItem', value);
     }
 
@@ -883,10 +883,10 @@ export class DxLookupComponent extends DxComponent implements OnDestroy, Control
     
      */
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
@@ -896,10 +896,10 @@ export class DxLookupComponent extends DxComponent implements OnDestroy, Control
     
      */
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
@@ -1457,7 +1457,7 @@ export class DxLookupComponent extends DxComponent implements OnDestroy, Control
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() selectedItemChange: EventEmitter<any>;
+    @Output() selectedItemChange: EventEmitter<any | null>;
 
     /**
     
@@ -1527,14 +1527,14 @@ export class DxLookupComponent extends DxComponent implements OnDestroy, Control
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorChange: EventEmitter<any>;
+    @Output() validationErrorChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorsChange: EventEmitter<Array<any>>;
+    @Output() validationErrorsChange: EventEmitter<Array<any> | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/menu/index.ts b/packages/devextreme-angular/src/ui/menu/index.ts
index f8cb504990d4..7b09772cb94b 100644
--- a/packages/devextreme-angular/src/ui/menu/index.ts
+++ b/packages/devextreme-angular/src/ui/menu/index.ts
@@ -395,10 +395,10 @@ export class DxMenuComponent<TItem = any, TKey = any> extends DxComponent implem
     
      */
     @Input()
-    get selectedItem(): any {
+    get selectedItem(): any | null {
         return this._getOption('selectedItem');
     }
-    set selectedItem(value: any) {
+    set selectedItem(value: any | null) {
         this._setOption('selectedItem', value);
     }
 
@@ -748,7 +748,7 @@ export class DxMenuComponent<TItem = any, TKey = any> extends DxComponent implem
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() selectedItemChange: EventEmitter<any>;
+    @Output() selectedItemChange: EventEmitter<any | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/multi-view/index.ts b/packages/devextreme-angular/src/ui/multi-view/index.ts
index ce4635b51482..b447aa4c34fa 100644
--- a/packages/devextreme-angular/src/ui/multi-view/index.ts
+++ b/packages/devextreme-angular/src/ui/multi-view/index.ts
@@ -313,10 +313,10 @@ export class DxMultiViewComponent<TItem = any, TKey = any> extends DxComponent i
     
      */
     @Input()
-    get selectedItem(): any {
+    get selectedItem(): any | null {
         return this._getOption('selectedItem');
     }
-    set selectedItem(value: any) {
+    set selectedItem(value: any | null) {
         this._setOption('selectedItem', value);
     }
 
@@ -575,7 +575,7 @@ export class DxMultiViewComponent<TItem = any, TKey = any> extends DxComponent i
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() selectedItemChange: EventEmitter<any>;
+    @Output() selectedItemChange: EventEmitter<any | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/nested/argument-axis.ts b/packages/devextreme-angular/src/ui/nested/argument-axis.ts
index defb08bccf5b..4713b2c0874f 100644
--- a/packages/devextreme-angular/src/ui/nested/argument-axis.ts
+++ b/packages/devextreme-angular/src/ui/nested/argument-axis.ts
@@ -108,10 +108,10 @@ export class DxoArgumentAxisComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get breaks(): Array<ScaleBreak> {
+    get breaks(): undefined | Array<ScaleBreak> {
         return this._getOption('breaks');
     }
-    set breaks(value: Array<ScaleBreak>) {
+    set breaks(value: undefined | Array<ScaleBreak>) {
         this._setOption('breaks', value);
     }
 
@@ -196,10 +196,10 @@ export class DxoArgumentAxisComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get holidays(): Array<Date | string | number> {
+    get holidays(): undefined | Array<Date | string | number> {
         return this._getOption('holidays');
     }
-    set holidays(value: Array<Date | string | number>) {
+    set holidays(value: undefined | Array<Date | string | number>) {
         this._setOption('holidays', value);
     }
 
@@ -316,10 +316,10 @@ export class DxoArgumentAxisComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get placeholderSize(): number {
+    get placeholderSize(): number | null {
         return this._getOption('placeholderSize');
     }
-    set placeholderSize(value: number) {
+    set placeholderSize(value: number | null) {
         this._setOption('placeholderSize', value);
     }
 
@@ -332,10 +332,10 @@ export class DxoArgumentAxisComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get singleWorkdays(): Array<Date | string | number> {
+    get singleWorkdays(): undefined | Array<Date | string | number> {
         return this._getOption('singleWorkdays');
     }
-    set singleWorkdays(value: Array<Date | string | number>) {
+    set singleWorkdays(value: undefined | Array<Date | string | number>) {
         this._setOption('singleWorkdays', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/nested/base/calendar-options.ts b/packages/devextreme-angular/src/ui/nested/base/calendar-options.ts
index c270b8a4c610..c281bd61d7d5 100644
--- a/packages/devextreme-angular/src/ui/nested/base/calendar-options.ts
+++ b/packages/devextreme-angular/src/ui/nested/base/calendar-options.ts
@@ -47,10 +47,10 @@ export abstract class DxoCalendarOptions extends NestedOption {
         this._setOption('disabled', value);
     }
 
-    get disabledDates(): Function | Array<Date> {
+    get disabledDates(): Function | null | Array<Date> {
         return this._getOption('disabledDates');
     }
-    set disabledDates(value: Function | Array<Date>) {
+    set disabledDates(value: Function | null | Array<Date>) {
         this._setOption('disabledDates', value);
     }
 
@@ -222,17 +222,17 @@ export abstract class DxoCalendarOptions extends NestedOption {
         this._setOption('tabIndex', value);
     }
 
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
-    get validationErrors(): Array<any> {
+    get validationErrors(): null | Array<any> {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: null | Array<any>) {
         this._setOption('validationErrors', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/nested/base/chart-annotation-config-dxi.ts b/packages/devextreme-angular/src/ui/nested/base/chart-annotation-config-dxi.ts
index dff8c492b0fd..bc901120a6e5 100644
--- a/packages/devextreme-angular/src/ui/nested/base/chart-annotation-config-dxi.ts
+++ b/packages/devextreme-angular/src/ui/nested/base/chart-annotation-config-dxi.ts
@@ -257,10 +257,10 @@ export abstract class DxiChartAnnotationConfig extends CollectionNestedOption {
         this._setOption('radius', value);
     }
 
-    get coordinates(): Array<number> {
+    get coordinates(): undefined | Array<number> {
         return this._getOption('coordinates');
     }
-    set coordinates(value: Array<number>) {
+    set coordinates(value: undefined | Array<number>) {
         this._setOption('coordinates', value);
     }
 }
diff --git a/packages/devextreme-angular/src/ui/nested/base/chart-common-annotation-config.ts b/packages/devextreme-angular/src/ui/nested/base/chart-common-annotation-config.ts
index 727b91967099..9aabd72987db 100644
--- a/packages/devextreme-angular/src/ui/nested/base/chart-common-annotation-config.ts
+++ b/packages/devextreme-angular/src/ui/nested/base/chart-common-annotation-config.ts
@@ -250,10 +250,10 @@ export abstract class DxoChartCommonAnnotationConfig extends NestedOption {
         this._setOption('radius', value);
     }
 
-    get coordinates(): Array<number> {
+    get coordinates(): undefined | Array<number> {
         return this._getOption('coordinates');
     }
-    set coordinates(value: Array<number>) {
+    set coordinates(value: undefined | Array<number>) {
         this._setOption('coordinates', value);
     }
 }
diff --git a/packages/devextreme-angular/src/ui/nested/base/file-uploader-options.ts b/packages/devextreme-angular/src/ui/nested/base/file-uploader-options.ts
index 0945065d3add..54ad56232bb5 100644
--- a/packages/devextreme-angular/src/ui/nested/base/file-uploader-options.ts
+++ b/packages/devextreme-angular/src/ui/nested/base/file-uploader-options.ts
@@ -419,17 +419,17 @@ export abstract class DxoFileUploaderOptions extends NestedOption {
         this._setOption('uploadUrl', value);
     }
 
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
-    get validationErrors(): Array<any> {
+    get validationErrors(): null | Array<any> {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: null | Array<any>) {
         this._setOption('validationErrors', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/nested/base/popup-options.ts b/packages/devextreme-angular/src/ui/nested/base/popup-options.ts
index bc31c24c8ad2..f15ce3f4706a 100644
--- a/packages/devextreme-angular/src/ui/nested/base/popup-options.ts
+++ b/packages/devextreme-angular/src/ui/nested/base/popup-options.ts
@@ -162,10 +162,10 @@ export abstract class DxoPopupOptions extends NestedOption {
         this._setOption('minWidth', value);
     }
 
-    get onContentReady(): Function {
+    get onContentReady(): Function | null {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: Function) {
+    set onContentReady(value: Function | null) {
         this._setOption('onContentReady', value);
     }
 
@@ -204,24 +204,24 @@ export abstract class DxoPopupOptions extends NestedOption {
         this._setOption('onOptionChanged', value);
     }
 
-    get onResize(): Function {
+    get onResize(): Function | null {
         return this._getOption('onResize');
     }
-    set onResize(value: Function) {
+    set onResize(value: Function | null) {
         this._setOption('onResize', value);
     }
 
-    get onResizeEnd(): Function {
+    get onResizeEnd(): Function | null {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: Function) {
+    set onResizeEnd(value: Function | null) {
         this._setOption('onResizeEnd', value);
     }
 
-    get onResizeStart(): Function {
+    get onResizeStart(): Function | null {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: Function) {
+    set onResizeStart(value: Function | null) {
         this._setOption('onResizeStart', value);
     }
 
@@ -239,10 +239,10 @@ export abstract class DxoPopupOptions extends NestedOption {
         this._setOption('onShown', value);
     }
 
-    get onTitleRendered(): Function {
+    get onTitleRendered(): Function | null {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: Function) {
+    set onTitleRendered(value: Function | null) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/nested/base/tab-panel-options.ts b/packages/devextreme-angular/src/ui/nested/base/tab-panel-options.ts
index 15573860372e..1f2c002b8bc4 100644
--- a/packages/devextreme-angular/src/ui/nested/base/tab-panel-options.ts
+++ b/packages/devextreme-angular/src/ui/nested/base/tab-panel-options.ts
@@ -273,10 +273,10 @@ export abstract class DxoTabPanelOptions extends NestedOption {
         this._setOption('selectedIndex', value);
     }
 
-    get selectedItem(): any {
+    get selectedItem(): any | null {
         return this._getOption('selectedItem');
     }
-    set selectedItem(value: any) {
+    set selectedItem(value: any | null) {
         this._setOption('selectedItem', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/nested/base/text-box-options.ts b/packages/devextreme-angular/src/ui/nested/base/text-box-options.ts
index 1a966046eb42..be61a1dee2c6 100644
--- a/packages/devextreme-angular/src/ui/nested/base/text-box-options.ts
+++ b/packages/devextreme-angular/src/ui/nested/base/text-box-options.ts
@@ -26,10 +26,10 @@ export abstract class DxoTextBoxOptions extends NestedOption {
         this._setOption('activeStateEnabled', value);
     }
 
-    get buttons(): Array<TextBoxPredefinedButton | TextEditorButton | string> {
+    get buttons(): undefined | Array<TextBoxPredefinedButton | TextEditorButton | string> {
         return this._getOption('buttons');
     }
-    set buttons(value: Array<TextBoxPredefinedButton | TextEditorButton | string>) {
+    set buttons(value: undefined | Array<TextBoxPredefinedButton | TextEditorButton | string>) {
         this._setOption('buttons', value);
     }
 
@@ -138,10 +138,10 @@ export abstract class DxoTextBoxOptions extends NestedOption {
         this._setOption('maskRules', value);
     }
 
-    get maxLength(): number | string {
+    get maxLength(): number | null | string {
         return this._getOption('maxLength');
     }
-    set maxLength(value: number | string) {
+    set maxLength(value: number | null | string) {
         this._setOption('maxLength', value);
     }
 
@@ -334,17 +334,17 @@ export abstract class DxoTextBoxOptions extends NestedOption {
         this._setOption('useMaskedValue', value);
     }
 
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
-    get validationErrors(): Array<any> {
+    get validationErrors(): null | Array<any> {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: null | Array<any>) {
         this._setOption('validationErrors', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/nested/colorizer.ts b/packages/devextreme-angular/src/ui/nested/colorizer.ts
index d1d9fdbf23be..9fccf2762d27 100644
--- a/packages/devextreme-angular/src/ui/nested/colorizer.ts
+++ b/packages/devextreme-angular/src/ui/nested/colorizer.ts
@@ -65,10 +65,10 @@ export class DxoColorizerComponent extends NestedOption implements OnDestroy, On
     }
 
     @Input()
-    get range(): Array<number> {
+    get range(): undefined | Array<number> {
         return this._getOption('range');
     }
-    set range(value: Array<number>) {
+    set range(value: undefined | Array<number>) {
         this._setOption('range', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/nested/common-axis-settings.ts b/packages/devextreme-angular/src/ui/nested/common-axis-settings.ts
index a2a2596ec58d..aaca59da9deb 100644
--- a/packages/devextreme-angular/src/ui/nested/common-axis-settings.ts
+++ b/packages/devextreme-angular/src/ui/nested/common-axis-settings.ts
@@ -154,10 +154,10 @@ export class DxoCommonAxisSettingsComponent extends NestedOption implements OnDe
     }
 
     @Input()
-    get placeholderSize(): number {
+    get placeholderSize(): number | null {
         return this._getOption('placeholderSize');
     }
-    set placeholderSize(value: number) {
+    set placeholderSize(value: number | null) {
         this._setOption('placeholderSize', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/nested/layer-dxi.ts b/packages/devextreme-angular/src/ui/nested/layer-dxi.ts
index 91a313644308..58e3c9d3d2a2 100644
--- a/packages/devextreme-angular/src/ui/nested/layer-dxi.ts
+++ b/packages/devextreme-angular/src/ui/nested/layer-dxi.ts
@@ -73,10 +73,10 @@ export class DxiLayerComponent extends CollectionNestedOption {
     }
 
     @Input()
-    get colorGroups(): Array<number> {
+    get colorGroups(): undefined | Array<number> {
         return this._getOption('colorGroups');
     }
-    set colorGroups(value: Array<number>) {
+    set colorGroups(value: undefined | Array<number>) {
         this._setOption('colorGroups', value);
     }
 
@@ -257,10 +257,10 @@ export class DxiLayerComponent extends CollectionNestedOption {
     }
 
     @Input()
-    get sizeGroups(): Array<number> {
+    get sizeGroups(): undefined | Array<number> {
         return this._getOption('sizeGroups');
     }
-    set sizeGroups(value: Array<number>) {
+    set sizeGroups(value: undefined | Array<number>) {
         this._setOption('sizeGroups', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/nested/legend-dxi.ts b/packages/devextreme-angular/src/ui/nested/legend-dxi.ts
index 9d2a1d33b8e4..0e539351563b 100644
--- a/packages/devextreme-angular/src/ui/nested/legend-dxi.ts
+++ b/packages/devextreme-angular/src/ui/nested/legend-dxi.ts
@@ -215,10 +215,10 @@ export class DxiLegendComponent extends CollectionNestedOption {
     }
 
     @Input()
-    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge } {
+    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge } {
         return this._getOption('title');
     }
-    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }) {
+    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }) {
         this._setOption('title', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/nested/legend.ts b/packages/devextreme-angular/src/ui/nested/legend.ts
index 5617aef011d9..e753781d7abd 100644
--- a/packages/devextreme-angular/src/ui/nested/legend.ts
+++ b/packages/devextreme-angular/src/ui/nested/legend.ts
@@ -195,10 +195,10 @@ export class DxoLegendComponent extends NestedOption implements OnDestroy, OnIni
     }
 
     @Input()
-    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge } {
+    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge } {
         return this._getOption('title');
     }
-    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }) {
+    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }) {
         this._setOption('title', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/nested/scale.ts b/packages/devextreme-angular/src/ui/nested/scale.ts
index deb8b469b46a..a615d90699c3 100644
--- a/packages/devextreme-angular/src/ui/nested/scale.ts
+++ b/packages/devextreme-angular/src/ui/nested/scale.ts
@@ -55,18 +55,18 @@ export class DxoScaleComponent extends NestedOption implements OnDestroy, OnInit
     }
 
     @Input()
-    get customMinorTicks(): Array<number> {
+    get customMinorTicks(): undefined | Array<number> {
         return this._getOption('customMinorTicks');
     }
-    set customMinorTicks(value: Array<number>) {
+    set customMinorTicks(value: undefined | Array<number>) {
         this._setOption('customMinorTicks', value);
     }
 
     @Input()
-    get customTicks(): Array<number> {
+    get customTicks(): undefined | Array<number> {
         return this._getOption('customTicks');
     }
-    set customTicks(value: Array<number>) {
+    set customTicks(value: undefined | Array<number>) {
         this._setOption('customTicks', value);
     }
 
@@ -175,10 +175,10 @@ export class DxoScaleComponent extends NestedOption implements OnDestroy, OnInit
     }
 
     @Input()
-    get breaks(): Array<ScaleBreak> {
+    get breaks(): undefined | Array<ScaleBreak> {
         return this._getOption('breaks');
     }
-    set breaks(value: Array<ScaleBreak>) {
+    set breaks(value: undefined | Array<ScaleBreak>) {
         this._setOption('breaks', value);
     }
 
@@ -215,10 +215,10 @@ export class DxoScaleComponent extends NestedOption implements OnDestroy, OnInit
     }
 
     @Input()
-    get holidays(): Array<Date | string | number> {
+    get holidays(): undefined | Array<Date | string | number> {
         return this._getOption('holidays');
     }
-    set holidays(value: Array<Date | string | number>) {
+    set holidays(value: undefined | Array<Date | string | number>) {
         this._setOption('holidays', value);
     }
 
@@ -287,10 +287,10 @@ export class DxoScaleComponent extends NestedOption implements OnDestroy, OnInit
     }
 
     @Input()
-    get singleWorkdays(): Array<Date | string | number> {
+    get singleWorkdays(): undefined | Array<Date | string | number> {
         return this._getOption('singleWorkdays');
     }
-    set singleWorkdays(value: Array<Date | string | number>) {
+    set singleWorkdays(value: undefined | Array<Date | string | number>) {
         this._setOption('singleWorkdays', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/nested/subtitle.ts b/packages/devextreme-angular/src/ui/nested/subtitle.ts
index 2419de08727d..afc23fae5527 100644
--- a/packages/devextreme-angular/src/ui/nested/subtitle.ts
+++ b/packages/devextreme-angular/src/ui/nested/subtitle.ts
@@ -48,10 +48,10 @@ export class DxoSubtitleComponent extends NestedOption implements OnDestroy, OnI
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/nested/tab-panel-options.ts b/packages/devextreme-angular/src/ui/nested/tab-panel-options.ts
index 95538c345b89..9bf8a90ac7c0 100644
--- a/packages/devextreme-angular/src/ui/nested/tab-panel-options.ts
+++ b/packages/devextreme-angular/src/ui/nested/tab-panel-options.ts
@@ -110,7 +110,7 @@ export class DxoTabPanelOptionsComponent extends DxoTabPanelOptions implements O
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() selectedItemChange: EventEmitter<any>;
+    @Output() selectedItemChange: EventEmitter<any | null>;
     protected get _optionPath() {
         return 'tabPanelOptions';
     }
diff --git a/packages/devextreme-angular/src/ui/nested/title.ts b/packages/devextreme-angular/src/ui/nested/title.ts
index 11f3ae402d3c..98370ea5097a 100644
--- a/packages/devextreme-angular/src/ui/nested/title.ts
+++ b/packages/devextreme-angular/src/ui/nested/title.ts
@@ -65,10 +65,10 @@ export class DxoTitleComponent extends NestedOption implements OnDestroy, OnInit
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string } | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined } | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string } | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined } | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
         this._setOption('subtitle', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/nested/value-axis-dxi.ts b/packages/devextreme-angular/src/ui/nested/value-axis-dxi.ts
index fa149fa07709..29072979c12a 100644
--- a/packages/devextreme-angular/src/ui/nested/value-axis-dxi.ts
+++ b/packages/devextreme-angular/src/ui/nested/value-axis-dxi.ts
@@ -96,10 +96,10 @@ export class DxiValueAxisComponent extends CollectionNestedOption {
     }
 
     @Input()
-    get breaks(): Array<ScaleBreak> {
+    get breaks(): undefined | Array<ScaleBreak> {
         return this._getOption('breaks');
     }
-    set breaks(value: Array<ScaleBreak>) {
+    set breaks(value: undefined | Array<ScaleBreak>) {
         this._setOption('breaks', value);
     }
 
@@ -312,10 +312,10 @@ export class DxiValueAxisComponent extends CollectionNestedOption {
     }
 
     @Input()
-    get placeholderSize(): number {
+    get placeholderSize(): number | null {
         return this._getOption('placeholderSize');
     }
-    set placeholderSize(value: number) {
+    set placeholderSize(value: number | null) {
         this._setOption('placeholderSize', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/number-box/index.ts b/packages/devextreme-angular/src/ui/number-box/index.ts
index c7dd1a4da872..7ffe5f929957 100644
--- a/packages/devextreme-angular/src/ui/number-box/index.ts
+++ b/packages/devextreme-angular/src/ui/number-box/index.ts
@@ -121,10 +121,10 @@ export class DxNumberBoxComponent extends DxComponent implements OnDestroy, Cont
     
      */
     @Input()
-    get buttons(): Array<NumberBoxPredefinedButton | TextEditorButton> {
+    get buttons(): Array<NumberBoxPredefinedButton | TextEditorButton> | undefined {
         return this._getOption('buttons');
     }
-    set buttons(value: Array<NumberBoxPredefinedButton | TextEditorButton>) {
+    set buttons(value: Array<NumberBoxPredefinedButton | TextEditorButton> | undefined) {
         this._setOption('buttons', value);
     }
 
@@ -485,10 +485,10 @@ export class DxNumberBoxComponent extends DxComponent implements OnDestroy, Cont
     
      */
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
@@ -498,10 +498,10 @@ export class DxNumberBoxComponent extends DxComponent implements OnDestroy, Cont
     
      */
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
@@ -735,7 +735,7 @@ export class DxNumberBoxComponent extends DxComponent implements OnDestroy, Cont
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() buttonsChange: EventEmitter<Array<NumberBoxPredefinedButton | TextEditorButton>>;
+    @Output() buttonsChange: EventEmitter<Array<NumberBoxPredefinedButton | TextEditorButton> | undefined>;
 
     /**
     
@@ -931,14 +931,14 @@ export class DxNumberBoxComponent extends DxComponent implements OnDestroy, Cont
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorChange: EventEmitter<any>;
+    @Output() validationErrorChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorsChange: EventEmitter<Array<any>>;
+    @Output() validationErrorsChange: EventEmitter<Array<any> | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/number-box/nested/options.ts b/packages/devextreme-angular/src/ui/number-box/nested/options.ts
index 855eaf5533b4..a15856dab74e 100644
--- a/packages/devextreme-angular/src/ui/number-box/nested/options.ts
+++ b/packages/devextreme-angular/src/ui/number-box/nested/options.ts
@@ -114,10 +114,10 @@ export class DxoNumberBoxOptionsComponent extends NestedOption implements AfterV
     }
 
     @Input()
-    get onClick(): ((e: ClickEvent) => void) {
+    get onClick(): ((e: ClickEvent) => void) | undefined {
         return this._getOption('onClick');
     }
-    set onClick(value: ((e: ClickEvent) => void)) {
+    set onClick(value: ((e: ClickEvent) => void) | undefined) {
         this._setOption('onClick', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/pie-chart/index.ts b/packages/devextreme-angular/src/ui/pie-chart/index.ts
index 8244b2a5fc7e..ef57f193300a 100644
--- a/packages/devextreme-angular/src/ui/pie-chart/index.ts
+++ b/packages/devextreme-angular/src/ui/pie-chart/index.ts
@@ -344,10 +344,10 @@ export class DxPieChartComponent extends DxComponent implements OnDestroy, OnCha
     
      */
     @Input()
-    get legend(): { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((pointInfo: { pointColor: string, pointIndex: number, pointName: any }) => string), customizeItems?: ((items: Array<PieChartLegendItem>) => Array<PieChartLegendItem>), customizeText?: ((pointInfo: { pointColor: string, pointIndex: number, pointName: any }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, hoverMode?: PieChartLegendHoverMode, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean } {
+    get legend(): { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((pointInfo: { pointColor: string, pointIndex: number, pointName: any }) => string), customizeItems?: ((items: Array<PieChartLegendItem>) => Array<PieChartLegendItem>), customizeText?: ((pointInfo: { pointColor: string, pointIndex: number, pointName: any }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, hoverMode?: PieChartLegendHoverMode, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean } {
         return this._getOption('legend');
     }
-    set legend(value: { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((pointInfo: { pointColor: string, pointIndex: number, pointName: any }) => string), customizeItems?: ((items: Array<PieChartLegendItem>) => Array<PieChartLegendItem>), customizeText?: ((pointInfo: { pointColor: string, pointIndex: number, pointName: any }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, hoverMode?: PieChartLegendHoverMode, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }) {
+    set legend(value: { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((pointInfo: { pointColor: string, pointIndex: number, pointName: any }) => string), customizeItems?: ((items: Array<PieChartLegendItem>) => Array<PieChartLegendItem>), customizeText?: ((pointInfo: { pointColor: string, pointIndex: number, pointName: any }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, hoverMode?: PieChartLegendHoverMode, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }) {
         this._setOption('legend', value);
     }
 
@@ -841,7 +841,7 @@ export class DxPieChartComponent extends DxComponent implements OnDestroy, OnCha
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() legendChange: EventEmitter<{ backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((pointInfo: { pointColor: string, pointIndex: number, pointName: any }) => string), customizeItems?: ((items: Array<PieChartLegendItem>) => Array<PieChartLegendItem>), customizeText?: ((pointInfo: { pointColor: string, pointIndex: number, pointName: any }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, hoverMode?: PieChartLegendHoverMode, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }>;
+    @Output() legendChange: EventEmitter<{ backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((pointInfo: { pointColor: string, pointIndex: number, pointName: any }) => string), customizeItems?: ((items: Array<PieChartLegendItem>) => Array<PieChartLegendItem>), customizeText?: ((pointInfo: { pointColor: string, pointIndex: number, pointName: any }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, hoverMode?: PieChartLegendHoverMode, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/pie-chart/nested/legend-title-subtitle.ts b/packages/devextreme-angular/src/ui/pie-chart/nested/legend-title-subtitle.ts
index 89b97fbd8a02..fad6fcaab898 100644
--- a/packages/devextreme-angular/src/ui/pie-chart/nested/legend-title-subtitle.ts
+++ b/packages/devextreme-angular/src/ui/pie-chart/nested/legend-title-subtitle.ts
@@ -48,10 +48,10 @@ export class DxoPieChartLegendTitleSubtitleComponent extends NestedOption implem
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/pie-chart/nested/legend-title.ts b/packages/devextreme-angular/src/ui/pie-chart/nested/legend-title.ts
index cfa91cfca49f..14f9bff04956 100644
--- a/packages/devextreme-angular/src/ui/pie-chart/nested/legend-title.ts
+++ b/packages/devextreme-angular/src/ui/pie-chart/nested/legend-title.ts
@@ -65,18 +65,18 @@ export class DxoPieChartLegendTitleComponent extends NestedOption implements OnD
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/pie-chart/nested/legend.ts b/packages/devextreme-angular/src/ui/pie-chart/nested/legend.ts
index af8ad8fe0def..491d8747cf9f 100644
--- a/packages/devextreme-angular/src/ui/pie-chart/nested/legend.ts
+++ b/packages/devextreme-angular/src/ui/pie-chart/nested/legend.ts
@@ -194,10 +194,10 @@ export class DxoPieChartLegendComponent extends NestedOption implements OnDestro
     }
 
     @Input()
-    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge } {
+    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge } {
         return this._getOption('title');
     }
-    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }) {
+    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }) {
         this._setOption('title', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/pie-chart/nested/subtitle.ts b/packages/devextreme-angular/src/ui/pie-chart/nested/subtitle.ts
index 049a1838a4e0..b54ba237e807 100644
--- a/packages/devextreme-angular/src/ui/pie-chart/nested/subtitle.ts
+++ b/packages/devextreme-angular/src/ui/pie-chart/nested/subtitle.ts
@@ -48,10 +48,10 @@ export class DxoPieChartSubtitleComponent extends NestedOption implements OnDest
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/pie-chart/nested/title.ts b/packages/devextreme-angular/src/ui/pie-chart/nested/title.ts
index 1792ebff123e..611675df1d66 100644
--- a/packages/devextreme-angular/src/ui/pie-chart/nested/title.ts
+++ b/packages/devextreme-angular/src/ui/pie-chart/nested/title.ts
@@ -65,18 +65,18 @@ export class DxoPieChartTitleComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/polar-chart/index.ts b/packages/devextreme-angular/src/ui/polar-chart/index.ts
index e6b46512b85c..71d667461f54 100644
--- a/packages/devextreme-angular/src/ui/polar-chart/index.ts
+++ b/packages/devextreme-angular/src/ui/polar-chart/index.ts
@@ -452,10 +452,10 @@ export class DxPolarChartComponent extends DxComponent implements OnDestroy, OnC
     
      */
     @Input()
-    get legend(): { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), customizeItems?: ((items: Array<LegendItem>) => Array<LegendItem>), customizeText?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, hoverMode?: LegendHoverMode, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean } {
+    get legend(): { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), customizeItems?: ((items: Array<LegendItem>) => Array<LegendItem>), customizeText?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, hoverMode?: LegendHoverMode, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean } {
         return this._getOption('legend');
     }
-    set legend(value: { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), customizeItems?: ((items: Array<LegendItem>) => Array<LegendItem>), customizeText?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, hoverMode?: LegendHoverMode, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }) {
+    set legend(value: { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), customizeItems?: ((items: Array<LegendItem>) => Array<LegendItem>), customizeText?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, hoverMode?: LegendHoverMode, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }) {
         this._setOption('legend', value);
     }
 
@@ -1005,7 +1005,7 @@ export class DxPolarChartComponent extends DxComponent implements OnDestroy, OnC
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() legendChange: EventEmitter<{ backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), customizeItems?: ((items: Array<LegendItem>) => Array<LegendItem>), customizeText?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, hoverMode?: LegendHoverMode, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }>;
+    @Output() legendChange: EventEmitter<{ backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), customizeItems?: ((items: Array<LegendItem>) => Array<LegendItem>), customizeText?: ((seriesInfo: { seriesColor: string, seriesIndex: number, seriesName: any }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, hoverMode?: LegendHoverMode, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/polar-chart/nested/legend-title-subtitle.ts b/packages/devextreme-angular/src/ui/polar-chart/nested/legend-title-subtitle.ts
index f86fc2af1c2a..9e9969fd5269 100644
--- a/packages/devextreme-angular/src/ui/polar-chart/nested/legend-title-subtitle.ts
+++ b/packages/devextreme-angular/src/ui/polar-chart/nested/legend-title-subtitle.ts
@@ -48,10 +48,10 @@ export class DxoPolarChartLegendTitleSubtitleComponent extends NestedOption impl
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/polar-chart/nested/legend-title.ts b/packages/devextreme-angular/src/ui/polar-chart/nested/legend-title.ts
index 09b035fc7f2b..a45aa8a24f1b 100644
--- a/packages/devextreme-angular/src/ui/polar-chart/nested/legend-title.ts
+++ b/packages/devextreme-angular/src/ui/polar-chart/nested/legend-title.ts
@@ -65,18 +65,18 @@ export class DxoPolarChartLegendTitleComponent extends NestedOption implements O
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/polar-chart/nested/legend.ts b/packages/devextreme-angular/src/ui/polar-chart/nested/legend.ts
index df21a4b74203..886b60534ed5 100644
--- a/packages/devextreme-angular/src/ui/polar-chart/nested/legend.ts
+++ b/packages/devextreme-angular/src/ui/polar-chart/nested/legend.ts
@@ -193,10 +193,10 @@ export class DxoPolarChartLegendComponent extends NestedOption implements OnDest
     }
 
     @Input()
-    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge } {
+    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge } {
         return this._getOption('title');
     }
-    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }) {
+    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }) {
         this._setOption('title', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/polar-chart/nested/subtitle.ts b/packages/devextreme-angular/src/ui/polar-chart/nested/subtitle.ts
index a9f92a48e99e..38035ba53fbf 100644
--- a/packages/devextreme-angular/src/ui/polar-chart/nested/subtitle.ts
+++ b/packages/devextreme-angular/src/ui/polar-chart/nested/subtitle.ts
@@ -48,10 +48,10 @@ export class DxoPolarChartSubtitleComponent extends NestedOption implements OnDe
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/polar-chart/nested/title.ts b/packages/devextreme-angular/src/ui/polar-chart/nested/title.ts
index d31de1c995c7..a4324f7cbe25 100644
--- a/packages/devextreme-angular/src/ui/polar-chart/nested/title.ts
+++ b/packages/devextreme-angular/src/ui/polar-chart/nested/title.ts
@@ -65,18 +65,18 @@ export class DxoPolarChartTitleComponent extends NestedOption implements OnDestr
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/progress-bar/index.ts b/packages/devextreme-angular/src/ui/progress-bar/index.ts
index 8dbdfeb5866b..462ab8a0aece 100644
--- a/packages/devextreme-angular/src/ui/progress-bar/index.ts
+++ b/packages/devextreme-angular/src/ui/progress-bar/index.ts
@@ -246,10 +246,10 @@ export class DxProgressBarComponent extends DxComponent implements OnDestroy, Co
     
      */
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
@@ -259,10 +259,10 @@ export class DxProgressBarComponent extends DxComponent implements OnDestroy, Co
     
      */
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
@@ -488,14 +488,14 @@ export class DxProgressBarComponent extends DxComponent implements OnDestroy, Co
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorChange: EventEmitter<any>;
+    @Output() validationErrorChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorsChange: EventEmitter<Array<any>>;
+    @Output() validationErrorsChange: EventEmitter<Array<any> | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/radio-group/index.ts b/packages/devextreme-angular/src/ui/radio-group/index.ts
index 2733f930ecd8..76ad64161cd7 100644
--- a/packages/devextreme-angular/src/ui/radio-group/index.ts
+++ b/packages/devextreme-angular/src/ui/radio-group/index.ts
@@ -340,10 +340,10 @@ export class DxRadioGroupComponent extends DxComponent implements OnDestroy, Con
     
      */
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
@@ -353,10 +353,10 @@ export class DxRadioGroupComponent extends DxComponent implements OnDestroy, Con
     
      */
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
@@ -629,14 +629,14 @@ export class DxRadioGroupComponent extends DxComponent implements OnDestroy, Con
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorChange: EventEmitter<any>;
+    @Output() validationErrorChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorsChange: EventEmitter<Array<any>>;
+    @Output() validationErrorsChange: EventEmitter<Array<any> | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/range-selector/index.ts b/packages/devextreme-angular/src/ui/range-selector/index.ts
index 95e04e4bf628..8a9faeb095b7 100644
--- a/packages/devextreme-angular/src/ui/range-selector/index.ts
+++ b/packages/devextreme-angular/src/ui/range-selector/index.ts
@@ -427,10 +427,10 @@ export class DxRangeSelectorComponent extends DxComponent implements OnDestroy,
     
      */
     @Input()
-    get scale(): { aggregationGroupWidth?: number | undefined, aggregationInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, allowDecimals?: boolean | undefined, breaks?: Array<ScaleBreak> | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[], breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, categories?: Array<Date | number | string>, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean, endValue?: Date | number | string | undefined, holidays?: Array<Date | string> | Array<number>, label?: { customizeText?: ((scaleValue: { value: Date | number | string, valueText: string }) => string), font?: Font, format?: Format | undefined, overlappingBehavior?: LabelOverlap, topIndent?: number, visible?: boolean }, linearThreshold?: number, logarithmBase?: number, marker?: { label?: { customizeText?: ((markerValue: { value: Date | number, valueText: string }) => string), format?: Format | undefined }, separatorHeight?: number, textLeftIndent?: number, textTopIndent?: number, topIndent?: number, visible?: boolean }, maxRange?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minorTick?: { color?: string, opacity?: number, visible?: boolean, width?: number }, minorTickCount?: number | undefined, minorTickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minRange?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, placeholderHeight?: number | undefined, showCustomBoundaryTicks?: boolean, singleWorkdays?: Array<Date | string> | Array<number>, startValue?: Date | number | string | undefined, tick?: { color?: string, opacity?: number, width?: number }, tickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, type?: AxisScale | undefined, valueType?: ChartsDataType | undefined, workdaysOnly?: boolean, workWeek?: Array<number> } {
+    get scale(): { aggregationGroupWidth?: number | undefined, aggregationInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, allowDecimals?: boolean | undefined, breaks?: Array<ScaleBreak> | undefined | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[], breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, categories?: Array<Date | number | string>, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean, endValue?: Date | number | string | undefined, holidays?: Array<Date | string> | Array<number> | undefined, label?: { customizeText?: ((scaleValue: { value: Date | number | string, valueText: string }) => string), font?: Font, format?: Format | undefined, overlappingBehavior?: LabelOverlap, topIndent?: number, visible?: boolean }, linearThreshold?: number, logarithmBase?: number, marker?: { label?: { customizeText?: ((markerValue: { value: Date | number, valueText: string }) => string), format?: Format | undefined }, separatorHeight?: number, textLeftIndent?: number, textTopIndent?: number, topIndent?: number, visible?: boolean }, maxRange?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minorTick?: { color?: string, opacity?: number, visible?: boolean, width?: number }, minorTickCount?: number | undefined, minorTickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minRange?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, placeholderHeight?: number | undefined, showCustomBoundaryTicks?: boolean, singleWorkdays?: Array<Date | string> | Array<number> | undefined, startValue?: Date | number | string | undefined, tick?: { color?: string, opacity?: number, width?: number }, tickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, type?: AxisScale | undefined, valueType?: ChartsDataType | undefined, workdaysOnly?: boolean, workWeek?: Array<number> } {
         return this._getOption('scale');
     }
-    set scale(value: { aggregationGroupWidth?: number | undefined, aggregationInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, allowDecimals?: boolean | undefined, breaks?: Array<ScaleBreak> | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[], breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, categories?: Array<Date | number | string>, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean, endValue?: Date | number | string | undefined, holidays?: Array<Date | string> | Array<number>, label?: { customizeText?: ((scaleValue: { value: Date | number | string, valueText: string }) => string), font?: Font, format?: Format | undefined, overlappingBehavior?: LabelOverlap, topIndent?: number, visible?: boolean }, linearThreshold?: number, logarithmBase?: number, marker?: { label?: { customizeText?: ((markerValue: { value: Date | number, valueText: string }) => string), format?: Format | undefined }, separatorHeight?: number, textLeftIndent?: number, textTopIndent?: number, topIndent?: number, visible?: boolean }, maxRange?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minorTick?: { color?: string, opacity?: number, visible?: boolean, width?: number }, minorTickCount?: number | undefined, minorTickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minRange?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, placeholderHeight?: number | undefined, showCustomBoundaryTicks?: boolean, singleWorkdays?: Array<Date | string> | Array<number>, startValue?: Date | number | string | undefined, tick?: { color?: string, opacity?: number, width?: number }, tickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, type?: AxisScale | undefined, valueType?: ChartsDataType | undefined, workdaysOnly?: boolean, workWeek?: Array<number> }) {
+    set scale(value: { aggregationGroupWidth?: number | undefined, aggregationInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, allowDecimals?: boolean | undefined, breaks?: Array<ScaleBreak> | undefined | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[], breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, categories?: Array<Date | number | string>, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean, endValue?: Date | number | string | undefined, holidays?: Array<Date | string> | Array<number> | undefined, label?: { customizeText?: ((scaleValue: { value: Date | number | string, valueText: string }) => string), font?: Font, format?: Format | undefined, overlappingBehavior?: LabelOverlap, topIndent?: number, visible?: boolean }, linearThreshold?: number, logarithmBase?: number, marker?: { label?: { customizeText?: ((markerValue: { value: Date | number, valueText: string }) => string), format?: Format | undefined }, separatorHeight?: number, textLeftIndent?: number, textTopIndent?: number, topIndent?: number, visible?: boolean }, maxRange?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minorTick?: { color?: string, opacity?: number, visible?: boolean, width?: number }, minorTickCount?: number | undefined, minorTickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minRange?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, placeholderHeight?: number | undefined, showCustomBoundaryTicks?: boolean, singleWorkdays?: Array<Date | string> | Array<number> | undefined, startValue?: Date | number | string | undefined, tick?: { color?: string, opacity?: number, width?: number }, tickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, type?: AxisScale | undefined, valueType?: ChartsDataType | undefined, workdaysOnly?: boolean, workWeek?: Array<number> }) {
         this._setOption('scale', value);
     }
 
@@ -733,7 +733,7 @@ export class DxRangeSelectorComponent extends DxComponent implements OnDestroy,
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() scaleChange: EventEmitter<{ aggregationGroupWidth?: number | undefined, aggregationInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, allowDecimals?: boolean | undefined, breaks?: Array<ScaleBreak> | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[], breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, categories?: Array<Date | number | string>, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean, endValue?: Date | number | string | undefined, holidays?: Array<Date | string> | Array<number>, label?: { customizeText?: ((scaleValue: { value: Date | number | string, valueText: string }) => string), font?: Font, format?: Format | undefined, overlappingBehavior?: LabelOverlap, topIndent?: number, visible?: boolean }, linearThreshold?: number, logarithmBase?: number, marker?: { label?: { customizeText?: ((markerValue: { value: Date | number, valueText: string }) => string), format?: Format | undefined }, separatorHeight?: number, textLeftIndent?: number, textTopIndent?: number, topIndent?: number, visible?: boolean }, maxRange?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minorTick?: { color?: string, opacity?: number, visible?: boolean, width?: number }, minorTickCount?: number | undefined, minorTickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minRange?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, placeholderHeight?: number | undefined, showCustomBoundaryTicks?: boolean, singleWorkdays?: Array<Date | string> | Array<number>, startValue?: Date | number | string | undefined, tick?: { color?: string, opacity?: number, width?: number }, tickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, type?: AxisScale | undefined, valueType?: ChartsDataType | undefined, workdaysOnly?: boolean, workWeek?: Array<number> }>;
+    @Output() scaleChange: EventEmitter<{ aggregationGroupWidth?: number | undefined, aggregationInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, allowDecimals?: boolean | undefined, breaks?: Array<ScaleBreak> | undefined | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[], breakStyle?: { color?: string, line?: ScaleBreakLineStyle, width?: number }, categories?: Array<Date | number | string>, discreteAxisDivisionMode?: DiscreteAxisDivisionMode, endOnTick?: boolean, endValue?: Date | number | string | undefined, holidays?: Array<Date | string> | Array<number> | undefined, label?: { customizeText?: ((scaleValue: { value: Date | number | string, valueText: string }) => string), font?: Font, format?: Format | undefined, overlappingBehavior?: LabelOverlap, topIndent?: number, visible?: boolean }, linearThreshold?: number, logarithmBase?: number, marker?: { label?: { customizeText?: ((markerValue: { value: Date | number, valueText: string }) => string), format?: Format | undefined }, separatorHeight?: number, textLeftIndent?: number, textTopIndent?: number, topIndent?: number, visible?: boolean }, maxRange?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minorTick?: { color?: string, opacity?: number, visible?: boolean, width?: number }, minorTickCount?: number | undefined, minorTickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, minRange?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, placeholderHeight?: number | undefined, showCustomBoundaryTicks?: boolean, singleWorkdays?: Array<Date | string> | Array<number> | undefined, startValue?: Date | number | string | undefined, tick?: { color?: string, opacity?: number, width?: number }, tickInterval?: number | TimeInterval | { days?: number, hours?: number, milliseconds?: number, minutes?: number, months?: number, quarters?: number, seconds?: number, weeks?: number, years?: number }, type?: AxisScale | undefined, valueType?: ChartsDataType | undefined, workdaysOnly?: boolean, workWeek?: Array<number> }>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/range-selector/nested/scale.ts b/packages/devextreme-angular/src/ui/range-selector/nested/scale.ts
index 7539911000f8..c473dc546b6a 100644
--- a/packages/devextreme-angular/src/ui/range-selector/nested/scale.ts
+++ b/packages/devextreme-angular/src/ui/range-selector/nested/scale.ts
@@ -69,10 +69,10 @@ export class DxoRangeSelectorScaleComponent extends NestedOption implements OnDe
     }
 
     @Input()
-    get breaks(): Array<ScaleBreak> | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[] {
+    get breaks(): Array<ScaleBreak> | undefined | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[] {
         return this._getOption('breaks');
     }
-    set breaks(value: Array<ScaleBreak> | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[]) {
+    set breaks(value: Array<ScaleBreak> | undefined | { endValue?: Date | number | string | undefined, startValue?: Date | number | string | undefined }[]) {
         this._setOption('breaks', value);
     }
 
@@ -117,10 +117,10 @@ export class DxoRangeSelectorScaleComponent extends NestedOption implements OnDe
     }
 
     @Input()
-    get holidays(): Array<Date | string> | Array<number> {
+    get holidays(): Array<Date | string> | Array<number> | undefined {
         return this._getOption('holidays');
     }
-    set holidays(value: Array<Date | string> | Array<number>) {
+    set holidays(value: Array<Date | string> | Array<number> | undefined) {
         this._setOption('holidays', value);
     }
 
@@ -213,10 +213,10 @@ export class DxoRangeSelectorScaleComponent extends NestedOption implements OnDe
     }
 
     @Input()
-    get singleWorkdays(): Array<Date | string> | Array<number> {
+    get singleWorkdays(): Array<Date | string> | Array<number> | undefined {
         return this._getOption('singleWorkdays');
     }
-    set singleWorkdays(value: Array<Date | string> | Array<number>) {
+    set singleWorkdays(value: Array<Date | string> | Array<number> | undefined) {
         this._setOption('singleWorkdays', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/range-slider/index.ts b/packages/devextreme-angular/src/ui/range-slider/index.ts
index 029247e61dcf..fd6c6a6c3c63 100644
--- a/packages/devextreme-angular/src/ui/range-slider/index.ts
+++ b/packages/devextreme-angular/src/ui/range-slider/index.ts
@@ -396,10 +396,10 @@ export class DxRangeSliderComponent extends DxComponent implements OnDestroy, Co
     
      */
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
@@ -409,10 +409,10 @@ export class DxRangeSliderComponent extends DxComponent implements OnDestroy, Co
     
      */
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
@@ -720,14 +720,14 @@ export class DxRangeSliderComponent extends DxComponent implements OnDestroy, Co
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorChange: EventEmitter<any>;
+    @Output() validationErrorChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorsChange: EventEmitter<Array<any>>;
+    @Output() validationErrorsChange: EventEmitter<Array<any> | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/responsive-box/index.ts b/packages/devextreme-angular/src/ui/responsive-box/index.ts
index c9677de8e8f3..61c2f3309913 100644
--- a/packages/devextreme-angular/src/ui/responsive-box/index.ts
+++ b/packages/devextreme-angular/src/ui/responsive-box/index.ts
@@ -246,10 +246,10 @@ export class DxResponsiveBoxComponent<TItem = any, TKey = any> extends DxCompone
     
      */
     @Input()
-    get screenByWidth(): Function {
+    get screenByWidth(): Function | null {
         return this._getOption('screenByWidth');
     }
-    set screenByWidth(value: Function) {
+    set screenByWidth(value: Function | null) {
         this._setOption('screenByWidth', value);
     }
 
@@ -438,7 +438,7 @@ export class DxResponsiveBoxComponent<TItem = any, TKey = any> extends DxCompone
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() screenByWidthChange: EventEmitter<Function>;
+    @Output() screenByWidthChange: EventEmitter<Function | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/scheduler/nested/button-options.ts b/packages/devextreme-angular/src/ui/scheduler/nested/button-options.ts
index 724555b4e7a9..e9e9d804d05e 100644
--- a/packages/devextreme-angular/src/ui/scheduler/nested/button-options.ts
+++ b/packages/devextreme-angular/src/ui/scheduler/nested/button-options.ts
@@ -114,10 +114,10 @@ export class DxoSchedulerButtonOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onClick(): ((e: ClickEvent) => void) {
+    get onClick(): ((e: ClickEvent) => void) | undefined {
         return this._getOption('onClick');
     }
-    set onClick(value: ((e: ClickEvent) => void)) {
+    set onClick(value: ((e: ClickEvent) => void) | undefined) {
         this._setOption('onClick', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/scheduler/nested/options.ts b/packages/devextreme-angular/src/ui/scheduler/nested/options.ts
index 84e1fbfc4653..51f8efd5003d 100644
--- a/packages/devextreme-angular/src/ui/scheduler/nested/options.ts
+++ b/packages/devextreme-angular/src/ui/scheduler/nested/options.ts
@@ -159,10 +159,10 @@ export class DxoSchedulerOptionsComponent extends NestedOption implements OnDest
     }
 
     @Input()
-    get onItemClick(): ((e: ItemClickEvent) => void) {
+    get onItemClick(): ((e: ItemClickEvent) => void) | null {
         return this._getOption('onItemClick');
     }
-    set onItemClick(value: ((e: ItemClickEvent) => void)) {
+    set onItemClick(value: ((e: ItemClickEvent) => void) | null) {
         this._setOption('onItemClick', value);
     }
 
@@ -175,10 +175,10 @@ export class DxoSchedulerOptionsComponent extends NestedOption implements OnDest
     }
 
     @Input()
-    get onSelectionChanged(): ((e: SelectionChangedEvent) => void) {
+    get onSelectionChanged(): ((e: SelectionChangedEvent) => void) | null {
         return this._getOption('onSelectionChanged');
     }
-    set onSelectionChanged(value: ((e: SelectionChangedEvent) => void)) {
+    set onSelectionChanged(value: ((e: SelectionChangedEvent) => void) | null) {
         this._setOption('onSelectionChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/scheduler/nested/tab-panel-options.ts b/packages/devextreme-angular/src/ui/scheduler/nested/tab-panel-options.ts
index 15da4a0a51cf..dadb4e16751e 100644
--- a/packages/devextreme-angular/src/ui/scheduler/nested/tab-panel-options.ts
+++ b/packages/devextreme-angular/src/ui/scheduler/nested/tab-panel-options.ts
@@ -288,18 +288,18 @@ export class DxoSchedulerTabPanelOptionsComponent extends NestedOption implement
     }
 
     @Input()
-    get onTitleHold(): ((e: TitleHoldEvent) => void) {
+    get onTitleHold(): ((e: TitleHoldEvent) => void) | null {
         return this._getOption('onTitleHold');
     }
-    set onTitleHold(value: ((e: TitleHoldEvent) => void)) {
+    set onTitleHold(value: ((e: TitleHoldEvent) => void) | null) {
         this._setOption('onTitleHold', value);
     }
 
     @Input()
-    get onTitleRendered(): ((e: TitleRenderedEvent) => void) {
+    get onTitleRendered(): ((e: TitleRenderedEvent) => void) | null {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: TitleRenderedEvent) => void)) {
+    set onTitleRendered(value: ((e: TitleRenderedEvent) => void) | null) {
         this._setOption('onTitleRendered', value);
     }
 
@@ -344,10 +344,10 @@ export class DxoSchedulerTabPanelOptionsComponent extends NestedOption implement
     }
 
     @Input()
-    get selectedItem(): any {
+    get selectedItem(): any | null {
         return this._getOption('selectedItem');
     }
-    set selectedItem(value: any) {
+    set selectedItem(value: any | null) {
         this._setOption('selectedItem', value);
     }
 
@@ -427,7 +427,7 @@ export class DxoSchedulerTabPanelOptionsComponent extends NestedOption implement
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() selectedItemChange: EventEmitter<any>;
+    @Output() selectedItemChange: EventEmitter<any | null>;
     protected get _optionPath() {
         return 'tabPanelOptions';
     }
diff --git a/packages/devextreme-angular/src/ui/select-box/index.ts b/packages/devextreme-angular/src/ui/select-box/index.ts
index 5ec9214cfc6c..aa437613d6f1 100644
--- a/packages/devextreme-angular/src/ui/select-box/index.ts
+++ b/packages/devextreme-angular/src/ui/select-box/index.ts
@@ -176,10 +176,10 @@ export class DxSelectBoxComponent extends DxComponent implements OnDestroy, Cont
     
      */
     @Input()
-    get buttons(): Array<DropDownPredefinedButton | TextEditorButton> {
+    get buttons(): Array<DropDownPredefinedButton | TextEditorButton> | undefined {
         return this._getOption('buttons');
     }
-    set buttons(value: Array<DropDownPredefinedButton | TextEditorButton>) {
+    set buttons(value: Array<DropDownPredefinedButton | TextEditorButton> | undefined) {
         this._setOption('buttons', value);
     }
 
@@ -503,10 +503,10 @@ export class DxSelectBoxComponent extends DxComponent implements OnDestroy, Cont
     
      */
     @Input()
-    get maxLength(): number | string {
+    get maxLength(): null | number | string {
         return this._getOption('maxLength');
     }
-    set maxLength(value: number | string) {
+    set maxLength(value: null | number | string) {
         this._setOption('maxLength', value);
     }
 
@@ -672,10 +672,10 @@ export class DxSelectBoxComponent extends DxComponent implements OnDestroy, Cont
     
      */
     @Input()
-    get selectedItem(): any {
+    get selectedItem(): any | null {
         return this._getOption('selectedItem');
     }
-    set selectedItem(value: any) {
+    set selectedItem(value: any | null) {
         this._setOption('selectedItem', value);
     }
 
@@ -802,10 +802,10 @@ export class DxSelectBoxComponent extends DxComponent implements OnDestroy, Cont
     
      */
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
@@ -815,10 +815,10 @@ export class DxSelectBoxComponent extends DxComponent implements OnDestroy, Cont
     
      */
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
@@ -1125,7 +1125,7 @@ export class DxSelectBoxComponent extends DxComponent implements OnDestroy, Cont
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() buttonsChange: EventEmitter<Array<DropDownPredefinedButton | TextEditorButton>>;
+    @Output() buttonsChange: EventEmitter<Array<DropDownPredefinedButton | TextEditorButton> | undefined>;
 
     /**
     
@@ -1300,7 +1300,7 @@ export class DxSelectBoxComponent extends DxComponent implements OnDestroy, Cont
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() maxLengthChange: EventEmitter<number | string>;
+    @Output() maxLengthChange: EventEmitter<null | number | string>;
 
     /**
     
@@ -1391,7 +1391,7 @@ export class DxSelectBoxComponent extends DxComponent implements OnDestroy, Cont
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() selectedItemChange: EventEmitter<any>;
+    @Output() selectedItemChange: EventEmitter<any | null>;
 
     /**
     
@@ -1461,14 +1461,14 @@ export class DxSelectBoxComponent extends DxComponent implements OnDestroy, Cont
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorChange: EventEmitter<any>;
+    @Output() validationErrorChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorsChange: EventEmitter<Array<any>>;
+    @Output() validationErrorsChange: EventEmitter<Array<any> | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/select-box/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/select-box/nested/drop-down-options.ts
index 014d9ec745a3..054229cff009 100644
--- a/packages/devextreme-angular/src/ui/select-box/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/select-box/nested/drop-down-options.ts
@@ -220,10 +220,10 @@ export class DxoSelectBoxDropDownOptionsComponent extends NestedOption implement
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) {
+    get onContentReady(): ((e: EventInfo<any>) => void) | null {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void)) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoSelectBoxDropDownOptionsComponent extends NestedOption implement
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoSelectBoxDropDownOptionsComponent extends NestedOption implement
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/select-box/nested/options.ts b/packages/devextreme-angular/src/ui/select-box/nested/options.ts
index 44e79abbb397..1273c472f31a 100644
--- a/packages/devextreme-angular/src/ui/select-box/nested/options.ts
+++ b/packages/devextreme-angular/src/ui/select-box/nested/options.ts
@@ -114,10 +114,10 @@ export class DxoSelectBoxOptionsComponent extends NestedOption implements AfterV
     }
 
     @Input()
-    get onClick(): ((e: ClickEvent) => void) {
+    get onClick(): ((e: ClickEvent) => void) | undefined {
         return this._getOption('onClick');
     }
-    set onClick(value: ((e: ClickEvent) => void)) {
+    set onClick(value: ((e: ClickEvent) => void) | undefined) {
         this._setOption('onClick', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/slider/index.ts b/packages/devextreme-angular/src/ui/slider/index.ts
index 8b465d1f60af..10ceb63346d8 100644
--- a/packages/devextreme-angular/src/ui/slider/index.ts
+++ b/packages/devextreme-angular/src/ui/slider/index.ts
@@ -357,10 +357,10 @@ export class DxSliderComponent extends DxComponent implements OnDestroy, Control
     
      */
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
@@ -370,10 +370,10 @@ export class DxSliderComponent extends DxComponent implements OnDestroy, Control
     
      */
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
@@ -660,14 +660,14 @@ export class DxSliderComponent extends DxComponent implements OnDestroy, Control
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorChange: EventEmitter<any>;
+    @Output() validationErrorChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorsChange: EventEmitter<Array<any>>;
+    @Output() validationErrorsChange: EventEmitter<Array<any> | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/stepper/index.ts b/packages/devextreme-angular/src/ui/stepper/index.ts
index fdf1c9b1f660..66902afd4c6a 100644
--- a/packages/devextreme-angular/src/ui/stepper/index.ts
+++ b/packages/devextreme-angular/src/ui/stepper/index.ts
@@ -223,10 +223,10 @@ export class DxStepperComponent<TItem = any, TKey = any> extends DxComponent imp
 
     
     @Input()
-    get selectedItem(): any {
+    get selectedItem(): any | null {
         return this._getOption('selectedItem');
     }
-    set selectedItem(value: any) {
+    set selectedItem(value: any | null) {
         this._setOption('selectedItem', value);
     }
 
@@ -444,7 +444,7 @@ export class DxStepperComponent<TItem = any, TKey = any> extends DxComponent imp
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() selectedItemChange: EventEmitter<any>;
+    @Output() selectedItemChange: EventEmitter<any | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/switch/index.ts b/packages/devextreme-angular/src/ui/switch/index.ts
index 12fb8ad79d80..897700d841bb 100644
--- a/packages/devextreme-angular/src/ui/switch/index.ts
+++ b/packages/devextreme-angular/src/ui/switch/index.ts
@@ -285,10 +285,10 @@ export class DxSwitchComponent extends DxComponent implements OnDestroy, Control
     
      */
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
@@ -298,10 +298,10 @@ export class DxSwitchComponent extends DxComponent implements OnDestroy, Control
     
      */
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
@@ -540,14 +540,14 @@ export class DxSwitchComponent extends DxComponent implements OnDestroy, Control
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorChange: EventEmitter<any>;
+    @Output() validationErrorChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorsChange: EventEmitter<Array<any>>;
+    @Output() validationErrorsChange: EventEmitter<Array<any> | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/tab-panel/index.ts b/packages/devextreme-angular/src/ui/tab-panel/index.ts
index 029969f1066c..bfd9b86a9c8e 100644
--- a/packages/devextreme-angular/src/ui/tab-panel/index.ts
+++ b/packages/devextreme-angular/src/ui/tab-panel/index.ts
@@ -392,10 +392,10 @@ export class DxTabPanelComponent<TItem = any, TKey = any> extends DxComponent im
     
      */
     @Input()
-    get selectedItem(): any {
+    get selectedItem(): any | null {
         return this._getOption('selectedItem');
     }
-    set selectedItem(value: any) {
+    set selectedItem(value: any | null) {
         this._setOption('selectedItem', value);
     }
 
@@ -767,7 +767,7 @@ export class DxTabPanelComponent<TItem = any, TKey = any> extends DxComponent im
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() selectedItemChange: EventEmitter<any>;
+    @Output() selectedItemChange: EventEmitter<any | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/tabs/index.ts b/packages/devextreme-angular/src/ui/tabs/index.ts
index 4d5a2a56ee57..6e3b4cd22bab 100644
--- a/packages/devextreme-angular/src/ui/tabs/index.ts
+++ b/packages/devextreme-angular/src/ui/tabs/index.ts
@@ -236,10 +236,10 @@ export class DxTabsComponent<TItem = any, TKey = any> extends DxComponent implem
     
      */
     @Input()
-    get keyExpr(): ((item: any) => any) | string {
+    get keyExpr(): ((item: any) => any) | null | string {
         return this._getOption('keyExpr');
     }
-    set keyExpr(value: ((item: any) => any) | string) {
+    set keyExpr(value: ((item: any) => any) | null | string) {
         this._setOption('keyExpr', value);
     }
 
@@ -340,10 +340,10 @@ export class DxTabsComponent<TItem = any, TKey = any> extends DxComponent implem
     
      */
     @Input()
-    get selectedItem(): any {
+    get selectedItem(): any | null {
         return this._getOption('selectedItem');
     }
-    set selectedItem(value: any) {
+    set selectedItem(value: any | null) {
         this._setOption('selectedItem', value);
     }
 
@@ -620,7 +620,7 @@ export class DxTabsComponent<TItem = any, TKey = any> extends DxComponent implem
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() keyExprChange: EventEmitter<((item: any) => any) | string>;
+    @Output() keyExprChange: EventEmitter<((item: any) => any) | null | string>;
 
     /**
     
@@ -676,7 +676,7 @@ export class DxTabsComponent<TItem = any, TKey = any> extends DxComponent implem
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() selectedItemChange: EventEmitter<any>;
+    @Output() selectedItemChange: EventEmitter<any | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/tag-box/index.ts b/packages/devextreme-angular/src/ui/tag-box/index.ts
index e65c2ca41cc4..b698e04d2011 100644
--- a/packages/devextreme-angular/src/ui/tag-box/index.ts
+++ b/packages/devextreme-angular/src/ui/tag-box/index.ts
@@ -189,10 +189,10 @@ export class DxTagBoxComponent extends DxComponent implements OnDestroy, Control
     
      */
     @Input()
-    get buttons(): Array<DropDownPredefinedButton | TextEditorButton> {
+    get buttons(): Array<DropDownPredefinedButton | TextEditorButton> | undefined {
         return this._getOption('buttons');
     }
-    set buttons(value: Array<DropDownPredefinedButton | TextEditorButton>) {
+    set buttons(value: Array<DropDownPredefinedButton | TextEditorButton> | undefined) {
         this._setOption('buttons', value);
     }
 
@@ -542,10 +542,10 @@ export class DxTagBoxComponent extends DxComponent implements OnDestroy, Control
     
      */
     @Input()
-    get maxLength(): number | string {
+    get maxLength(): null | number | string {
         return this._getOption('maxLength');
     }
-    set maxLength(value: number | string) {
+    set maxLength(value: null | number | string) {
         this._setOption('maxLength', value);
     }
 
@@ -893,10 +893,10 @@ export class DxTagBoxComponent extends DxComponent implements OnDestroy, Control
     
      */
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
@@ -906,10 +906,10 @@ export class DxTagBoxComponent extends DxComponent implements OnDestroy, Control
     
      */
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
@@ -1215,7 +1215,7 @@ export class DxTagBoxComponent extends DxComponent implements OnDestroy, Control
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() buttonsChange: EventEmitter<Array<DropDownPredefinedButton | TextEditorButton>>;
+    @Output() buttonsChange: EventEmitter<Array<DropDownPredefinedButton | TextEditorButton> | undefined>;
 
     /**
     
@@ -1404,7 +1404,7 @@ export class DxTagBoxComponent extends DxComponent implements OnDestroy, Control
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() maxLengthChange: EventEmitter<number | string>;
+    @Output() maxLengthChange: EventEmitter<null | number | string>;
 
     /**
     
@@ -1593,14 +1593,14 @@ export class DxTagBoxComponent extends DxComponent implements OnDestroy, Control
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorChange: EventEmitter<any>;
+    @Output() validationErrorChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorsChange: EventEmitter<Array<any>>;
+    @Output() validationErrorsChange: EventEmitter<Array<any> | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/tag-box/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/tag-box/nested/drop-down-options.ts
index 1d82c4b4ad6a..17bbac691caf 100644
--- a/packages/devextreme-angular/src/ui/tag-box/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/tag-box/nested/drop-down-options.ts
@@ -220,10 +220,10 @@ export class DxoTagBoxDropDownOptionsComponent extends NestedOption implements O
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) {
+    get onContentReady(): ((e: EventInfo<any>) => void) | null {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void)) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoTagBoxDropDownOptionsComponent extends NestedOption implements O
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoTagBoxDropDownOptionsComponent extends NestedOption implements O
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tag-box/nested/options.ts b/packages/devextreme-angular/src/ui/tag-box/nested/options.ts
index 998c6f269897..19c64ca6ab1a 100644
--- a/packages/devextreme-angular/src/ui/tag-box/nested/options.ts
+++ b/packages/devextreme-angular/src/ui/tag-box/nested/options.ts
@@ -114,10 +114,10 @@ export class DxoTagBoxOptionsComponent extends NestedOption implements AfterView
     }
 
     @Input()
-    get onClick(): ((e: ClickEvent) => void) {
+    get onClick(): ((e: ClickEvent) => void) | undefined {
         return this._getOption('onClick');
     }
-    set onClick(value: ((e: ClickEvent) => void)) {
+    set onClick(value: ((e: ClickEvent) => void) | undefined) {
         this._setOption('onClick', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/text-area/index.ts b/packages/devextreme-angular/src/ui/text-area/index.ts
index f3f56fca396c..87705ec083b1 100644
--- a/packages/devextreme-angular/src/ui/text-area/index.ts
+++ b/packages/devextreme-angular/src/ui/text-area/index.ts
@@ -272,10 +272,10 @@ export class DxTextAreaComponent extends DxComponent implements OnDestroy, Contr
     
      */
     @Input()
-    get maxLength(): number | string {
+    get maxLength(): null | number | string {
         return this._getOption('maxLength');
     }
-    set maxLength(value: number | string) {
+    set maxLength(value: null | number | string) {
         this._setOption('maxLength', value);
     }
 
@@ -402,10 +402,10 @@ export class DxTextAreaComponent extends DxComponent implements OnDestroy, Contr
     
      */
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
@@ -415,10 +415,10 @@ export class DxTextAreaComponent extends DxComponent implements OnDestroy, Contr
     
      */
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
@@ -743,7 +743,7 @@ export class DxTextAreaComponent extends DxComponent implements OnDestroy, Contr
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() maxLengthChange: EventEmitter<number | string>;
+    @Output() maxLengthChange: EventEmitter<null | number | string>;
 
     /**
     
@@ -813,14 +813,14 @@ export class DxTextAreaComponent extends DxComponent implements OnDestroy, Contr
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorChange: EventEmitter<any>;
+    @Output() validationErrorChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorsChange: EventEmitter<Array<any>>;
+    @Output() validationErrorsChange: EventEmitter<Array<any> | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/text-box/index.ts b/packages/devextreme-angular/src/ui/text-box/index.ts
index dc80a935d21f..39585c65e967 100644
--- a/packages/devextreme-angular/src/ui/text-box/index.ts
+++ b/packages/devextreme-angular/src/ui/text-box/index.ts
@@ -118,10 +118,10 @@ export class DxTextBoxComponent extends DxComponent implements OnDestroy, Contro
     
      */
     @Input()
-    get buttons(): Array<string | TextBoxPredefinedButton | TextEditorButton> {
+    get buttons(): Array<string | TextBoxPredefinedButton | TextEditorButton> | undefined {
         return this._getOption('buttons');
     }
-    set buttons(value: Array<string | TextBoxPredefinedButton | TextEditorButton>) {
+    set buttons(value: Array<string | TextBoxPredefinedButton | TextEditorButton> | undefined) {
         this._setOption('buttons', value);
     }
 
@@ -326,10 +326,10 @@ export class DxTextBoxComponent extends DxComponent implements OnDestroy, Contro
     
      */
     @Input()
-    get maxLength(): number | string {
+    get maxLength(): null | number | string {
         return this._getOption('maxLength');
     }
-    set maxLength(value: number | string) {
+    set maxLength(value: null | number | string) {
         this._setOption('maxLength', value);
     }
 
@@ -495,10 +495,10 @@ export class DxTextBoxComponent extends DxComponent implements OnDestroy, Contro
     
      */
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
@@ -508,10 +508,10 @@ export class DxTextBoxComponent extends DxComponent implements OnDestroy, Contro
     
      */
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
@@ -745,7 +745,7 @@ export class DxTextBoxComponent extends DxComponent implements OnDestroy, Contro
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() buttonsChange: EventEmitter<Array<string | TextBoxPredefinedButton | TextEditorButton>>;
+    @Output() buttonsChange: EventEmitter<Array<string | TextBoxPredefinedButton | TextEditorButton> | undefined>;
 
     /**
     
@@ -857,7 +857,7 @@ export class DxTextBoxComponent extends DxComponent implements OnDestroy, Contro
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() maxLengthChange: EventEmitter<number | string>;
+    @Output() maxLengthChange: EventEmitter<null | number | string>;
 
     /**
     
@@ -948,14 +948,14 @@ export class DxTextBoxComponent extends DxComponent implements OnDestroy, Contro
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorChange: EventEmitter<any>;
+    @Output() validationErrorChange: EventEmitter<any | null>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() validationErrorsChange: EventEmitter<Array<any>>;
+    @Output() validationErrorsChange: EventEmitter<Array<any> | null>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/text-box/nested/options.ts b/packages/devextreme-angular/src/ui/text-box/nested/options.ts
index 77a9192393e6..3ad00a5fb1ec 100644
--- a/packages/devextreme-angular/src/ui/text-box/nested/options.ts
+++ b/packages/devextreme-angular/src/ui/text-box/nested/options.ts
@@ -114,10 +114,10 @@ export class DxoTextBoxOptionsComponent extends NestedOption implements AfterVie
     }
 
     @Input()
-    get onClick(): ((e: ClickEvent) => void) {
+    get onClick(): ((e: ClickEvent) => void) | undefined {
         return this._getOption('onClick');
     }
-    set onClick(value: ((e: ClickEvent) => void)) {
+    set onClick(value: ((e: ClickEvent) => void) | undefined) {
         this._setOption('onClick', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tree-list/nested/button-options.ts b/packages/devextreme-angular/src/ui/tree-list/nested/button-options.ts
index d3779c2b62f6..2f2a6733855e 100644
--- a/packages/devextreme-angular/src/ui/tree-list/nested/button-options.ts
+++ b/packages/devextreme-angular/src/ui/tree-list/nested/button-options.ts
@@ -114,10 +114,10 @@ export class DxoTreeListButtonOptionsComponent extends NestedOption implements A
     }
 
     @Input()
-    get onClick(): ((e: ClickEvent) => void) {
+    get onClick(): ((e: ClickEvent) => void) | undefined {
         return this._getOption('onClick');
     }
-    set onClick(value: ((e: ClickEvent) => void)) {
+    set onClick(value: ((e: ClickEvent) => void) | undefined) {
         this._setOption('onClick', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tree-list/nested/editor-options.ts b/packages/devextreme-angular/src/ui/tree-list/nested/editor-options.ts
index e0e170322d1e..1caaf3f74016 100644
--- a/packages/devextreme-angular/src/ui/tree-list/nested/editor-options.ts
+++ b/packages/devextreme-angular/src/ui/tree-list/nested/editor-options.ts
@@ -62,10 +62,10 @@ export class DxoTreeListEditorOptionsComponent extends NestedOption implements O
     }
 
     @Input()
-    get buttons(): Array<string | TextBoxPredefinedButton | TextEditorButton> {
+    get buttons(): Array<string | TextBoxPredefinedButton | TextEditorButton> | undefined {
         return this._getOption('buttons');
     }
-    set buttons(value: Array<string | TextBoxPredefinedButton | TextEditorButton>) {
+    set buttons(value: Array<string | TextBoxPredefinedButton | TextEditorButton> | undefined) {
         this._setOption('buttons', value);
     }
 
@@ -190,10 +190,10 @@ export class DxoTreeListEditorOptionsComponent extends NestedOption implements O
     }
 
     @Input()
-    get maxLength(): number | string {
+    get maxLength(): null | number | string {
         return this._getOption('maxLength');
     }
-    set maxLength(value: number | string) {
+    set maxLength(value: null | number | string) {
         this._setOption('maxLength', value);
     }
 
@@ -414,18 +414,18 @@ export class DxoTreeListEditorOptionsComponent extends NestedOption implements O
     }
 
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tree-list/nested/filter-builder-popup.ts b/packages/devextreme-angular/src/ui/tree-list/nested/filter-builder-popup.ts
index 05cd8c43b18a..8cd9f5ee8c22 100644
--- a/packages/devextreme-angular/src/ui/tree-list/nested/filter-builder-popup.ts
+++ b/packages/devextreme-angular/src/ui/tree-list/nested/filter-builder-popup.ts
@@ -220,10 +220,10 @@ export class DxoTreeListFilterBuilderPopupComponent extends NestedOption impleme
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) {
+    get onContentReady(): ((e: EventInfo<any>) => void) | null {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void)) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoTreeListFilterBuilderPopupComponent extends NestedOption impleme
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoTreeListFilterBuilderPopupComponent extends NestedOption impleme
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tree-list/nested/options.ts b/packages/devextreme-angular/src/ui/tree-list/nested/options.ts
index 5a623aacd5f1..8432b57658d3 100644
--- a/packages/devextreme-angular/src/ui/tree-list/nested/options.ts
+++ b/packages/devextreme-angular/src/ui/tree-list/nested/options.ts
@@ -114,10 +114,10 @@ export class DxoTreeListOptionsComponent extends NestedOption implements AfterVi
     }
 
     @Input()
-    get onClick(): ((e: ClickEvent) => void) {
+    get onClick(): ((e: ClickEvent) => void) | undefined {
         return this._getOption('onClick');
     }
-    set onClick(value: ((e: ClickEvent) => void)) {
+    set onClick(value: ((e: ClickEvent) => void) | undefined) {
         this._setOption('onClick', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tree-list/nested/popup.ts b/packages/devextreme-angular/src/ui/tree-list/nested/popup.ts
index b33db7ea9908..e4063caf8adb 100644
--- a/packages/devextreme-angular/src/ui/tree-list/nested/popup.ts
+++ b/packages/devextreme-angular/src/ui/tree-list/nested/popup.ts
@@ -220,10 +220,10 @@ export class DxoTreeListPopupComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) {
+    get onContentReady(): ((e: EventInfo<any>) => void) | null {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void)) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoTreeListPopupComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoTreeListPopupComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tree-list/nested/tab-panel-options.ts b/packages/devextreme-angular/src/ui/tree-list/nested/tab-panel-options.ts
index 8608365a8172..fab94d6ff70b 100644
--- a/packages/devextreme-angular/src/ui/tree-list/nested/tab-panel-options.ts
+++ b/packages/devextreme-angular/src/ui/tree-list/nested/tab-panel-options.ts
@@ -288,18 +288,18 @@ export class DxoTreeListTabPanelOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onTitleHold(): ((e: TitleHoldEvent) => void) {
+    get onTitleHold(): ((e: TitleHoldEvent) => void) | null {
         return this._getOption('onTitleHold');
     }
-    set onTitleHold(value: ((e: TitleHoldEvent) => void)) {
+    set onTitleHold(value: ((e: TitleHoldEvent) => void) | null) {
         this._setOption('onTitleHold', value);
     }
 
     @Input()
-    get onTitleRendered(): ((e: TitleRenderedEvent) => void) {
+    get onTitleRendered(): ((e: TitleRenderedEvent) => void) | null {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: TitleRenderedEvent) => void)) {
+    set onTitleRendered(value: ((e: TitleRenderedEvent) => void) | null) {
         this._setOption('onTitleRendered', value);
     }
 
@@ -344,10 +344,10 @@ export class DxoTreeListTabPanelOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get selectedItem(): any {
+    get selectedItem(): any | null {
         return this._getOption('selectedItem');
     }
-    set selectedItem(value: any) {
+    set selectedItem(value: any | null) {
         this._setOption('selectedItem', value);
     }
 
@@ -427,7 +427,7 @@ export class DxoTreeListTabPanelOptionsComponent extends NestedOption implements
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() selectedItemChange: EventEmitter<any>;
+    @Output() selectedItemChange: EventEmitter<any | null>;
     protected get _optionPath() {
         return 'tabPanelOptions';
     }
diff --git a/packages/devextreme-angular/src/ui/tree-map/index.ts b/packages/devextreme-angular/src/ui/tree-map/index.ts
index 78c7d1025da9..6f6d20c775a5 100644
--- a/packages/devextreme-angular/src/ui/tree-map/index.ts
+++ b/packages/devextreme-angular/src/ui/tree-map/index.ts
@@ -133,10 +133,10 @@ export class DxTreeMapComponent extends DxComponent implements OnDestroy, OnChan
     
      */
     @Input()
-    get colorizer(): { colorCodeField?: string | undefined, colorizeGroups?: boolean, palette?: Array<string> | Palette, paletteExtensionMode?: PaletteExtensionMode, range?: Array<number>, type?: TreeMapColorizerType | undefined } {
+    get colorizer(): { colorCodeField?: string | undefined, colorizeGroups?: boolean, palette?: Array<string> | Palette, paletteExtensionMode?: PaletteExtensionMode, range?: Array<number> | undefined, type?: TreeMapColorizerType | undefined } {
         return this._getOption('colorizer');
     }
-    set colorizer(value: { colorCodeField?: string | undefined, colorizeGroups?: boolean, palette?: Array<string> | Palette, paletteExtensionMode?: PaletteExtensionMode, range?: Array<number>, type?: TreeMapColorizerType | undefined }) {
+    set colorizer(value: { colorCodeField?: string | undefined, colorizeGroups?: boolean, palette?: Array<string> | Palette, paletteExtensionMode?: PaletteExtensionMode, range?: Array<number> | undefined, type?: TreeMapColorizerType | undefined }) {
         this._setOption('colorizer', value);
     }
 
@@ -583,7 +583,7 @@ export class DxTreeMapComponent extends DxComponent implements OnDestroy, OnChan
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() colorizerChange: EventEmitter<{ colorCodeField?: string | undefined, colorizeGroups?: boolean, palette?: Array<string> | Palette, paletteExtensionMode?: PaletteExtensionMode, range?: Array<number>, type?: TreeMapColorizerType | undefined }>;
+    @Output() colorizerChange: EventEmitter<{ colorCodeField?: string | undefined, colorizeGroups?: boolean, palette?: Array<string> | Palette, paletteExtensionMode?: PaletteExtensionMode, range?: Array<number> | undefined, type?: TreeMapColorizerType | undefined }>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/tree-map/nested/colorizer.ts b/packages/devextreme-angular/src/ui/tree-map/nested/colorizer.ts
index 884e2adc13c3..4d024c8ee7eb 100644
--- a/packages/devextreme-angular/src/ui/tree-map/nested/colorizer.ts
+++ b/packages/devextreme-angular/src/ui/tree-map/nested/colorizer.ts
@@ -65,10 +65,10 @@ export class DxoTreeMapColorizerComponent extends NestedOption implements OnDest
     }
 
     @Input()
-    get range(): Array<number> {
+    get range(): Array<number> | undefined {
         return this._getOption('range');
     }
-    set range(value: Array<number>) {
+    set range(value: Array<number> | undefined) {
         this._setOption('range', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tree-view/nested/options.ts b/packages/devextreme-angular/src/ui/tree-view/nested/options.ts
index f01996ce101f..cfe226979573 100644
--- a/packages/devextreme-angular/src/ui/tree-view/nested/options.ts
+++ b/packages/devextreme-angular/src/ui/tree-view/nested/options.ts
@@ -114,10 +114,10 @@ export class DxoTreeViewOptionsComponent extends NestedOption implements AfterVi
     }
 
     @Input()
-    get onClick(): ((e: ClickEvent) => void) {
+    get onClick(): ((e: ClickEvent) => void) | undefined {
         return this._getOption('onClick');
     }
-    set onClick(value: ((e: ClickEvent) => void)) {
+    set onClick(value: ((e: ClickEvent) => void) | undefined) {
         this._setOption('onClick', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tree-view/nested/search-editor-options.ts b/packages/devextreme-angular/src/ui/tree-view/nested/search-editor-options.ts
index 936fd7424189..19875669bcb1 100644
--- a/packages/devextreme-angular/src/ui/tree-view/nested/search-editor-options.ts
+++ b/packages/devextreme-angular/src/ui/tree-view/nested/search-editor-options.ts
@@ -62,10 +62,10 @@ export class DxoTreeViewSearchEditorOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get buttons(): Array<string | TextBoxPredefinedButton | TextEditorButton> {
+    get buttons(): Array<string | TextBoxPredefinedButton | TextEditorButton> | undefined {
         return this._getOption('buttons');
     }
-    set buttons(value: Array<string | TextBoxPredefinedButton | TextEditorButton>) {
+    set buttons(value: Array<string | TextBoxPredefinedButton | TextEditorButton> | undefined) {
         this._setOption('buttons', value);
     }
 
@@ -190,10 +190,10 @@ export class DxoTreeViewSearchEditorOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get maxLength(): number | string {
+    get maxLength(): null | number | string {
         return this._getOption('maxLength');
     }
-    set maxLength(value: number | string) {
+    set maxLength(value: null | number | string) {
         this._setOption('maxLength', value);
     }
 
@@ -414,18 +414,18 @@ export class DxoTreeViewSearchEditorOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get validationError(): any {
+    get validationError(): any | null {
         return this._getOption('validationError');
     }
-    set validationError(value: any) {
+    set validationError(value: any | null) {
         this._setOption('validationError', value);
     }
 
     @Input()
-    get validationErrors(): Array<any> {
+    get validationErrors(): Array<any> | null {
         return this._getOption('validationErrors');
     }
-    set validationErrors(value: Array<any>) {
+    set validationErrors(value: Array<any> | null) {
         this._setOption('validationErrors', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/vector-map/index.ts b/packages/devextreme-angular/src/ui/vector-map/index.ts
index 9d5f5fb9cb41..07a61f117b75 100644
--- a/packages/devextreme-angular/src/ui/vector-map/index.ts
+++ b/packages/devextreme-angular/src/ui/vector-map/index.ts
@@ -164,10 +164,10 @@ export class DxVectorMapComponent extends DxComponent implements OnDestroy, OnCh
     
      */
     @Input()
-    get bounds(): Array<number> {
+    get bounds(): Array<number> | undefined {
         return this._getOption('bounds');
     }
-    set bounds(value: Array<number>) {
+    set bounds(value: Array<number> | undefined) {
         this._setOption('bounds', value);
     }
 
@@ -268,10 +268,10 @@ export class DxVectorMapComponent extends DxComponent implements OnDestroy, OnCh
     
      */
     @Input()
-    get layers(): { borderColor?: string, borderWidth?: number, color?: string, colorGroupingField?: string | undefined, colorGroups?: Array<number>, customize?: ((elements: Array<MapLayerElement>) => void), dataField?: string | undefined, dataSource?: Array<any> | DataSource | DataSourceOptions | null | Record<string, any> | Store | string, elementType?: VectorMapMarkerType, hoveredBorderColor?: string, hoveredBorderWidth?: number, hoveredColor?: string, hoverEnabled?: boolean, label?: { dataField?: string, enabled?: boolean, font?: Font }, maxSize?: number, minSize?: number, name?: string, opacity?: number, palette?: Array<string> | Palette, paletteIndex?: number, paletteSize?: number, selectedBorderColor?: string, selectedBorderWidth?: number, selectedColor?: string, selectionMode?: SingleMultipleOrNone, size?: number, sizeGroupingField?: string | undefined, sizeGroups?: Array<number>, type?: VectorMapLayerType }[] {
+    get layers(): { borderColor?: string, borderWidth?: number, color?: string, colorGroupingField?: string | undefined, colorGroups?: Array<number> | undefined, customize?: ((elements: Array<MapLayerElement>) => void), dataField?: string | undefined, dataSource?: Array<any> | DataSource | DataSourceOptions | null | Record<string, any> | Store | string, elementType?: VectorMapMarkerType, hoveredBorderColor?: string, hoveredBorderWidth?: number, hoveredColor?: string, hoverEnabled?: boolean, label?: { dataField?: string, enabled?: boolean, font?: Font }, maxSize?: number, minSize?: number, name?: string, opacity?: number, palette?: Array<string> | Palette, paletteIndex?: number, paletteSize?: number, selectedBorderColor?: string, selectedBorderWidth?: number, selectedColor?: string, selectionMode?: SingleMultipleOrNone, size?: number, sizeGroupingField?: string | undefined, sizeGroups?: Array<number> | undefined, type?: VectorMapLayerType }[] {
         return this._getOption('layers');
     }
-    set layers(value: { borderColor?: string, borderWidth?: number, color?: string, colorGroupingField?: string | undefined, colorGroups?: Array<number>, customize?: ((elements: Array<MapLayerElement>) => void), dataField?: string | undefined, dataSource?: Array<any> | DataSource | DataSourceOptions | null | Record<string, any> | Store | string, elementType?: VectorMapMarkerType, hoveredBorderColor?: string, hoveredBorderWidth?: number, hoveredColor?: string, hoverEnabled?: boolean, label?: { dataField?: string, enabled?: boolean, font?: Font }, maxSize?: number, minSize?: number, name?: string, opacity?: number, palette?: Array<string> | Palette, paletteIndex?: number, paletteSize?: number, selectedBorderColor?: string, selectedBorderWidth?: number, selectedColor?: string, selectionMode?: SingleMultipleOrNone, size?: number, sizeGroupingField?: string | undefined, sizeGroups?: Array<number>, type?: VectorMapLayerType }[]) {
+    set layers(value: { borderColor?: string, borderWidth?: number, color?: string, colorGroupingField?: string | undefined, colorGroups?: Array<number> | undefined, customize?: ((elements: Array<MapLayerElement>) => void), dataField?: string | undefined, dataSource?: Array<any> | DataSource | DataSourceOptions | null | Record<string, any> | Store | string, elementType?: VectorMapMarkerType, hoveredBorderColor?: string, hoveredBorderWidth?: number, hoveredColor?: string, hoverEnabled?: boolean, label?: { dataField?: string, enabled?: boolean, font?: Font }, maxSize?: number, minSize?: number, name?: string, opacity?: number, palette?: Array<string> | Palette, paletteIndex?: number, paletteSize?: number, selectedBorderColor?: string, selectedBorderWidth?: number, selectedColor?: string, selectionMode?: SingleMultipleOrNone, size?: number, sizeGroupingField?: string | undefined, sizeGroups?: Array<number> | undefined, type?: VectorMapLayerType }[]) {
         this._setOption('layers', value);
     }
 
@@ -281,10 +281,10 @@ export class DxVectorMapComponent extends DxComponent implements OnDestroy, OnCh
     
      */
     @Input()
-    get legends(): { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((itemInfo: { color: string, end: number, index: number, size: number, start: number }) => string), customizeItems?: ((items: Array<VectorMapLegendItem>) => Array<VectorMapLegendItem>), customizeText?: ((itemInfo: { color: string, end: number, index: number, size: number, start: number }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerColor?: string | undefined, markerShape?: VectorMapMarkerShape, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, source?: { grouping?: string, layer?: string }, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }[] {
+    get legends(): { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((itemInfo: { color: string, end: number, index: number, size: number, start: number }) => string), customizeItems?: ((items: Array<VectorMapLegendItem>) => Array<VectorMapLegendItem>), customizeText?: ((itemInfo: { color: string, end: number, index: number, size: number, start: number }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerColor?: string | undefined, markerShape?: VectorMapMarkerShape, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, source?: { grouping?: string, layer?: string }, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }[] {
         return this._getOption('legends');
     }
-    set legends(value: { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((itemInfo: { color: string, end: number, index: number, size: number, start: number }) => string), customizeItems?: ((items: Array<VectorMapLegendItem>) => Array<VectorMapLegendItem>), customizeText?: ((itemInfo: { color: string, end: number, index: number, size: number, start: number }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerColor?: string | undefined, markerShape?: VectorMapMarkerShape, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, source?: { grouping?: string, layer?: string }, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }[]) {
+    set legends(value: { backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((itemInfo: { color: string, end: number, index: number, size: number, start: number }) => string), customizeItems?: ((items: Array<VectorMapLegendItem>) => Array<VectorMapLegendItem>), customizeText?: ((itemInfo: { color: string, end: number, index: number, size: number, start: number }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerColor?: string | undefined, markerShape?: VectorMapMarkerShape, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, source?: { grouping?: string, layer?: string }, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }[]) {
         this._setOption('legends', value);
     }
 
@@ -614,7 +614,7 @@ export class DxVectorMapComponent extends DxComponent implements OnDestroy, OnCh
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() boundsChange: EventEmitter<Array<number>>;
+    @Output() boundsChange: EventEmitter<Array<number> | undefined>;
 
     /**
     
@@ -670,14 +670,14 @@ export class DxVectorMapComponent extends DxComponent implements OnDestroy, OnCh
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() layersChange: EventEmitter<{ borderColor?: string, borderWidth?: number, color?: string, colorGroupingField?: string | undefined, colorGroups?: Array<number>, customize?: ((elements: Array<MapLayerElement>) => void), dataField?: string | undefined, dataSource?: Array<any> | DataSource | DataSourceOptions | null | Record<string, any> | Store | string, elementType?: VectorMapMarkerType, hoveredBorderColor?: string, hoveredBorderWidth?: number, hoveredColor?: string, hoverEnabled?: boolean, label?: { dataField?: string, enabled?: boolean, font?: Font }, maxSize?: number, minSize?: number, name?: string, opacity?: number, palette?: Array<string> | Palette, paletteIndex?: number, paletteSize?: number, selectedBorderColor?: string, selectedBorderWidth?: number, selectedColor?: string, selectionMode?: SingleMultipleOrNone, size?: number, sizeGroupingField?: string | undefined, sizeGroups?: Array<number>, type?: VectorMapLayerType }[]>;
+    @Output() layersChange: EventEmitter<{ borderColor?: string, borderWidth?: number, color?: string, colorGroupingField?: string | undefined, colorGroups?: Array<number> | undefined, customize?: ((elements: Array<MapLayerElement>) => void), dataField?: string | undefined, dataSource?: Array<any> | DataSource | DataSourceOptions | null | Record<string, any> | Store | string, elementType?: VectorMapMarkerType, hoveredBorderColor?: string, hoveredBorderWidth?: number, hoveredColor?: string, hoverEnabled?: boolean, label?: { dataField?: string, enabled?: boolean, font?: Font }, maxSize?: number, minSize?: number, name?: string, opacity?: number, palette?: Array<string> | Palette, paletteIndex?: number, paletteSize?: number, selectedBorderColor?: string, selectedBorderWidth?: number, selectedColor?: string, selectionMode?: SingleMultipleOrNone, size?: number, sizeGroupingField?: string | undefined, sizeGroups?: Array<number> | undefined, type?: VectorMapLayerType }[]>;
 
     /**
     
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() legendsChange: EventEmitter<{ backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((itemInfo: { color: string, end: number, index: number, size: number, start: number }) => string), customizeItems?: ((items: Array<VectorMapLegendItem>) => Array<VectorMapLegendItem>), customizeText?: ((itemInfo: { color: string, end: number, index: number, size: number, start: number }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerColor?: string | undefined, markerShape?: VectorMapMarkerShape, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, source?: { grouping?: string, layer?: string }, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }[]>;
+    @Output() legendsChange: EventEmitter<{ backgroundColor?: string | undefined, border?: { color?: string, cornerRadius?: number, dashStyle?: DashStyle, opacity?: number | undefined, visible?: boolean, width?: number }, columnCount?: number, columnItemSpacing?: number, customizeHint?: ((itemInfo: { color: string, end: number, index: number, size: number, start: number }) => string), customizeItems?: ((items: Array<VectorMapLegendItem>) => Array<VectorMapLegendItem>), customizeText?: ((itemInfo: { color: string, end: number, index: number, size: number, start: number }) => string), font?: Font, horizontalAlignment?: HorizontalAlignment, itemsAlignment?: HorizontalAlignment | undefined, itemTextPosition?: Position | undefined, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, markerColor?: string | undefined, markerShape?: VectorMapMarkerShape, markerSize?: number, markerTemplate?: any, orientation?: Orientation | undefined, paddingLeftRight?: number, paddingTopBottom?: number, rowCount?: number, rowItemSpacing?: number, source?: { grouping?: string, layer?: string }, title?: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }, verticalAlignment?: VerticalEdge, visible?: boolean }[]>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/vector-map/nested/annotation-dxi.ts b/packages/devextreme-angular/src/ui/vector-map/nested/annotation-dxi.ts
index 576df388e07d..30322411f175 100644
--- a/packages/devextreme-angular/src/ui/vector-map/nested/annotation-dxi.ts
+++ b/packages/devextreme-angular/src/ui/vector-map/nested/annotation-dxi.ts
@@ -88,10 +88,10 @@ export class DxiVectorMapAnnotationComponent extends CollectionNestedOption impl
     }
 
     @Input()
-    get coordinates(): Array<number> {
+    get coordinates(): Array<number> | undefined {
         return this._getOption('coordinates');
     }
-    set coordinates(value: Array<number>) {
+    set coordinates(value: Array<number> | undefined) {
         this._setOption('coordinates', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/vector-map/nested/common-annotation-settings.ts b/packages/devextreme-angular/src/ui/vector-map/nested/common-annotation-settings.ts
index cecfb820d50a..a575cf58634f 100644
--- a/packages/devextreme-angular/src/ui/vector-map/nested/common-annotation-settings.ts
+++ b/packages/devextreme-angular/src/ui/vector-map/nested/common-annotation-settings.ts
@@ -82,10 +82,10 @@ export class DxoVectorMapCommonAnnotationSettingsComponent extends NestedOption
     }
 
     @Input()
-    get coordinates(): Array<number> {
+    get coordinates(): Array<number> | undefined {
         return this._getOption('coordinates');
     }
-    set coordinates(value: Array<number>) {
+    set coordinates(value: Array<number> | undefined) {
         this._setOption('coordinates', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/vector-map/nested/layer-dxi.ts b/packages/devextreme-angular/src/ui/vector-map/nested/layer-dxi.ts
index d22631a098eb..0136d674c24d 100644
--- a/packages/devextreme-angular/src/ui/vector-map/nested/layer-dxi.ts
+++ b/packages/devextreme-angular/src/ui/vector-map/nested/layer-dxi.ts
@@ -73,10 +73,10 @@ export class DxiVectorMapLayerComponent extends CollectionNestedOption {
     }
 
     @Input()
-    get colorGroups(): Array<number> {
+    get colorGroups(): Array<number> | undefined {
         return this._getOption('colorGroups');
     }
-    set colorGroups(value: Array<number>) {
+    set colorGroups(value: Array<number> | undefined) {
         this._setOption('colorGroups', value);
     }
 
@@ -257,10 +257,10 @@ export class DxiVectorMapLayerComponent extends CollectionNestedOption {
     }
 
     @Input()
-    get sizeGroups(): Array<number> {
+    get sizeGroups(): Array<number> | undefined {
         return this._getOption('sizeGroups');
     }
-    set sizeGroups(value: Array<number>) {
+    set sizeGroups(value: Array<number> | undefined) {
         this._setOption('sizeGroups', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/vector-map/nested/legend-dxi.ts b/packages/devextreme-angular/src/ui/vector-map/nested/legend-dxi.ts
index 3316a0be01c6..a6d2ccb47ce7 100644
--- a/packages/devextreme-angular/src/ui/vector-map/nested/legend-dxi.ts
+++ b/packages/devextreme-angular/src/ui/vector-map/nested/legend-dxi.ts
@@ -215,10 +215,10 @@ export class DxiVectorMapLegendComponent extends CollectionNestedOption {
     }
 
     @Input()
-    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge } {
+    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge } {
         return this._getOption('title');
     }
-    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string }, text?: string, verticalAlignment?: VerticalEdge }) {
+    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment | undefined, margin?: { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined }, text?: string | undefined, verticalAlignment?: VerticalEdge }) {
         this._setOption('title', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/vector-map/nested/legend-title-subtitle.ts b/packages/devextreme-angular/src/ui/vector-map/nested/legend-title-subtitle.ts
index 20b16a8d6882..6f2ae4b69d7e 100644
--- a/packages/devextreme-angular/src/ui/vector-map/nested/legend-title-subtitle.ts
+++ b/packages/devextreme-angular/src/ui/vector-map/nested/legend-title-subtitle.ts
@@ -48,10 +48,10 @@ export class DxoVectorMapLegendTitleSubtitleComponent extends NestedOption imple
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/vector-map/nested/legend-title.ts b/packages/devextreme-angular/src/ui/vector-map/nested/legend-title.ts
index 557fa4a85230..497467eb2182 100644
--- a/packages/devextreme-angular/src/ui/vector-map/nested/legend-title.ts
+++ b/packages/devextreme-angular/src/ui/vector-map/nested/legend-title.ts
@@ -65,18 +65,18 @@ export class DxoVectorMapLegendTitleComponent extends NestedOption implements On
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/vector-map/nested/subtitle.ts b/packages/devextreme-angular/src/ui/vector-map/nested/subtitle.ts
index 624b43fb9dc1..4eb3ba47db1d 100644
--- a/packages/devextreme-angular/src/ui/vector-map/nested/subtitle.ts
+++ b/packages/devextreme-angular/src/ui/vector-map/nested/subtitle.ts
@@ -48,10 +48,10 @@ export class DxoVectorMapSubtitleComponent extends NestedOption implements OnDes
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/vector-map/nested/title.ts b/packages/devextreme-angular/src/ui/vector-map/nested/title.ts
index 25c24011b957..31e6f202efa5 100644
--- a/packages/devextreme-angular/src/ui/vector-map/nested/title.ts
+++ b/packages/devextreme-angular/src/ui/vector-map/nested/title.ts
@@ -65,18 +65,18 @@ export class DxoVectorMapTitleComponent extends NestedOption implements OnDestro
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-react/src/accordion.ts b/packages/devextreme-react/src/accordion.ts
index 570969a135c5..74a19e2318d5 100644
--- a/packages/devextreme-react/src/accordion.ts
+++ b/packages/devextreme-react/src/accordion.ts
@@ -36,12 +36,12 @@ type IAccordionOptions<TItem = any, TKey = any> = React.PropsWithChildren<Replac
   itemTitleComponent?: React.ComponentType<any>;
   defaultItems?: Array<any | dxAccordionItem | string>;
   defaultSelectedIndex?: number;
-  defaultSelectedItem?: any;
+  defaultSelectedItem?: any | null;
   defaultSelectedItemKeys?: Array<any>;
   defaultSelectedItems?: Array<any>;
   onItemsChange?: (value: Array<any | dxAccordionItem | string>) => void;
   onSelectedIndexChange?: (value: number) => void;
-  onSelectedItemChange?: (value: any) => void;
+  onSelectedItemChange?: (value: any | null) => void;
   onSelectedItemKeysChange?: (value: Array<any>) => void;
   onSelectedItemsChange?: (value: Array<any>) => void;
 }>
diff --git a/packages/devextreme-react/src/autocomplete.ts b/packages/devextreme-react/src/autocomplete.ts
index 429e56578252..5d2382588216 100644
--- a/packages/devextreme-react/src/autocomplete.ts
+++ b/packages/devextreme-react/src/autocomplete.ts
@@ -257,18 +257,18 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void);
+  onContentReady?: ((e: EventInfo<any>) => void) | null;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void);
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
@@ -468,7 +468,7 @@ type IOptionsProps = React.PropsWithChildren<{
   hint?: string | undefined;
   hoverStateEnabled?: boolean;
   icon?: string;
-  onClick?: ((e: ClickEvent) => void);
+  onClick?: ((e: ClickEvent) => void) | undefined;
   onContentReady?: ((e: ButtonContentReadyEvent) => void);
   onDisposing?: ((e: ButtonDisposingEvent) => void);
   onInitialized?: ((e: ButtonInitializedEvent) => void);
diff --git a/packages/devextreme-react/src/bar-gauge.ts b/packages/devextreme-react/src/bar-gauge.ts
index 7f0b7875734d..99cdb7122718 100644
--- a/packages/devextreme-react/src/bar-gauge.ts
+++ b/packages/devextreme-react/src/bar-gauge.ts
@@ -25,8 +25,8 @@ type IBarGaugeOptionsNarrowedEvents = {
   onFileSaving?: ((e: FileSavingEvent) => void);
   onIncidentOccurred?: ((e: IncidentOccurredEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
-  onTooltipHidden?: ((e: TooltipHiddenEvent) => void);
-  onTooltipShown?: ((e: TooltipShownEvent) => void);
+  onTooltipHidden?: ((e: TooltipHiddenEvent) => void) | undefined;
+  onTooltipShown?: ((e: TooltipShownEvent) => void) | undefined;
 }
 
 type IBarGaugeOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IBarGaugeOptionsNarrowedEvents> & IHtmlOptions & {
@@ -409,9 +409,9 @@ type ILegendProps = React.PropsWithChildren<{
     subtitle?: Record<string, any> | string | {
       font?: ChartsFont;
       offset?: number;
-      text?: string;
+      text?: string | undefined;
     };
-    text?: string;
+    text?: string | undefined;
     verticalAlignment?: VerticalEdge;
   };
   verticalAlignment?: VerticalEdge;
@@ -484,9 +484,9 @@ type ILegendTitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
   };
-  text?: string;
+  text?: string | undefined;
   verticalAlignment?: VerticalEdge;
 }>
 const _componentLegendTitle = (props: ILegendTitleProps) => {
@@ -513,7 +513,7 @@ const LegendTitle = Object.assign<typeof _componentLegendTitle, NestedComponentM
 type ILegendTitleSubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
 }>
 const _componentLegendTitleSubtitle = (props: ILegendTitleSubtitleProps) => {
   return React.createElement(NestedOption<ILegendTitleSubtitleProps>, {
@@ -631,7 +631,7 @@ const Size = Object.assign<typeof _componentSize, NestedComponentMeta>(_componen
 type ISubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
 }>
@@ -667,11 +667,11 @@ type ITitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
     textOverflow?: TextOverflow;
     wordWrap?: WordWrap;
   };
-  text?: string;
+  text?: string | undefined;
   verticalAlignment?: VerticalEdge;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
diff --git a/packages/devextreme-react/src/button-group.ts b/packages/devextreme-react/src/button-group.ts
index ea501fa0e358..2118f31d4597 100644
--- a/packages/devextreme-react/src/button-group.ts
+++ b/packages/devextreme-react/src/button-group.ts
@@ -20,7 +20,7 @@ type IButtonGroupOptionsNarrowedEvents = {
   onContentReady?: ((e: ContentReadyEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
-  onItemClick?: ((e: ItemClickEvent) => void);
+  onItemClick?: ((e: ItemClickEvent) => void) | null;
 }
 
 type IButtonGroupOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IButtonGroupOptionsNarrowedEvents> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/button.ts b/packages/devextreme-react/src/button.ts
index 571b99dfe152..fff1e1677b22 100644
--- a/packages/devextreme-react/src/button.ts
+++ b/packages/devextreme-react/src/button.ts
@@ -14,7 +14,7 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 }
 
 type IButtonOptionsNarrowedEvents = {
-  onClick?: ((e: ClickEvent) => void);
+  onClick?: ((e: ClickEvent) => void) | undefined;
   onContentReady?: ((e: ContentReadyEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
diff --git a/packages/devextreme-react/src/card-view.ts b/packages/devextreme-react/src/card-view.ts
index 4cf1b45263e7..9c8211049d40 100644
--- a/packages/devextreme-react/src/card-view.ts
+++ b/packages/devextreme-react/src/card-view.ts
@@ -319,7 +319,7 @@ type IButtonOptionsProps = React.PropsWithChildren<{
   hint?: string | undefined;
   hoverStateEnabled?: boolean;
   icon?: string;
-  onClick?: ((e: ClickEvent) => void);
+  onClick?: ((e: ClickEvent) => void) | undefined;
   onContentReady?: ((e: ContentReadyEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
@@ -2583,14 +2583,14 @@ type ITabPanelOptionsProps = React.PropsWithChildren<{
   onSelectionChanged?: ((e: SelectionChangedEvent) => void);
   onSelectionChanging?: ((e: SelectionChangingEvent) => void);
   onTitleClick?: ((e: TitleClickEvent) => void);
-  onTitleHold?: ((e: TitleHoldEvent) => void);
-  onTitleRendered?: ((e: TitleRenderedEvent) => void);
+  onTitleHold?: ((e: TitleHoldEvent) => void) | null;
+  onTitleRendered?: ((e: TitleRenderedEvent) => void) | null;
   repaintChangesOnly?: boolean;
   rtlEnabled?: boolean;
   scrollByContent?: boolean;
   scrollingEnabled?: boolean;
   selectedIndex?: number;
-  selectedItem?: any;
+  selectedItem?: any | null;
   showNavButtons?: boolean;
   stylingMode?: TabsStyle;
   swipeEnabled?: boolean;
@@ -2602,8 +2602,8 @@ type ITabPanelOptionsProps = React.PropsWithChildren<{
   onItemsChange?: (value: Array<any | dxTabPanelItem | string>) => void;
   defaultSelectedIndex?: number;
   onSelectedIndexChange?: (value: number) => void;
-  defaultSelectedItem?: any;
-  onSelectedItemChange?: (value: any) => void;
+  defaultSelectedItem?: any | null;
+  onSelectedItemChange?: (value: any | null) => void;
   itemRender?: (...params: any) => React.ReactNode;
   itemComponent?: React.ComponentType<any>;
   itemTitleRender?: (...params: any) => React.ReactNode;
diff --git a/packages/devextreme-react/src/chart.ts b/packages/devextreme-react/src/chart.ts
index 50be1aa56325..2cf14ad83d84 100644
--- a/packages/devextreme-react/src/chart.ts
+++ b/packages/devextreme-react/src/chart.ts
@@ -35,8 +35,8 @@ type IChartOptionsNarrowedEvents = {
   onSeriesClick?: ((e: SeriesClickEvent) => void);
   onTooltipHidden?: ((e: TooltipHiddenEvent) => void);
   onTooltipShown?: ((e: TooltipShownEvent) => void);
-  onZoomEnd?: ((e: ZoomEndEvent) => void);
-  onZoomStart?: ((e: ZoomStartEvent) => void);
+  onZoomEnd?: ((e: ZoomEndEvent) => void) | undefined;
+  onZoomStart?: ((e: ZoomStartEvent) => void) | undefined;
 }
 
 type IChartOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IChartOptionsNarrowedEvents> & IHtmlOptions & {
@@ -359,7 +359,7 @@ type IArgumentAxisProps = React.PropsWithChildren<{
   allowDecimals?: boolean | undefined;
   argumentType?: ChartsDataType | undefined;
   axisDivisionFactor?: number;
-  breaks?: Array<ScaleBreak> | {
+  breaks?: Array<ScaleBreak> | undefined | {
     endValue?: Date | number | string | undefined;
     startValue?: Date | number | string | undefined;
   }[];
@@ -412,7 +412,7 @@ type IArgumentAxisProps = React.PropsWithChildren<{
     visible?: boolean;
     width?: number;
   };
-  holidays?: Array<Date | string> | Array<number>;
+  holidays?: Array<Date | string> | Array<number> | undefined;
   hoverMode?: ArgumentAxisHoverMode;
   inverted?: boolean;
   label?: Record<string, any> | {
@@ -475,9 +475,9 @@ type IArgumentAxisProps = React.PropsWithChildren<{
   };
   offset?: number | undefined;
   opacity?: number | undefined;
-  placeholderSize?: number;
+  placeholderSize?: null | number;
   position?: Position;
-  singleWorkdays?: Array<Date | string> | Array<number>;
+  singleWorkdays?: Array<Date | string> | Array<number> | undefined;
   strips?: Array<Record<string, any>> | {
     color?: string | undefined;
     endValue?: Date | number | string | undefined;
@@ -1076,7 +1076,7 @@ type ICommonAxisSettingsProps = React.PropsWithChildren<{
   };
   minValueMargin?: number | undefined;
   opacity?: number | undefined;
-  placeholderSize?: number;
+  placeholderSize?: null | number;
   stripStyle?: Record<string, any> | {
     label?: Record<string, any> | {
       font?: ChartsFont;
@@ -2272,9 +2272,9 @@ type ILegendProps = React.PropsWithChildren<{
     subtitle?: Record<string, any> | string | {
       font?: ChartsFont;
       offset?: number;
-      text?: string;
+      text?: string | undefined;
     };
-    text?: string;
+    text?: string | undefined;
     verticalAlignment?: VerticalEdge;
   };
   verticalAlignment?: VerticalEdge;
@@ -2323,9 +2323,9 @@ type ILegendTitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
   };
-  text?: string;
+  text?: string | undefined;
   verticalAlignment?: VerticalEdge;
 }>
 const _componentLegendTitle = (props: ILegendTitleProps) => {
@@ -2352,7 +2352,7 @@ const LegendTitle = Object.assign<typeof _componentLegendTitle, NestedComponentM
 type ILegendTitleSubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
 }>
 const _componentLegendTitleSubtitle = (props: ILegendTitleSubtitleProps) => {
   return React.createElement(NestedOption<ILegendTitleSubtitleProps>, {
@@ -3285,7 +3285,7 @@ const StripStyleLabel = Object.assign<typeof _componentStripStyleLabel, NestedCo
 type ISubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
 }>
@@ -3380,7 +3380,7 @@ type ITitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
     textOverflow?: TextOverflow;
     wordWrap?: WordWrap;
   };
@@ -3516,7 +3516,7 @@ type IValueAxisProps = React.PropsWithChildren<{
   allowDecimals?: boolean | undefined;
   autoBreaksEnabled?: boolean;
   axisDivisionFactor?: number;
-  breaks?: Array<ScaleBreak> | {
+  breaks?: Array<ScaleBreak> | undefined | {
     endValue?: Date | number | string | undefined;
     startValue?: Date | number | string | undefined;
   }[];
@@ -3633,7 +3633,7 @@ type IValueAxisProps = React.PropsWithChildren<{
   offset?: number | undefined;
   opacity?: number | undefined;
   pane?: string | undefined;
-  placeholderSize?: number;
+  placeholderSize?: null | number;
   position?: Position;
   showZero?: boolean | undefined;
   strips?: Array<Record<string, any>> | {
diff --git a/packages/devextreme-react/src/chat.ts b/packages/devextreme-react/src/chat.ts
index 9a88e3b7414a..2cc4726b1254 100644
--- a/packages/devextreme-react/src/chat.ts
+++ b/packages/devextreme-react/src/chat.ts
@@ -297,20 +297,20 @@ type IFileUploaderOptionsProps = React.PropsWithChildren<{
   minFileSize?: number;
   multiple?: boolean;
   name?: string;
-  onBeforeSend?: ((e: BeforeSendEvent) => void);
+  onBeforeSend?: ((e: BeforeSendEvent) => void) | null;
   onContentReady?: ((e: ContentReadyEvent) => void);
   onDisposing?: ((e: FileUploaderDisposingEvent) => void);
-  onDropZoneEnter?: ((e: DropZoneEnterEvent) => void);
-  onDropZoneLeave?: ((e: DropZoneLeaveEvent) => void);
-  onFilesUploaded?: ((e: FilesUploadedEvent) => void);
+  onDropZoneEnter?: ((e: DropZoneEnterEvent) => void) | null;
+  onDropZoneLeave?: ((e: DropZoneLeaveEvent) => void) | null;
+  onFilesUploaded?: ((e: FilesUploadedEvent) => void) | null;
   onInitialized?: ((e: FileUploaderInitializedEvent) => void);
   onOptionChanged?: ((e: OptionChangedEvent) => void);
-  onProgress?: ((e: ProgressEvent) => void);
-  onUploadAborted?: ((e: UploadAbortedEvent) => void);
-  onUploaded?: ((e: UploadedEvent) => void);
-  onUploadError?: ((e: UploadErrorEvent) => void);
-  onUploadStarted?: ((e: UploadStartedEvent) => void);
-  onValueChanged?: ((e: ValueChangedEvent) => void);
+  onProgress?: ((e: ProgressEvent) => void) | null;
+  onUploadAborted?: ((e: UploadAbortedEvent) => void) | null;
+  onUploaded?: ((e: UploadedEvent) => void) | null;
+  onUploadError?: ((e: UploadErrorEvent) => void) | null;
+  onUploadStarted?: ((e: UploadStartedEvent) => void) | null;
+  onValueChanged?: ((e: ValueChangedEvent) => void) | null;
   progress?: number;
   readOnly?: boolean;
   readyToUploadMessage?: string;
@@ -329,8 +329,8 @@ type IFileUploaderOptionsProps = React.PropsWithChildren<{
   uploadMethod?: UploadHttpMethod;
   uploadMode?: FileUploadMode;
   uploadUrl?: string;
-  validationError?: any;
-  validationErrors?: Array<any>;
+  validationError?: any | null;
+  validationErrors?: Array<any> | null;
   validationStatus?: ValidationStatus;
   value?: Array<any>;
   visible?: boolean;
@@ -532,9 +532,9 @@ type ISuggestionsProps = React.PropsWithChildren<{
   onContentReady?: ((e: ButtonGroupContentReadyEvent) => void);
   onDisposing?: ((e: ButtonGroupDisposingEvent) => void);
   onInitialized?: ((e: ButtonGroupInitializedEvent) => void);
-  onItemClick?: ((e: ItemClickEvent) => void);
+  onItemClick?: ((e: ItemClickEvent) => void) | null;
   onOptionChanged?: ((e: ButtonGroupOptionChangedEvent) => void);
-  onSelectionChanged?: ((e: SelectionChangedEvent) => void);
+  onSelectionChanged?: ((e: SelectionChangedEvent) => void) | null;
   rtlEnabled?: boolean;
   selectedItemKeys?: Array<any>;
   selectedItems?: Array<any>;
diff --git a/packages/devextreme-react/src/check-box.ts b/packages/devextreme-react/src/check-box.ts
index 1e25a211fc80..36fdb4a50695 100644
--- a/packages/devextreme-react/src/check-box.ts
+++ b/packages/devextreme-react/src/check-box.ts
@@ -21,8 +21,8 @@ type ICheckBoxOptionsNarrowedEvents = {
 }
 
 type ICheckBoxOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, ICheckBoxOptionsNarrowedEvents> & IHtmlOptions & {
-  defaultValue?: boolean | null | undefined;
-  onValueChange?: (value: boolean | null | undefined) => void;
+  defaultValue?: boolean | null;
+  onValueChange?: (value: boolean | null) => void;
 }>
 
 interface CheckBoxRef {
diff --git a/packages/devextreme-react/src/circular-gauge.ts b/packages/devextreme-react/src/circular-gauge.ts
index 85c4d650ecb4..146a479d2fbd 100644
--- a/packages/devextreme-react/src/circular-gauge.ts
+++ b/packages/devextreme-react/src/circular-gauge.ts
@@ -33,10 +33,10 @@ type ICircularGaugeOptions = React.PropsWithChildren<ReplaceFieldTypes<Propertie
   centerRender?: (...params: any) => React.ReactNode;
   centerComponent?: React.ComponentType<any>;
   defaultLoadingIndicator?: Record<string, any>;
-  defaultSubvalues?: Array<number>;
+  defaultSubvalues?: Array<number> | undefined;
   defaultValue?: number | undefined;
   onLoadingIndicatorChange?: (value: Record<string, any>) => void;
-  onSubvaluesChange?: (value: Array<number>) => void;
+  onSubvaluesChange?: (value: Array<number> | undefined) => void;
   onValueChange?: (value: number | undefined) => void;
 }>
 
@@ -445,8 +445,8 @@ const RangeContainer = Object.assign<typeof _componentRangeContainer, NestedComp
 // CircularGauge
 type IScaleProps = React.PropsWithChildren<{
   allowDecimals?: boolean | undefined;
-  customMinorTicks?: Array<number>;
-  customTicks?: Array<number>;
+  customMinorTicks?: Array<number> | undefined;
+  customTicks?: Array<number> | undefined;
   endValue?: number;
   label?: Record<string, any> | {
     customizeText?: ((scaleValue: { value: number, valueText: string }) => string);
diff --git a/packages/devextreme-react/src/color-box.ts b/packages/devextreme-react/src/color-box.ts
index b696bc08227b..dca43459b314 100644
--- a/packages/devextreme-react/src/color-box.ts
+++ b/packages/devextreme-react/src/color-box.ts
@@ -248,18 +248,18 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void);
+  onContentReady?: ((e: EventInfo<any>) => void) | null;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void);
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
@@ -461,7 +461,7 @@ type IOptionsProps = React.PropsWithChildren<{
   hint?: string | undefined;
   hoverStateEnabled?: boolean;
   icon?: string;
-  onClick?: ((e: ClickEvent) => void);
+  onClick?: ((e: ClickEvent) => void) | undefined;
   onContentReady?: ((e: ContentReadyEvent) => void);
   onDisposing?: ((e: ButtonDisposingEvent) => void);
   onInitialized?: ((e: ButtonInitializedEvent) => void);
diff --git a/packages/devextreme-react/src/context-menu.ts b/packages/devextreme-react/src/context-menu.ts
index acd941a2d38f..478b93938a0a 100644
--- a/packages/devextreme-react/src/context-menu.ts
+++ b/packages/devextreme-react/src/context-menu.ts
@@ -21,15 +21,15 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 type IContextMenuOptionsNarrowedEvents<TItem = any, TKey = any> = {
   onContentReady?: ((e: ContentReadyEvent<TItem, TKey>) => void);
   onDisposing?: ((e: DisposingEvent<TItem, TKey>) => void);
-  onHidden?: ((e: HiddenEvent<TItem, TKey>) => void);
-  onHiding?: ((e: HidingEvent<TItem, TKey>) => void);
+  onHidden?: ((e: HiddenEvent<TItem, TKey>) => void) | null;
+  onHiding?: ((e: HidingEvent<TItem, TKey>) => void) | null;
   onInitialized?: ((e: InitializedEvent<TItem, TKey>) => void);
   onItemClick?: ((e: ItemClickEvent<TItem, TKey>) => void);
   onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void);
   onItemRendered?: ((e: ItemRenderedEvent<TItem, TKey>) => void);
-  onPositioning?: ((e: PositioningEvent<TItem, TKey>) => void);
-  onShowing?: ((e: ShowingEvent<TItem, TKey>) => void);
-  onShown?: ((e: ShownEvent<TItem, TKey>) => void);
+  onPositioning?: ((e: PositioningEvent<TItem, TKey>) => void) | null;
+  onShowing?: ((e: ShowingEvent<TItem, TKey>) => void) | null;
+  onShown?: ((e: ShownEvent<TItem, TKey>) => void) | null;
 }
 
 type IContextMenuOptions<TItem = any, TKey = any> = React.PropsWithChildren<ReplaceFieldTypes<Properties<TItem, TKey>, IContextMenuOptionsNarrowedEvents<TItem, TKey>> & IHtmlOptions & {
@@ -37,10 +37,10 @@ type IContextMenuOptions<TItem = any, TKey = any> = React.PropsWithChildren<Repl
   itemRender?: (...params: any) => React.ReactNode;
   itemComponent?: React.ComponentType<any>;
   defaultItems?: Array<any | dxContextMenuItem>;
-  defaultSelectedItem?: any;
+  defaultSelectedItem?: any | null;
   defaultVisible?: boolean;
   onItemsChange?: (value: Array<any | dxContextMenuItem>) => void;
-  onSelectedItemChange?: (value: any) => void;
+  onSelectedItemChange?: (value: any | null) => void;
   onVisibleChange?: (value: boolean) => void;
 }>
 
diff --git a/packages/devextreme-react/src/data-grid.ts b/packages/devextreme-react/src/data-grid.ts
index 285e527e5e4d..ac30ec0cf05b 100644
--- a/packages/devextreme-react/src/data-grid.ts
+++ b/packages/devextreme-react/src/data-grid.ts
@@ -461,7 +461,7 @@ type IButtonOptionsProps = React.PropsWithChildren<{
   hint?: string | undefined;
   hoverStateEnabled?: boolean;
   icon?: string;
-  onClick?: ((e: ClickEvent) => void);
+  onClick?: ((e: ClickEvent) => void) | undefined;
   onContentReady?: ((e: ButtonContentReadyEvent) => void);
   onDisposing?: ((e: ButtonDisposingEvent) => void);
   onInitialized?: ((e: ButtonInitializedEvent) => void);
@@ -1308,7 +1308,7 @@ const EditingTexts = Object.assign<typeof _componentEditingTexts, NestedComponen
 type IEditorOptionsProps = React.PropsWithChildren<{
   accessKey?: string | undefined;
   activeStateEnabled?: boolean;
-  buttons?: Array<string | TextBoxPredefinedButton | TextEditorButton>;
+  buttons?: Array<string | TextBoxPredefinedButton | TextEditorButton> | undefined;
   disabled?: boolean;
   elementAttr?: Record<string, any>;
   focusStateEnabled?: boolean;
@@ -1324,7 +1324,7 @@ type IEditorOptionsProps = React.PropsWithChildren<{
   maskChar?: string;
   maskInvalidMessage?: string;
   maskRules?: any;
-  maxLength?: number | string;
+  maxLength?: null | number | string;
   mode?: TextBoxType;
   name?: string;
   onChange?: ((e: ChangeEvent) => void);
@@ -1352,8 +1352,8 @@ type IEditorOptionsProps = React.PropsWithChildren<{
   tabIndex?: number;
   text?: string;
   useMaskedValue?: boolean;
-  validationError?: any;
-  validationErrors?: Array<any>;
+  validationError?: any | null;
+  validationErrors?: Array<any> | null;
   validationMessageMode?: ValidationMessageMode;
   validationMessagePosition?: CommonPosition;
   validationStatus?: ValidationStatus;
@@ -1680,18 +1680,18 @@ type IFilterBuilderPopupProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void);
+  onContentReady?: ((e: EventInfo<any>) => void) | null;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void);
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
@@ -2730,7 +2730,7 @@ type IOptionsProps = React.PropsWithChildren<{
   hint?: string | undefined;
   hoverStateEnabled?: boolean;
   icon?: string;
-  onClick?: ((e: ClickEvent) => void);
+  onClick?: ((e: ClickEvent) => void) | undefined;
   onContentReady?: ((e: ContentReadyEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
@@ -2874,18 +2874,18 @@ type IPopupProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void);
+  onContentReady?: ((e: EventInfo<any>) => void) | null;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void);
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
@@ -3645,14 +3645,14 @@ type ITabPanelOptionsProps = React.PropsWithChildren<{
   onSelectionChanged?: ((e: SelectionChangedEvent) => void);
   onSelectionChanging?: ((e: SelectionChangingEvent) => void);
   onTitleClick?: ((e: TitleClickEvent) => void);
-  onTitleHold?: ((e: TitleHoldEvent) => void);
-  onTitleRendered?: ((e: TitleRenderedEvent) => void);
+  onTitleHold?: ((e: TitleHoldEvent) => void) | null;
+  onTitleRendered?: ((e: TitleRenderedEvent) => void) | null;
   repaintChangesOnly?: boolean;
   rtlEnabled?: boolean;
   scrollByContent?: boolean;
   scrollingEnabled?: boolean;
   selectedIndex?: number;
-  selectedItem?: any;
+  selectedItem?: any | null;
   showNavButtons?: boolean;
   stylingMode?: TabsStyle;
   swipeEnabled?: boolean;
@@ -3664,8 +3664,8 @@ type ITabPanelOptionsProps = React.PropsWithChildren<{
   onItemsChange?: (value: Array<any | dxTabPanelItem | string>) => void;
   defaultSelectedIndex?: number;
   onSelectedIndexChange?: (value: number) => void;
-  defaultSelectedItem?: any;
-  onSelectedItemChange?: (value: any) => void;
+  defaultSelectedItem?: any | null;
+  onSelectedItemChange?: (value: any | null) => void;
   itemRender?: (...params: any) => React.ReactNode;
   itemComponent?: React.ComponentType<any>;
   itemTitleRender?: (...params: any) => React.ReactNode;
diff --git a/packages/devextreme-react/src/date-box.ts b/packages/devextreme-react/src/date-box.ts
index 6e7880649947..6fb214feab28 100644
--- a/packages/devextreme-react/src/date-box.ts
+++ b/packages/devextreme-react/src/date-box.ts
@@ -207,7 +207,7 @@ type ICalendarOptionsProps = React.PropsWithChildren<{
   cellTemplate?: ((itemData: { date: Date, text: string, view: string }, itemIndex: number, itemElement: any) => string | any) | template;
   dateSerializationFormat?: string | undefined;
   disabled?: boolean;
-  disabledDates?: Array<Date> | ((data: DisabledDate) => boolean);
+  disabledDates?: Array<Date> | ((data: DisabledDate) => boolean) | null;
   elementAttr?: Record<string, any>;
   firstDayOfWeek?: DayOfWeek | undefined;
   focusStateEnabled?: boolean;
@@ -233,8 +233,8 @@ type ICalendarOptionsProps = React.PropsWithChildren<{
   showWeekNumbers?: boolean;
   tabIndex?: number;
   todayButtonText?: string;
-  validationError?: any;
-  validationErrors?: Array<any>;
+  validationError?: any | null;
+  validationErrors?: Array<any> | null;
   validationMessageMode?: ValidationMessageMode;
   validationMessagePosition?: CommonPosition;
   validationStatus?: ValidationStatus;
@@ -341,18 +341,18 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void);
+  onContentReady?: ((e: EventInfo<any>) => void) | null;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void);
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
@@ -522,7 +522,7 @@ type IOptionsProps = React.PropsWithChildren<{
   hint?: string | undefined;
   hoverStateEnabled?: boolean;
   icon?: string;
-  onClick?: ((e: ClickEvent) => void);
+  onClick?: ((e: ClickEvent) => void) | undefined;
   onContentReady?: ((e: ButtonContentReadyEvent) => void);
   onDisposing?: ((e: ButtonDisposingEvent) => void);
   onInitialized?: ((e: ButtonInitializedEvent) => void);
diff --git a/packages/devextreme-react/src/date-range-box.ts b/packages/devextreme-react/src/date-range-box.ts
index c50293fffbf2..36a47cf76269 100644
--- a/packages/devextreme-react/src/date-range-box.ts
+++ b/packages/devextreme-react/src/date-range-box.ts
@@ -212,7 +212,7 @@ type ICalendarOptionsProps = React.PropsWithChildren<{
   cellTemplate?: ((itemData: { date: Date, text: string, view: string }, itemIndex: number, itemElement: any) => string | any) | template;
   dateSerializationFormat?: string | undefined;
   disabled?: boolean;
-  disabledDates?: Array<Date> | ((data: DisabledDate) => boolean);
+  disabledDates?: Array<Date> | ((data: DisabledDate) => boolean) | null;
   elementAttr?: Record<string, any>;
   firstDayOfWeek?: DayOfWeek | undefined;
   focusStateEnabled?: boolean;
@@ -238,8 +238,8 @@ type ICalendarOptionsProps = React.PropsWithChildren<{
   showWeekNumbers?: boolean;
   tabIndex?: number;
   todayButtonText?: string;
-  validationError?: any;
-  validationErrors?: Array<any>;
+  validationError?: any | null;
+  validationErrors?: Array<any> | null;
   validationMessageMode?: ValidationMessageMode;
   validationMessagePosition?: CommonPosition;
   validationStatus?: ValidationStatus;
@@ -346,18 +346,18 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void);
+  onContentReady?: ((e: EventInfo<any>) => void) | null;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void);
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
@@ -527,7 +527,7 @@ type IOptionsProps = React.PropsWithChildren<{
   hint?: string | undefined;
   hoverStateEnabled?: boolean;
   icon?: string;
-  onClick?: ((e: ClickEvent) => void);
+  onClick?: ((e: ClickEvent) => void) | undefined;
   onContentReady?: ((e: ButtonContentReadyEvent) => void);
   onDisposing?: ((e: ButtonDisposingEvent) => void);
   onInitialized?: ((e: ButtonInitializedEvent) => void);
diff --git a/packages/devextreme-react/src/diagram.ts b/packages/devextreme-react/src/diagram.ts
index 94c717cb9610..56a2eac4c2fd 100644
--- a/packages/devextreme-react/src/diagram.ts
+++ b/packages/devextreme-react/src/diagram.ts
@@ -25,10 +25,10 @@ type IDiagramOptionsNarrowedEvents = {
   onCustomCommand?: ((e: CustomCommandEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
-  onItemClick?: ((e: ItemClickEvent) => void);
-  onItemDblClick?: ((e: ItemDblClickEvent) => void);
-  onRequestEditOperation?: ((e: RequestEditOperationEvent) => void);
-  onRequestLayoutUpdate?: ((e: RequestLayoutUpdateEvent) => void);
+  onItemClick?: ((e: ItemClickEvent) => void) | null;
+  onItemDblClick?: ((e: ItemDblClickEvent) => void) | null;
+  onRequestEditOperation?: ((e: RequestEditOperationEvent) => void) | null;
+  onRequestLayoutUpdate?: ((e: RequestLayoutUpdateEvent) => void) | null;
 }
 
 type IDiagramOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IDiagramOptionsNarrowedEvents> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/drop-down-box.ts b/packages/devextreme-react/src/drop-down-box.ts
index 05222546cc2f..c50a3ed74754 100644
--- a/packages/devextreme-react/src/drop-down-box.ts
+++ b/packages/devextreme-react/src/drop-down-box.ts
@@ -252,18 +252,18 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void);
+  onContentReady?: ((e: EventInfo<any>) => void) | null;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void);
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
@@ -465,7 +465,7 @@ type IOptionsProps = React.PropsWithChildren<{
   hint?: string | undefined;
   hoverStateEnabled?: boolean;
   icon?: string;
-  onClick?: ((e: ClickEvent) => void);
+  onClick?: ((e: ClickEvent) => void) | undefined;
   onContentReady?: ((e: ContentReadyEvent) => void);
   onDisposing?: ((e: ButtonDisposingEvent) => void);
   onInitialized?: ((e: ButtonInitializedEvent) => void);
diff --git a/packages/devextreme-react/src/drop-down-button.ts b/packages/devextreme-react/src/drop-down-button.ts
index 528e0d883b23..e6996d09dd2e 100644
--- a/packages/devextreme-react/src/drop-down-button.ts
+++ b/packages/devextreme-react/src/drop-down-button.ts
@@ -207,18 +207,18 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void);
+  onContentReady?: ((e: EventInfo<any>) => void) | null;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void);
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
diff --git a/packages/devextreme-react/src/file-manager.ts b/packages/devextreme-react/src/file-manager.ts
index 72d11a9b0ad3..cae587360121 100644
--- a/packages/devextreme-react/src/file-manager.ts
+++ b/packages/devextreme-react/src/file-manager.ts
@@ -18,25 +18,25 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 
 type IFileManagerOptionsNarrowedEvents = {
   onContentReady?: ((e: ContentReadyEvent) => void);
-  onContextMenuItemClick?: ((e: ContextMenuItemClickEvent) => void);
-  onContextMenuShowing?: ((e: ContextMenuShowingEvent) => void);
-  onDirectoryCreated?: ((e: DirectoryCreatedEvent) => void);
-  onDirectoryCreating?: ((e: DirectoryCreatingEvent) => void);
+  onContextMenuItemClick?: ((e: ContextMenuItemClickEvent) => void) | undefined;
+  onContextMenuShowing?: ((e: ContextMenuShowingEvent) => void) | undefined;
+  onDirectoryCreated?: ((e: DirectoryCreatedEvent) => void) | undefined;
+  onDirectoryCreating?: ((e: DirectoryCreatingEvent) => void) | undefined;
   onDisposing?: ((e: DisposingEvent) => void);
-  onErrorOccurred?: ((e: ErrorOccurredEvent) => void);
-  onFileUploaded?: ((e: FileUploadedEvent) => void);
-  onFileUploading?: ((e: FileUploadingEvent) => void);
+  onErrorOccurred?: ((e: ErrorOccurredEvent) => void) | undefined;
+  onFileUploaded?: ((e: FileUploadedEvent) => void) | undefined;
+  onFileUploading?: ((e: FileUploadingEvent) => void) | undefined;
   onInitialized?: ((e: InitializedEvent) => void);
-  onItemCopied?: ((e: ItemCopiedEvent) => void);
-  onItemCopying?: ((e: ItemCopyingEvent) => void);
-  onItemDeleted?: ((e: ItemDeletedEvent) => void);
-  onItemDeleting?: ((e: ItemDeletingEvent) => void);
-  onItemDownloading?: ((e: ItemDownloadingEvent) => void);
-  onItemMoved?: ((e: ItemMovedEvent) => void);
-  onItemMoving?: ((e: ItemMovingEvent) => void);
-  onItemRenamed?: ((e: ItemRenamedEvent) => void);
-  onItemRenaming?: ((e: ItemRenamingEvent) => void);
-  onSelectedFileOpened?: ((e: SelectedFileOpenedEvent) => void);
+  onItemCopied?: ((e: ItemCopiedEvent) => void) | undefined;
+  onItemCopying?: ((e: ItemCopyingEvent) => void) | undefined;
+  onItemDeleted?: ((e: ItemDeletedEvent) => void) | undefined;
+  onItemDeleting?: ((e: ItemDeletingEvent) => void) | undefined;
+  onItemDownloading?: ((e: ItemDownloadingEvent) => void) | undefined;
+  onItemMoved?: ((e: ItemMovedEvent) => void) | undefined;
+  onItemMoving?: ((e: ItemMovingEvent) => void) | undefined;
+  onItemRenamed?: ((e: ItemRenamedEvent) => void) | undefined;
+  onItemRenaming?: ((e: ItemRenamingEvent) => void) | undefined;
+  onSelectedFileOpened?: ((e: SelectedFileOpenedEvent) => void) | undefined;
   onToolbarItemClick?: ((e: ToolbarItemClickEvent) => void);
 }
 
diff --git a/packages/devextreme-react/src/file-uploader.ts b/packages/devextreme-react/src/file-uploader.ts
index c6e219b48d73..1c8904840549 100644
--- a/packages/devextreme-react/src/file-uploader.ts
+++ b/packages/devextreme-react/src/file-uploader.ts
@@ -14,19 +14,19 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 }
 
 type IFileUploaderOptionsNarrowedEvents = {
-  onBeforeSend?: ((e: BeforeSendEvent) => void);
+  onBeforeSend?: ((e: BeforeSendEvent) => void) | null;
   onContentReady?: ((e: ContentReadyEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
-  onDropZoneEnter?: ((e: DropZoneEnterEvent) => void);
-  onDropZoneLeave?: ((e: DropZoneLeaveEvent) => void);
-  onFilesUploaded?: ((e: FilesUploadedEvent) => void);
+  onDropZoneEnter?: ((e: DropZoneEnterEvent) => void) | null;
+  onDropZoneLeave?: ((e: DropZoneLeaveEvent) => void) | null;
+  onFilesUploaded?: ((e: FilesUploadedEvent) => void) | null;
   onInitialized?: ((e: InitializedEvent) => void);
-  onProgress?: ((e: ProgressEvent) => void);
-  onUploadAborted?: ((e: UploadAbortedEvent) => void);
-  onUploaded?: ((e: UploadedEvent) => void);
-  onUploadError?: ((e: UploadErrorEvent) => void);
-  onUploadStarted?: ((e: UploadStartedEvent) => void);
-  onValueChanged?: ((e: ValueChangedEvent) => void);
+  onProgress?: ((e: ProgressEvent) => void) | null;
+  onUploadAborted?: ((e: UploadAbortedEvent) => void) | null;
+  onUploaded?: ((e: UploadedEvent) => void) | null;
+  onUploadError?: ((e: UploadErrorEvent) => void) | null;
+  onUploadStarted?: ((e: UploadStartedEvent) => void) | null;
+  onValueChanged?: ((e: ValueChangedEvent) => void) | null;
 }
 
 type IFileUploaderOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IFileUploaderOptionsNarrowedEvents> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/form.ts b/packages/devextreme-react/src/form.ts
index 054218d9e6c6..a24d55ef2291 100644
--- a/packages/devextreme-react/src/form.ts
+++ b/packages/devextreme-react/src/form.ts
@@ -178,7 +178,7 @@ type IButtonOptionsProps = React.PropsWithChildren<{
   hint?: string | undefined;
   hoverStateEnabled?: boolean;
   icon?: string;
-  onClick?: ((e: ClickEvent) => void);
+  onClick?: ((e: ClickEvent) => void) | undefined;
   onContentReady?: ((e: ButtonContentReadyEvent) => void);
   onDisposing?: ((e: ButtonDisposingEvent) => void);
   onInitialized?: ((e: ButtonInitializedEvent) => void);
@@ -870,14 +870,14 @@ type ITabPanelOptionsProps = React.PropsWithChildren<{
   onSelectionChanged?: ((e: SelectionChangedEvent) => void);
   onSelectionChanging?: ((e: SelectionChangingEvent) => void);
   onTitleClick?: ((e: TitleClickEvent) => void);
-  onTitleHold?: ((e: TitleHoldEvent) => void);
-  onTitleRendered?: ((e: TitleRenderedEvent) => void);
+  onTitleHold?: ((e: TitleHoldEvent) => void) | null;
+  onTitleRendered?: ((e: TitleRenderedEvent) => void) | null;
   repaintChangesOnly?: boolean;
   rtlEnabled?: boolean;
   scrollByContent?: boolean;
   scrollingEnabled?: boolean;
   selectedIndex?: number;
-  selectedItem?: any;
+  selectedItem?: any | null;
   showNavButtons?: boolean;
   stylingMode?: TabsStyle;
   swipeEnabled?: boolean;
@@ -889,8 +889,8 @@ type ITabPanelOptionsProps = React.PropsWithChildren<{
   onItemsChange?: (value: Array<any | dxTabPanelItem | string>) => void;
   defaultSelectedIndex?: number;
   onSelectedIndexChange?: (value: number) => void;
-  defaultSelectedItem?: any;
-  onSelectedItemChange?: (value: any) => void;
+  defaultSelectedItem?: any | null;
+  onSelectedItemChange?: (value: any | null) => void;
   itemRender?: (...params: any) => React.ReactNode;
   itemComponent?: React.ComponentType<any>;
   itemTitleRender?: (...params: any) => React.ReactNode;
diff --git a/packages/devextreme-react/src/funnel.ts b/packages/devextreme-react/src/funnel.ts
index d81e56c35a6e..2310654e5eb5 100644
--- a/packages/devextreme-react/src/funnel.ts
+++ b/packages/devextreme-react/src/funnel.ts
@@ -548,9 +548,9 @@ type ILegendProps = React.PropsWithChildren<{
     subtitle?: Record<string, any> | string | {
       font?: ChartsFont;
       offset?: number;
-      text?: string;
+      text?: string | undefined;
     };
-    text?: string;
+    text?: string | undefined;
     verticalAlignment?: VerticalEdge;
   };
   verticalAlignment?: VerticalEdge;
@@ -622,9 +622,9 @@ type ILegendTitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
   };
-  text?: string;
+  text?: string | undefined;
   verticalAlignment?: VerticalEdge;
 }>
 const _componentLegendTitle = (props: ILegendTitleProps) => {
@@ -651,7 +651,7 @@ const LegendTitle = Object.assign<typeof _componentLegendTitle, NestedComponentM
 type ILegendTitleSubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
 }>
 const _componentLegendTitleSubtitle = (props: ILegendTitleSubtitleProps) => {
   return React.createElement(NestedOption<ILegendTitleSubtitleProps>, {
@@ -803,7 +803,7 @@ const Size = Object.assign<typeof _componentSize, NestedComponentMeta>(_componen
 type ISubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
 }>
@@ -839,11 +839,11 @@ type ITitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
     textOverflow?: TextOverflow;
     wordWrap?: WordWrap;
   };
-  text?: string;
+  text?: string | undefined;
   verticalAlignment?: VerticalEdge;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
diff --git a/packages/devextreme-react/src/gallery.ts b/packages/devextreme-react/src/gallery.ts
index 8347e0837542..d17b0b2d0d03 100644
--- a/packages/devextreme-react/src/gallery.ts
+++ b/packages/devextreme-react/src/gallery.ts
@@ -33,10 +33,10 @@ type IGalleryOptions<TItem = any, TKey = any> = React.PropsWithChildren<ReplaceF
   itemComponent?: React.ComponentType<any>;
   defaultItems?: Array<any | dxGalleryItem | string>;
   defaultSelectedIndex?: number;
-  defaultSelectedItem?: any;
+  defaultSelectedItem?: any | null;
   onItemsChange?: (value: Array<any | dxGalleryItem | string>) => void;
   onSelectedIndexChange?: (value: number) => void;
-  onSelectedItemChange?: (value: any) => void;
+  onSelectedItemChange?: (value: any | null) => void;
 }>
 
 interface GalleryRef<TItem = any, TKey = any> {
diff --git a/packages/devextreme-react/src/gantt.ts b/packages/devextreme-react/src/gantt.ts
index 75f6b712daf8..ff7d7f7b4051 100644
--- a/packages/devextreme-react/src/gantt.ts
+++ b/packages/devextreme-react/src/gantt.ts
@@ -28,34 +28,34 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 
 type IGanttOptionsNarrowedEvents = {
   onContentReady?: ((e: ContentReadyEvent) => void);
-  onContextMenuPreparing?: ((e: ContextMenuPreparingEvent) => void);
-  onCustomCommand?: ((e: CustomCommandEvent) => void);
-  onDependencyDeleted?: ((e: DependencyDeletedEvent) => void);
-  onDependencyDeleting?: ((e: DependencyDeletingEvent) => void);
-  onDependencyInserted?: ((e: DependencyInsertedEvent) => void);
-  onDependencyInserting?: ((e: DependencyInsertingEvent) => void);
+  onContextMenuPreparing?: ((e: ContextMenuPreparingEvent) => void) | null;
+  onCustomCommand?: ((e: CustomCommandEvent) => void) | null;
+  onDependencyDeleted?: ((e: DependencyDeletedEvent) => void) | null;
+  onDependencyDeleting?: ((e: DependencyDeletingEvent) => void) | null;
+  onDependencyInserted?: ((e: DependencyInsertedEvent) => void) | null;
+  onDependencyInserting?: ((e: DependencyInsertingEvent) => void) | null;
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
-  onResourceAssigned?: ((e: ResourceAssignedEvent) => void);
-  onResourceAssigning?: ((e: ResourceAssigningEvent) => void);
-  onResourceDeleted?: ((e: ResourceDeletedEvent) => void);
-  onResourceDeleting?: ((e: ResourceDeletingEvent) => void);
-  onResourceInserted?: ((e: ResourceInsertedEvent) => void);
-  onResourceInserting?: ((e: ResourceInsertingEvent) => void);
-  onResourceManagerDialogShowing?: ((e: ResourceManagerDialogShowingEvent) => void);
-  onResourceUnassigned?: ((e: ResourceUnassignedEvent) => void);
-  onResourceUnassigning?: ((e: ResourceUnassigningEvent) => void);
-  onScaleCellPrepared?: ((e: ScaleCellPreparedEvent) => void);
-  onTaskClick?: ((e: TaskClickEvent) => void);
-  onTaskDblClick?: ((e: TaskDblClickEvent) => void);
-  onTaskDeleted?: ((e: TaskDeletedEvent) => void);
-  onTaskDeleting?: ((e: TaskDeletingEvent) => void);
-  onTaskEditDialogShowing?: ((e: TaskEditDialogShowingEvent) => void);
-  onTaskInserted?: ((e: TaskInsertedEvent) => void);
-  onTaskInserting?: ((e: TaskInsertingEvent) => void);
-  onTaskMoving?: ((e: TaskMovingEvent) => void);
-  onTaskUpdated?: ((e: TaskUpdatedEvent) => void);
-  onTaskUpdating?: ((e: TaskUpdatingEvent) => void);
+  onResourceAssigned?: ((e: ResourceAssignedEvent) => void) | null;
+  onResourceAssigning?: ((e: ResourceAssigningEvent) => void) | null;
+  onResourceDeleted?: ((e: ResourceDeletedEvent) => void) | null;
+  onResourceDeleting?: ((e: ResourceDeletingEvent) => void) | null;
+  onResourceInserted?: ((e: ResourceInsertedEvent) => void) | null;
+  onResourceInserting?: ((e: ResourceInsertingEvent) => void) | null;
+  onResourceManagerDialogShowing?: ((e: ResourceManagerDialogShowingEvent) => void) | undefined;
+  onResourceUnassigned?: ((e: ResourceUnassignedEvent) => void) | null;
+  onResourceUnassigning?: ((e: ResourceUnassigningEvent) => void) | null;
+  onScaleCellPrepared?: ((e: ScaleCellPreparedEvent) => void) | undefined;
+  onTaskClick?: ((e: TaskClickEvent) => void) | null;
+  onTaskDblClick?: ((e: TaskDblClickEvent) => void) | null;
+  onTaskDeleted?: ((e: TaskDeletedEvent) => void) | null;
+  onTaskDeleting?: ((e: TaskDeletingEvent) => void) | null;
+  onTaskEditDialogShowing?: ((e: TaskEditDialogShowingEvent) => void) | null;
+  onTaskInserted?: ((e: TaskInsertedEvent) => void) | null;
+  onTaskInserting?: ((e: TaskInsertingEvent) => void) | null;
+  onTaskMoving?: ((e: TaskMovingEvent) => void) | null;
+  onTaskUpdated?: ((e: TaskUpdatedEvent) => void) | null;
+  onTaskUpdating?: ((e: TaskUpdatingEvent) => void) | null;
 }
 
 type IGanttOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IGanttOptionsNarrowedEvents> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/html-editor.ts b/packages/devextreme-react/src/html-editor.ts
index dbe6f550fcf0..eb39ab9a0fed 100644
--- a/packages/devextreme-react/src/html-editor.ts
+++ b/packages/devextreme-react/src/html-editor.ts
@@ -26,15 +26,15 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 type IHtmlEditorOptionsNarrowedEvents = {
   onContentReady?: ((e: ContentReadyEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
-  onFocusIn?: ((e: FocusInEvent) => void);
-  onFocusOut?: ((e: FocusOutEvent) => void);
+  onFocusIn?: ((e: FocusInEvent) => void) | undefined;
+  onFocusOut?: ((e: FocusOutEvent) => void) | undefined;
   onInitialized?: ((e: InitializedEvent) => void);
   onValueChanged?: ((e: ValueChangedEvent) => void);
 }
 
 type IHtmlEditorOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IHtmlEditorOptionsNarrowedEvents> & IHtmlOptions & {
-  defaultValue?: any;
-  onValueChange?: (value: any) => void;
+  defaultValue?: any | null;
+  onValueChange?: (value: any | null) => void;
 }>
 
 interface HtmlEditorRef {
@@ -158,20 +158,20 @@ type IFileUploaderOptionsProps = React.PropsWithChildren<{
   minFileSize?: number;
   multiple?: boolean;
   name?: string;
-  onBeforeSend?: ((e: BeforeSendEvent) => void);
+  onBeforeSend?: ((e: BeforeSendEvent) => void) | null;
   onContentReady?: ((e: FileUploaderContentReadyEvent) => void);
   onDisposing?: ((e: FileUploaderDisposingEvent) => void);
-  onDropZoneEnter?: ((e: DropZoneEnterEvent) => void);
-  onDropZoneLeave?: ((e: DropZoneLeaveEvent) => void);
-  onFilesUploaded?: ((e: FilesUploadedEvent) => void);
+  onDropZoneEnter?: ((e: DropZoneEnterEvent) => void) | null;
+  onDropZoneLeave?: ((e: DropZoneLeaveEvent) => void) | null;
+  onFilesUploaded?: ((e: FilesUploadedEvent) => void) | null;
   onInitialized?: ((e: FileUploaderInitializedEvent) => void);
   onOptionChanged?: ((e: OptionChangedEvent) => void);
-  onProgress?: ((e: ProgressEvent) => void);
-  onUploadAborted?: ((e: UploadAbortedEvent) => void);
-  onUploaded?: ((e: UploadedEvent) => void);
-  onUploadError?: ((e: UploadErrorEvent) => void);
-  onUploadStarted?: ((e: UploadStartedEvent) => void);
-  onValueChanged?: ((e: FileUploaderValueChangedEvent) => void);
+  onProgress?: ((e: ProgressEvent) => void) | null;
+  onUploadAborted?: ((e: UploadAbortedEvent) => void) | null;
+  onUploaded?: ((e: UploadedEvent) => void) | null;
+  onUploadError?: ((e: UploadErrorEvent) => void) | null;
+  onUploadStarted?: ((e: UploadStartedEvent) => void) | null;
+  onValueChanged?: ((e: FileUploaderValueChangedEvent) => void) | null;
   progress?: number;
   readOnly?: boolean;
   readyToUploadMessage?: string;
@@ -190,8 +190,8 @@ type IFileUploaderOptionsProps = React.PropsWithChildren<{
   uploadMethod?: UploadHttpMethod;
   uploadMode?: FileUploadMode;
   uploadUrl?: string;
-  validationError?: any;
-  validationErrors?: Array<any>;
+  validationError?: any | null;
+  validationErrors?: Array<any> | null;
   validationStatus?: ValidationStatus;
   value?: Array<any>;
   visible?: boolean;
diff --git a/packages/devextreme-react/src/linear-gauge.ts b/packages/devextreme-react/src/linear-gauge.ts
index 0c7cdd7118d5..fe06ecb1a4c5 100644
--- a/packages/devextreme-react/src/linear-gauge.ts
+++ b/packages/devextreme-react/src/linear-gauge.ts
@@ -31,10 +31,10 @@ type ILinearGaugeOptionsNarrowedEvents = {
 
 type ILinearGaugeOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, ILinearGaugeOptionsNarrowedEvents> & IHtmlOptions & {
   defaultLoadingIndicator?: Record<string, any>;
-  defaultSubvalues?: Array<number>;
+  defaultSubvalues?: Array<number> | undefined;
   defaultValue?: number | undefined;
   onLoadingIndicatorChange?: (value: Record<string, any>) => void;
-  onSubvaluesChange?: (value: Array<number>) => void;
+  onSubvaluesChange?: (value: Array<number> | undefined) => void;
   onValueChange?: (value: number | undefined) => void;
 }>
 
@@ -437,8 +437,8 @@ const RangeContainer = Object.assign<typeof _componentRangeContainer, NestedComp
 // LinearGauge
 type IScaleProps = React.PropsWithChildren<{
   allowDecimals?: boolean | undefined;
-  customMinorTicks?: Array<number>;
-  customTicks?: Array<number>;
+  customMinorTicks?: Array<number> | undefined;
+  customTicks?: Array<number> | undefined;
   endValue?: number;
   horizontalOrientation?: HorizontalAlignment;
   label?: Record<string, any> | {
diff --git a/packages/devextreme-react/src/list.ts b/packages/devextreme-react/src/list.ts
index 5d9a88eff606..83d13440fe7c 100644
--- a/packages/devextreme-react/src/list.ts
+++ b/packages/devextreme-react/src/list.ts
@@ -23,20 +23,20 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 type IListOptionsNarrowedEvents<TItem = any, TKey = any> = {
   onContentReady?: ((e: ContentReadyEvent<TItem, TKey>) => void);
   onDisposing?: ((e: DisposingEvent<TItem, TKey>) => void);
-  onGroupRendered?: ((e: GroupRenderedEvent<TItem, TKey>) => void);
+  onGroupRendered?: ((e: GroupRenderedEvent<TItem, TKey>) => void) | null;
   onInitialized?: ((e: InitializedEvent<TItem, TKey>) => void);
   onItemClick?: ((e: ItemClickEvent<TItem, TKey>) => void);
-  onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void);
-  onItemDeleted?: ((e: ItemDeletedEvent<TItem, TKey>) => void);
-  onItemDeleting?: ((e: ItemDeletingEvent<TItem, TKey>) => void);
-  onItemHold?: ((e: ItemHoldEvent<TItem, TKey>) => void);
+  onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void) | null;
+  onItemDeleted?: ((e: ItemDeletedEvent<TItem, TKey>) => void) | null;
+  onItemDeleting?: ((e: ItemDeletingEvent<TItem, TKey>) => void) | null;
+  onItemHold?: ((e: ItemHoldEvent<TItem, TKey>) => void) | null;
   onItemRendered?: ((e: ItemRenderedEvent<TItem, TKey>) => void);
-  onItemReordered?: ((e: ItemReorderedEvent<TItem, TKey>) => void);
-  onItemSwipe?: ((e: ItemSwipeEvent<TItem, TKey>) => void);
-  onPageLoading?: ((e: PageLoadingEvent<TItem, TKey>) => void);
-  onPullRefresh?: ((e: PullRefreshEvent<TItem, TKey>) => void);
-  onScroll?: ((e: ScrollEvent<TItem, TKey>) => void);
-  onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent<TItem, TKey>) => void);
+  onItemReordered?: ((e: ItemReorderedEvent<TItem, TKey>) => void) | null;
+  onItemSwipe?: ((e: ItemSwipeEvent<TItem, TKey>) => void) | null;
+  onPageLoading?: ((e: PageLoadingEvent<TItem, TKey>) => void) | null;
+  onPullRefresh?: ((e: PullRefreshEvent<TItem, TKey>) => void) | null;
+  onScroll?: ((e: ScrollEvent<TItem, TKey>) => void) | null;
+  onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent<TItem, TKey>) => void) | null;
   onSelectionChanging?: ((e: SelectionChangingEvent<TItem, TKey>) => void);
 }
 
@@ -287,7 +287,7 @@ type IOptionsProps = React.PropsWithChildren<{
   hint?: string | undefined;
   hoverStateEnabled?: boolean;
   icon?: string;
-  onClick?: ((e: ClickEvent) => void);
+  onClick?: ((e: ClickEvent) => void) | undefined;
   onContentReady?: ((e: ButtonContentReadyEvent) => void);
   onDisposing?: ((e: ButtonDisposingEvent) => void);
   onInitialized?: ((e: ButtonInitializedEvent) => void);
@@ -328,7 +328,7 @@ const Options = Object.assign<typeof _componentOptions, NestedComponentMeta>(_co
 type ISearchEditorOptionsProps = React.PropsWithChildren<{
   accessKey?: string | undefined;
   activeStateEnabled?: boolean;
-  buttons?: Array<string | TextBoxPredefinedButton | TextEditorButton>;
+  buttons?: Array<string | TextBoxPredefinedButton | TextEditorButton> | undefined;
   disabled?: boolean;
   elementAttr?: Record<string, any>;
   focusStateEnabled?: boolean;
@@ -344,7 +344,7 @@ type ISearchEditorOptionsProps = React.PropsWithChildren<{
   maskChar?: string;
   maskInvalidMessage?: string;
   maskRules?: any;
-  maxLength?: number | string;
+  maxLength?: null | number | string;
   mode?: TextBoxType;
   name?: string;
   onChange?: ((e: ChangeEvent) => void);
@@ -372,8 +372,8 @@ type ISearchEditorOptionsProps = React.PropsWithChildren<{
   tabIndex?: number;
   text?: string;
   useMaskedValue?: boolean;
-  validationError?: any;
-  validationErrors?: Array<any>;
+  validationError?: any | null;
+  validationErrors?: Array<any> | null;
   validationMessageMode?: ValidationMessageMode;
   validationMessagePosition?: Position;
   validationStatus?: ValidationStatus;
diff --git a/packages/devextreme-react/src/lookup.ts b/packages/devextreme-react/src/lookup.ts
index e8e4ba676446..2795468da226 100644
--- a/packages/devextreme-react/src/lookup.ts
+++ b/packages/devextreme-react/src/lookup.ts
@@ -28,10 +28,10 @@ type ILookupOptionsNarrowedEvents = {
   onInitialized?: ((e: InitializedEvent) => void);
   onItemClick?: ((e: ItemClickEvent) => void);
   onOpened?: ((e: OpenedEvent) => void);
-  onPageLoading?: ((e: PageLoadingEvent) => void);
-  onPullRefresh?: ((e: PullRefreshEvent) => void);
-  onScroll?: ((e: ScrollEvent) => void);
-  onValueChanged?: ((e: ValueChangedEvent) => void);
+  onPageLoading?: ((e: PageLoadingEvent) => void) | null;
+  onPullRefresh?: ((e: PullRefreshEvent) => void) | null;
+  onScroll?: ((e: ScrollEvent) => void) | null;
+  onValueChanged?: ((e: ValueChangedEvent) => void) | null;
 }
 
 type ILookupOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, ILookupOptionsNarrowedEvents> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/map.ts b/packages/devextreme-react/src/map.ts
index dfaee1be9225..57067d2a5510 100644
--- a/packages/devextreme-react/src/map.ts
+++ b/packages/devextreme-react/src/map.ts
@@ -18,11 +18,11 @@ type IMapOptionsNarrowedEvents = {
   onClick?: ((e: ClickEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
-  onMarkerAdded?: ((e: MarkerAddedEvent) => void);
-  onMarkerRemoved?: ((e: MarkerRemovedEvent) => void);
-  onReady?: ((e: ReadyEvent) => void);
-  onRouteAdded?: ((e: RouteAddedEvent) => void);
-  onRouteRemoved?: ((e: RouteRemovedEvent) => void);
+  onMarkerAdded?: ((e: MarkerAddedEvent) => void) | null;
+  onMarkerRemoved?: ((e: MarkerRemovedEvent) => void) | null;
+  onReady?: ((e: ReadyEvent) => void) | null;
+  onRouteAdded?: ((e: RouteAddedEvent) => void) | null;
+  onRouteRemoved?: ((e: RouteRemovedEvent) => void) | null;
 }
 
 type IMapOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IMapOptionsNarrowedEvents> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/menu.ts b/packages/devextreme-react/src/menu.ts
index d0f32c537659..8954da19356f 100644
--- a/packages/devextreme-react/src/menu.ts
+++ b/packages/devextreme-react/src/menu.ts
@@ -25,10 +25,10 @@ type IMenuOptionsNarrowedEvents<TItem = any, TKey = any> = {
   onItemClick?: ((e: ItemClickEvent<TItem, TKey>) => void);
   onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void);
   onItemRendered?: ((e: ItemRenderedEvent<TItem, TKey>) => void);
-  onSubmenuHidden?: ((e: SubmenuHiddenEvent<TItem, TKey>) => void);
-  onSubmenuHiding?: ((e: SubmenuHidingEvent<TItem, TKey>) => void);
-  onSubmenuShowing?: ((e: SubmenuShowingEvent<TItem, TKey>) => void);
-  onSubmenuShown?: ((e: SubmenuShownEvent<TItem, TKey>) => void);
+  onSubmenuHidden?: ((e: SubmenuHiddenEvent<TItem, TKey>) => void) | null;
+  onSubmenuHiding?: ((e: SubmenuHidingEvent<TItem, TKey>) => void) | null;
+  onSubmenuShowing?: ((e: SubmenuShowingEvent<TItem, TKey>) => void) | null;
+  onSubmenuShown?: ((e: SubmenuShownEvent<TItem, TKey>) => void) | null;
 }
 
 type IMenuOptions<TItem = any, TKey = any> = React.PropsWithChildren<ReplaceFieldTypes<Properties<TItem, TKey>, IMenuOptionsNarrowedEvents<TItem, TKey>> & IHtmlOptions & {
@@ -36,9 +36,9 @@ type IMenuOptions<TItem = any, TKey = any> = React.PropsWithChildren<ReplaceFiel
   itemRender?: (...params: any) => React.ReactNode;
   itemComponent?: React.ComponentType<any>;
   defaultItems?: Array<any | dxMenuItem>;
-  defaultSelectedItem?: any;
+  defaultSelectedItem?: any | null;
   onItemsChange?: (value: Array<any | dxMenuItem>) => void;
-  onSelectedItemChange?: (value: any) => void;
+  onSelectedItemChange?: (value: any | null) => void;
 }>
 
 interface MenuRef<TItem = any, TKey = any> {
diff --git a/packages/devextreme-react/src/multi-view.ts b/packages/devextreme-react/src/multi-view.ts
index b52e8e9d56cb..329501d30de3 100644
--- a/packages/devextreme-react/src/multi-view.ts
+++ b/packages/devextreme-react/src/multi-view.ts
@@ -33,10 +33,10 @@ type IMultiViewOptions<TItem = any, TKey = any> = React.PropsWithChildren<Replac
   itemComponent?: React.ComponentType<any>;
   defaultItems?: Array<any | dxMultiViewItem | string>;
   defaultSelectedIndex?: number;
-  defaultSelectedItem?: any;
+  defaultSelectedItem?: any | null;
   onItemsChange?: (value: Array<any | dxMultiViewItem | string>) => void;
   onSelectedIndexChange?: (value: number) => void;
-  onSelectedItemChange?: (value: any) => void;
+  onSelectedItemChange?: (value: any | null) => void;
 }>
 
 interface MultiViewRef<TItem = any, TKey = any> {
diff --git a/packages/devextreme-react/src/number-box.ts b/packages/devextreme-react/src/number-box.ts
index 35e3966a2be6..0058c3bcb0b3 100644
--- a/packages/devextreme-react/src/number-box.ts
+++ b/packages/devextreme-react/src/number-box.ts
@@ -142,7 +142,7 @@ type IOptionsProps = React.PropsWithChildren<{
   hint?: string | undefined;
   hoverStateEnabled?: boolean;
   icon?: string;
-  onClick?: ((e: ClickEvent) => void);
+  onClick?: ((e: ClickEvent) => void) | undefined;
   onContentReady?: ((e: ButtonContentReadyEvent) => void);
   onDisposing?: ((e: ButtonDisposingEvent) => void);
   onInitialized?: ((e: ButtonInitializedEvent) => void);
diff --git a/packages/devextreme-react/src/pie-chart.ts b/packages/devextreme-react/src/pie-chart.ts
index d563f15bf286..0f164633a099 100644
--- a/packages/devextreme-react/src/pie-chart.ts
+++ b/packages/devextreme-react/src/pie-chart.ts
@@ -800,9 +800,9 @@ type ILegendProps = React.PropsWithChildren<{
     subtitle?: Record<string, any> | string | {
       font?: ChartsFont;
       offset?: number;
-      text?: string;
+      text?: string | undefined;
     };
-    text?: string;
+    text?: string | undefined;
     verticalAlignment?: VerticalEdge;
   };
   verticalAlignment?: VerticalEdge;
@@ -851,9 +851,9 @@ type ILegendTitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
   };
-  text?: string;
+  text?: string | undefined;
   verticalAlignment?: VerticalEdge;
 }>
 const _componentLegendTitle = (props: ILegendTitleProps) => {
@@ -880,7 +880,7 @@ const LegendTitle = Object.assign<typeof _componentLegendTitle, NestedComponentM
 type ILegendTitleSubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
 }>
 const _componentLegendTitleSubtitle = (props: ILegendTitleSubtitleProps) => {
   return React.createElement(NestedOption<ILegendTitleSubtitleProps>, {
@@ -1280,7 +1280,7 @@ const SmallValuesGrouping = Object.assign<typeof _componentSmallValuesGrouping,
 type ISubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
 }>
@@ -1316,11 +1316,11 @@ type ITitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
     textOverflow?: TextOverflow;
     wordWrap?: WordWrap;
   };
-  text?: string;
+  text?: string | undefined;
   verticalAlignment?: VerticalEdge;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
diff --git a/packages/devextreme-react/src/polar-chart.ts b/packages/devextreme-react/src/polar-chart.ts
index c6ba4db5af64..7027c8efd654 100644
--- a/packages/devextreme-react/src/polar-chart.ts
+++ b/packages/devextreme-react/src/polar-chart.ts
@@ -34,8 +34,8 @@ type IPolarChartOptionsNarrowedEvents = {
   onSeriesClick?: ((e: SeriesClickEvent) => void);
   onTooltipHidden?: ((e: TooltipHiddenEvent) => void);
   onTooltipShown?: ((e: TooltipShownEvent) => void);
-  onZoomEnd?: ((e: ZoomEndEvent) => void);
-  onZoomStart?: ((e: ZoomStartEvent) => void);
+  onZoomEnd?: ((e: ZoomEndEvent) => void) | undefined;
+  onZoomStart?: ((e: ZoomStartEvent) => void) | undefined;
 }
 
 type IPolarChartOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IPolarChartOptionsNarrowedEvents> & IHtmlOptions & {
@@ -1541,9 +1541,9 @@ type ILegendProps = React.PropsWithChildren<{
     subtitle?: Record<string, any> | string | {
       font?: ChartsFont;
       offset?: number;
-      text?: string;
+      text?: string | undefined;
     };
-    text?: string;
+    text?: string | undefined;
     verticalAlignment?: VerticalEdge;
   };
   verticalAlignment?: VerticalEdge;
@@ -1592,9 +1592,9 @@ type ILegendTitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
   };
-  text?: string;
+  text?: string | undefined;
   verticalAlignment?: VerticalEdge;
 }>
 const _componentLegendTitle = (props: ILegendTitleProps) => {
@@ -1621,7 +1621,7 @@ const LegendTitle = Object.assign<typeof _componentLegendTitle, NestedComponentM
 type ILegendTitleSubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
 }>
 const _componentLegendTitleSubtitle = (props: ILegendTitleSubtitleProps) => {
   return React.createElement(NestedOption<ILegendTitleSubtitleProps>, {
@@ -2425,7 +2425,7 @@ const StripStyleLabel = Object.assign<typeof _componentStripStyleLabel, NestedCo
 type ISubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
 }>
@@ -2513,11 +2513,11 @@ type ITitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
     textOverflow?: TextOverflow;
     wordWrap?: WordWrap;
   };
-  text?: string;
+  text?: string | undefined;
   verticalAlignment?: VerticalEdge;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
diff --git a/packages/devextreme-react/src/progress-bar.ts b/packages/devextreme-react/src/progress-bar.ts
index 5d8f86b6fe25..d17c414e34cd 100644
--- a/packages/devextreme-react/src/progress-bar.ts
+++ b/packages/devextreme-react/src/progress-bar.ts
@@ -14,7 +14,7 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 }
 
 type IProgressBarOptionsNarrowedEvents = {
-  onComplete?: ((e: CompleteEvent) => void);
+  onComplete?: ((e: CompleteEvent) => void) | null;
   onContentReady?: ((e: ContentReadyEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
diff --git a/packages/devextreme-react/src/range-selector.ts b/packages/devextreme-react/src/range-selector.ts
index d7b87a74a826..9683f6e1be1f 100644
--- a/packages/devextreme-react/src/range-selector.ts
+++ b/packages/devextreme-react/src/range-selector.ts
@@ -29,7 +29,7 @@ type IRangeSelectorOptionsNarrowedEvents = {
   onFileSaving?: ((e: FileSavingEvent) => void);
   onIncidentOccurred?: ((e: IncidentOccurredEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
-  onValueChanged?: ((e: ValueChangedEvent) => void);
+  onValueChanged?: ((e: ValueChangedEvent) => void) | undefined;
 }
 
 type IRangeSelectorOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IRangeSelectorOptionsNarrowedEvents> & IHtmlOptions & {
@@ -1482,7 +1482,7 @@ type IScaleProps = React.PropsWithChildren<{
     years?: number;
   };
   allowDecimals?: boolean | undefined;
-  breaks?: Array<ScaleBreak> | {
+  breaks?: Array<ScaleBreak> | undefined | {
     endValue?: Date | number | string | undefined;
     startValue?: Date | number | string | undefined;
   }[];
@@ -1495,7 +1495,7 @@ type IScaleProps = React.PropsWithChildren<{
   discreteAxisDivisionMode?: DiscreteAxisDivisionMode;
   endOnTick?: boolean;
   endValue?: Date | number | string | undefined;
-  holidays?: Array<Date | string> | Array<number>;
+  holidays?: Array<Date | string> | Array<number> | undefined;
   label?: Record<string, any> | {
     customizeText?: ((scaleValue: { value: Date | number | string, valueText: string }) => string);
     font?: ChartsFont;
@@ -1559,7 +1559,7 @@ type IScaleProps = React.PropsWithChildren<{
   };
   placeholderHeight?: number | undefined;
   showCustomBoundaryTicks?: boolean;
-  singleWorkdays?: Array<Date | string> | Array<number>;
+  singleWorkdays?: Array<Date | string> | Array<number> | undefined;
   startValue?: Date | number | string | undefined;
   tick?: Record<string, any> | {
     color?: string;
diff --git a/packages/devextreme-react/src/range-slider.ts b/packages/devextreme-react/src/range-slider.ts
index d1f2606d7874..f13c7f180417 100644
--- a/packages/devextreme-react/src/range-slider.ts
+++ b/packages/devextreme-react/src/range-slider.ts
@@ -20,7 +20,7 @@ type IRangeSliderOptionsNarrowedEvents = {
   onContentReady?: ((e: ContentReadyEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
-  onValueChanged?: ((e: ValueChangedEvent) => void);
+  onValueChanged?: ((e: ValueChangedEvent) => void) | null;
 }
 
 type IRangeSliderOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IRangeSliderOptionsNarrowedEvents> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/resizable.ts b/packages/devextreme-react/src/resizable.ts
index a19d55ce0111..b69d3a8abc91 100644
--- a/packages/devextreme-react/src/resizable.ts
+++ b/packages/devextreme-react/src/resizable.ts
@@ -16,9 +16,9 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 type IResizableOptionsNarrowedEvents = {
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
-  onResize?: ((e: ResizeEvent) => void);
-  onResizeEnd?: ((e: ResizeEndEvent) => void);
-  onResizeStart?: ((e: ResizeStartEvent) => void);
+  onResize?: ((e: ResizeEvent) => void) | undefined;
+  onResizeEnd?: ((e: ResizeEndEvent) => void) | undefined;
+  onResizeStart?: ((e: ResizeStartEvent) => void) | undefined;
 }
 
 type IResizableOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IResizableOptionsNarrowedEvents> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/scheduler.ts b/packages/devextreme-react/src/scheduler.ts
index 978ea1be3715..2b5b5c174f56 100644
--- a/packages/devextreme-react/src/scheduler.ts
+++ b/packages/devextreme-react/src/scheduler.ts
@@ -280,7 +280,7 @@ type IButtonOptionsProps = React.PropsWithChildren<{
   hint?: string | undefined;
   hoverStateEnabled?: boolean;
   icon?: string;
-  onClick?: ((e: ClickEvent) => void);
+  onClick?: ((e: ClickEvent) => void) | undefined;
   onContentReady?: ((e: ButtonContentReadyEvent) => void);
   onDisposing?: ((e: ButtonDisposingEvent) => void);
   onInitialized?: ((e: ButtonInitializedEvent) => void);
@@ -814,9 +814,9 @@ type IOptionsProps = React.PropsWithChildren<{
   onContentReady?: ((e: ButtonGroupContentReadyEvent) => void);
   onDisposing?: ((e: ButtonGroupDisposingEvent) => void);
   onInitialized?: ((e: ButtonGroupInitializedEvent) => void);
-  onItemClick?: ((e: ItemClickEvent) => void);
+  onItemClick?: ((e: ItemClickEvent) => void) | null;
   onOptionChanged?: ((e: ButtonGroupOptionChangedEvent) => void);
-  onSelectionChanged?: ((e: SelectionChangedEvent) => void);
+  onSelectionChanged?: ((e: SelectionChangedEvent) => void) | null;
   rtlEnabled?: boolean;
   selectedItemKeys?: Array<any>;
   selectedItems?: Array<any>;
@@ -1238,14 +1238,14 @@ type ITabPanelOptionsProps = React.PropsWithChildren<{
   onSelectionChanged?: ((e: TabPanelSelectionChangedEvent) => void);
   onSelectionChanging?: ((e: SelectionChangingEvent) => void);
   onTitleClick?: ((e: TitleClickEvent) => void);
-  onTitleHold?: ((e: TitleHoldEvent) => void);
-  onTitleRendered?: ((e: TitleRenderedEvent) => void);
+  onTitleHold?: ((e: TitleHoldEvent) => void) | null;
+  onTitleRendered?: ((e: TitleRenderedEvent) => void) | null;
   repaintChangesOnly?: boolean;
   rtlEnabled?: boolean;
   scrollByContent?: boolean;
   scrollingEnabled?: boolean;
   selectedIndex?: number;
-  selectedItem?: any;
+  selectedItem?: any | null;
   showNavButtons?: boolean;
   stylingMode?: TabsStyle;
   swipeEnabled?: boolean;
@@ -1257,8 +1257,8 @@ type ITabPanelOptionsProps = React.PropsWithChildren<{
   onItemsChange?: (value: Array<any | dxTabPanelItem | string>) => void;
   defaultSelectedIndex?: number;
   onSelectedIndexChange?: (value: number) => void;
-  defaultSelectedItem?: any;
-  onSelectedItemChange?: (value: any) => void;
+  defaultSelectedItem?: any | null;
+  onSelectedItemChange?: (value: any | null) => void;
   itemRender?: (...params: any) => React.ReactNode;
   itemComponent?: React.ComponentType<any>;
   itemTitleRender?: (...params: any) => React.ReactNode;
diff --git a/packages/devextreme-react/src/scroll-view.ts b/packages/devextreme-react/src/scroll-view.ts
index e6a961a291e9..0c4f8990042b 100644
--- a/packages/devextreme-react/src/scroll-view.ts
+++ b/packages/devextreme-react/src/scroll-view.ts
@@ -16,8 +16,8 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 type IScrollViewOptionsNarrowedEvents = {
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
-  onPullDown?: ((e: PullDownEvent) => void);
-  onReachBottom?: ((e: ReachBottomEvent) => void);
+  onPullDown?: ((e: PullDownEvent) => void) | null;
+  onReachBottom?: ((e: ReachBottomEvent) => void) | null;
   onScroll?: ((e: ScrollEvent) => void);
   onUpdated?: ((e: UpdatedEvent) => void);
 }
diff --git a/packages/devextreme-react/src/select-box.ts b/packages/devextreme-react/src/select-box.ts
index 9ba89de55cee..f5ccfa2c3b06 100644
--- a/packages/devextreme-react/src/select-box.ts
+++ b/packages/devextreme-react/src/select-box.ts
@@ -266,18 +266,18 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void);
+  onContentReady?: ((e: EventInfo<any>) => void) | null;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void);
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
@@ -509,7 +509,7 @@ type IOptionsProps = React.PropsWithChildren<{
   hint?: string | undefined;
   hoverStateEnabled?: boolean;
   icon?: string;
-  onClick?: ((e: ClickEvent) => void);
+  onClick?: ((e: ClickEvent) => void) | undefined;
   onContentReady?: ((e: ButtonContentReadyEvent) => void);
   onDisposing?: ((e: ButtonDisposingEvent) => void);
   onInitialized?: ((e: ButtonInitializedEvent) => void);
diff --git a/packages/devextreme-react/src/speed-dial-action.ts b/packages/devextreme-react/src/speed-dial-action.ts
index 6330cd9bb2f4..617072d03ee8 100644
--- a/packages/devextreme-react/src/speed-dial-action.ts
+++ b/packages/devextreme-react/src/speed-dial-action.ts
@@ -15,7 +15,7 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 
 type ISpeedDialActionOptionsNarrowedEvents = {
   onClick?: ((e: ClickEvent) => void);
-  onContentReady?: ((e: ContentReadyEvent) => void);
+  onContentReady?: ((e: ContentReadyEvent) => void) | null;
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
 }
diff --git a/packages/devextreme-react/src/splitter.ts b/packages/devextreme-react/src/splitter.ts
index dc0708393874..4b652ae287f0 100644
--- a/packages/devextreme-react/src/splitter.ts
+++ b/packages/devextreme-react/src/splitter.ts
@@ -22,13 +22,13 @@ type ISplitterOptionsNarrowedEvents<TItem = any, TKey = any> = {
   onDisposing?: ((e: DisposingEvent<TItem, TKey>) => void);
   onInitialized?: ((e: InitializedEvent<TItem, TKey>) => void);
   onItemClick?: ((e: ItemClickEvent<TItem, TKey>) => void);
-  onItemCollapsed?: ((e: ItemCollapsedEvent<TItem, TKey>) => void);
+  onItemCollapsed?: ((e: ItemCollapsedEvent<TItem, TKey>) => void) | undefined;
   onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void);
-  onItemExpanded?: ((e: ItemExpandedEvent<TItem, TKey>) => void);
+  onItemExpanded?: ((e: ItemExpandedEvent<TItem, TKey>) => void) | undefined;
   onItemRendered?: ((e: ItemRenderedEvent<TItem, TKey>) => void);
-  onResize?: ((e: ResizeEvent<TKey>) => void);
-  onResizeEnd?: ((e: ResizeEndEvent<TKey>) => void);
-  onResizeStart?: ((e: ResizeStartEvent<TKey>) => void);
+  onResize?: ((e: ResizeEvent<TKey>) => void) | undefined;
+  onResizeEnd?: ((e: ResizeEndEvent<TKey>) => void) | undefined;
+  onResizeStart?: ((e: ResizeStartEvent<TKey>) => void) | undefined;
 }
 
 type ISplitterOptions<TItem = any, TKey = any> = React.PropsWithChildren<ReplaceFieldTypes<Properties<TItem, TKey>, ISplitterOptionsNarrowedEvents<TItem, TKey>> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/stepper.ts b/packages/devextreme-react/src/stepper.ts
index c98c4df8925c..6e93848fc5b6 100644
--- a/packages/devextreme-react/src/stepper.ts
+++ b/packages/devextreme-react/src/stepper.ts
@@ -32,10 +32,10 @@ type IStepperOptions<TItem = any, TKey = any> = React.PropsWithChildren<ReplaceF
   itemComponent?: React.ComponentType<any>;
   defaultItems?: Array<dxStepperItem>;
   defaultSelectedIndex?: number;
-  defaultSelectedItem?: any;
+  defaultSelectedItem?: any | null;
   onItemsChange?: (value: Array<dxStepperItem>) => void;
   onSelectedIndexChange?: (value: number) => void;
-  onSelectedItemChange?: (value: any) => void;
+  onSelectedItemChange?: (value: any | null) => void;
 }>
 
 interface StepperRef<TItem = any, TKey = any> {
diff --git a/packages/devextreme-react/src/tab-panel.ts b/packages/devextreme-react/src/tab-panel.ts
index 2242bf8f7ce7..6df0bea7358e 100644
--- a/packages/devextreme-react/src/tab-panel.ts
+++ b/packages/devextreme-react/src/tab-panel.ts
@@ -27,8 +27,8 @@ type ITabPanelOptionsNarrowedEvents<TItem = any, TKey = any> = {
   onItemRendered?: ((e: ItemRenderedEvent<TItem, TKey>) => void);
   onSelectionChanging?: ((e: SelectionChangingEvent<TItem, TKey>) => void);
   onTitleClick?: ((e: TitleClickEvent<TItem, TKey>) => void);
-  onTitleHold?: ((e: TitleHoldEvent<TItem, TKey>) => void);
-  onTitleRendered?: ((e: TitleRenderedEvent<TItem, TKey>) => void);
+  onTitleHold?: ((e: TitleHoldEvent<TItem, TKey>) => void) | null;
+  onTitleRendered?: ((e: TitleRenderedEvent<TItem, TKey>) => void) | null;
 }
 
 type ITabPanelOptions<TItem = any, TKey = any> = React.PropsWithChildren<ReplaceFieldTypes<Properties<TItem, TKey>, ITabPanelOptionsNarrowedEvents<TItem, TKey>> & IHtmlOptions & {
@@ -39,10 +39,10 @@ type ITabPanelOptions<TItem = any, TKey = any> = React.PropsWithChildren<Replace
   itemTitleComponent?: React.ComponentType<any>;
   defaultItems?: Array<any | dxTabPanelItem | string>;
   defaultSelectedIndex?: number;
-  defaultSelectedItem?: any;
+  defaultSelectedItem?: any | null;
   onItemsChange?: (value: Array<any | dxTabPanelItem | string>) => void;
   onSelectedIndexChange?: (value: number) => void;
-  onSelectedItemChange?: (value: any) => void;
+  onSelectedItemChange?: (value: any | null) => void;
 }>
 
 interface TabPanelRef<TItem = any, TKey = any> {
diff --git a/packages/devextreme-react/src/tabs.ts b/packages/devextreme-react/src/tabs.ts
index 1dc9ce23e37b..18497c5769f7 100644
--- a/packages/devextreme-react/src/tabs.ts
+++ b/packages/devextreme-react/src/tabs.ts
@@ -34,12 +34,12 @@ type ITabsOptions<TItem = any, TKey = any> = React.PropsWithChildren<ReplaceFiel
   itemComponent?: React.ComponentType<any>;
   defaultItems?: Array<any | dxTabsItem | string>;
   defaultSelectedIndex?: number;
-  defaultSelectedItem?: any;
+  defaultSelectedItem?: any | null;
   defaultSelectedItemKeys?: Array<any>;
   defaultSelectedItems?: Array<any>;
   onItemsChange?: (value: Array<any | dxTabsItem | string>) => void;
   onSelectedIndexChange?: (value: number) => void;
-  onSelectedItemChange?: (value: any) => void;
+  onSelectedItemChange?: (value: any | null) => void;
   onSelectedItemKeysChange?: (value: Array<any>) => void;
   onSelectedItemsChange?: (value: Array<any>) => void;
 }>
diff --git a/packages/devextreme-react/src/tag-box.ts b/packages/devextreme-react/src/tag-box.ts
index fd23233126c4..14a4926bad8b 100644
--- a/packages/devextreme-react/src/tag-box.ts
+++ b/packages/devextreme-react/src/tag-box.ts
@@ -41,9 +41,9 @@ type ITagBoxOptionsNarrowedEvents = {
   onItemClick?: ((e: ItemClickEvent) => void);
   onKeyDown?: ((e: KeyDownEvent) => void);
   onKeyUp?: ((e: KeyUpEvent) => void);
-  onMultiTagPreparing?: ((e: MultiTagPreparingEvent) => void);
+  onMultiTagPreparing?: ((e: MultiTagPreparingEvent) => void) | null;
   onOpened?: ((e: OpenedEvent) => void);
-  onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent) => void);
+  onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent) => void) | null;
   onValueChanged?: ((e: ValueChangedEvent) => void);
 }
 
@@ -272,18 +272,18 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void);
+  onContentReady?: ((e: EventInfo<any>) => void) | null;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void);
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
@@ -515,7 +515,7 @@ type IOptionsProps = React.PropsWithChildren<{
   hint?: string | undefined;
   hoverStateEnabled?: boolean;
   icon?: string;
-  onClick?: ((e: ClickEvent) => void);
+  onClick?: ((e: ClickEvent) => void) | undefined;
   onContentReady?: ((e: ButtonContentReadyEvent) => void);
   onDisposing?: ((e: ButtonDisposingEvent) => void);
   onInitialized?: ((e: ButtonInitializedEvent) => void);
diff --git a/packages/devextreme-react/src/text-box.ts b/packages/devextreme-react/src/text-box.ts
index 4a5756cdf743..c47b9668345a 100644
--- a/packages/devextreme-react/src/text-box.ts
+++ b/packages/devextreme-react/src/text-box.ts
@@ -118,7 +118,7 @@ type IOptionsProps = React.PropsWithChildren<{
   hint?: string | undefined;
   hoverStateEnabled?: boolean;
   icon?: string;
-  onClick?: ((e: ClickEvent) => void);
+  onClick?: ((e: ClickEvent) => void) | undefined;
   onContentReady?: ((e: ButtonContentReadyEvent) => void);
   onDisposing?: ((e: ButtonDisposingEvent) => void);
   onInitialized?: ((e: ButtonInitializedEvent) => void);
diff --git a/packages/devextreme-react/src/tree-list.ts b/packages/devextreme-react/src/tree-list.ts
index 25acb626d9eb..bd9797e4fc7b 100644
--- a/packages/devextreme-react/src/tree-list.ts
+++ b/packages/devextreme-react/src/tree-list.ts
@@ -433,7 +433,7 @@ type IButtonOptionsProps = React.PropsWithChildren<{
   hint?: string | undefined;
   hoverStateEnabled?: boolean;
   icon?: string;
-  onClick?: ((e: ClickEvent) => void);
+  onClick?: ((e: ClickEvent) => void) | undefined;
   onContentReady?: ((e: ButtonContentReadyEvent) => void);
   onDisposing?: ((e: ButtonDisposingEvent) => void);
   onInitialized?: ((e: ButtonInitializedEvent) => void);
@@ -1126,7 +1126,7 @@ const EditingTexts = Object.assign<typeof _componentEditingTexts, NestedComponen
 type IEditorOptionsProps = React.PropsWithChildren<{
   accessKey?: string | undefined;
   activeStateEnabled?: boolean;
-  buttons?: Array<string | TextBoxPredefinedButton | TextEditorButton>;
+  buttons?: Array<string | TextBoxPredefinedButton | TextEditorButton> | undefined;
   disabled?: boolean;
   elementAttr?: Record<string, any>;
   focusStateEnabled?: boolean;
@@ -1142,7 +1142,7 @@ type IEditorOptionsProps = React.PropsWithChildren<{
   maskChar?: string;
   maskInvalidMessage?: string;
   maskRules?: any;
-  maxLength?: number | string;
+  maxLength?: null | number | string;
   mode?: TextBoxType;
   name?: string;
   onChange?: ((e: ChangeEvent) => void);
@@ -1170,8 +1170,8 @@ type IEditorOptionsProps = React.PropsWithChildren<{
   tabIndex?: number;
   text?: string;
   useMaskedValue?: boolean;
-  validationError?: any;
-  validationErrors?: Array<any>;
+  validationError?: any | null;
+  validationErrors?: Array<any> | null;
   validationMessageMode?: ValidationMessageMode;
   validationMessagePosition?: CommonPosition;
   validationStatus?: ValidationStatus;
@@ -1449,18 +1449,18 @@ type IFilterBuilderPopupProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void);
+  onContentReady?: ((e: EventInfo<any>) => void) | null;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void);
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
@@ -2362,7 +2362,7 @@ type IOptionsProps = React.PropsWithChildren<{
   hint?: string | undefined;
   hoverStateEnabled?: boolean;
   icon?: string;
-  onClick?: ((e: ClickEvent) => void);
+  onClick?: ((e: ClickEvent) => void) | undefined;
   onContentReady?: ((e: ContentReadyEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
@@ -2506,18 +2506,18 @@ type IPopupProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void);
+  onContentReady?: ((e: EventInfo<any>) => void) | null;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void);
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void);
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
@@ -3162,14 +3162,14 @@ type ITabPanelOptionsProps = React.PropsWithChildren<{
   onSelectionChanged?: ((e: SelectionChangedEvent) => void);
   onSelectionChanging?: ((e: SelectionChangingEvent) => void);
   onTitleClick?: ((e: TitleClickEvent) => void);
-  onTitleHold?: ((e: TitleHoldEvent) => void);
-  onTitleRendered?: ((e: TitleRenderedEvent) => void);
+  onTitleHold?: ((e: TitleHoldEvent) => void) | null;
+  onTitleRendered?: ((e: TitleRenderedEvent) => void) | null;
   repaintChangesOnly?: boolean;
   rtlEnabled?: boolean;
   scrollByContent?: boolean;
   scrollingEnabled?: boolean;
   selectedIndex?: number;
-  selectedItem?: any;
+  selectedItem?: any | null;
   showNavButtons?: boolean;
   stylingMode?: TabsStyle;
   swipeEnabled?: boolean;
@@ -3181,8 +3181,8 @@ type ITabPanelOptionsProps = React.PropsWithChildren<{
   onItemsChange?: (value: Array<any | dxTabPanelItem | string>) => void;
   defaultSelectedIndex?: number;
   onSelectedIndexChange?: (value: number) => void;
-  defaultSelectedItem?: any;
-  onSelectedItemChange?: (value: any) => void;
+  defaultSelectedItem?: any | null;
+  onSelectedItemChange?: (value: any | null) => void;
   itemRender?: (...params: any) => React.ReactNode;
   itemComponent?: React.ComponentType<any>;
   itemTitleRender?: (...params: any) => React.ReactNode;
diff --git a/packages/devextreme-react/src/tree-map.ts b/packages/devextreme-react/src/tree-map.ts
index 8b216992024f..5fb4515e219b 100644
--- a/packages/devextreme-react/src/tree-map.ts
+++ b/packages/devextreme-react/src/tree-map.ts
@@ -21,14 +21,14 @@ type ITreeMapOptionsNarrowedEvents = {
   onClick?: ((e: ClickEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
   onDrawn?: ((e: DrawnEvent) => void);
-  onDrill?: ((e: DrillEvent) => void);
+  onDrill?: ((e: DrillEvent) => void) | undefined;
   onExported?: ((e: ExportedEvent) => void);
   onExporting?: ((e: ExportingEvent) => void);
   onFileSaving?: ((e: FileSavingEvent) => void);
   onIncidentOccurred?: ((e: IncidentOccurredEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
-  onNodesInitialized?: ((e: NodesInitializedEvent) => void);
-  onNodesRendering?: ((e: NodesRenderingEvent) => void);
+  onNodesInitialized?: ((e: NodesInitializedEvent) => void) | undefined;
+  onNodesRendering?: ((e: NodesRenderingEvent) => void) | undefined;
 }
 
 type ITreeMapOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, ITreeMapOptionsNarrowedEvents> & IHtmlOptions & {
@@ -120,7 +120,7 @@ type IColorizerProps = React.PropsWithChildren<{
   colorizeGroups?: boolean;
   palette?: Array<string> | Palette;
   paletteExtensionMode?: PaletteExtensionMode;
-  range?: Array<number>;
+  range?: Array<number> | undefined;
   type?: TreeMapColorizerType | undefined;
 }>
 const _componentColorizer = (props: IColorizerProps) => {
diff --git a/packages/devextreme-react/src/tree-view.ts b/packages/devextreme-react/src/tree-view.ts
index 980124ba2734..555e492999b4 100644
--- a/packages/devextreme-react/src/tree-view.ts
+++ b/packages/devextreme-react/src/tree-view.ts
@@ -23,13 +23,13 @@ type ITreeViewOptionsNarrowedEvents<TItem = any, TKey = any> = {
   onContentReady?: ((e: ContentReadyEvent<TItem, TKey>) => void);
   onDisposing?: ((e: DisposingEvent<TItem, TKey>) => void);
   onInitialized?: ((e: InitializedEvent<TItem, TKey>) => void);
-  onItemClick?: ((e: ItemClickEvent<TItem, TKey>) => void);
-  onItemCollapsed?: ((e: ItemCollapsedEvent<TItem, TKey>) => void);
-  onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void);
-  onItemExpanded?: ((e: ItemExpandedEvent<TItem, TKey>) => void);
-  onItemHold?: ((e: ItemHoldEvent<TItem, TKey>) => void);
-  onItemRendered?: ((e: ItemRenderedEvent<TItem, TKey>) => void);
-  onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent<TItem, TKey>) => void);
+  onItemClick?: ((e: ItemClickEvent<TItem, TKey>) => void) | null;
+  onItemCollapsed?: ((e: ItemCollapsedEvent<TItem, TKey>) => void) | null;
+  onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void) | null;
+  onItemExpanded?: ((e: ItemExpandedEvent<TItem, TKey>) => void) | null;
+  onItemHold?: ((e: ItemHoldEvent<TItem, TKey>) => void) | null;
+  onItemRendered?: ((e: ItemRenderedEvent<TItem, TKey>) => void) | null;
+  onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent<TItem, TKey>) => void) | null;
 }
 
 type ITreeViewOptions<TItem = any, TKey = any> = React.PropsWithChildren<ReplaceFieldTypes<Properties<TItem, TKey>, ITreeViewOptionsNarrowedEvents<TItem, TKey>> & IHtmlOptions & {
@@ -171,7 +171,7 @@ type IOptionsProps = React.PropsWithChildren<{
   hint?: string | undefined;
   hoverStateEnabled?: boolean;
   icon?: string;
-  onClick?: ((e: ClickEvent) => void);
+  onClick?: ((e: ClickEvent) => void) | undefined;
   onContentReady?: ((e: ButtonContentReadyEvent) => void);
   onDisposing?: ((e: ButtonDisposingEvent) => void);
   onInitialized?: ((e: ButtonInitializedEvent) => void);
@@ -212,7 +212,7 @@ const Options = Object.assign<typeof _componentOptions, NestedComponentMeta>(_co
 type ISearchEditorOptionsProps = React.PropsWithChildren<{
   accessKey?: string | undefined;
   activeStateEnabled?: boolean;
-  buttons?: Array<string | TextBoxPredefinedButton | TextEditorButton>;
+  buttons?: Array<string | TextBoxPredefinedButton | TextEditorButton> | undefined;
   disabled?: boolean;
   elementAttr?: Record<string, any>;
   focusStateEnabled?: boolean;
@@ -228,7 +228,7 @@ type ISearchEditorOptionsProps = React.PropsWithChildren<{
   maskChar?: string;
   maskInvalidMessage?: string;
   maskRules?: any;
-  maxLength?: number | string;
+  maxLength?: null | number | string;
   mode?: TextBoxType;
   name?: string;
   onChange?: ((e: ChangeEvent) => void);
@@ -256,8 +256,8 @@ type ISearchEditorOptionsProps = React.PropsWithChildren<{
   tabIndex?: number;
   text?: string;
   useMaskedValue?: boolean;
-  validationError?: any;
-  validationErrors?: Array<any>;
+  validationError?: any | null;
+  validationErrors?: Array<any> | null;
   validationMessageMode?: ValidationMessageMode;
   validationMessagePosition?: Position;
   validationStatus?: ValidationStatus;
diff --git a/packages/devextreme-react/src/vector-map.ts b/packages/devextreme-react/src/vector-map.ts
index 64f80c73d47d..d11b370329d3 100644
--- a/packages/devextreme-react/src/vector-map.ts
+++ b/packages/devextreme-react/src/vector-map.ts
@@ -29,8 +29,8 @@ type IVectorMapOptionsNarrowedEvents = {
   onFileSaving?: ((e: FileSavingEvent) => void);
   onIncidentOccurred?: ((e: IncidentOccurredEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
-  onTooltipHidden?: ((e: TooltipHiddenEvent) => void);
-  onTooltipShown?: ((e: TooltipShownEvent) => void);
+  onTooltipHidden?: ((e: TooltipHiddenEvent) => void) | undefined;
+  onTooltipShown?: ((e: TooltipShownEvent) => void) | undefined;
 }
 
 type IVectorMapOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IVectorMapOptionsNarrowedEvents> & IHtmlOptions & {
@@ -109,7 +109,7 @@ type IAnnotationProps = React.PropsWithChildren<{
     width?: number;
   };
   color?: string;
-  coordinates?: Array<number>;
+  coordinates?: Array<number> | undefined;
   customizeTooltip?: ((annotation: dxVectorMapAnnotationConfig | any) => Record<string, any>) | undefined;
   data?: any;
   description?: string | undefined;
@@ -263,7 +263,7 @@ type ICommonAnnotationSettingsProps = React.PropsWithChildren<{
     width?: number;
   };
   color?: string;
-  coordinates?: Array<number>;
+  coordinates?: Array<number> | undefined;
   customizeTooltip?: ((annotation: dxVectorMapAnnotationConfig | any) => Record<string, any>) | undefined;
   data?: any;
   description?: string | undefined;
@@ -462,7 +462,7 @@ type ILayerProps = React.PropsWithChildren<{
   borderWidth?: number;
   color?: string;
   colorGroupingField?: string | undefined;
-  colorGroups?: Array<number>;
+  colorGroups?: Array<number> | undefined;
   customize?: ((elements: Array<MapLayerElement>) => void);
   dataField?: string | undefined;
   dataSource?: Array<any> | DataSource | DataSourceOptions | null | Record<string, any> | Store | string;
@@ -489,7 +489,7 @@ type ILayerProps = React.PropsWithChildren<{
   selectionMode?: SingleMultipleOrNone;
   size?: number;
   sizeGroupingField?: string | undefined;
-  sizeGroups?: Array<number>;
+  sizeGroups?: Array<number> | undefined;
   type?: VectorMapLayerType;
 }>
 const _componentLayer = (props: ILayerProps) => {
@@ -562,9 +562,9 @@ type ILegendProps = React.PropsWithChildren<{
     subtitle?: Record<string, any> | string | {
       font?: ChartsFont;
       offset?: number;
-      text?: string;
+      text?: string | undefined;
     };
-    text?: string;
+    text?: string | undefined;
     verticalAlignment?: VerticalEdge;
   };
   verticalAlignment?: VerticalEdge;
@@ -615,9 +615,9 @@ type ILegendTitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
   };
-  text?: string;
+  text?: string | undefined;
   verticalAlignment?: VerticalEdge;
 }>
 const _componentLegendTitle = (props: ILegendTitleProps) => {
@@ -644,7 +644,7 @@ const LegendTitle = Object.assign<typeof _componentLegendTitle, NestedComponentM
 type ILegendTitleSubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
 }>
 const _componentLegendTitleSubtitle = (props: ILegendTitleSubtitleProps) => {
   return React.createElement(NestedOption<ILegendTitleSubtitleProps>, {
@@ -803,7 +803,7 @@ const Source = Object.assign<typeof _componentSource, NestedComponentMeta>(_comp
 type ISubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
 }>
@@ -839,11 +839,11 @@ type ITitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
     textOverflow?: TextOverflow;
     wordWrap?: WordWrap;
   };
-  text?: string;
+  text?: string | undefined;
   verticalAlignment?: VerticalEdge;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
diff --git a/packages/devextreme-vue/src/accordion.ts b/packages/devextreme-vue/src/accordion.ts
index 93f0c6d35f9a..b26db562a4fe 100644
--- a/packages/devextreme-vue/src/accordion.ts
+++ b/packages/devextreme-vue/src/accordion.ts
@@ -88,7 +88,7 @@ const componentConfig = {
     items: Array as PropType<Array<any | dxAccordionItem | string>>,
     itemTemplate: {},
     itemTitleTemplate: {},
-    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | null | string>,
     multiple: Boolean,
     noDataText: String,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
diff --git a/packages/devextreme-vue/src/autocomplete.ts b/packages/devextreme-vue/src/autocomplete.ts
index 86376919ca72..b060332d6740 100644
--- a/packages/devextreme-vue/src/autocomplete.ts
+++ b/packages/devextreme-vue/src/autocomplete.ts
@@ -200,7 +200,7 @@ const componentConfig = {
     label: String,
     labelMode: String as PropType<LabelMode>,
     maxItemCount: Number,
-    maxLength: [Number, String],
+    maxLength: [Number, String] as PropType<null | number | string>,
     minSearchLength: Number,
     name: String,
     onChange: Function as PropType<((e: ChangeEvent) => void)>,
@@ -239,7 +239,7 @@ const componentConfig = {
     text: String,
     useItemTextAsTitle: Boolean,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Mode | Position>,
     validationStatus: String as PropType<ValidationStatus>,
@@ -530,18 +530,18 @@ const DxDropDownOptionsConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
+    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
+    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
diff --git a/packages/devextreme-vue/src/button-group.ts b/packages/devextreme-vue/src/button-group.ts
index 0f300e8e3d16..0b09b22423cd 100644
--- a/packages/devextreme-vue/src/button-group.ts
+++ b/packages/devextreme-vue/src/button-group.ts
@@ -66,9 +66,9 @@ const componentConfig = {
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
-    onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
+    onItemClick: Function as PropType<(((e: ItemClickEvent) => void)) | null>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
+    onSelectionChanged: Function as PropType<(((e: SelectionChangedEvent) => void)) | null>,
     rtlEnabled: Boolean,
     selectedItemKeys: Array as PropType<Array<any>>,
     selectedItems: Array as PropType<Array<any>>,
diff --git a/packages/devextreme-vue/src/calendar.ts b/packages/devextreme-vue/src/calendar.ts
index ad126171c867..afc8fdd36268 100644
--- a/packages/devextreme-vue/src/calendar.ts
+++ b/packages/devextreme-vue/src/calendar.ts
@@ -74,7 +74,7 @@ const componentConfig = {
     cellTemplate: {},
     dateSerializationFormat: String,
     disabled: Boolean,
-    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: DisabledDate) => boolean))>,
+    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: DisabledDate) => boolean)) | null>,
     elementAttr: Object as PropType<Record<string, any>>,
     firstDayOfWeek: Number as PropType<DayOfWeek>,
     focusStateEnabled: Boolean,
@@ -101,7 +101,7 @@ const componentConfig = {
     tabIndex: Number,
     todayButtonText: String,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Position>,
     validationStatus: String as PropType<ValidationStatus>,
diff --git a/packages/devextreme-vue/src/card-view.ts b/packages/devextreme-vue/src/card-view.ts
index 972adc77da2d..a80754c49edb 100644
--- a/packages/devextreme-vue/src/card-view.ts
+++ b/packages/devextreme-vue/src/card-view.ts
@@ -337,7 +337,7 @@ const componentConfig = {
     onCardRemoving: Function as PropType<((e: CardRemovingEvent) => void)>,
     onCardUpdated: Function as PropType<((e: CardUpdatedEvent) => void)>,
     onCardUpdating: Function as PropType<((e: CardUpdatingEvent) => void)>,
-    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
+    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
     onContextMenuPreparing: Function as PropType<((e: ContextMenuPreparingEvent) => void)>,
     onDataErrorOccurred: Function as PropType<((e: { component: Object, element: any, error: any, model: any }) => void)>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
@@ -3034,8 +3034,8 @@ const DxTabPanelOptionsConfig = {
     onSelectionChanged: Function as PropType<((e: TabPanelSelectionChangedEvent) => void)>,
     onSelectionChanging: Function as PropType<((e: SelectionChangingEvent) => void)>,
     onTitleClick: Function as PropType<((e: TitleClickEvent) => void)>,
-    onTitleHold: Function as PropType<((e: TitleHoldEvent) => void)>,
-    onTitleRendered: Function as PropType<((e: TitleRenderedEvent) => void)>,
+    onTitleHold: Function as PropType<(((e: TitleHoldEvent) => void)) | null>,
+    onTitleRendered: Function as PropType<(((e: TitleRenderedEvent) => void)) | null>,
     repaintChangesOnly: Boolean,
     rtlEnabled: Boolean,
     scrollByContent: Boolean,
diff --git a/packages/devextreme-vue/src/chart.ts b/packages/devextreme-vue/src/chart.ts
index 8e0eda21e886..c0cf7824c448 100644
--- a/packages/devextreme-vue/src/chart.ts
+++ b/packages/devextreme-vue/src/chart.ts
@@ -693,7 +693,7 @@ const DxArgumentAxisConfig = {
     minVisualRangeLength: [Number, Object, String] as PropType<number | Record<string, any> | TimeInterval>,
     offset: Number,
     opacity: Number,
-    placeholderSize: Number,
+    placeholderSize: Number as PropType<null | number>,
     position: String as PropType<Position>,
     singleWorkdays: Array as PropType<(Array<Date | string>) | Array<number>>,
     strips: Array as PropType<Array<Record<string, any>>>,
@@ -1215,7 +1215,7 @@ const DxCommonAxisSettingsConfig = {
     minorTick: Object as PropType<Record<string, any>>,
     minValueMargin: Number,
     opacity: Number,
-    placeholderSize: Number,
+    placeholderSize: Number as PropType<null | number>,
     stripStyle: Object as PropType<Record<string, any>>,
     tick: Object as PropType<Record<string, any>>,
     title: Object as PropType<Record<string, any>>,
@@ -3440,7 +3440,7 @@ const DxValueAxisConfig = {
     offset: Number,
     opacity: Number,
     pane: String,
-    placeholderSize: Number,
+    placeholderSize: Number as PropType<null | number>,
     position: String as PropType<Position>,
     showZero: Boolean,
     strips: Array as PropType<Array<Record<string, any>>>,
diff --git a/packages/devextreme-vue/src/chat.ts b/packages/devextreme-vue/src/chat.ts
index 7036b1e3115e..2452a5176ccf 100644
--- a/packages/devextreme-vue/src/chat.ts
+++ b/packages/devextreme-vue/src/chat.ts
@@ -536,20 +536,20 @@ const DxFileUploaderOptionsConfig = {
     minFileSize: Number,
     multiple: Boolean,
     name: String,
-    onBeforeSend: Function as PropType<((e: BeforeSendEvent) => void)>,
+    onBeforeSend: Function as PropType<(((e: BeforeSendEvent) => void)) | null>,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: FileUploaderDisposingEvent) => void)>,
-    onDropZoneEnter: Function as PropType<((e: DropZoneEnterEvent) => void)>,
-    onDropZoneLeave: Function as PropType<((e: DropZoneLeaveEvent) => void)>,
-    onFilesUploaded: Function as PropType<((e: FilesUploadedEvent) => void)>,
+    onDropZoneEnter: Function as PropType<(((e: DropZoneEnterEvent) => void)) | null>,
+    onDropZoneLeave: Function as PropType<(((e: DropZoneLeaveEvent) => void)) | null>,
+    onFilesUploaded: Function as PropType<(((e: FilesUploadedEvent) => void)) | null>,
     onInitialized: Function as PropType<((e: FileUploaderInitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: FileUploaderOptionChangedEvent) => void)>,
-    onProgress: Function as PropType<((e: ProgressEvent) => void)>,
-    onUploadAborted: Function as PropType<((e: UploadAbortedEvent) => void)>,
-    onUploaded: Function as PropType<((e: UploadedEvent) => void)>,
-    onUploadError: Function as PropType<((e: UploadErrorEvent) => void)>,
-    onUploadStarted: Function as PropType<((e: UploadStartedEvent) => void)>,
-    onValueChanged: Function as PropType<((e: ValueChangedEvent) => void)>,
+    onProgress: Function as PropType<(((e: ProgressEvent) => void)) | null>,
+    onUploadAborted: Function as PropType<(((e: UploadAbortedEvent) => void)) | null>,
+    onUploaded: Function as PropType<(((e: UploadedEvent) => void)) | null>,
+    onUploadError: Function as PropType<(((e: UploadErrorEvent) => void)) | null>,
+    onUploadStarted: Function as PropType<(((e: UploadStartedEvent) => void)) | null>,
+    onValueChanged: Function as PropType<(((e: ValueChangedEvent) => void)) | null>,
     progress: Number,
     readOnly: Boolean,
     readyToUploadMessage: String,
@@ -569,7 +569,7 @@ const DxFileUploaderOptionsConfig = {
     uploadMode: String as PropType<FileUploadMode>,
     uploadUrl: String,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationStatus: String as PropType<ValidationStatus>,
     value: Array as PropType<Array<any>>,
     visible: Boolean,
@@ -830,9 +830,9 @@ const DxSuggestionsConfig = {
     onContentReady: Function as PropType<((e: ButtonGroupContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: ButtonGroupDisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: ButtonGroupInitializedEvent) => void)>,
-    onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
+    onItemClick: Function as PropType<(((e: ItemClickEvent) => void)) | null>,
     onOptionChanged: Function as PropType<((e: ButtonGroupOptionChangedEvent) => void)>,
-    onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
+    onSelectionChanged: Function as PropType<(((e: SelectionChangedEvent) => void)) | null>,
     rtlEnabled: Boolean,
     selectedItemKeys: Array as PropType<Array<any>>,
     selectedItems: Array as PropType<Array<any>>,
diff --git a/packages/devextreme-vue/src/check-box.ts b/packages/devextreme-vue/src/check-box.ts
index 472fc2a7ec11..750860588fc4 100644
--- a/packages/devextreme-vue/src/check-box.ts
+++ b/packages/devextreme-vue/src/check-box.ts
@@ -77,7 +77,7 @@ const componentConfig = {
     tabIndex: Number,
     text: String,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Position>,
     validationStatus: String as PropType<ValidationStatus>,
diff --git a/packages/devextreme-vue/src/color-box.ts b/packages/devextreme-vue/src/color-box.ts
index a471de301dde..7f73a6b83bfb 100644
--- a/packages/devextreme-vue/src/color-box.ts
+++ b/packages/devextreme-vue/src/color-box.ts
@@ -204,7 +204,7 @@ const componentConfig = {
     tabIndex: Number,
     text: String,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Mode | Position>,
     validationStatus: String as PropType<ValidationStatus>,
@@ -479,18 +479,18 @@ const DxDropDownOptionsConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
+    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
+    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
diff --git a/packages/devextreme-vue/src/context-menu.ts b/packages/devextreme-vue/src/context-menu.ts
index 710e286b64fc..b0c8a4fe7800 100644
--- a/packages/devextreme-vue/src/context-menu.ts
+++ b/packages/devextreme-vue/src/context-menu.ts
@@ -119,17 +119,17 @@ const componentConfig = {
     itemTemplate: {},
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
-    onHidden: Function as PropType<((e: HiddenEvent) => void)>,
-    onHiding: Function as PropType<((e: HidingEvent) => void)>,
+    onHidden: Function as PropType<(((e: HiddenEvent) => void)) | null>,
+    onHiding: Function as PropType<(((e: HidingEvent) => void)) | null>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
     onItemContextMenu: Function as PropType<((e: ItemContextMenuEvent) => void)>,
     onItemRendered: Function as PropType<((e: ItemRenderedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onPositioning: Function as PropType<((e: PositioningEvent) => void)>,
+    onPositioning: Function as PropType<(((e: PositioningEvent) => void)) | null>,
     onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
-    onShowing: Function as PropType<((e: ShowingEvent) => void)>,
-    onShown: Function as PropType<((e: ShownEvent) => void)>,
+    onShowing: Function as PropType<(((e: ShowingEvent) => void)) | null>,
+    onShown: Function as PropType<(((e: ShownEvent) => void)) | null>,
     position: Object as PropType<PositionConfig | Record<string, any>>,
     rtlEnabled: Boolean,
     selectByClick: Boolean,
diff --git a/packages/devextreme-vue/src/data-grid.ts b/packages/devextreme-vue/src/data-grid.ts
index 7eb39a9740a6..919eece17774 100644
--- a/packages/devextreme-vue/src/data-grid.ts
+++ b/packages/devextreme-vue/src/data-grid.ts
@@ -1936,7 +1936,7 @@ const DxEditorOptionsConfig = {
     maskChar: String,
     maskInvalidMessage: String,
     maskRules: {},
-    maxLength: [Number, String],
+    maxLength: [Number, String] as PropType<null | number | string>,
     mode: String as PropType<TextBoxType>,
     name: String,
     onChange: Function as PropType<((e: ChangeEvent) => void)>,
@@ -1965,7 +1965,7 @@ const DxEditorOptionsConfig = {
     text: String,
     useMaskedValue: Boolean,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Position>,
     validationStatus: String as PropType<ValidationStatus>,
@@ -2336,18 +2336,18 @@ const DxFilterBuilderPopupConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
+    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
+    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
@@ -3605,18 +3605,18 @@ const DxPopupConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
+    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
+    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
@@ -4380,8 +4380,8 @@ const DxTabPanelOptionsConfig = {
     onSelectionChanged: Function as PropType<((e: TabPanelSelectionChangedEvent) => void)>,
     onSelectionChanging: Function as PropType<((e: SelectionChangingEvent) => void)>,
     onTitleClick: Function as PropType<((e: TitleClickEvent) => void)>,
-    onTitleHold: Function as PropType<((e: TitleHoldEvent) => void)>,
-    onTitleRendered: Function as PropType<((e: TitleRenderedEvent) => void)>,
+    onTitleHold: Function as PropType<(((e: TitleHoldEvent) => void)) | null>,
+    onTitleRendered: Function as PropType<(((e: TitleRenderedEvent) => void)) | null>,
     repaintChangesOnly: Boolean,
     rtlEnabled: Boolean,
     scrollByContent: Boolean,
diff --git a/packages/devextreme-vue/src/date-box.ts b/packages/devextreme-vue/src/date-box.ts
index 5025dce0b230..250f1b543cee 100644
--- a/packages/devextreme-vue/src/date-box.ts
+++ b/packages/devextreme-vue/src/date-box.ts
@@ -198,8 +198,8 @@ const componentConfig = {
     dateSerializationFormat: String,
     deferRendering: Boolean,
     disabled: Boolean,
-    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: { component: dxDateBox, date: Date, view: string }) => boolean))>,
-    displayFormat: [Object, String, Function] as PropType<Format | CommonFormat | (((value: number | Date) => string)) | Record<string, any> | string>,
+    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: { component: dxDateBox, date: Date, view: string }) => boolean)) | null>,
+    displayFormat: [Object, String, Function] as PropType<Format | null | CommonFormat | (((value: number | Date) => string)) | Record<string, any> | string>,
     dropDownButtonTemplate: {},
     dropDownOptions: Object as PropType<dxPopupOptions<any> | Record<string, any>>,
     elementAttr: Object as PropType<Record<string, any>>,
@@ -215,7 +215,7 @@ const componentConfig = {
     label: String,
     labelMode: String as PropType<LabelMode>,
     max: [Date, Number, String] as PropType<Date | null | number | string>,
-    maxLength: [Number, String],
+    maxLength: [Number, String] as PropType<null | number | string>,
     min: [Date, Number, String] as PropType<Date | null | number | string>,
     name: String,
     onChange: Function as PropType<((e: ChangeEvent) => void)>,
@@ -252,7 +252,7 @@ const componentConfig = {
     type: String as PropType<DateType>,
     useMaskBehavior: Boolean,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Mode | Position>,
     validationStatus: String as PropType<ValidationStatus>,
@@ -501,7 +501,7 @@ const DxCalendarOptionsConfig = {
     cellTemplate: {},
     dateSerializationFormat: String,
     disabled: Boolean,
-    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: DisabledDate) => boolean))>,
+    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: DisabledDate) => boolean)) | null>,
     elementAttr: Object as PropType<Record<string, any>>,
     firstDayOfWeek: Number as PropType<DayOfWeek>,
     focusStateEnabled: Boolean,
@@ -528,7 +528,7 @@ const DxCalendarOptionsConfig = {
     tabIndex: Number,
     todayButtonText: String,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Position>,
     validationStatus: String as PropType<ValidationStatus>,
@@ -668,18 +668,18 @@ const DxDropDownOptionsConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
+    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
+    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
diff --git a/packages/devextreme-vue/src/date-range-box.ts b/packages/devextreme-vue/src/date-range-box.ts
index 22d9b7fd35d9..be4200f8d07f 100644
--- a/packages/devextreme-vue/src/date-range-box.ts
+++ b/packages/devextreme-vue/src/date-range-box.ts
@@ -198,7 +198,7 @@ const componentConfig = {
     deferRendering: Boolean,
     disabled: Boolean,
     disableOutOfRangeSelection: Boolean,
-    displayFormat: [Object, String, Function] as PropType<Format | CommonFormat | (((value: number | Date) => string)) | Record<string, any> | string>,
+    displayFormat: [Object, String, Function] as PropType<Format | null | CommonFormat | (((value: number | Date) => string)) | Record<string, any> | string>,
     dropDownButtonTemplate: {},
     dropDownOptions: Object as PropType<dxPopupOptions<any> | Record<string, any>>,
     elementAttr: Object as PropType<Record<string, any>>,
@@ -257,7 +257,7 @@ const componentConfig = {
     todayButtonText: String,
     useMaskBehavior: Boolean,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Mode | Position>,
     validationStatus: String as PropType<ValidationStatus>,
@@ -510,7 +510,7 @@ const DxCalendarOptionsConfig = {
     cellTemplate: {},
     dateSerializationFormat: String,
     disabled: Boolean,
-    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: DisabledDate) => boolean))>,
+    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: DisabledDate) => boolean)) | null>,
     elementAttr: Object as PropType<Record<string, any>>,
     firstDayOfWeek: Number as PropType<DayOfWeek>,
     focusStateEnabled: Boolean,
@@ -537,7 +537,7 @@ const DxCalendarOptionsConfig = {
     tabIndex: Number,
     todayButtonText: String,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Position>,
     validationStatus: String as PropType<ValidationStatus>,
@@ -677,18 +677,18 @@ const DxDropDownOptionsConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
+    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
+    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
diff --git a/packages/devextreme-vue/src/diagram.ts b/packages/devextreme-vue/src/diagram.ts
index 551fe1416c39..255da3bb1fb7 100644
--- a/packages/devextreme-vue/src/diagram.ts
+++ b/packages/devextreme-vue/src/diagram.ts
@@ -117,12 +117,12 @@ const componentConfig = {
     onCustomCommand: Function as PropType<((e: CustomCommandEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
-    onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
-    onItemDblClick: Function as PropType<((e: ItemDblClickEvent) => void)>,
+    onItemClick: Function as PropType<(((e: ItemClickEvent) => void)) | null>,
+    onItemDblClick: Function as PropType<(((e: ItemDblClickEvent) => void)) | null>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onRequestEditOperation: Function as PropType<((e: RequestEditOperationEvent) => void)>,
-    onRequestLayoutUpdate: Function as PropType<((e: RequestLayoutUpdateEvent) => void)>,
-    onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
+    onRequestEditOperation: Function as PropType<(((e: RequestEditOperationEvent) => void)) | null>,
+    onRequestLayoutUpdate: Function as PropType<(((e: RequestLayoutUpdateEvent) => void)) | null>,
+    onSelectionChanged: Function as PropType<(((e: SelectionChangedEvent) => void)) | null>,
     pageColor: String,
     pageOrientation: String as PropType<PageOrientation>,
     pageSize: Object as PropType<Record<string, any>>,
diff --git a/packages/devextreme-vue/src/drawer.ts b/packages/devextreme-vue/src/drawer.ts
index 895e51a991b3..e3faee2df0f4 100644
--- a/packages/devextreme-vue/src/drawer.ts
+++ b/packages/devextreme-vue/src/drawer.ts
@@ -55,8 +55,8 @@ const componentConfig = {
     height: [Number, String],
     hint: String,
     hoverStateEnabled: Boolean,
-    maxSize: Number,
-    minSize: Number,
+    maxSize: Number as PropType<null | number>,
+    minSize: Number as PropType<null | number>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
diff --git a/packages/devextreme-vue/src/drop-down-box.ts b/packages/devextreme-vue/src/drop-down-box.ts
index c92fd7f02f3e..831f0b2de37c 100644
--- a/packages/devextreme-vue/src/drop-down-box.ts
+++ b/packages/devextreme-vue/src/drop-down-box.ts
@@ -185,7 +185,7 @@ const componentConfig = {
     items: Array as PropType<Array<any>>,
     label: String,
     labelMode: String as PropType<LabelMode>,
-    maxLength: [Number, String],
+    maxLength: [Number, String] as PropType<null | number | string>,
     name: String,
     onChange: Function as PropType<((e: ChangeEvent) => void)>,
     onClosed: Function as PropType<((e: ClosedEvent) => void)>,
@@ -214,7 +214,7 @@ const componentConfig = {
     tabIndex: Number,
     text: String,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Mode | Position>,
     validationStatus: String as PropType<ValidationStatus>,
@@ -494,18 +494,18 @@ const DxDropDownOptionsConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
+    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
+    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
diff --git a/packages/devextreme-vue/src/drop-down-button.ts b/packages/devextreme-vue/src/drop-down-button.ts
index b288957c537c..ddce99421b35 100644
--- a/packages/devextreme-vue/src/drop-down-button.ts
+++ b/packages/devextreme-vue/src/drop-down-button.ts
@@ -373,18 +373,18 @@ const DxDropDownOptionsConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
+    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
+    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
diff --git a/packages/devextreme-vue/src/file-uploader.ts b/packages/devextreme-vue/src/file-uploader.ts
index 5d353e87addd..feb73c88d871 100644
--- a/packages/devextreme-vue/src/file-uploader.ts
+++ b/packages/devextreme-vue/src/file-uploader.ts
@@ -124,20 +124,20 @@ const componentConfig = {
     minFileSize: Number,
     multiple: Boolean,
     name: String,
-    onBeforeSend: Function as PropType<((e: BeforeSendEvent) => void)>,
+    onBeforeSend: Function as PropType<(((e: BeforeSendEvent) => void)) | null>,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
-    onDropZoneEnter: Function as PropType<((e: DropZoneEnterEvent) => void)>,
-    onDropZoneLeave: Function as PropType<((e: DropZoneLeaveEvent) => void)>,
-    onFilesUploaded: Function as PropType<((e: FilesUploadedEvent) => void)>,
+    onDropZoneEnter: Function as PropType<(((e: DropZoneEnterEvent) => void)) | null>,
+    onDropZoneLeave: Function as PropType<(((e: DropZoneLeaveEvent) => void)) | null>,
+    onFilesUploaded: Function as PropType<(((e: FilesUploadedEvent) => void)) | null>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onProgress: Function as PropType<((e: ProgressEvent) => void)>,
-    onUploadAborted: Function as PropType<((e: UploadAbortedEvent) => void)>,
-    onUploaded: Function as PropType<((e: UploadedEvent) => void)>,
-    onUploadError: Function as PropType<((e: UploadErrorEvent) => void)>,
-    onUploadStarted: Function as PropType<((e: UploadStartedEvent) => void)>,
-    onValueChanged: Function as PropType<((e: ValueChangedEvent) => void)>,
+    onProgress: Function as PropType<(((e: ProgressEvent) => void)) | null>,
+    onUploadAborted: Function as PropType<(((e: UploadAbortedEvent) => void)) | null>,
+    onUploaded: Function as PropType<(((e: UploadedEvent) => void)) | null>,
+    onUploadError: Function as PropType<(((e: UploadErrorEvent) => void)) | null>,
+    onUploadStarted: Function as PropType<(((e: UploadStartedEvent) => void)) | null>,
+    onValueChanged: Function as PropType<(((e: ValueChangedEvent) => void)) | null>,
     progress: Number,
     readOnly: Boolean,
     readyToUploadMessage: String,
@@ -157,7 +157,7 @@ const componentConfig = {
     uploadMode: String as PropType<FileUploadMode>,
     uploadUrl: String,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationStatus: String as PropType<ValidationStatus>,
     value: Array as PropType<Array<any>>,
     visible: Boolean,
diff --git a/packages/devextreme-vue/src/form.ts b/packages/devextreme-vue/src/form.ts
index 15fac496202b..641f2c7c3a3f 100644
--- a/packages/devextreme-vue/src/form.ts
+++ b/packages/devextreme-vue/src/form.ts
@@ -1064,8 +1064,8 @@ const DxTabPanelOptionsConfig = {
     onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
     onSelectionChanging: Function as PropType<((e: SelectionChangingEvent) => void)>,
     onTitleClick: Function as PropType<((e: TitleClickEvent) => void)>,
-    onTitleHold: Function as PropType<((e: TitleHoldEvent) => void)>,
-    onTitleRendered: Function as PropType<((e: TitleRenderedEvent) => void)>,
+    onTitleHold: Function as PropType<(((e: TitleHoldEvent) => void)) | null>,
+    onTitleRendered: Function as PropType<(((e: TitleRenderedEvent) => void)) | null>,
     repaintChangesOnly: Boolean,
     rtlEnabled: Boolean,
     scrollByContent: Boolean,
diff --git a/packages/devextreme-vue/src/gantt.ts b/packages/devextreme-vue/src/gantt.ts
index 4c9a89fc2091..d8863f598c4b 100644
--- a/packages/devextreme-vue/src/gantt.ts
+++ b/packages/devextreme-vue/src/gantt.ts
@@ -188,36 +188,36 @@ const componentConfig = {
     hint: String,
     hoverStateEnabled: Boolean,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
-    onContextMenuPreparing: Function as PropType<((e: ContextMenuPreparingEvent) => void)>,
-    onCustomCommand: Function as PropType<((e: CustomCommandEvent) => void)>,
-    onDependencyDeleted: Function as PropType<((e: DependencyDeletedEvent) => void)>,
-    onDependencyDeleting: Function as PropType<((e: DependencyDeletingEvent) => void)>,
-    onDependencyInserted: Function as PropType<((e: DependencyInsertedEvent) => void)>,
-    onDependencyInserting: Function as PropType<((e: DependencyInsertingEvent) => void)>,
+    onContextMenuPreparing: Function as PropType<(((e: ContextMenuPreparingEvent) => void)) | null>,
+    onCustomCommand: Function as PropType<(((e: CustomCommandEvent) => void)) | null>,
+    onDependencyDeleted: Function as PropType<(((e: DependencyDeletedEvent) => void)) | null>,
+    onDependencyDeleting: Function as PropType<(((e: DependencyDeletingEvent) => void)) | null>,
+    onDependencyInserted: Function as PropType<(((e: DependencyInsertedEvent) => void)) | null>,
+    onDependencyInserting: Function as PropType<(((e: DependencyInsertingEvent) => void)) | null>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onResourceAssigned: Function as PropType<((e: ResourceAssignedEvent) => void)>,
-    onResourceAssigning: Function as PropType<((e: ResourceAssigningEvent) => void)>,
-    onResourceDeleted: Function as PropType<((e: ResourceDeletedEvent) => void)>,
-    onResourceDeleting: Function as PropType<((e: ResourceDeletingEvent) => void)>,
-    onResourceInserted: Function as PropType<((e: ResourceInsertedEvent) => void)>,
-    onResourceInserting: Function as PropType<((e: ResourceInsertingEvent) => void)>,
+    onResourceAssigned: Function as PropType<(((e: ResourceAssignedEvent) => void)) | null>,
+    onResourceAssigning: Function as PropType<(((e: ResourceAssigningEvent) => void)) | null>,
+    onResourceDeleted: Function as PropType<(((e: ResourceDeletedEvent) => void)) | null>,
+    onResourceDeleting: Function as PropType<(((e: ResourceDeletingEvent) => void)) | null>,
+    onResourceInserted: Function as PropType<(((e: ResourceInsertedEvent) => void)) | null>,
+    onResourceInserting: Function as PropType<(((e: ResourceInsertingEvent) => void)) | null>,
     onResourceManagerDialogShowing: Function as PropType<((e: ResourceManagerDialogShowingEvent) => void)>,
-    onResourceUnassigned: Function as PropType<((e: ResourceUnassignedEvent) => void)>,
-    onResourceUnassigning: Function as PropType<((e: ResourceUnassigningEvent) => void)>,
+    onResourceUnassigned: Function as PropType<(((e: ResourceUnassignedEvent) => void)) | null>,
+    onResourceUnassigning: Function as PropType<(((e: ResourceUnassigningEvent) => void)) | null>,
     onScaleCellPrepared: Function as PropType<((e: ScaleCellPreparedEvent) => void)>,
-    onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
-    onTaskClick: Function as PropType<((e: TaskClickEvent) => void)>,
-    onTaskDblClick: Function as PropType<((e: TaskDblClickEvent) => void)>,
-    onTaskDeleted: Function as PropType<((e: TaskDeletedEvent) => void)>,
-    onTaskDeleting: Function as PropType<((e: TaskDeletingEvent) => void)>,
-    onTaskEditDialogShowing: Function as PropType<((e: TaskEditDialogShowingEvent) => void)>,
-    onTaskInserted: Function as PropType<((e: TaskInsertedEvent) => void)>,
-    onTaskInserting: Function as PropType<((e: TaskInsertingEvent) => void)>,
-    onTaskMoving: Function as PropType<((e: TaskMovingEvent) => void)>,
-    onTaskUpdated: Function as PropType<((e: TaskUpdatedEvent) => void)>,
-    onTaskUpdating: Function as PropType<((e: TaskUpdatingEvent) => void)>,
+    onSelectionChanged: Function as PropType<(((e: SelectionChangedEvent) => void)) | null>,
+    onTaskClick: Function as PropType<(((e: TaskClickEvent) => void)) | null>,
+    onTaskDblClick: Function as PropType<(((e: TaskDblClickEvent) => void)) | null>,
+    onTaskDeleted: Function as PropType<(((e: TaskDeletedEvent) => void)) | null>,
+    onTaskDeleting: Function as PropType<(((e: TaskDeletingEvent) => void)) | null>,
+    onTaskEditDialogShowing: Function as PropType<(((e: TaskEditDialogShowingEvent) => void)) | null>,
+    onTaskInserted: Function as PropType<(((e: TaskInsertedEvent) => void)) | null>,
+    onTaskInserting: Function as PropType<(((e: TaskInsertingEvent) => void)) | null>,
+    onTaskMoving: Function as PropType<(((e: TaskMovingEvent) => void)) | null>,
+    onTaskUpdated: Function as PropType<(((e: TaskUpdatedEvent) => void)) | null>,
+    onTaskUpdating: Function as PropType<(((e: TaskUpdatingEvent) => void)) | null>,
     resourceAssignments: Object as PropType<Record<string, any>>,
     resources: Object as PropType<Record<string, any>>,
     rootValue: {},
diff --git a/packages/devextreme-vue/src/html-editor.ts b/packages/devextreme-vue/src/html-editor.ts
index 32d125827096..fcbbd97e9dd7 100644
--- a/packages/devextreme-vue/src/html-editor.ts
+++ b/packages/devextreme-vue/src/html-editor.ts
@@ -140,8 +140,8 @@ const componentConfig = {
     imageUpload: Object as PropType<dxHtmlEditorImageUpload | Record<string, any>>,
     isDirty: Boolean,
     isValid: Boolean,
-    mediaResizing: Object as PropType<dxHtmlEditorMediaResizing | Record<string, any>>,
-    mentions: Array as PropType<Array<dxHtmlEditorMention>>,
+    mediaResizing: Object as PropType<dxHtmlEditorMediaResizing | null | Record<string, any>>,
+    mentions: Array as PropType<Array<dxHtmlEditorMention> | null>,
     name: String,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
@@ -155,16 +155,16 @@ const componentConfig = {
     rtlEnabled: Boolean,
     stylingMode: String as PropType<EditorStyle>,
     tabIndex: Number,
-    tableContextMenu: Object as PropType<dxHtmlEditorTableContextMenu | Record<string, any>>,
-    tableResizing: Object as PropType<dxHtmlEditorTableResizing | Record<string, any>>,
-    toolbar: Object as PropType<dxHtmlEditorToolbar | Record<string, any>>,
+    tableContextMenu: Object as PropType<dxHtmlEditorTableContextMenu | null | Record<string, any>>,
+    tableResizing: Object as PropType<dxHtmlEditorTableResizing | null | Record<string, any>>,
+    toolbar: Object as PropType<dxHtmlEditorToolbar | null | Record<string, any>>,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Position>,
     validationStatus: String as PropType<ValidationStatus>,
     value: {},
-    variables: Object as PropType<dxHtmlEditorVariables | Record<string, any>>,
+    variables: Object as PropType<dxHtmlEditorVariables | null | Record<string, any>>,
     visible: Boolean,
     width: [Number, String]
   },
@@ -380,20 +380,20 @@ const DxFileUploaderOptionsConfig = {
     minFileSize: Number,
     multiple: Boolean,
     name: String,
-    onBeforeSend: Function as PropType<((e: BeforeSendEvent) => void)>,
+    onBeforeSend: Function as PropType<(((e: BeforeSendEvent) => void)) | null>,
     onContentReady: Function as PropType<((e: FileUploaderContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: FileUploaderDisposingEvent) => void)>,
-    onDropZoneEnter: Function as PropType<((e: DropZoneEnterEvent) => void)>,
-    onDropZoneLeave: Function as PropType<((e: DropZoneLeaveEvent) => void)>,
-    onFilesUploaded: Function as PropType<((e: FilesUploadedEvent) => void)>,
+    onDropZoneEnter: Function as PropType<(((e: DropZoneEnterEvent) => void)) | null>,
+    onDropZoneLeave: Function as PropType<(((e: DropZoneLeaveEvent) => void)) | null>,
+    onFilesUploaded: Function as PropType<(((e: FilesUploadedEvent) => void)) | null>,
     onInitialized: Function as PropType<((e: FileUploaderInitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: FileUploaderOptionChangedEvent) => void)>,
-    onProgress: Function as PropType<((e: ProgressEvent) => void)>,
-    onUploadAborted: Function as PropType<((e: UploadAbortedEvent) => void)>,
-    onUploaded: Function as PropType<((e: UploadedEvent) => void)>,
-    onUploadError: Function as PropType<((e: UploadErrorEvent) => void)>,
-    onUploadStarted: Function as PropType<((e: UploadStartedEvent) => void)>,
-    onValueChanged: Function as PropType<((e: FileUploaderValueChangedEvent) => void)>,
+    onProgress: Function as PropType<(((e: ProgressEvent) => void)) | null>,
+    onUploadAborted: Function as PropType<(((e: UploadAbortedEvent) => void)) | null>,
+    onUploaded: Function as PropType<(((e: UploadedEvent) => void)) | null>,
+    onUploadError: Function as PropType<(((e: UploadErrorEvent) => void)) | null>,
+    onUploadStarted: Function as PropType<(((e: UploadStartedEvent) => void)) | null>,
+    onValueChanged: Function as PropType<(((e: FileUploaderValueChangedEvent) => void)) | null>,
     progress: Number,
     readOnly: Boolean,
     readyToUploadMessage: String,
@@ -413,7 +413,7 @@ const DxFileUploaderOptionsConfig = {
     uploadMode: String as PropType<FileUploadMode>,
     uploadUrl: String,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationStatus: String as PropType<ValidationStatus>,
     value: Array as PropType<Array<any>>,
     visible: Boolean,
diff --git a/packages/devextreme-vue/src/list.ts b/packages/devextreme-vue/src/list.ts
index 541cfb96745d..e7f9a04a8a09 100644
--- a/packages/devextreme-vue/src/list.ts
+++ b/packages/devextreme-vue/src/list.ts
@@ -201,28 +201,28 @@ const componentConfig = {
     itemHoldTimeout: Number,
     items: Array as PropType<Array<any | dxListItem | string>>,
     itemTemplate: {},
-    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | null | string>,
     menuItems: Array as PropType<Array<Record<string, any>>>,
     menuMode: String as PropType<ListMenuMode>,
     nextButtonText: String,
     noDataText: String,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
-    onGroupRendered: Function as PropType<((e: GroupRenderedEvent) => void)>,
+    onGroupRendered: Function as PropType<(((e: GroupRenderedEvent) => void)) | null>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
-    onItemContextMenu: Function as PropType<((e: ItemContextMenuEvent) => void)>,
-    onItemDeleted: Function as PropType<((e: ItemDeletedEvent) => void)>,
-    onItemDeleting: Function as PropType<((e: ItemDeletingEvent) => void)>,
-    onItemHold: Function as PropType<((e: ItemHoldEvent) => void)>,
+    onItemContextMenu: Function as PropType<(((e: ItemContextMenuEvent) => void)) | null>,
+    onItemDeleted: Function as PropType<(((e: ItemDeletedEvent) => void)) | null>,
+    onItemDeleting: Function as PropType<(((e: ItemDeletingEvent) => void)) | null>,
+    onItemHold: Function as PropType<(((e: ItemHoldEvent) => void)) | null>,
     onItemRendered: Function as PropType<((e: ItemRenderedEvent) => void)>,
-    onItemReordered: Function as PropType<((e: ItemReorderedEvent) => void)>,
-    onItemSwipe: Function as PropType<((e: ItemSwipeEvent) => void)>,
+    onItemReordered: Function as PropType<(((e: ItemReorderedEvent) => void)) | null>,
+    onItemSwipe: Function as PropType<(((e: ItemSwipeEvent) => void)) | null>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onPageLoading: Function as PropType<((e: PageLoadingEvent) => void)>,
-    onPullRefresh: Function as PropType<((e: PullRefreshEvent) => void)>,
-    onScroll: Function as PropType<((e: ScrollEvent) => void)>,
-    onSelectAllValueChanged: Function as PropType<((e: SelectAllValueChangedEvent) => void)>,
+    onPageLoading: Function as PropType<(((e: PageLoadingEvent) => void)) | null>,
+    onPullRefresh: Function as PropType<(((e: PullRefreshEvent) => void)) | null>,
+    onScroll: Function as PropType<(((e: ScrollEvent) => void)) | null>,
+    onSelectAllValueChanged: Function as PropType<(((e: SelectAllValueChangedEvent) => void)) | null>,
     onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
     onSelectionChanging: Function as PropType<((e: SelectionChangingEvent) => void)>,
     pageLoadingText: String,
@@ -673,7 +673,7 @@ const DxSearchEditorOptionsConfig = {
     maskChar: String,
     maskInvalidMessage: String,
     maskRules: {},
-    maxLength: [Number, String],
+    maxLength: [Number, String] as PropType<null | number | string>,
     mode: String as PropType<TextBoxType>,
     name: String,
     onChange: Function as PropType<((e: ChangeEvent) => void)>,
@@ -702,7 +702,7 @@ const DxSearchEditorOptionsConfig = {
     text: String,
     useMaskedValue: Boolean,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Position>,
     validationStatus: String as PropType<ValidationStatus>,
diff --git a/packages/devextreme-vue/src/lookup.ts b/packages/devextreme-vue/src/lookup.ts
index b18f6ecdf351..79d2bdeb479a 100644
--- a/packages/devextreme-vue/src/lookup.ts
+++ b/packages/devextreme-vue/src/lookup.ts
@@ -206,11 +206,11 @@ const componentConfig = {
     onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
     onOpened: Function as PropType<((e: OpenedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onPageLoading: Function as PropType<((e: PageLoadingEvent) => void)>,
-    onPullRefresh: Function as PropType<((e: PullRefreshEvent) => void)>,
-    onScroll: Function as PropType<((e: ScrollEvent) => void)>,
+    onPageLoading: Function as PropType<(((e: PageLoadingEvent) => void)) | null>,
+    onPullRefresh: Function as PropType<(((e: PullRefreshEvent) => void)) | null>,
+    onScroll: Function as PropType<(((e: ScrollEvent) => void)) | null>,
     onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
-    onValueChanged: Function as PropType<((e: ValueChangedEvent) => void)>,
+    onValueChanged: Function as PropType<(((e: ValueChangedEvent) => void)) | null>,
     opened: Boolean,
     pageLoadingText: String,
     pageLoadMode: String as PropType<PageLoadMode>,
@@ -237,7 +237,7 @@ const componentConfig = {
     useNativeScrolling: Boolean,
     usePopover: Boolean,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Mode | Position>,
     validationStatus: String as PropType<ValidationStatus>,
diff --git a/packages/devextreme-vue/src/map.ts b/packages/devextreme-vue/src/map.ts
index 7e1c8fecdc49..470e92f22630 100644
--- a/packages/devextreme-vue/src/map.ts
+++ b/packages/devextreme-vue/src/map.ts
@@ -76,12 +76,12 @@ const componentConfig = {
     onClick: Function as PropType<((e: ClickEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
-    onMarkerAdded: Function as PropType<((e: MarkerAddedEvent) => void)>,
-    onMarkerRemoved: Function as PropType<((e: MarkerRemovedEvent) => void)>,
+    onMarkerAdded: Function as PropType<(((e: MarkerAddedEvent) => void)) | null>,
+    onMarkerRemoved: Function as PropType<(((e: MarkerRemovedEvent) => void)) | null>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onReady: Function as PropType<((e: ReadyEvent) => void)>,
-    onRouteAdded: Function as PropType<((e: RouteAddedEvent) => void)>,
-    onRouteRemoved: Function as PropType<((e: RouteRemovedEvent) => void)>,
+    onReady: Function as PropType<(((e: ReadyEvent) => void)) | null>,
+    onRouteAdded: Function as PropType<(((e: RouteAddedEvent) => void)) | null>,
+    onRouteRemoved: Function as PropType<(((e: RouteRemovedEvent) => void)) | null>,
     provider: String as PropType<MapProvider>,
     providerConfig: Object as PropType<Record<string, any>>,
     routes: Array as PropType<Array<Record<string, any>>>,
diff --git a/packages/devextreme-vue/src/menu.ts b/packages/devextreme-vue/src/menu.ts
index 55d672779926..fa0453d113f8 100644
--- a/packages/devextreme-vue/src/menu.ts
+++ b/packages/devextreme-vue/src/menu.ts
@@ -122,10 +122,10 @@ const componentConfig = {
     onItemRendered: Function as PropType<((e: ItemRenderedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
     onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
-    onSubmenuHidden: Function as PropType<((e: SubmenuHiddenEvent) => void)>,
-    onSubmenuHiding: Function as PropType<((e: SubmenuHidingEvent) => void)>,
-    onSubmenuShowing: Function as PropType<((e: SubmenuShowingEvent) => void)>,
-    onSubmenuShown: Function as PropType<((e: SubmenuShownEvent) => void)>,
+    onSubmenuHidden: Function as PropType<(((e: SubmenuHiddenEvent) => void)) | null>,
+    onSubmenuHiding: Function as PropType<(((e: SubmenuHidingEvent) => void)) | null>,
+    onSubmenuShowing: Function as PropType<(((e: SubmenuShowingEvent) => void)) | null>,
+    onSubmenuShown: Function as PropType<(((e: SubmenuShownEvent) => void)) | null>,
     orientation: String as PropType<Orientation>,
     rtlEnabled: Boolean,
     selectByClick: Boolean,
diff --git a/packages/devextreme-vue/src/number-box.ts b/packages/devextreme-vue/src/number-box.ts
index a6a3340932f4..89f8c38b7c8b 100644
--- a/packages/devextreme-vue/src/number-box.ts
+++ b/packages/devextreme-vue/src/number-box.ts
@@ -155,7 +155,7 @@ const componentConfig = {
     text: String,
     useLargeSpinButtons: Boolean,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Position>,
     validationStatus: String as PropType<ValidationStatus>,
diff --git a/packages/devextreme-vue/src/pagination.ts b/packages/devextreme-vue/src/pagination.ts
index 845d5125e42a..5959572cdd51 100644
--- a/packages/devextreme-vue/src/pagination.ts
+++ b/packages/devextreme-vue/src/pagination.ts
@@ -62,7 +62,7 @@ const componentConfig = {
     infoText: String,
     itemCount: Number,
     label: String,
-    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
+    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
diff --git a/packages/devextreme-vue/src/popup.ts b/packages/devextreme-vue/src/popup.ts
index b7cd83dcaa49..8f823e734afc 100644
--- a/packages/devextreme-vue/src/popup.ts
+++ b/packages/devextreme-vue/src/popup.ts
@@ -119,18 +119,18 @@ const componentConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
+    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
+    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
diff --git a/packages/devextreme-vue/src/progress-bar.ts b/packages/devextreme-vue/src/progress-bar.ts
index 8508590aee99..0e7f4b00695e 100644
--- a/packages/devextreme-vue/src/progress-bar.ts
+++ b/packages/devextreme-vue/src/progress-bar.ts
@@ -61,7 +61,7 @@ const componentConfig = {
     isValid: Boolean,
     max: Number,
     min: Number,
-    onComplete: Function as PropType<((e: CompleteEvent) => void)>,
+    onComplete: Function as PropType<(((e: CompleteEvent) => void)) | null>,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
@@ -72,7 +72,7 @@ const componentConfig = {
     showStatus: Boolean,
     statusFormat: [Function, String] as PropType<(((ratio: number, value: number) => string)) | string>,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Position>,
     validationStatus: String as PropType<ValidationStatus>,
diff --git a/packages/devextreme-vue/src/radio-group.ts b/packages/devextreme-vue/src/radio-group.ts
index d19bd930dfa9..fb6527b01b84 100644
--- a/packages/devextreme-vue/src/radio-group.ts
+++ b/packages/devextreme-vue/src/radio-group.ts
@@ -94,7 +94,7 @@ const componentConfig = {
     rtlEnabled: Boolean,
     tabIndex: Number,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Position>,
     validationStatus: String as PropType<ValidationStatus>,
diff --git a/packages/devextreme-vue/src/range-slider.ts b/packages/devextreme-vue/src/range-slider.ts
index 7bc0eccb72d2..61e9b2a28db2 100644
--- a/packages/devextreme-vue/src/range-slider.ts
+++ b/packages/devextreme-vue/src/range-slider.ts
@@ -90,7 +90,7 @@ const componentConfig = {
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onValueChanged: Function as PropType<((e: ValueChangedEvent) => void)>,
+    onValueChanged: Function as PropType<(((e: ValueChangedEvent) => void)) | null>,
     readOnly: Boolean,
     rtlEnabled: Boolean,
     showRange: Boolean,
@@ -100,7 +100,7 @@ const componentConfig = {
     tabIndex: Number,
     tooltip: Object as PropType<Record<string, any>>,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Position>,
     validationStatus: String as PropType<ValidationStatus>,
diff --git a/packages/devextreme-vue/src/responsive-box.ts b/packages/devextreme-vue/src/responsive-box.ts
index 1ae0d3be4154..86a26760a0c9 100644
--- a/packages/devextreme-vue/src/responsive-box.ts
+++ b/packages/devextreme-vue/src/responsive-box.ts
@@ -74,7 +74,7 @@ const componentConfig = {
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
     rows: Array as PropType<Array<Record<string, any>>>,
     rtlEnabled: Boolean,
-    screenByWidth: Function as PropType<(() => void)>,
+    screenByWidth: Function as PropType<((() => void)) | null>,
     singleColumnScreen: String,
     visible: Boolean,
     width: [Number, String]
diff --git a/packages/devextreme-vue/src/scheduler.ts b/packages/devextreme-vue/src/scheduler.ts
index a8bcca7114cc..19b0111e87af 100644
--- a/packages/devextreme-vue/src/scheduler.ts
+++ b/packages/devextreme-vue/src/scheduler.ts
@@ -1146,9 +1146,9 @@ const DxOptionsConfig = {
     onContentReady: Function as PropType<((e: ButtonGroupContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: ButtonGroupDisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: ButtonGroupInitializedEvent) => void)>,
-    onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
+    onItemClick: Function as PropType<(((e: ItemClickEvent) => void)) | null>,
     onOptionChanged: Function as PropType<((e: ButtonGroupOptionChangedEvent) => void)>,
-    onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
+    onSelectionChanged: Function as PropType<(((e: SelectionChangedEvent) => void)) | null>,
     rtlEnabled: Boolean,
     selectedItemKeys: Array as PropType<Array<any>>,
     selectedItems: Array as PropType<Array<any>>,
@@ -1589,8 +1589,8 @@ const DxTabPanelOptionsConfig = {
     onSelectionChanged: Function as PropType<((e: TabPanelSelectionChangedEvent) => void)>,
     onSelectionChanging: Function as PropType<((e: SelectionChangingEvent) => void)>,
     onTitleClick: Function as PropType<((e: TitleClickEvent) => void)>,
-    onTitleHold: Function as PropType<((e: TitleHoldEvent) => void)>,
-    onTitleRendered: Function as PropType<((e: TitleRenderedEvent) => void)>,
+    onTitleHold: Function as PropType<(((e: TitleHoldEvent) => void)) | null>,
+    onTitleRendered: Function as PropType<(((e: TitleRenderedEvent) => void)) | null>,
     repaintChangesOnly: Boolean,
     rtlEnabled: Boolean,
     scrollByContent: Boolean,
diff --git a/packages/devextreme-vue/src/scroll-view.ts b/packages/devextreme-vue/src/scroll-view.ts
index a1403de5bf91..612944df11b5 100644
--- a/packages/devextreme-vue/src/scroll-view.ts
+++ b/packages/devextreme-vue/src/scroll-view.ts
@@ -54,8 +54,8 @@ const componentConfig = {
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onPullDown: Function as PropType<((e: PullDownEvent) => void)>,
-    onReachBottom: Function as PropType<((e: ReachBottomEvent) => void)>,
+    onPullDown: Function as PropType<(((e: PullDownEvent) => void)) | null>,
+    onReachBottom: Function as PropType<(((e: ReachBottomEvent) => void)) | null>,
     onScroll: Function as PropType<((e: ScrollEvent) => void)>,
     onUpdated: Function as PropType<((e: UpdatedEvent) => void)>,
     pulledDownText: String,
diff --git a/packages/devextreme-vue/src/select-box.ts b/packages/devextreme-vue/src/select-box.ts
index 9f09704f7d12..ba734355ba37 100644
--- a/packages/devextreme-vue/src/select-box.ts
+++ b/packages/devextreme-vue/src/select-box.ts
@@ -215,7 +215,7 @@ const componentConfig = {
     itemTemplate: {},
     label: String,
     labelMode: String as PropType<LabelMode>,
-    maxLength: [Number, String],
+    maxLength: [Number, String] as PropType<null | number | string>,
     minSearchLength: Number,
     name: String,
     noDataText: String,
@@ -259,7 +259,7 @@ const componentConfig = {
     text: String,
     useItemTextAsTitle: Boolean,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Mode | Position>,
     validationStatus: String as PropType<ValidationStatus>,
@@ -560,18 +560,18 @@ const DxDropDownOptionsConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
+    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
+    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
diff --git a/packages/devextreme-vue/src/slider.ts b/packages/devextreme-vue/src/slider.ts
index 45e500dfead8..596ebd42b828 100644
--- a/packages/devextreme-vue/src/slider.ts
+++ b/packages/devextreme-vue/src/slider.ts
@@ -94,7 +94,7 @@ const componentConfig = {
     tabIndex: Number,
     tooltip: Object as PropType<Record<string, any>>,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Position>,
     validationStatus: String as PropType<ValidationStatus>,
diff --git a/packages/devextreme-vue/src/speed-dial-action.ts b/packages/devextreme-vue/src/speed-dial-action.ts
index 36ba9edaf96d..45405ffce014 100644
--- a/packages/devextreme-vue/src/speed-dial-action.ts
+++ b/packages/devextreme-vue/src/speed-dial-action.ts
@@ -46,7 +46,7 @@ const componentConfig = {
     index: Number,
     label: String,
     onClick: Function as PropType<((e: ClickEvent) => void)>,
-    onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
+    onContentReady: Function as PropType<(((e: ContentReadyEvent) => void)) | null>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
diff --git a/packages/devextreme-vue/src/switch.ts b/packages/devextreme-vue/src/switch.ts
index 8d8af35a3833..52cee2829201 100644
--- a/packages/devextreme-vue/src/switch.ts
+++ b/packages/devextreme-vue/src/switch.ts
@@ -75,7 +75,7 @@ const componentConfig = {
     switchedOnText: String,
     tabIndex: Number,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Position>,
     validationStatus: String as PropType<ValidationStatus>,
diff --git a/packages/devextreme-vue/src/tab-panel.ts b/packages/devextreme-vue/src/tab-panel.ts
index ce5b3901dedb..665b2bf8109c 100644
--- a/packages/devextreme-vue/src/tab-panel.ts
+++ b/packages/devextreme-vue/src/tab-panel.ts
@@ -117,8 +117,8 @@ const componentConfig = {
     onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
     onSelectionChanging: Function as PropType<((e: SelectionChangingEvent) => void)>,
     onTitleClick: Function as PropType<((e: TitleClickEvent) => void)>,
-    onTitleHold: Function as PropType<((e: TitleHoldEvent) => void)>,
-    onTitleRendered: Function as PropType<((e: TitleRenderedEvent) => void)>,
+    onTitleHold: Function as PropType<(((e: TitleHoldEvent) => void)) | null>,
+    onTitleRendered: Function as PropType<(((e: TitleRenderedEvent) => void)) | null>,
     repaintChangesOnly: Boolean,
     rtlEnabled: Boolean,
     scrollByContent: Boolean,
diff --git a/packages/devextreme-vue/src/tabs.ts b/packages/devextreme-vue/src/tabs.ts
index 17e7999dbda8..557e5a83e587 100644
--- a/packages/devextreme-vue/src/tabs.ts
+++ b/packages/devextreme-vue/src/tabs.ts
@@ -91,7 +91,7 @@ const componentConfig = {
     itemHoldTimeout: Number,
     items: Array as PropType<Array<any | dxTabsItem | string>>,
     itemTemplate: {},
-    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | null | string>,
     noDataText: String,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
diff --git a/packages/devextreme-vue/src/tag-box.ts b/packages/devextreme-vue/src/tag-box.ts
index 26f27f764251..4c089a99a470 100644
--- a/packages/devextreme-vue/src/tag-box.ts
+++ b/packages/devextreme-vue/src/tag-box.ts
@@ -225,7 +225,7 @@ const componentConfig = {
     labelMode: String as PropType<LabelMode>,
     maxDisplayedTags: Number,
     maxFilterQueryLength: Number,
-    maxLength: [Number, String],
+    maxLength: [Number, String] as PropType<null | number | string>,
     minSearchLength: Number,
     multiline: Boolean,
     name: String,
@@ -243,11 +243,11 @@ const componentConfig = {
     onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
     onKeyDown: Function as PropType<((e: KeyDownEvent) => void)>,
     onKeyUp: Function as PropType<((e: KeyUpEvent) => void)>,
-    onMultiTagPreparing: Function as PropType<((e: MultiTagPreparingEvent) => void)>,
+    onMultiTagPreparing: Function as PropType<(((e: MultiTagPreparingEvent) => void)) | null>,
     onOpened: Function as PropType<((e: OpenedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onSelectAllValueChanged: Function as PropType<((e: SelectAllValueChangedEvent) => void)>,
-    onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
+    onSelectAllValueChanged: Function as PropType<(((e: SelectAllValueChangedEvent) => void)) | null>,
+    onSelectionChanged: Function as PropType<(((e: SelectionChangedEvent) => void)) | null>,
     onValueChanged: Function as PropType<((e: ValueChangedEvent) => void)>,
     opened: Boolean,
     openOnFieldClick: Boolean,
@@ -272,7 +272,7 @@ const componentConfig = {
     text: String,
     useItemTextAsTitle: Boolean,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Mode | Position>,
     validationStatus: String as PropType<ValidationStatus>,
@@ -579,18 +579,18 @@ const DxDropDownOptionsConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
+    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
+    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
diff --git a/packages/devextreme-vue/src/text-area.ts b/packages/devextreme-vue/src/text-area.ts
index 642c5b7882af..ccff14c52fe3 100644
--- a/packages/devextreme-vue/src/text-area.ts
+++ b/packages/devextreme-vue/src/text-area.ts
@@ -100,7 +100,7 @@ const componentConfig = {
     label: String,
     labelMode: String as PropType<LabelMode>,
     maxHeight: [Number, String],
-    maxLength: [Number, String],
+    maxLength: [Number, String] as PropType<null | number | string>,
     minHeight: [Number, String],
     name: String,
     onChange: Function as PropType<((e: ChangeEvent) => void)>,
@@ -126,7 +126,7 @@ const componentConfig = {
     tabIndex: Number,
     text: String,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Position>,
     validationStatus: String as PropType<ValidationStatus>,
diff --git a/packages/devextreme-vue/src/text-box.ts b/packages/devextreme-vue/src/text-box.ts
index de9e1d52f1a0..3e8d5585e12b 100644
--- a/packages/devextreme-vue/src/text-box.ts
+++ b/packages/devextreme-vue/src/text-box.ts
@@ -125,7 +125,7 @@ const componentConfig = {
     maskChar: String,
     maskInvalidMessage: String,
     maskRules: {},
-    maxLength: [Number, String],
+    maxLength: [Number, String] as PropType<null | number | string>,
     mode: String as PropType<TextBoxType>,
     name: String,
     onChange: Function as PropType<((e: ChangeEvent) => void)>,
@@ -154,7 +154,7 @@ const componentConfig = {
     text: String,
     useMaskedValue: Boolean,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Position>,
     validationStatus: String as PropType<ValidationStatus>,
diff --git a/packages/devextreme-vue/src/tree-list.ts b/packages/devextreme-vue/src/tree-list.ts
index a6abed1aea26..4e13a6a39c85 100644
--- a/packages/devextreme-vue/src/tree-list.ts
+++ b/packages/devextreme-vue/src/tree-list.ts
@@ -1761,7 +1761,7 @@ const DxEditorOptionsConfig = {
     maskChar: String,
     maskInvalidMessage: String,
     maskRules: {},
-    maxLength: [Number, String],
+    maxLength: [Number, String] as PropType<null | number | string>,
     mode: String as PropType<TextBoxType>,
     name: String,
     onChange: Function as PropType<((e: ChangeEvent) => void)>,
@@ -1790,7 +1790,7 @@ const DxEditorOptionsConfig = {
     text: String,
     useMaskedValue: Boolean,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Position>,
     validationStatus: String as PropType<ValidationStatus>,
@@ -2113,18 +2113,18 @@ const DxFilterBuilderPopupConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
+    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
+    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
@@ -3247,18 +3247,18 @@ const DxPopupConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
+    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
-    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
+    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
@@ -3920,8 +3920,8 @@ const DxTabPanelOptionsConfig = {
     onSelectionChanged: Function as PropType<((e: TabPanelSelectionChangedEvent) => void)>,
     onSelectionChanging: Function as PropType<((e: SelectionChangingEvent) => void)>,
     onTitleClick: Function as PropType<((e: TitleClickEvent) => void)>,
-    onTitleHold: Function as PropType<((e: TitleHoldEvent) => void)>,
-    onTitleRendered: Function as PropType<((e: TitleRenderedEvent) => void)>,
+    onTitleHold: Function as PropType<(((e: TitleHoldEvent) => void)) | null>,
+    onTitleRendered: Function as PropType<(((e: TitleRenderedEvent) => void)) | null>,
     repaintChangesOnly: Boolean,
     rtlEnabled: Boolean,
     scrollByContent: Boolean,
diff --git a/packages/devextreme-vue/src/tree-view.ts b/packages/devextreme-vue/src/tree-view.ts
index 3300c962b618..21db8042f48d 100644
--- a/packages/devextreme-vue/src/tree-view.ts
+++ b/packages/devextreme-vue/src/tree-view.ts
@@ -178,16 +178,16 @@ const componentConfig = {
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
-    onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
-    onItemCollapsed: Function as PropType<((e: ItemCollapsedEvent) => void)>,
-    onItemContextMenu: Function as PropType<((e: ItemContextMenuEvent) => void)>,
-    onItemExpanded: Function as PropType<((e: ItemExpandedEvent) => void)>,
-    onItemHold: Function as PropType<((e: ItemHoldEvent) => void)>,
-    onItemRendered: Function as PropType<((e: ItemRenderedEvent) => void)>,
-    onItemSelectionChanged: Function as PropType<((e: ItemSelectionChangedEvent) => void)>,
+    onItemClick: Function as PropType<(((e: ItemClickEvent) => void)) | null>,
+    onItemCollapsed: Function as PropType<(((e: ItemCollapsedEvent) => void)) | null>,
+    onItemContextMenu: Function as PropType<(((e: ItemContextMenuEvent) => void)) | null>,
+    onItemExpanded: Function as PropType<(((e: ItemExpandedEvent) => void)) | null>,
+    onItemHold: Function as PropType<(((e: ItemHoldEvent) => void)) | null>,
+    onItemRendered: Function as PropType<(((e: ItemRenderedEvent) => void)) | null>,
+    onItemSelectionChanged: Function as PropType<(((e: ItemSelectionChangedEvent) => void)) | null>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onSelectAllValueChanged: Function as PropType<((e: SelectAllValueChangedEvent) => void)>,
-    onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
+    onSelectAllValueChanged: Function as PropType<(((e: SelectAllValueChangedEvent) => void)) | null>,
+    onSelectionChanged: Function as PropType<(((e: SelectionChangedEvent) => void)) | null>,
     parentIdExpr: [Function, String] as PropType<(((item: any) => any | undefined)) | string>,
     rootValue: {},
     rtlEnabled: Boolean,
@@ -506,7 +506,7 @@ const DxSearchEditorOptionsConfig = {
     maskChar: String,
     maskInvalidMessage: String,
     maskRules: {},
-    maxLength: [Number, String],
+    maxLength: [Number, String] as PropType<null | number | string>,
     mode: String as PropType<TextBoxType>,
     name: String,
     onChange: Function as PropType<((e: ChangeEvent) => void)>,
@@ -535,7 +535,7 @@ const DxSearchEditorOptionsConfig = {
     text: String,
     useMaskedValue: Boolean,
     validationError: {},
-    validationErrors: Array as PropType<Array<any>>,
+    validationErrors: Array as PropType<Array<any> | null>,
     validationMessageMode: String as PropType<ValidationMessageMode>,
     validationMessagePosition: String as PropType<Position>,
     validationStatus: String as PropType<ValidationStatus>,
diff --git a/packages/devextreme/ts/dx.all.d.ts b/packages/devextreme/ts/dx.all.d.ts
index 93a49fa19a29..677214817445 100644
--- a/packages/devextreme/ts/dx.all.d.ts
+++ b/packages/devextreme/ts/dx.all.d.ts
@@ -2216,11 +2216,11 @@ declare module DevExpress.common.charts {
       /**
        * [descr:dxChartSeriesTypes.CommonSeries.label.border.color]
        */
-      color?: string;
+      color?: string | undefined;
       /**
        * [descr:dxChartSeriesTypes.CommonSeries.label.border.dashStyle]
        */
-      dashStyle?: DashStyle;
+      dashStyle?: DashStyle | undefined;
       /**
        * [descr:dxChartSeriesTypes.CommonSeries.label.border.visible]
        */
@@ -21482,7 +21482,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxGanttOptions.toolbar]
      */
-    toolbar?: dxGanttToolbar | null;
+    toolbar?: dxGanttToolbar;
     /**
      * [descr:dxGanttOptions.contextMenu]
      */
@@ -21490,7 +21490,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxGanttOptions.stripLines]
      */
-    stripLines?: Array<dxGanttStripLine> | undefined;
+    stripLines?: Array<dxGanttStripLine>;
     /**
      * [descr:dxGanttOptions.taskTooltipContentTemplate]
      */
@@ -39496,18 +39496,16 @@ declare module DevExpress.viz {
     /**
      * [descr:dxChartOptions.seriesTemplate]
      */
-    seriesTemplate?:
-      | {
-          /**
-           * [descr:dxChartOptions.seriesTemplate.customizeSeries]
-           */
-          customizeSeries?: (seriesName: any) => ChartSeries;
-          /**
-           * [descr:dxChartOptions.seriesTemplate.nameField]
-           */
-          nameField?: string;
-        }
-      | undefined;
+    seriesTemplate?: {
+      /**
+       * [descr:dxChartOptions.seriesTemplate.customizeSeries]
+       */
+      customizeSeries?: (seriesName: any) => ChartSeries;
+      /**
+       * [descr:dxChartOptions.seriesTemplate.nameField]
+       */
+      nameField?: string;
+    };
     /**
      * [descr:dxChartOptions.stickyHovering]
      */
@@ -41701,15 +41699,15 @@ declare module DevExpress.viz {
         /**
          * [descr:dxFunnelOptions.item.border.color]
          */
-        color?: string;
+        color?: string | undefined;
         /**
          * [descr:dxFunnelOptions.item.border.visible]
          */
-        visible?: boolean;
+        visible?: boolean | undefined;
         /**
          * [descr:dxFunnelOptions.item.border.width]
          */
-        width?: number;
+        width?: number | undefined;
       };
       /**
        * [descr:dxFunnelOptions.item.hoverStyle]
@@ -42442,18 +42440,16 @@ declare module DevExpress.viz {
     /**
      * [descr:dxPieChartOptions.seriesTemplate]
      */
-    seriesTemplate?:
-      | {
-          /**
-           * [descr:dxPieChartOptions.seriesTemplate.customizeSeries]
-           */
-          customizeSeries?: (seriesName: any) => PieChartSeries;
-          /**
-           * [descr:dxPieChartOptions.seriesTemplate.nameField]
-           */
-          nameField?: string;
-        }
-      | undefined;
+    seriesTemplate?: {
+      /**
+       * [descr:dxPieChartOptions.seriesTemplate.customizeSeries]
+       */
+      customizeSeries?: (seriesName: any) => PieChartSeries;
+      /**
+       * [descr:dxPieChartOptions.seriesTemplate.nameField]
+       */
+      nameField?: string;
+    };
     /**
      * [descr:dxPieChartOptions.sizeGroup]
      */
@@ -42620,11 +42616,11 @@ declare module DevExpress.viz {
         /**
          * [descr:dxPieChartSeriesTypes.CommonPieChartSeries.label.border.color]
          */
-        color?: string;
+        color?: string | undefined;
         /**
          * [descr:dxPieChartSeriesTypes.CommonPieChartSeries.label.border.dashStyle]
          */
-        dashStyle?: DevExpress.common.charts.DashStyle;
+        dashStyle?: DevExpress.common.charts.DashStyle | undefined;
         /**
          * [descr:dxPieChartSeriesTypes.CommonPieChartSeries.label.border.visible]
          */
@@ -43897,18 +43893,16 @@ declare module DevExpress.viz {
     /**
      * [descr:dxPolarChartOptions.seriesTemplate]
      */
-    seriesTemplate?:
-      | {
-          /**
-           * [descr:dxPolarChartOptions.seriesTemplate.customizeSeries]
-           */
-          customizeSeries?: (seriesName: any) => PolarChartSeries;
-          /**
-           * [descr:dxPolarChartOptions.seriesTemplate.nameField]
-           */
-          nameField?: string;
-        }
-      | undefined;
+    seriesTemplate?: {
+      /**
+       * [descr:dxPolarChartOptions.seriesTemplate.customizeSeries]
+       */
+      customizeSeries?: (seriesName: any) => PolarChartSeries;
+      /**
+       * [descr:dxPolarChartOptions.seriesTemplate.nameField]
+       */
+      nameField?: string;
+    };
     /**
      * [descr:dxPolarChartOptions.tooltip]
      */
@@ -44290,11 +44284,11 @@ declare module DevExpress.viz {
       /**
        * [descr:dxPolarChartSeriesTypes.CommonPolarChartSeries.label.border.color]
        */
-      color?: string;
+      color?: string | undefined;
       /**
        * [descr:dxPolarChartSeriesTypes.CommonPolarChartSeries.label.border.dashStyle]
        */
-      dashStyle?: DevExpress.common.charts.DashStyle;
+      dashStyle?: DevExpress.common.charts.DashStyle | undefined;
       /**
        * [descr:dxPolarChartSeriesTypes.CommonPolarChartSeries.label.border.visible]
        */
@@ -44760,18 +44754,16 @@ declare module DevExpress.viz {
       /**
        * [descr:dxRangeSelectorOptions.chart.seriesTemplate]
        */
-      seriesTemplate?:
-        | {
-            /**
-             * [descr:dxRangeSelectorOptions.chart.seriesTemplate.customizeSeries]
-             */
-            customizeSeries?: (seriesName: any) => ChartSeries;
-            /**
-             * [descr:dxRangeSelectorOptions.chart.seriesTemplate.nameField]
-             */
-            nameField?: string;
-          }
-        | undefined;
+      seriesTemplate?: {
+        /**
+         * [descr:dxRangeSelectorOptions.chart.seriesTemplate.customizeSeries]
+         */
+        customizeSeries?: (seriesName: any) => ChartSeries;
+        /**
+         * [descr:dxRangeSelectorOptions.chart.seriesTemplate.nameField]
+         */
+        nameField?: string;
+      };
       /**
        * [descr:dxRangeSelectorOptions.chart.topIndent]
        */
@@ -45439,15 +45431,15 @@ declare module DevExpress.viz {
         /**
          * [descr:dxSankeyOptions.label.border.color]
          */
-        color?: string;
+        color?: string | undefined;
         /**
          * [descr:dxSankeyOptions.label.border.visible]
          */
-        visible?: boolean;
+        visible?: boolean | undefined;
         /**
          * [descr:dxSankeyOptions.label.border.width]
          */
-        width?: number;
+        width?: number | undefined;
       };
       /**
        * [descr:dxSankeyOptions.label.customizeText]
@@ -45514,15 +45506,15 @@ declare module DevExpress.viz {
         /**
          * [descr:dxSankeyOptions.link.border.color]
          */
-        color?: string;
+        color?: string | undefined;
         /**
          * [descr:dxSankeyOptions.link.border.visible]
          */
-        visible?: boolean;
+        visible?: boolean | undefined;
         /**
          * [descr:dxSankeyOptions.link.border.width]
          */
-        width?: number;
+        width?: number | undefined;
       };
       /**
        * [descr:dxSankeyOptions.link.color]
@@ -45599,15 +45591,15 @@ declare module DevExpress.viz {
         /**
          * [descr:dxSankeyOptions.node.border.color]
          */
-        color?: string;
+        color?: string | undefined;
         /**
          * [descr:dxSankeyOptions.node.border.visible]
          */
-        visible?: boolean;
+        visible?: boolean | undefined;
         /**
          * [descr:dxSankeyOptions.node.border.width]
          */
-        width?: number;
+        width?: number | undefined;
       };
       /**
        * [descr:dxSankeyOptions.node.color]
@@ -46223,7 +46215,7 @@ declare module DevExpress.viz {
         /**
          * [descr:dxTreeMapOptions.group.border.width]
          */
-        width?: number;
+        width?: number | undefined;
       };
       /**
        * [descr:dxTreeMapOptions.group.color]
@@ -46395,11 +46387,11 @@ declare module DevExpress.viz {
         /**
          * [descr:dxTreeMapOptions.tile.border.color]
          */
-        color?: string;
+        color?: string | undefined;
         /**
          * [descr:dxTreeMapOptions.tile.border.width]
          */
-        width?: number;
+        width?: number | undefined;
       };
       /**
        * [descr:dxTreeMapOptions.tile.color]
@@ -47019,8 +47011,7 @@ declare module DevExpress.viz {
           sizeGroupingField?: string;
           sizeGroups?: Array<number>;
           type?: 'area' | 'line' | 'marker';
-        }
-      | undefined;
+        };
     /**
      * [descr:dxVectorMapOptions.legends]
      */

From 0053e672d94f1ba722300b5e4293cd0c5cf922b3 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:42 +0300
Subject: [PATCH 061/100] fix(vue-generator): prevent Function as PropType
 union null typescript error

Vue component wrapper generation fails typescript compilation when event handler/function properties are annotated with PropType<... | null> because FunctionConstructor does not sufficiently overlap with PropType<FunctionType | null> in TS 5.x.

Adds a metadata cleanup step to nx-infra-plugin that removes the Null type descriptor from any property in the metadata if it represents a function or event handler (starts with 'on[A-Z]' or has Function type). This ensures that the generated Vue props are typed as PropType<FunctionType> without the | null suffix, which matches standard Vue/TS patterns and compiles successfully.
---
 .../generate-components/framework-handlers.ts | 43 ++++++++++++++++++-
 1 file changed, 42 insertions(+), 1 deletion(-)

diff --git a/packages/nx-infra-plugin/src/executors/generate-components/framework-handlers.ts b/packages/nx-infra-plugin/src/executors/generate-components/framework-handlers.ts
index 3d84e6161667..56f64bdb1d4a 100644
--- a/packages/nx-infra-plugin/src/executors/generate-components/framework-handlers.ts
+++ b/packages/nx-infra-plugin/src/executors/generate-components/framework-handlers.ts
@@ -50,6 +50,46 @@ function createReactHandler(): FrameworkHandler {
   };
 }
 
+function cleanVueMetadata(metaData: any): any {
+  if (!metaData) return metaData;
+
+  const cleanProp = (prop: any) => {
+    if (prop && Array.isArray(prop.types)) {
+      const isFunction = /^on[A-Z]/.test(prop.name) || prop.types.some((t: any) => t && (t.type === 'Function' || t.acceptableValueType === 'Function'));
+      if (isFunction) {
+        prop.types = prop.types.filter((t: any) => t && t.type !== 'Null');
+      }
+    }
+    if (prop && Array.isArray(prop.props)) {
+      prop.props.forEach(cleanProp);
+    }
+  };
+
+  if (Array.isArray(metaData.widgets)) {
+    metaData.widgets.forEach((widget: any) => {
+      if (widget) {
+        if (Array.isArray(widget.options)) {
+          widget.options.forEach(cleanProp);
+        }
+        if (Array.isArray(widget.complexOptions)) {
+          widget.complexOptions.forEach((co: any) => {
+            if (co) {
+              if (Array.isArray(co.options)) {
+                co.options.forEach(cleanProp);
+              }
+              if (Array.isArray(co.props)) {
+                co.props.forEach(cleanProp);
+              }
+            }
+          });
+        }
+      }
+    });
+  }
+
+  return metaData;
+}
+
 function createVueHandler(): FrameworkHandler {
   return {
     getDefaults: () => ({
@@ -59,9 +99,10 @@ function createVueHandler(): FrameworkHandler {
 
     executeGeneration: async (generateFunction, config, metaData) => {
       const componentGeneratorTplConfig = config.componentGeneratorTplConfig || {};
+      const cleanedMetaData = cleanVueMetadata(JSON.parse(JSON.stringify(metaData)));
 
       await generateFunction(
-        metaData,
+        cleanedMetaData,
         componentGeneratorTplConfig,
         config.out,
         config.widgetsPackage,

From ae28d9f66338331a5d176d4909c3134f930fc239 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:42 +0300
Subject: [PATCH 062/100] chore(vue): commit regenerated Vue components with
 clean PropType definitions

---
 packages/devextreme-vue/src/accordion.ts      |  2 +-
 packages/devextreme-vue/src/autocomplete.ts   | 10 ++--
 packages/devextreme-vue/src/button-group.ts   |  4 +-
 packages/devextreme-vue/src/calendar.ts       |  2 +-
 packages/devextreme-vue/src/card-view.ts      | 10 ++--
 packages/devextreme-vue/src/chat.ts           | 24 ++++-----
 packages/devextreme-vue/src/color-box.ts      | 10 ++--
 packages/devextreme-vue/src/context-menu.ts   | 10 ++--
 packages/devextreme-vue/src/data-grid.ts      | 32 +++++------
 packages/devextreme-vue/src/date-box.ts       | 14 ++---
 packages/devextreme-vue/src/date-range-box.ts | 12 ++---
 packages/devextreme-vue/src/diagram.ts        | 10 ++--
 packages/devextreme-vue/src/drop-down-box.ts  | 10 ++--
 .../devextreme-vue/src/drop-down-button.ts    | 10 ++--
 packages/devextreme-vue/src/file-uploader.ts  | 20 +++----
 packages/devextreme-vue/src/form.ts           |  4 +-
 packages/devextreme-vue/src/gantt.ts          | 54 +++++++++----------
 packages/devextreme-vue/src/html-editor.ts    | 20 +++----
 packages/devextreme-vue/src/list.ts           | 24 ++++-----
 packages/devextreme-vue/src/lookup.ts         |  8 +--
 packages/devextreme-vue/src/map.ts            | 10 ++--
 packages/devextreme-vue/src/menu.ts           |  8 +--
 packages/devextreme-vue/src/pagination.ts     |  2 +-
 packages/devextreme-vue/src/popup.ts          | 10 ++--
 packages/devextreme-vue/src/progress-bar.ts   |  2 +-
 packages/devextreme-vue/src/range-slider.ts   |  2 +-
 packages/devextreme-vue/src/responsive-box.ts |  2 +-
 packages/devextreme-vue/src/scheduler.ts      |  8 +--
 packages/devextreme-vue/src/scroll-view.ts    |  4 +-
 packages/devextreme-vue/src/select-box.ts     | 10 ++--
 .../devextreme-vue/src/speed-dial-action.ts   |  2 +-
 packages/devextreme-vue/src/tab-panel.ts      |  4 +-
 packages/devextreme-vue/src/tabs.ts           |  2 +-
 packages/devextreme-vue/src/tag-box.ts        | 16 +++---
 packages/devextreme-vue/src/tree-list.ts      | 32 +++++------
 packages/devextreme-vue/src/tree-view.ts      | 18 +++----
 36 files changed, 211 insertions(+), 211 deletions(-)

diff --git a/packages/devextreme-vue/src/accordion.ts b/packages/devextreme-vue/src/accordion.ts
index b26db562a4fe..93f0c6d35f9a 100644
--- a/packages/devextreme-vue/src/accordion.ts
+++ b/packages/devextreme-vue/src/accordion.ts
@@ -88,7 +88,7 @@ const componentConfig = {
     items: Array as PropType<Array<any | dxAccordionItem | string>>,
     itemTemplate: {},
     itemTitleTemplate: {},
-    keyExpr: [Function, String] as PropType<(((item: any) => any)) | null | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
     multiple: Boolean,
     noDataText: String,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
diff --git a/packages/devextreme-vue/src/autocomplete.ts b/packages/devextreme-vue/src/autocomplete.ts
index b060332d6740..8917f694b7bd 100644
--- a/packages/devextreme-vue/src/autocomplete.ts
+++ b/packages/devextreme-vue/src/autocomplete.ts
@@ -530,18 +530,18 @@ const DxDropDownOptionsConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
+    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
+    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
diff --git a/packages/devextreme-vue/src/button-group.ts b/packages/devextreme-vue/src/button-group.ts
index 0b09b22423cd..0f300e8e3d16 100644
--- a/packages/devextreme-vue/src/button-group.ts
+++ b/packages/devextreme-vue/src/button-group.ts
@@ -66,9 +66,9 @@ const componentConfig = {
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
-    onItemClick: Function as PropType<(((e: ItemClickEvent) => void)) | null>,
+    onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onSelectionChanged: Function as PropType<(((e: SelectionChangedEvent) => void)) | null>,
+    onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
     rtlEnabled: Boolean,
     selectedItemKeys: Array as PropType<Array<any>>,
     selectedItems: Array as PropType<Array<any>>,
diff --git a/packages/devextreme-vue/src/calendar.ts b/packages/devextreme-vue/src/calendar.ts
index afc8fdd36268..9d668d33a533 100644
--- a/packages/devextreme-vue/src/calendar.ts
+++ b/packages/devextreme-vue/src/calendar.ts
@@ -74,7 +74,7 @@ const componentConfig = {
     cellTemplate: {},
     dateSerializationFormat: String,
     disabled: Boolean,
-    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: DisabledDate) => boolean)) | null>,
+    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: DisabledDate) => boolean))>,
     elementAttr: Object as PropType<Record<string, any>>,
     firstDayOfWeek: Number as PropType<DayOfWeek>,
     focusStateEnabled: Boolean,
diff --git a/packages/devextreme-vue/src/card-view.ts b/packages/devextreme-vue/src/card-view.ts
index a80754c49edb..ca1a100bacd8 100644
--- a/packages/devextreme-vue/src/card-view.ts
+++ b/packages/devextreme-vue/src/card-view.ts
@@ -337,7 +337,7 @@ const componentConfig = {
     onCardRemoving: Function as PropType<((e: CardRemovingEvent) => void)>,
     onCardUpdated: Function as PropType<((e: CardUpdatedEvent) => void)>,
     onCardUpdating: Function as PropType<((e: CardUpdatingEvent) => void)>,
-    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
+    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
     onContextMenuPreparing: Function as PropType<((e: ContextMenuPreparingEvent) => void)>,
     onDataErrorOccurred: Function as PropType<((e: { component: Object, element: any, error: any, model: any }) => void)>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
@@ -1181,7 +1181,7 @@ const DxColumnHeaderFilterConfig = {
   props: {
     allowSearch: Boolean,
     allowSelectAll: Boolean,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | null | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | Store | Record<string, any>>,
     groupInterval: [Array, String, Number] as PropType<(Array<number | string>) | HeaderFilterGroupInterval | number>,
     height: [Number, String],
     search: Object as PropType<ColumnHeaderFilterSearchConfig | HeaderFilterSearchConfig | Record<string, any>>,
@@ -1994,7 +1994,7 @@ const DxHeaderFilterConfig = {
   props: {
     allowSearch: Boolean,
     allowSelectAll: Boolean,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | null | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | Store | Record<string, any>>,
     groupInterval: [Array, String, Number] as PropType<(Array<number | string>) | HeaderFilterGroupInterval | number>,
     height: [Number, String],
     search: Object as PropType<ColumnHeaderFilterSearchConfig | HeaderFilterSearchConfig | Record<string, any>>,
@@ -3034,8 +3034,8 @@ const DxTabPanelOptionsConfig = {
     onSelectionChanged: Function as PropType<((e: TabPanelSelectionChangedEvent) => void)>,
     onSelectionChanging: Function as PropType<((e: SelectionChangingEvent) => void)>,
     onTitleClick: Function as PropType<((e: TitleClickEvent) => void)>,
-    onTitleHold: Function as PropType<(((e: TitleHoldEvent) => void)) | null>,
-    onTitleRendered: Function as PropType<(((e: TitleRenderedEvent) => void)) | null>,
+    onTitleHold: Function as PropType<((e: TitleHoldEvent) => void)>,
+    onTitleRendered: Function as PropType<((e: TitleRenderedEvent) => void)>,
     repaintChangesOnly: Boolean,
     rtlEnabled: Boolean,
     scrollByContent: Boolean,
diff --git a/packages/devextreme-vue/src/chat.ts b/packages/devextreme-vue/src/chat.ts
index 2452a5176ccf..62b453875482 100644
--- a/packages/devextreme-vue/src/chat.ts
+++ b/packages/devextreme-vue/src/chat.ts
@@ -536,20 +536,20 @@ const DxFileUploaderOptionsConfig = {
     minFileSize: Number,
     multiple: Boolean,
     name: String,
-    onBeforeSend: Function as PropType<(((e: BeforeSendEvent) => void)) | null>,
+    onBeforeSend: Function as PropType<((e: BeforeSendEvent) => void)>,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: FileUploaderDisposingEvent) => void)>,
-    onDropZoneEnter: Function as PropType<(((e: DropZoneEnterEvent) => void)) | null>,
-    onDropZoneLeave: Function as PropType<(((e: DropZoneLeaveEvent) => void)) | null>,
-    onFilesUploaded: Function as PropType<(((e: FilesUploadedEvent) => void)) | null>,
+    onDropZoneEnter: Function as PropType<((e: DropZoneEnterEvent) => void)>,
+    onDropZoneLeave: Function as PropType<((e: DropZoneLeaveEvent) => void)>,
+    onFilesUploaded: Function as PropType<((e: FilesUploadedEvent) => void)>,
     onInitialized: Function as PropType<((e: FileUploaderInitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: FileUploaderOptionChangedEvent) => void)>,
-    onProgress: Function as PropType<(((e: ProgressEvent) => void)) | null>,
-    onUploadAborted: Function as PropType<(((e: UploadAbortedEvent) => void)) | null>,
-    onUploaded: Function as PropType<(((e: UploadedEvent) => void)) | null>,
-    onUploadError: Function as PropType<(((e: UploadErrorEvent) => void)) | null>,
-    onUploadStarted: Function as PropType<(((e: UploadStartedEvent) => void)) | null>,
-    onValueChanged: Function as PropType<(((e: ValueChangedEvent) => void)) | null>,
+    onProgress: Function as PropType<((e: ProgressEvent) => void)>,
+    onUploadAborted: Function as PropType<((e: UploadAbortedEvent) => void)>,
+    onUploaded: Function as PropType<((e: UploadedEvent) => void)>,
+    onUploadError: Function as PropType<((e: UploadErrorEvent) => void)>,
+    onUploadStarted: Function as PropType<((e: UploadStartedEvent) => void)>,
+    onValueChanged: Function as PropType<((e: ValueChangedEvent) => void)>,
     progress: Number,
     readOnly: Boolean,
     readyToUploadMessage: String,
@@ -830,9 +830,9 @@ const DxSuggestionsConfig = {
     onContentReady: Function as PropType<((e: ButtonGroupContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: ButtonGroupDisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: ButtonGroupInitializedEvent) => void)>,
-    onItemClick: Function as PropType<(((e: ItemClickEvent) => void)) | null>,
+    onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
     onOptionChanged: Function as PropType<((e: ButtonGroupOptionChangedEvent) => void)>,
-    onSelectionChanged: Function as PropType<(((e: SelectionChangedEvent) => void)) | null>,
+    onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
     rtlEnabled: Boolean,
     selectedItemKeys: Array as PropType<Array<any>>,
     selectedItems: Array as PropType<Array<any>>,
diff --git a/packages/devextreme-vue/src/color-box.ts b/packages/devextreme-vue/src/color-box.ts
index 7f73a6b83bfb..e49215f78451 100644
--- a/packages/devextreme-vue/src/color-box.ts
+++ b/packages/devextreme-vue/src/color-box.ts
@@ -479,18 +479,18 @@ const DxDropDownOptionsConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
+    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
+    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
diff --git a/packages/devextreme-vue/src/context-menu.ts b/packages/devextreme-vue/src/context-menu.ts
index b0c8a4fe7800..710e286b64fc 100644
--- a/packages/devextreme-vue/src/context-menu.ts
+++ b/packages/devextreme-vue/src/context-menu.ts
@@ -119,17 +119,17 @@ const componentConfig = {
     itemTemplate: {},
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
-    onHidden: Function as PropType<(((e: HiddenEvent) => void)) | null>,
-    onHiding: Function as PropType<(((e: HidingEvent) => void)) | null>,
+    onHidden: Function as PropType<((e: HiddenEvent) => void)>,
+    onHiding: Function as PropType<((e: HidingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
     onItemContextMenu: Function as PropType<((e: ItemContextMenuEvent) => void)>,
     onItemRendered: Function as PropType<((e: ItemRenderedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onPositioning: Function as PropType<(((e: PositioningEvent) => void)) | null>,
+    onPositioning: Function as PropType<((e: PositioningEvent) => void)>,
     onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
-    onShowing: Function as PropType<(((e: ShowingEvent) => void)) | null>,
-    onShown: Function as PropType<(((e: ShownEvent) => void)) | null>,
+    onShowing: Function as PropType<((e: ShowingEvent) => void)>,
+    onShown: Function as PropType<((e: ShownEvent) => void)>,
     position: Object as PropType<PositionConfig | Record<string, any>>,
     rtlEnabled: Boolean,
     selectByClick: Boolean,
diff --git a/packages/devextreme-vue/src/data-grid.ts b/packages/devextreme-vue/src/data-grid.ts
index 919eece17774..36058017ad2e 100644
--- a/packages/devextreme-vue/src/data-grid.ts
+++ b/packages/devextreme-vue/src/data-grid.ts
@@ -1438,7 +1438,7 @@ const DxColumnHeaderFilterConfig = {
   props: {
     allowSearch: Boolean,
     allowSelectAll: Boolean,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | null | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | Store | Record<string, any>>,
     groupInterval: [Array, String, Number] as PropType<(Array<number | string>) | HeaderFilterGroupInterval | number>,
     height: [Number, String],
     search: Object as PropType<ColumnHeaderFilterSearchConfig | HeaderFilterSearchConfig | Record<string, any>>,
@@ -1495,7 +1495,7 @@ const DxColumnLookupConfig = {
   props: {
     allowClearing: Boolean,
     calculateCellValue: Function as PropType<((rowData: any) => any)>,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { data: Record<string, any>, key: any }) => Array<any> | Store | DataSourceOptions)) | null | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { data: Record<string, any>, key: any }) => Array<any> | Store | DataSourceOptions)) | Store | Record<string, any>>,
     displayExpr: [Function, String] as PropType<(((data: any) => string)) | string>,
     valueExpr: String
   }
@@ -2336,18 +2336,18 @@ const DxFilterBuilderPopupConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
+    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
+    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
@@ -2931,7 +2931,7 @@ const DxHeaderFilterConfig = {
   props: {
     allowSearch: Boolean,
     allowSelectAll: Boolean,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | null | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | Store | Record<string, any>>,
     groupInterval: [Array, String, Number] as PropType<(Array<number | string>) | HeaderFilterGroupInterval | number>,
     height: [Number, String],
     search: Object as PropType<ColumnHeaderFilterSearchConfig | HeaderFilterSearchConfig | Record<string, any>>,
@@ -3254,7 +3254,7 @@ const DxLookupConfig = {
   props: {
     allowClearing: Boolean,
     calculateCellValue: Function as PropType<((rowData: any) => any)>,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { data: Record<string, any>, key: any }) => Array<any> | Store | DataSourceOptions)) | null | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { data: Record<string, any>, key: any }) => Array<any> | Store | DataSourceOptions)) | Store | Record<string, any>>,
     displayExpr: [Function, String] as PropType<(((data: any) => string)) | string>,
     valueExpr: [String, Function] as PropType<string | (((data: any) => string | number | boolean))>
   }
@@ -3605,18 +3605,18 @@ const DxPopupConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
+    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
+    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
@@ -4380,8 +4380,8 @@ const DxTabPanelOptionsConfig = {
     onSelectionChanged: Function as PropType<((e: TabPanelSelectionChangedEvent) => void)>,
     onSelectionChanging: Function as PropType<((e: SelectionChangingEvent) => void)>,
     onTitleClick: Function as PropType<((e: TitleClickEvent) => void)>,
-    onTitleHold: Function as PropType<(((e: TitleHoldEvent) => void)) | null>,
-    onTitleRendered: Function as PropType<(((e: TitleRenderedEvent) => void)) | null>,
+    onTitleHold: Function as PropType<((e: TitleHoldEvent) => void)>,
+    onTitleRendered: Function as PropType<((e: TitleRenderedEvent) => void)>,
     repaintChangesOnly: Boolean,
     rtlEnabled: Boolean,
     scrollByContent: Boolean,
diff --git a/packages/devextreme-vue/src/date-box.ts b/packages/devextreme-vue/src/date-box.ts
index 250f1b543cee..91ebdf640f70 100644
--- a/packages/devextreme-vue/src/date-box.ts
+++ b/packages/devextreme-vue/src/date-box.ts
@@ -198,7 +198,7 @@ const componentConfig = {
     dateSerializationFormat: String,
     deferRendering: Boolean,
     disabled: Boolean,
-    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: { component: dxDateBox, date: Date, view: string }) => boolean)) | null>,
+    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: { component: dxDateBox, date: Date, view: string }) => boolean))>,
     displayFormat: [Object, String, Function] as PropType<Format | null | CommonFormat | (((value: number | Date) => string)) | Record<string, any> | string>,
     dropDownButtonTemplate: {},
     dropDownOptions: Object as PropType<dxPopupOptions<any> | Record<string, any>>,
@@ -501,7 +501,7 @@ const DxCalendarOptionsConfig = {
     cellTemplate: {},
     dateSerializationFormat: String,
     disabled: Boolean,
-    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: DisabledDate) => boolean)) | null>,
+    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: DisabledDate) => boolean))>,
     elementAttr: Object as PropType<Record<string, any>>,
     firstDayOfWeek: Number as PropType<DayOfWeek>,
     focusStateEnabled: Boolean,
@@ -668,18 +668,18 @@ const DxDropDownOptionsConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
+    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
+    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
diff --git a/packages/devextreme-vue/src/date-range-box.ts b/packages/devextreme-vue/src/date-range-box.ts
index be4200f8d07f..3523cdfbd031 100644
--- a/packages/devextreme-vue/src/date-range-box.ts
+++ b/packages/devextreme-vue/src/date-range-box.ts
@@ -510,7 +510,7 @@ const DxCalendarOptionsConfig = {
     cellTemplate: {},
     dateSerializationFormat: String,
     disabled: Boolean,
-    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: DisabledDate) => boolean)) | null>,
+    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: DisabledDate) => boolean))>,
     elementAttr: Object as PropType<Record<string, any>>,
     firstDayOfWeek: Number as PropType<DayOfWeek>,
     focusStateEnabled: Boolean,
@@ -677,18 +677,18 @@ const DxDropDownOptionsConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
+    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
+    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
diff --git a/packages/devextreme-vue/src/diagram.ts b/packages/devextreme-vue/src/diagram.ts
index 255da3bb1fb7..551fe1416c39 100644
--- a/packages/devextreme-vue/src/diagram.ts
+++ b/packages/devextreme-vue/src/diagram.ts
@@ -117,12 +117,12 @@ const componentConfig = {
     onCustomCommand: Function as PropType<((e: CustomCommandEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
-    onItemClick: Function as PropType<(((e: ItemClickEvent) => void)) | null>,
-    onItemDblClick: Function as PropType<(((e: ItemDblClickEvent) => void)) | null>,
+    onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
+    onItemDblClick: Function as PropType<((e: ItemDblClickEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onRequestEditOperation: Function as PropType<(((e: RequestEditOperationEvent) => void)) | null>,
-    onRequestLayoutUpdate: Function as PropType<(((e: RequestLayoutUpdateEvent) => void)) | null>,
-    onSelectionChanged: Function as PropType<(((e: SelectionChangedEvent) => void)) | null>,
+    onRequestEditOperation: Function as PropType<((e: RequestEditOperationEvent) => void)>,
+    onRequestLayoutUpdate: Function as PropType<((e: RequestLayoutUpdateEvent) => void)>,
+    onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
     pageColor: String,
     pageOrientation: String as PropType<PageOrientation>,
     pageSize: Object as PropType<Record<string, any>>,
diff --git a/packages/devextreme-vue/src/drop-down-box.ts b/packages/devextreme-vue/src/drop-down-box.ts
index 831f0b2de37c..d488c718cb50 100644
--- a/packages/devextreme-vue/src/drop-down-box.ts
+++ b/packages/devextreme-vue/src/drop-down-box.ts
@@ -494,18 +494,18 @@ const DxDropDownOptionsConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
+    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
+    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
diff --git a/packages/devextreme-vue/src/drop-down-button.ts b/packages/devextreme-vue/src/drop-down-button.ts
index ddce99421b35..b288957c537c 100644
--- a/packages/devextreme-vue/src/drop-down-button.ts
+++ b/packages/devextreme-vue/src/drop-down-button.ts
@@ -373,18 +373,18 @@ const DxDropDownOptionsConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
+    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
+    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
diff --git a/packages/devextreme-vue/src/file-uploader.ts b/packages/devextreme-vue/src/file-uploader.ts
index feb73c88d871..8c9946b4ef78 100644
--- a/packages/devextreme-vue/src/file-uploader.ts
+++ b/packages/devextreme-vue/src/file-uploader.ts
@@ -124,20 +124,20 @@ const componentConfig = {
     minFileSize: Number,
     multiple: Boolean,
     name: String,
-    onBeforeSend: Function as PropType<(((e: BeforeSendEvent) => void)) | null>,
+    onBeforeSend: Function as PropType<((e: BeforeSendEvent) => void)>,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
-    onDropZoneEnter: Function as PropType<(((e: DropZoneEnterEvent) => void)) | null>,
-    onDropZoneLeave: Function as PropType<(((e: DropZoneLeaveEvent) => void)) | null>,
-    onFilesUploaded: Function as PropType<(((e: FilesUploadedEvent) => void)) | null>,
+    onDropZoneEnter: Function as PropType<((e: DropZoneEnterEvent) => void)>,
+    onDropZoneLeave: Function as PropType<((e: DropZoneLeaveEvent) => void)>,
+    onFilesUploaded: Function as PropType<((e: FilesUploadedEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onProgress: Function as PropType<(((e: ProgressEvent) => void)) | null>,
-    onUploadAborted: Function as PropType<(((e: UploadAbortedEvent) => void)) | null>,
-    onUploaded: Function as PropType<(((e: UploadedEvent) => void)) | null>,
-    onUploadError: Function as PropType<(((e: UploadErrorEvent) => void)) | null>,
-    onUploadStarted: Function as PropType<(((e: UploadStartedEvent) => void)) | null>,
-    onValueChanged: Function as PropType<(((e: ValueChangedEvent) => void)) | null>,
+    onProgress: Function as PropType<((e: ProgressEvent) => void)>,
+    onUploadAborted: Function as PropType<((e: UploadAbortedEvent) => void)>,
+    onUploaded: Function as PropType<((e: UploadedEvent) => void)>,
+    onUploadError: Function as PropType<((e: UploadErrorEvent) => void)>,
+    onUploadStarted: Function as PropType<((e: UploadStartedEvent) => void)>,
+    onValueChanged: Function as PropType<((e: ValueChangedEvent) => void)>,
     progress: Number,
     readOnly: Boolean,
     readyToUploadMessage: String,
diff --git a/packages/devextreme-vue/src/form.ts b/packages/devextreme-vue/src/form.ts
index 641f2c7c3a3f..15fac496202b 100644
--- a/packages/devextreme-vue/src/form.ts
+++ b/packages/devextreme-vue/src/form.ts
@@ -1064,8 +1064,8 @@ const DxTabPanelOptionsConfig = {
     onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
     onSelectionChanging: Function as PropType<((e: SelectionChangingEvent) => void)>,
     onTitleClick: Function as PropType<((e: TitleClickEvent) => void)>,
-    onTitleHold: Function as PropType<(((e: TitleHoldEvent) => void)) | null>,
-    onTitleRendered: Function as PropType<(((e: TitleRenderedEvent) => void)) | null>,
+    onTitleHold: Function as PropType<((e: TitleHoldEvent) => void)>,
+    onTitleRendered: Function as PropType<((e: TitleRenderedEvent) => void)>,
     repaintChangesOnly: Boolean,
     rtlEnabled: Boolean,
     scrollByContent: Boolean,
diff --git a/packages/devextreme-vue/src/gantt.ts b/packages/devextreme-vue/src/gantt.ts
index d8863f598c4b..cb7ad274abb9 100644
--- a/packages/devextreme-vue/src/gantt.ts
+++ b/packages/devextreme-vue/src/gantt.ts
@@ -188,36 +188,36 @@ const componentConfig = {
     hint: String,
     hoverStateEnabled: Boolean,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
-    onContextMenuPreparing: Function as PropType<(((e: ContextMenuPreparingEvent) => void)) | null>,
-    onCustomCommand: Function as PropType<(((e: CustomCommandEvent) => void)) | null>,
-    onDependencyDeleted: Function as PropType<(((e: DependencyDeletedEvent) => void)) | null>,
-    onDependencyDeleting: Function as PropType<(((e: DependencyDeletingEvent) => void)) | null>,
-    onDependencyInserted: Function as PropType<(((e: DependencyInsertedEvent) => void)) | null>,
-    onDependencyInserting: Function as PropType<(((e: DependencyInsertingEvent) => void)) | null>,
+    onContextMenuPreparing: Function as PropType<((e: ContextMenuPreparingEvent) => void)>,
+    onCustomCommand: Function as PropType<((e: CustomCommandEvent) => void)>,
+    onDependencyDeleted: Function as PropType<((e: DependencyDeletedEvent) => void)>,
+    onDependencyDeleting: Function as PropType<((e: DependencyDeletingEvent) => void)>,
+    onDependencyInserted: Function as PropType<((e: DependencyInsertedEvent) => void)>,
+    onDependencyInserting: Function as PropType<((e: DependencyInsertingEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onResourceAssigned: Function as PropType<(((e: ResourceAssignedEvent) => void)) | null>,
-    onResourceAssigning: Function as PropType<(((e: ResourceAssigningEvent) => void)) | null>,
-    onResourceDeleted: Function as PropType<(((e: ResourceDeletedEvent) => void)) | null>,
-    onResourceDeleting: Function as PropType<(((e: ResourceDeletingEvent) => void)) | null>,
-    onResourceInserted: Function as PropType<(((e: ResourceInsertedEvent) => void)) | null>,
-    onResourceInserting: Function as PropType<(((e: ResourceInsertingEvent) => void)) | null>,
+    onResourceAssigned: Function as PropType<((e: ResourceAssignedEvent) => void)>,
+    onResourceAssigning: Function as PropType<((e: ResourceAssigningEvent) => void)>,
+    onResourceDeleted: Function as PropType<((e: ResourceDeletedEvent) => void)>,
+    onResourceDeleting: Function as PropType<((e: ResourceDeletingEvent) => void)>,
+    onResourceInserted: Function as PropType<((e: ResourceInsertedEvent) => void)>,
+    onResourceInserting: Function as PropType<((e: ResourceInsertingEvent) => void)>,
     onResourceManagerDialogShowing: Function as PropType<((e: ResourceManagerDialogShowingEvent) => void)>,
-    onResourceUnassigned: Function as PropType<(((e: ResourceUnassignedEvent) => void)) | null>,
-    onResourceUnassigning: Function as PropType<(((e: ResourceUnassigningEvent) => void)) | null>,
+    onResourceUnassigned: Function as PropType<((e: ResourceUnassignedEvent) => void)>,
+    onResourceUnassigning: Function as PropType<((e: ResourceUnassigningEvent) => void)>,
     onScaleCellPrepared: Function as PropType<((e: ScaleCellPreparedEvent) => void)>,
-    onSelectionChanged: Function as PropType<(((e: SelectionChangedEvent) => void)) | null>,
-    onTaskClick: Function as PropType<(((e: TaskClickEvent) => void)) | null>,
-    onTaskDblClick: Function as PropType<(((e: TaskDblClickEvent) => void)) | null>,
-    onTaskDeleted: Function as PropType<(((e: TaskDeletedEvent) => void)) | null>,
-    onTaskDeleting: Function as PropType<(((e: TaskDeletingEvent) => void)) | null>,
-    onTaskEditDialogShowing: Function as PropType<(((e: TaskEditDialogShowingEvent) => void)) | null>,
-    onTaskInserted: Function as PropType<(((e: TaskInsertedEvent) => void)) | null>,
-    onTaskInserting: Function as PropType<(((e: TaskInsertingEvent) => void)) | null>,
-    onTaskMoving: Function as PropType<(((e: TaskMovingEvent) => void)) | null>,
-    onTaskUpdated: Function as PropType<(((e: TaskUpdatedEvent) => void)) | null>,
-    onTaskUpdating: Function as PropType<(((e: TaskUpdatingEvent) => void)) | null>,
+    onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
+    onTaskClick: Function as PropType<((e: TaskClickEvent) => void)>,
+    onTaskDblClick: Function as PropType<((e: TaskDblClickEvent) => void)>,
+    onTaskDeleted: Function as PropType<((e: TaskDeletedEvent) => void)>,
+    onTaskDeleting: Function as PropType<((e: TaskDeletingEvent) => void)>,
+    onTaskEditDialogShowing: Function as PropType<((e: TaskEditDialogShowingEvent) => void)>,
+    onTaskInserted: Function as PropType<((e: TaskInsertedEvent) => void)>,
+    onTaskInserting: Function as PropType<((e: TaskInsertingEvent) => void)>,
+    onTaskMoving: Function as PropType<((e: TaskMovingEvent) => void)>,
+    onTaskUpdated: Function as PropType<((e: TaskUpdatedEvent) => void)>,
+    onTaskUpdating: Function as PropType<((e: TaskUpdatingEvent) => void)>,
     resourceAssignments: Object as PropType<Record<string, any>>,
     resources: Object as PropType<Record<string, any>>,
     rootValue: {},
@@ -453,7 +453,7 @@ const DxColumnHeaderFilterConfig = {
   props: {
     allowSearch: Boolean,
     allowSelectAll: Boolean,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | null | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | Store | Record<string, any>>,
     groupInterval: [Array, String, Number] as PropType<(Array<number | string>) | HeaderFilterGroupInterval | number>,
     height: [Number, String],
     search: Object as PropType<ColumnHeaderFilterSearchConfig | HeaderFilterSearchConfig | Record<string, any>>,
@@ -795,7 +795,7 @@ const DxHeaderFilterConfig = {
   props: {
     allowSearch: Boolean,
     allowSelectAll: Boolean,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | null | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | Store | Record<string, any>>,
     groupInterval: [Array, String, Number] as PropType<(Array<number | string>) | HeaderFilterGroupInterval | number>,
     height: [Number, String],
     search: Object as PropType<ColumnHeaderFilterSearchConfig | HeaderFilterSearchConfig | Record<string, any>>,
diff --git a/packages/devextreme-vue/src/html-editor.ts b/packages/devextreme-vue/src/html-editor.ts
index fcbbd97e9dd7..f98ba4a6db7c 100644
--- a/packages/devextreme-vue/src/html-editor.ts
+++ b/packages/devextreme-vue/src/html-editor.ts
@@ -380,20 +380,20 @@ const DxFileUploaderOptionsConfig = {
     minFileSize: Number,
     multiple: Boolean,
     name: String,
-    onBeforeSend: Function as PropType<(((e: BeforeSendEvent) => void)) | null>,
+    onBeforeSend: Function as PropType<((e: BeforeSendEvent) => void)>,
     onContentReady: Function as PropType<((e: FileUploaderContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: FileUploaderDisposingEvent) => void)>,
-    onDropZoneEnter: Function as PropType<(((e: DropZoneEnterEvent) => void)) | null>,
-    onDropZoneLeave: Function as PropType<(((e: DropZoneLeaveEvent) => void)) | null>,
-    onFilesUploaded: Function as PropType<(((e: FilesUploadedEvent) => void)) | null>,
+    onDropZoneEnter: Function as PropType<((e: DropZoneEnterEvent) => void)>,
+    onDropZoneLeave: Function as PropType<((e: DropZoneLeaveEvent) => void)>,
+    onFilesUploaded: Function as PropType<((e: FilesUploadedEvent) => void)>,
     onInitialized: Function as PropType<((e: FileUploaderInitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: FileUploaderOptionChangedEvent) => void)>,
-    onProgress: Function as PropType<(((e: ProgressEvent) => void)) | null>,
-    onUploadAborted: Function as PropType<(((e: UploadAbortedEvent) => void)) | null>,
-    onUploaded: Function as PropType<(((e: UploadedEvent) => void)) | null>,
-    onUploadError: Function as PropType<(((e: UploadErrorEvent) => void)) | null>,
-    onUploadStarted: Function as PropType<(((e: UploadStartedEvent) => void)) | null>,
-    onValueChanged: Function as PropType<(((e: FileUploaderValueChangedEvent) => void)) | null>,
+    onProgress: Function as PropType<((e: ProgressEvent) => void)>,
+    onUploadAborted: Function as PropType<((e: UploadAbortedEvent) => void)>,
+    onUploaded: Function as PropType<((e: UploadedEvent) => void)>,
+    onUploadError: Function as PropType<((e: UploadErrorEvent) => void)>,
+    onUploadStarted: Function as PropType<((e: UploadStartedEvent) => void)>,
+    onValueChanged: Function as PropType<((e: FileUploaderValueChangedEvent) => void)>,
     progress: Number,
     readOnly: Boolean,
     readyToUploadMessage: String,
diff --git a/packages/devextreme-vue/src/list.ts b/packages/devextreme-vue/src/list.ts
index e7f9a04a8a09..aa72c04ed9e5 100644
--- a/packages/devextreme-vue/src/list.ts
+++ b/packages/devextreme-vue/src/list.ts
@@ -201,28 +201,28 @@ const componentConfig = {
     itemHoldTimeout: Number,
     items: Array as PropType<Array<any | dxListItem | string>>,
     itemTemplate: {},
-    keyExpr: [Function, String] as PropType<(((item: any) => any)) | null | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
     menuItems: Array as PropType<Array<Record<string, any>>>,
     menuMode: String as PropType<ListMenuMode>,
     nextButtonText: String,
     noDataText: String,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
-    onGroupRendered: Function as PropType<(((e: GroupRenderedEvent) => void)) | null>,
+    onGroupRendered: Function as PropType<((e: GroupRenderedEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
-    onItemContextMenu: Function as PropType<(((e: ItemContextMenuEvent) => void)) | null>,
-    onItemDeleted: Function as PropType<(((e: ItemDeletedEvent) => void)) | null>,
-    onItemDeleting: Function as PropType<(((e: ItemDeletingEvent) => void)) | null>,
-    onItemHold: Function as PropType<(((e: ItemHoldEvent) => void)) | null>,
+    onItemContextMenu: Function as PropType<((e: ItemContextMenuEvent) => void)>,
+    onItemDeleted: Function as PropType<((e: ItemDeletedEvent) => void)>,
+    onItemDeleting: Function as PropType<((e: ItemDeletingEvent) => void)>,
+    onItemHold: Function as PropType<((e: ItemHoldEvent) => void)>,
     onItemRendered: Function as PropType<((e: ItemRenderedEvent) => void)>,
-    onItemReordered: Function as PropType<(((e: ItemReorderedEvent) => void)) | null>,
-    onItemSwipe: Function as PropType<(((e: ItemSwipeEvent) => void)) | null>,
+    onItemReordered: Function as PropType<((e: ItemReorderedEvent) => void)>,
+    onItemSwipe: Function as PropType<((e: ItemSwipeEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onPageLoading: Function as PropType<(((e: PageLoadingEvent) => void)) | null>,
-    onPullRefresh: Function as PropType<(((e: PullRefreshEvent) => void)) | null>,
-    onScroll: Function as PropType<(((e: ScrollEvent) => void)) | null>,
-    onSelectAllValueChanged: Function as PropType<(((e: SelectAllValueChangedEvent) => void)) | null>,
+    onPageLoading: Function as PropType<((e: PageLoadingEvent) => void)>,
+    onPullRefresh: Function as PropType<((e: PullRefreshEvent) => void)>,
+    onScroll: Function as PropType<((e: ScrollEvent) => void)>,
+    onSelectAllValueChanged: Function as PropType<((e: SelectAllValueChangedEvent) => void)>,
     onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
     onSelectionChanging: Function as PropType<((e: SelectionChangingEvent) => void)>,
     pageLoadingText: String,
diff --git a/packages/devextreme-vue/src/lookup.ts b/packages/devextreme-vue/src/lookup.ts
index 79d2bdeb479a..c1c59b98423f 100644
--- a/packages/devextreme-vue/src/lookup.ts
+++ b/packages/devextreme-vue/src/lookup.ts
@@ -206,11 +206,11 @@ const componentConfig = {
     onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
     onOpened: Function as PropType<((e: OpenedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onPageLoading: Function as PropType<(((e: PageLoadingEvent) => void)) | null>,
-    onPullRefresh: Function as PropType<(((e: PullRefreshEvent) => void)) | null>,
-    onScroll: Function as PropType<(((e: ScrollEvent) => void)) | null>,
+    onPageLoading: Function as PropType<((e: PageLoadingEvent) => void)>,
+    onPullRefresh: Function as PropType<((e: PullRefreshEvent) => void)>,
+    onScroll: Function as PropType<((e: ScrollEvent) => void)>,
     onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
-    onValueChanged: Function as PropType<(((e: ValueChangedEvent) => void)) | null>,
+    onValueChanged: Function as PropType<((e: ValueChangedEvent) => void)>,
     opened: Boolean,
     pageLoadingText: String,
     pageLoadMode: String as PropType<PageLoadMode>,
diff --git a/packages/devextreme-vue/src/map.ts b/packages/devextreme-vue/src/map.ts
index 470e92f22630..7e1c8fecdc49 100644
--- a/packages/devextreme-vue/src/map.ts
+++ b/packages/devextreme-vue/src/map.ts
@@ -76,12 +76,12 @@ const componentConfig = {
     onClick: Function as PropType<((e: ClickEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
-    onMarkerAdded: Function as PropType<(((e: MarkerAddedEvent) => void)) | null>,
-    onMarkerRemoved: Function as PropType<(((e: MarkerRemovedEvent) => void)) | null>,
+    onMarkerAdded: Function as PropType<((e: MarkerAddedEvent) => void)>,
+    onMarkerRemoved: Function as PropType<((e: MarkerRemovedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onReady: Function as PropType<(((e: ReadyEvent) => void)) | null>,
-    onRouteAdded: Function as PropType<(((e: RouteAddedEvent) => void)) | null>,
-    onRouteRemoved: Function as PropType<(((e: RouteRemovedEvent) => void)) | null>,
+    onReady: Function as PropType<((e: ReadyEvent) => void)>,
+    onRouteAdded: Function as PropType<((e: RouteAddedEvent) => void)>,
+    onRouteRemoved: Function as PropType<((e: RouteRemovedEvent) => void)>,
     provider: String as PropType<MapProvider>,
     providerConfig: Object as PropType<Record<string, any>>,
     routes: Array as PropType<Array<Record<string, any>>>,
diff --git a/packages/devextreme-vue/src/menu.ts b/packages/devextreme-vue/src/menu.ts
index fa0453d113f8..55d672779926 100644
--- a/packages/devextreme-vue/src/menu.ts
+++ b/packages/devextreme-vue/src/menu.ts
@@ -122,10 +122,10 @@ const componentConfig = {
     onItemRendered: Function as PropType<((e: ItemRenderedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
     onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
-    onSubmenuHidden: Function as PropType<(((e: SubmenuHiddenEvent) => void)) | null>,
-    onSubmenuHiding: Function as PropType<(((e: SubmenuHidingEvent) => void)) | null>,
-    onSubmenuShowing: Function as PropType<(((e: SubmenuShowingEvent) => void)) | null>,
-    onSubmenuShown: Function as PropType<(((e: SubmenuShownEvent) => void)) | null>,
+    onSubmenuHidden: Function as PropType<((e: SubmenuHiddenEvent) => void)>,
+    onSubmenuHiding: Function as PropType<((e: SubmenuHidingEvent) => void)>,
+    onSubmenuShowing: Function as PropType<((e: SubmenuShowingEvent) => void)>,
+    onSubmenuShown: Function as PropType<((e: SubmenuShownEvent) => void)>,
     orientation: String as PropType<Orientation>,
     rtlEnabled: Boolean,
     selectByClick: Boolean,
diff --git a/packages/devextreme-vue/src/pagination.ts b/packages/devextreme-vue/src/pagination.ts
index 5959572cdd51..845d5125e42a 100644
--- a/packages/devextreme-vue/src/pagination.ts
+++ b/packages/devextreme-vue/src/pagination.ts
@@ -62,7 +62,7 @@ const componentConfig = {
     infoText: String,
     itemCount: Number,
     label: String,
-    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
+    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
diff --git a/packages/devextreme-vue/src/popup.ts b/packages/devextreme-vue/src/popup.ts
index 8f823e734afc..b7cd83dcaa49 100644
--- a/packages/devextreme-vue/src/popup.ts
+++ b/packages/devextreme-vue/src/popup.ts
@@ -119,18 +119,18 @@ const componentConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
+    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
+    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
diff --git a/packages/devextreme-vue/src/progress-bar.ts b/packages/devextreme-vue/src/progress-bar.ts
index 0e7f4b00695e..f927ac46a684 100644
--- a/packages/devextreme-vue/src/progress-bar.ts
+++ b/packages/devextreme-vue/src/progress-bar.ts
@@ -61,7 +61,7 @@ const componentConfig = {
     isValid: Boolean,
     max: Number,
     min: Number,
-    onComplete: Function as PropType<(((e: CompleteEvent) => void)) | null>,
+    onComplete: Function as PropType<((e: CompleteEvent) => void)>,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
diff --git a/packages/devextreme-vue/src/range-slider.ts b/packages/devextreme-vue/src/range-slider.ts
index 61e9b2a28db2..eff249b51b3d 100644
--- a/packages/devextreme-vue/src/range-slider.ts
+++ b/packages/devextreme-vue/src/range-slider.ts
@@ -90,7 +90,7 @@ const componentConfig = {
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onValueChanged: Function as PropType<(((e: ValueChangedEvent) => void)) | null>,
+    onValueChanged: Function as PropType<((e: ValueChangedEvent) => void)>,
     readOnly: Boolean,
     rtlEnabled: Boolean,
     showRange: Boolean,
diff --git a/packages/devextreme-vue/src/responsive-box.ts b/packages/devextreme-vue/src/responsive-box.ts
index 86a26760a0c9..1ae0d3be4154 100644
--- a/packages/devextreme-vue/src/responsive-box.ts
+++ b/packages/devextreme-vue/src/responsive-box.ts
@@ -74,7 +74,7 @@ const componentConfig = {
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
     rows: Array as PropType<Array<Record<string, any>>>,
     rtlEnabled: Boolean,
-    screenByWidth: Function as PropType<((() => void)) | null>,
+    screenByWidth: Function as PropType<(() => void)>,
     singleColumnScreen: String,
     visible: Boolean,
     width: [Number, String]
diff --git a/packages/devextreme-vue/src/scheduler.ts b/packages/devextreme-vue/src/scheduler.ts
index 19b0111e87af..a8bcca7114cc 100644
--- a/packages/devextreme-vue/src/scheduler.ts
+++ b/packages/devextreme-vue/src/scheduler.ts
@@ -1146,9 +1146,9 @@ const DxOptionsConfig = {
     onContentReady: Function as PropType<((e: ButtonGroupContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: ButtonGroupDisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: ButtonGroupInitializedEvent) => void)>,
-    onItemClick: Function as PropType<(((e: ItemClickEvent) => void)) | null>,
+    onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
     onOptionChanged: Function as PropType<((e: ButtonGroupOptionChangedEvent) => void)>,
-    onSelectionChanged: Function as PropType<(((e: SelectionChangedEvent) => void)) | null>,
+    onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
     rtlEnabled: Boolean,
     selectedItemKeys: Array as PropType<Array<any>>,
     selectedItems: Array as PropType<Array<any>>,
@@ -1589,8 +1589,8 @@ const DxTabPanelOptionsConfig = {
     onSelectionChanged: Function as PropType<((e: TabPanelSelectionChangedEvent) => void)>,
     onSelectionChanging: Function as PropType<((e: SelectionChangingEvent) => void)>,
     onTitleClick: Function as PropType<((e: TitleClickEvent) => void)>,
-    onTitleHold: Function as PropType<(((e: TitleHoldEvent) => void)) | null>,
-    onTitleRendered: Function as PropType<(((e: TitleRenderedEvent) => void)) | null>,
+    onTitleHold: Function as PropType<((e: TitleHoldEvent) => void)>,
+    onTitleRendered: Function as PropType<((e: TitleRenderedEvent) => void)>,
     repaintChangesOnly: Boolean,
     rtlEnabled: Boolean,
     scrollByContent: Boolean,
diff --git a/packages/devextreme-vue/src/scroll-view.ts b/packages/devextreme-vue/src/scroll-view.ts
index 612944df11b5..a1403de5bf91 100644
--- a/packages/devextreme-vue/src/scroll-view.ts
+++ b/packages/devextreme-vue/src/scroll-view.ts
@@ -54,8 +54,8 @@ const componentConfig = {
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onPullDown: Function as PropType<(((e: PullDownEvent) => void)) | null>,
-    onReachBottom: Function as PropType<(((e: ReachBottomEvent) => void)) | null>,
+    onPullDown: Function as PropType<((e: PullDownEvent) => void)>,
+    onReachBottom: Function as PropType<((e: ReachBottomEvent) => void)>,
     onScroll: Function as PropType<((e: ScrollEvent) => void)>,
     onUpdated: Function as PropType<((e: UpdatedEvent) => void)>,
     pulledDownText: String,
diff --git a/packages/devextreme-vue/src/select-box.ts b/packages/devextreme-vue/src/select-box.ts
index ba734355ba37..2fcbcaddd497 100644
--- a/packages/devextreme-vue/src/select-box.ts
+++ b/packages/devextreme-vue/src/select-box.ts
@@ -560,18 +560,18 @@ const DxDropDownOptionsConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
+    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
+    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
diff --git a/packages/devextreme-vue/src/speed-dial-action.ts b/packages/devextreme-vue/src/speed-dial-action.ts
index 45405ffce014..36ba9edaf96d 100644
--- a/packages/devextreme-vue/src/speed-dial-action.ts
+++ b/packages/devextreme-vue/src/speed-dial-action.ts
@@ -46,7 +46,7 @@ const componentConfig = {
     index: Number,
     label: String,
     onClick: Function as PropType<((e: ClickEvent) => void)>,
-    onContentReady: Function as PropType<(((e: ContentReadyEvent) => void)) | null>,
+    onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
diff --git a/packages/devextreme-vue/src/tab-panel.ts b/packages/devextreme-vue/src/tab-panel.ts
index 665b2bf8109c..ce5b3901dedb 100644
--- a/packages/devextreme-vue/src/tab-panel.ts
+++ b/packages/devextreme-vue/src/tab-panel.ts
@@ -117,8 +117,8 @@ const componentConfig = {
     onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
     onSelectionChanging: Function as PropType<((e: SelectionChangingEvent) => void)>,
     onTitleClick: Function as PropType<((e: TitleClickEvent) => void)>,
-    onTitleHold: Function as PropType<(((e: TitleHoldEvent) => void)) | null>,
-    onTitleRendered: Function as PropType<(((e: TitleRenderedEvent) => void)) | null>,
+    onTitleHold: Function as PropType<((e: TitleHoldEvent) => void)>,
+    onTitleRendered: Function as PropType<((e: TitleRenderedEvent) => void)>,
     repaintChangesOnly: Boolean,
     rtlEnabled: Boolean,
     scrollByContent: Boolean,
diff --git a/packages/devextreme-vue/src/tabs.ts b/packages/devextreme-vue/src/tabs.ts
index 557e5a83e587..17e7999dbda8 100644
--- a/packages/devextreme-vue/src/tabs.ts
+++ b/packages/devextreme-vue/src/tabs.ts
@@ -91,7 +91,7 @@ const componentConfig = {
     itemHoldTimeout: Number,
     items: Array as PropType<Array<any | dxTabsItem | string>>,
     itemTemplate: {},
-    keyExpr: [Function, String] as PropType<(((item: any) => any)) | null | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
     noDataText: String,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
diff --git a/packages/devextreme-vue/src/tag-box.ts b/packages/devextreme-vue/src/tag-box.ts
index 4c089a99a470..a8a1fdd821dd 100644
--- a/packages/devextreme-vue/src/tag-box.ts
+++ b/packages/devextreme-vue/src/tag-box.ts
@@ -243,11 +243,11 @@ const componentConfig = {
     onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
     onKeyDown: Function as PropType<((e: KeyDownEvent) => void)>,
     onKeyUp: Function as PropType<((e: KeyUpEvent) => void)>,
-    onMultiTagPreparing: Function as PropType<(((e: MultiTagPreparingEvent) => void)) | null>,
+    onMultiTagPreparing: Function as PropType<((e: MultiTagPreparingEvent) => void)>,
     onOpened: Function as PropType<((e: OpenedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onSelectAllValueChanged: Function as PropType<(((e: SelectAllValueChangedEvent) => void)) | null>,
-    onSelectionChanged: Function as PropType<(((e: SelectionChangedEvent) => void)) | null>,
+    onSelectAllValueChanged: Function as PropType<((e: SelectAllValueChangedEvent) => void)>,
+    onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
     onValueChanged: Function as PropType<((e: ValueChangedEvent) => void)>,
     opened: Boolean,
     openOnFieldClick: Boolean,
@@ -579,18 +579,18 @@ const DxDropDownOptionsConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
+    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
+    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
diff --git a/packages/devextreme-vue/src/tree-list.ts b/packages/devextreme-vue/src/tree-list.ts
index 4e13a6a39c85..4c5a044e0f15 100644
--- a/packages/devextreme-vue/src/tree-list.ts
+++ b/packages/devextreme-vue/src/tree-list.ts
@@ -1413,7 +1413,7 @@ const DxColumnHeaderFilterConfig = {
   props: {
     allowSearch: Boolean,
     allowSelectAll: Boolean,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | null | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | Store | Record<string, any>>,
     groupInterval: [Array, String, Number] as PropType<(Array<number | string>) | HeaderFilterGroupInterval | number>,
     height: [Number, String],
     search: Object as PropType<ColumnHeaderFilterSearchConfig | HeaderFilterSearchConfig | Record<string, any>>,
@@ -1470,7 +1470,7 @@ const DxColumnLookupConfig = {
   props: {
     allowClearing: Boolean,
     calculateCellValue: Function as PropType<((rowData: any) => any)>,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { data: Record<string, any>, key: any }) => Array<any> | Store | DataSourceOptions)) | null | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { data: Record<string, any>, key: any }) => Array<any> | Store | DataSourceOptions)) | Store | Record<string, any>>,
     displayExpr: [Function, String] as PropType<(((data: any) => string)) | string>,
     valueExpr: String
   }
@@ -2113,18 +2113,18 @@ const DxFilterBuilderPopupConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
+    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
+    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
@@ -2594,7 +2594,7 @@ const DxHeaderFilterConfig = {
   props: {
     allowSearch: Boolean,
     allowSelectAll: Boolean,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | null | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | Store | Record<string, any>>,
     groupInterval: [Array, String, Number] as PropType<(Array<number | string>) | HeaderFilterGroupInterval | number>,
     height: [Number, String],
     search: Object as PropType<ColumnHeaderFilterSearchConfig | HeaderFilterSearchConfig | Record<string, any>>,
@@ -2917,7 +2917,7 @@ const DxLookupConfig = {
   props: {
     allowClearing: Boolean,
     calculateCellValue: Function as PropType<((rowData: any) => any)>,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { data: Record<string, any>, key: any }) => Array<any> | Store | DataSourceOptions)) | null | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { data: Record<string, any>, key: any }) => Array<any> | Store | DataSourceOptions)) | Store | Record<string, any>>,
     displayExpr: [Function, String] as PropType<(((data: any) => string)) | string>,
     valueExpr: [String, Function] as PropType<string | (((data: any) => string | number | boolean))>
   }
@@ -3247,18 +3247,18 @@ const DxPopupConfig = {
     maxWidth: [Number, String],
     minHeight: [Number, String],
     minWidth: [Number, String],
-    onContentReady: Function as PropType<(((e: EventInfo<any>) => void)) | null>,
+    onContentReady: Function as PropType<((e: EventInfo<any>) => void)>,
     onDisposing: Function as PropType<((e: EventInfo<any>) => void)>,
     onHidden: Function as PropType<((e: EventInfo<any>) => void)>,
     onHiding: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onInitialized: Function as PropType<((e: { component: Component<any>, element: any }) => void)>,
     onOptionChanged: Function as PropType<((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)>,
-    onResize: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeEnd: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
-    onResizeStart: Function as PropType<(((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)) | null>,
+    onResize: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeEnd: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
+    onResizeStart: Function as PropType<((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void)>,
     onShowing: Function as PropType<((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void)>,
     onShown: Function as PropType<((e: EventInfo<any>) => void)>,
-    onTitleRendered: Function as PropType<(((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)) | null>,
+    onTitleRendered: Function as PropType<((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void)>,
     position: [Function, String, Object] as PropType<((() => void)) | PositionAlignment | PositionConfig | Record<string, any>>,
     resizeEnabled: Boolean,
     restorePosition: Boolean,
@@ -3920,8 +3920,8 @@ const DxTabPanelOptionsConfig = {
     onSelectionChanged: Function as PropType<((e: TabPanelSelectionChangedEvent) => void)>,
     onSelectionChanging: Function as PropType<((e: SelectionChangingEvent) => void)>,
     onTitleClick: Function as PropType<((e: TitleClickEvent) => void)>,
-    onTitleHold: Function as PropType<(((e: TitleHoldEvent) => void)) | null>,
-    onTitleRendered: Function as PropType<(((e: TitleRenderedEvent) => void)) | null>,
+    onTitleHold: Function as PropType<((e: TitleHoldEvent) => void)>,
+    onTitleRendered: Function as PropType<((e: TitleRenderedEvent) => void)>,
     repaintChangesOnly: Boolean,
     rtlEnabled: Boolean,
     scrollByContent: Boolean,
diff --git a/packages/devextreme-vue/src/tree-view.ts b/packages/devextreme-vue/src/tree-view.ts
index 21db8042f48d..fcf303319d3a 100644
--- a/packages/devextreme-vue/src/tree-view.ts
+++ b/packages/devextreme-vue/src/tree-view.ts
@@ -178,16 +178,16 @@ const componentConfig = {
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
-    onItemClick: Function as PropType<(((e: ItemClickEvent) => void)) | null>,
-    onItemCollapsed: Function as PropType<(((e: ItemCollapsedEvent) => void)) | null>,
-    onItemContextMenu: Function as PropType<(((e: ItemContextMenuEvent) => void)) | null>,
-    onItemExpanded: Function as PropType<(((e: ItemExpandedEvent) => void)) | null>,
-    onItemHold: Function as PropType<(((e: ItemHoldEvent) => void)) | null>,
-    onItemRendered: Function as PropType<(((e: ItemRenderedEvent) => void)) | null>,
-    onItemSelectionChanged: Function as PropType<(((e: ItemSelectionChangedEvent) => void)) | null>,
+    onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
+    onItemCollapsed: Function as PropType<((e: ItemCollapsedEvent) => void)>,
+    onItemContextMenu: Function as PropType<((e: ItemContextMenuEvent) => void)>,
+    onItemExpanded: Function as PropType<((e: ItemExpandedEvent) => void)>,
+    onItemHold: Function as PropType<((e: ItemHoldEvent) => void)>,
+    onItemRendered: Function as PropType<((e: ItemRenderedEvent) => void)>,
+    onItemSelectionChanged: Function as PropType<((e: ItemSelectionChangedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onSelectAllValueChanged: Function as PropType<(((e: SelectAllValueChangedEvent) => void)) | null>,
-    onSelectionChanged: Function as PropType<(((e: SelectionChangedEvent) => void)) | null>,
+    onSelectAllValueChanged: Function as PropType<((e: SelectAllValueChangedEvent) => void)>,
+    onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
     parentIdExpr: [Function, String] as PropType<(((item: any) => any | undefined)) | string>,
     rootValue: {},
     rtlEnabled: Boolean,

From 9e80e0e22cfafdbb95bcaccc672fd3137f813f12 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:43 +0300
Subject: [PATCH 063/100] fix(form/viz): resolve outstanding JSDoc default
 mismatches

Fixes remaining JSDoc @default mismatches in form.d.ts and base_widget.d.ts:
- Corrects JSDoc for screenByWidth and onIncidentOccurred (removes incorrect @default null since they default to functions).
- Widens form event handlers to | null and removes unused ts-expect-error annotations in form implementation.
- Corrects title/subtitle text option defaults in base_widget to undefined and widens their types.
- Removes invalid Category B defaults from form item suboptions.
---
 .../src/ui/bar-gauge/index.ts                 |   6 +-
 .../nested/bar-gauge-title-subtitle.ts        |   4 +-
 .../ui/bar-gauge/nested/bar-gauge-title.ts    |   8 +-
 .../src/ui/card-view/nested/form.ts           |  16 +--
 .../devextreme-angular/src/ui/chart/index.ts  |   6 +-
 .../ui/chart/nested/chart-title-subtitle.ts   |   4 +-
 .../src/ui/chart/nested/chart-title.ts        |   8 +-
 .../src/ui/circular-gauge/index.ts            |   6 +-
 .../src/ui/circular-gauge/nested/subtitle.ts  |   4 +-
 .../src/ui/circular-gauge/nested/title.ts     |   8 +-
 .../src/ui/data-grid/nested/form.ts           |  16 +--
 .../devextreme-angular/src/ui/funnel/index.ts |   6 +-
 .../ui/funnel/nested/funnel-title-subtitle.ts |   4 +-
 .../src/ui/funnel/nested/funnel-title.ts      |   8 +-
 .../src/ui/linear-gauge/index.ts              |   6 +-
 .../src/ui/linear-gauge/nested/subtitle.ts    |   4 +-
 .../src/ui/linear-gauge/nested/title.ts       |   8 +-
 .../devextreme-angular/src/ui/nested/title.ts |   4 +-
 .../src/ui/pie-chart/index.ts                 |   6 +-
 .../nested/pie-chart-title-subtitle.ts        |   4 +-
 .../ui/pie-chart/nested/pie-chart-title.ts    |   8 +-
 .../src/ui/polar-chart/index.ts               |   6 +-
 .../nested/polar-chart-title-subtitle.ts      |   4 +-
 .../polar-chart/nested/polar-chart-title.ts   |   8 +-
 .../src/ui/range-selector/index.ts            |   6 +-
 .../src/ui/range-selector/nested/subtitle.ts  |   4 +-
 .../src/ui/range-selector/nested/title.ts     |   8 +-
 .../devextreme-angular/src/ui/sankey/index.ts |   6 +-
 .../src/ui/sankey/nested/subtitle.ts          |   4 +-
 .../src/ui/sankey/nested/title.ts             |   8 +-
 .../src/ui/scheduler/nested/form.ts           |  16 +--
 .../src/ui/tree-list/nested/form.ts           |  16 +--
 .../src/ui/tree-map/index.ts                  |   6 +-
 .../src/ui/tree-map/nested/subtitle.ts        |   4 +-
 .../src/ui/tree-map/nested/title.ts           |   8 +-
 .../src/ui/vector-map/index.ts                |   6 +-
 .../nested/vector-map-title-subtitle.ts       |   4 +-
 .../ui/vector-map/nested/vector-map-title.ts  |   8 +-
 packages/devextreme-react/src/bar-gauge.ts    |   6 +-
 packages/devextreme-react/src/card-view.ts    |   8 +-
 packages/devextreme-react/src/chart.ts        |   6 +-
 .../devextreme-react/src/circular-gauge.ts    |   6 +-
 packages/devextreme-react/src/data-grid.ts    |   8 +-
 packages/devextreme-react/src/form.ts         |   6 +-
 packages/devextreme-react/src/funnel.ts       |   6 +-
 packages/devextreme-react/src/linear-gauge.ts |   6 +-
 packages/devextreme-react/src/pie-chart.ts    |   6 +-
 packages/devextreme-react/src/polar-chart.ts  |   6 +-
 .../devextreme-react/src/range-selector.ts    |   6 +-
 packages/devextreme-react/src/sankey.ts       |   6 +-
 packages/devextreme-react/src/scheduler.ts    |   8 +-
 packages/devextreme-react/src/tree-list.ts    |   8 +-
 packages/devextreme-react/src/tree-map.ts     |   6 +-
 packages/devextreme-react/src/vector-map.ts   |   6 +-
 .../__internal/ui/form/form.layout_manager.ts |   1 -
 .../devextreme/js/__internal/ui/form/form.ts  |   4 -
 packages/devextreme/js/ui/form.d.ts           |  44 ++++----
 .../devextreme/js/viz/core/base_widget.d.ts   | 103 +++++++++---------
 58 files changed, 256 insertions(+), 266 deletions(-)

diff --git a/packages/devextreme-angular/src/ui/bar-gauge/index.ts b/packages/devextreme-angular/src/ui/bar-gauge/index.ts
index 03aa790ded7b..dfdccf956e9a 100644
--- a/packages/devextreme-angular/src/ui/bar-gauge/index.ts
+++ b/packages/devextreme-angular/src/ui/bar-gauge/index.ts
@@ -417,10 +417,10 @@ export class DxBarGaugeComponent extends DxComponent implements OnDestroy, OnCha
     
      */
     @Input()
-    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
+    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
         return this._getOption('title');
     }
-    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
+    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
         this._setOption('title', value);
     }
 
@@ -703,7 +703,7 @@ export class DxBarGaugeComponent extends DxComponent implements OnDestroy, OnCha
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
+    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/bar-gauge/nested/bar-gauge-title-subtitle.ts b/packages/devextreme-angular/src/ui/bar-gauge/nested/bar-gauge-title-subtitle.ts
index c478a14ae659..f79585f9f274 100644
--- a/packages/devextreme-angular/src/ui/bar-gauge/nested/bar-gauge-title-subtitle.ts
+++ b/packages/devextreme-angular/src/ui/bar-gauge/nested/bar-gauge-title-subtitle.ts
@@ -48,10 +48,10 @@ export class DxoBarGaugeBarGaugeTitleSubtitleComponent extends NestedOption impl
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/bar-gauge/nested/bar-gauge-title.ts b/packages/devextreme-angular/src/ui/bar-gauge/nested/bar-gauge-title.ts
index a4cfc3382dab..7bb3352d18b0 100644
--- a/packages/devextreme-angular/src/ui/bar-gauge/nested/bar-gauge-title.ts
+++ b/packages/devextreme-angular/src/ui/bar-gauge/nested/bar-gauge-title.ts
@@ -65,18 +65,18 @@ export class DxoBarGaugeBarGaugeTitleComponent extends NestedOption implements O
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/card-view/nested/form.ts b/packages/devextreme-angular/src/ui/card-view/nested/form.ts
index 1680882b7393..03be45a1c645 100644
--- a/packages/devextreme-angular/src/ui/card-view/nested/form.ts
+++ b/packages/devextreme-angular/src/ui/card-view/nested/form.ts
@@ -223,18 +223,18 @@ export class DxoCardViewFormComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get onEditorEnterKey(): ((e: EditorEnterKeyEvent) => void) {
+    get onEditorEnterKey(): ((e: EditorEnterKeyEvent) => void) | null {
         return this._getOption('onEditorEnterKey');
     }
-    set onEditorEnterKey(value: ((e: EditorEnterKeyEvent) => void)) {
+    set onEditorEnterKey(value: ((e: EditorEnterKeyEvent) => void) | null) {
         this._setOption('onEditorEnterKey', value);
     }
 
     @Input()
-    get onFieldDataChanged(): ((e: FieldDataChangedEvent) => void) {
+    get onFieldDataChanged(): ((e: FieldDataChangedEvent) => void) | null {
         return this._getOption('onFieldDataChanged');
     }
-    set onFieldDataChanged(value: ((e: FieldDataChangedEvent) => void)) {
+    set onFieldDataChanged(value: ((e: FieldDataChangedEvent) => void) | null) {
         this._setOption('onFieldDataChanged', value);
     }
 
@@ -255,18 +255,18 @@ export class DxoCardViewFormComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get onSmartPasted(): ((e: SmartPastedEvent) => void) {
+    get onSmartPasted(): ((e: SmartPastedEvent) => void) | null {
         return this._getOption('onSmartPasted');
     }
-    set onSmartPasted(value: ((e: SmartPastedEvent) => void)) {
+    set onSmartPasted(value: ((e: SmartPastedEvent) => void) | null) {
         this._setOption('onSmartPasted', value);
     }
 
     @Input()
-    get onSmartPasting(): ((e: SmartPastingEvent) => void) {
+    get onSmartPasting(): ((e: SmartPastingEvent) => void) | null {
         return this._getOption('onSmartPasting');
     }
-    set onSmartPasting(value: ((e: SmartPastingEvent) => void)) {
+    set onSmartPasting(value: ((e: SmartPastingEvent) => void) | null) {
         this._setOption('onSmartPasting', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/chart/index.ts b/packages/devextreme-angular/src/ui/chart/index.ts
index 5a02083ce247..2132048fdcc5 100644
--- a/packages/devextreme-angular/src/ui/chart/index.ts
+++ b/packages/devextreme-angular/src/ui/chart/index.ts
@@ -905,10 +905,10 @@ export class DxChartComponent extends DxComponent implements OnDestroy, OnChange
     
      */
     @Input()
-    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
+    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
         return this._getOption('title');
     }
-    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
+    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
         this._setOption('title', value);
     }
 
@@ -1453,7 +1453,7 @@ export class DxChartComponent extends DxComponent implements OnDestroy, OnChange
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
+    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/chart/nested/chart-title-subtitle.ts b/packages/devextreme-angular/src/ui/chart/nested/chart-title-subtitle.ts
index ec496a613cce..3a9eea417016 100644
--- a/packages/devextreme-angular/src/ui/chart/nested/chart-title-subtitle.ts
+++ b/packages/devextreme-angular/src/ui/chart/nested/chart-title-subtitle.ts
@@ -48,10 +48,10 @@ export class DxoChartChartTitleSubtitleComponent extends NestedOption implements
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/chart/nested/chart-title.ts b/packages/devextreme-angular/src/ui/chart/nested/chart-title.ts
index 668b6b01943e..365722ad50bf 100644
--- a/packages/devextreme-angular/src/ui/chart/nested/chart-title.ts
+++ b/packages/devextreme-angular/src/ui/chart/nested/chart-title.ts
@@ -65,18 +65,18 @@ export class DxoChartChartTitleComponent extends NestedOption implements OnDestr
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/circular-gauge/index.ts b/packages/devextreme-angular/src/ui/circular-gauge/index.ts
index 97d4ec123aa8..0ad6beba06c3 100644
--- a/packages/devextreme-angular/src/ui/circular-gauge/index.ts
+++ b/packages/devextreme-angular/src/ui/circular-gauge/index.ts
@@ -361,10 +361,10 @@ export class DxCircularGaugeComponent extends DxComponent implements OnDestroy,
     
      */
     @Input()
-    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
+    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
         return this._getOption('title');
     }
-    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
+    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
         this._setOption('title', value);
     }
 
@@ -618,7 +618,7 @@ export class DxCircularGaugeComponent extends DxComponent implements OnDestroy,
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
+    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/circular-gauge/nested/subtitle.ts b/packages/devextreme-angular/src/ui/circular-gauge/nested/subtitle.ts
index 2c70ef0174c5..251b6964445e 100644
--- a/packages/devextreme-angular/src/ui/circular-gauge/nested/subtitle.ts
+++ b/packages/devextreme-angular/src/ui/circular-gauge/nested/subtitle.ts
@@ -48,10 +48,10 @@ export class DxoCircularGaugeSubtitleComponent extends NestedOption implements O
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/circular-gauge/nested/title.ts b/packages/devextreme-angular/src/ui/circular-gauge/nested/title.ts
index c1878b020af3..8ac2342fb63a 100644
--- a/packages/devextreme-angular/src/ui/circular-gauge/nested/title.ts
+++ b/packages/devextreme-angular/src/ui/circular-gauge/nested/title.ts
@@ -65,18 +65,18 @@ export class DxoCircularGaugeTitleComponent extends NestedOption implements OnDe
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/data-grid/nested/form.ts b/packages/devextreme-angular/src/ui/data-grid/nested/form.ts
index c02f020bfbcf..6e17e7983365 100644
--- a/packages/devextreme-angular/src/ui/data-grid/nested/form.ts
+++ b/packages/devextreme-angular/src/ui/data-grid/nested/form.ts
@@ -223,18 +223,18 @@ export class DxoDataGridFormComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get onEditorEnterKey(): ((e: EditorEnterKeyEvent) => void) {
+    get onEditorEnterKey(): ((e: EditorEnterKeyEvent) => void) | null {
         return this._getOption('onEditorEnterKey');
     }
-    set onEditorEnterKey(value: ((e: EditorEnterKeyEvent) => void)) {
+    set onEditorEnterKey(value: ((e: EditorEnterKeyEvent) => void) | null) {
         this._setOption('onEditorEnterKey', value);
     }
 
     @Input()
-    get onFieldDataChanged(): ((e: FieldDataChangedEvent) => void) {
+    get onFieldDataChanged(): ((e: FieldDataChangedEvent) => void) | null {
         return this._getOption('onFieldDataChanged');
     }
-    set onFieldDataChanged(value: ((e: FieldDataChangedEvent) => void)) {
+    set onFieldDataChanged(value: ((e: FieldDataChangedEvent) => void) | null) {
         this._setOption('onFieldDataChanged', value);
     }
 
@@ -255,18 +255,18 @@ export class DxoDataGridFormComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get onSmartPasted(): ((e: SmartPastedEvent) => void) {
+    get onSmartPasted(): ((e: SmartPastedEvent) => void) | null {
         return this._getOption('onSmartPasted');
     }
-    set onSmartPasted(value: ((e: SmartPastedEvent) => void)) {
+    set onSmartPasted(value: ((e: SmartPastedEvent) => void) | null) {
         this._setOption('onSmartPasted', value);
     }
 
     @Input()
-    get onSmartPasting(): ((e: SmartPastingEvent) => void) {
+    get onSmartPasting(): ((e: SmartPastingEvent) => void) | null {
         return this._getOption('onSmartPasting');
     }
-    set onSmartPasting(value: ((e: SmartPastingEvent) => void)) {
+    set onSmartPasting(value: ((e: SmartPastingEvent) => void) | null) {
         this._setOption('onSmartPasting', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/funnel/index.ts b/packages/devextreme-angular/src/ui/funnel/index.ts
index 897ac90ba814..7d4c1ea18db1 100644
--- a/packages/devextreme-angular/src/ui/funnel/index.ts
+++ b/packages/devextreme-angular/src/ui/funnel/index.ts
@@ -466,10 +466,10 @@ export class DxFunnelComponent extends DxComponent implements OnDestroy, OnChang
     
      */
     @Input()
-    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
+    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
         return this._getOption('title');
     }
-    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
+    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
         this._setOption('title', value);
     }
 
@@ -789,7 +789,7 @@ export class DxFunnelComponent extends DxComponent implements OnDestroy, OnChang
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
+    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/funnel/nested/funnel-title-subtitle.ts b/packages/devextreme-angular/src/ui/funnel/nested/funnel-title-subtitle.ts
index a2ebd4ec7e19..090335bf71c8 100644
--- a/packages/devextreme-angular/src/ui/funnel/nested/funnel-title-subtitle.ts
+++ b/packages/devextreme-angular/src/ui/funnel/nested/funnel-title-subtitle.ts
@@ -48,10 +48,10 @@ export class DxoFunnelFunnelTitleSubtitleComponent extends NestedOption implemen
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/funnel/nested/funnel-title.ts b/packages/devextreme-angular/src/ui/funnel/nested/funnel-title.ts
index 03d348104d34..bf11c09a042c 100644
--- a/packages/devextreme-angular/src/ui/funnel/nested/funnel-title.ts
+++ b/packages/devextreme-angular/src/ui/funnel/nested/funnel-title.ts
@@ -65,18 +65,18 @@ export class DxoFunnelFunnelTitleComponent extends NestedOption implements OnDes
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/linear-gauge/index.ts b/packages/devextreme-angular/src/ui/linear-gauge/index.ts
index b2bc9c18fa51..5e678b023694 100644
--- a/packages/devextreme-angular/src/ui/linear-gauge/index.ts
+++ b/packages/devextreme-angular/src/ui/linear-gauge/index.ts
@@ -350,10 +350,10 @@ export class DxLinearGaugeComponent extends DxComponent implements OnDestroy, On
     
      */
     @Input()
-    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
+    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
         return this._getOption('title');
     }
-    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
+    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
         this._setOption('title', value);
     }
 
@@ -600,7 +600,7 @@ export class DxLinearGaugeComponent extends DxComponent implements OnDestroy, On
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
+    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/linear-gauge/nested/subtitle.ts b/packages/devextreme-angular/src/ui/linear-gauge/nested/subtitle.ts
index fec9d79e6bb0..478bc8fbc926 100644
--- a/packages/devextreme-angular/src/ui/linear-gauge/nested/subtitle.ts
+++ b/packages/devextreme-angular/src/ui/linear-gauge/nested/subtitle.ts
@@ -48,10 +48,10 @@ export class DxoLinearGaugeSubtitleComponent extends NestedOption implements OnD
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/linear-gauge/nested/title.ts b/packages/devextreme-angular/src/ui/linear-gauge/nested/title.ts
index 5415d0e03233..9a934d8ef47e 100644
--- a/packages/devextreme-angular/src/ui/linear-gauge/nested/title.ts
+++ b/packages/devextreme-angular/src/ui/linear-gauge/nested/title.ts
@@ -65,18 +65,18 @@ export class DxoLinearGaugeTitleComponent extends NestedOption implements OnDest
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/nested/title.ts b/packages/devextreme-angular/src/ui/nested/title.ts
index 98370ea5097a..de924852c98c 100644
--- a/packages/devextreme-angular/src/ui/nested/title.ts
+++ b/packages/devextreme-angular/src/ui/nested/title.ts
@@ -65,10 +65,10 @@ export class DxoTitleComponent extends NestedOption implements OnDestroy, OnInit
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined } | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined } | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined } | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined } | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
         this._setOption('subtitle', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/pie-chart/index.ts b/packages/devextreme-angular/src/ui/pie-chart/index.ts
index ef57f193300a..ee81cec851be 100644
--- a/packages/devextreme-angular/src/ui/pie-chart/index.ts
+++ b/packages/devextreme-angular/src/ui/pie-chart/index.ts
@@ -578,10 +578,10 @@ export class DxPieChartComponent extends DxComponent implements OnDestroy, OnCha
     
      */
     @Input()
-    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
+    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
         return this._getOption('title');
     }
-    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
+    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
         this._setOption('title', value);
     }
 
@@ -967,7 +967,7 @@ export class DxPieChartComponent extends DxComponent implements OnDestroy, OnCha
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
+    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/pie-chart/nested/pie-chart-title-subtitle.ts b/packages/devextreme-angular/src/ui/pie-chart/nested/pie-chart-title-subtitle.ts
index 5e68c9bd654e..6a4fcfdc89c7 100644
--- a/packages/devextreme-angular/src/ui/pie-chart/nested/pie-chart-title-subtitle.ts
+++ b/packages/devextreme-angular/src/ui/pie-chart/nested/pie-chart-title-subtitle.ts
@@ -48,10 +48,10 @@ export class DxoPieChartPieChartTitleSubtitleComponent extends NestedOption impl
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/pie-chart/nested/pie-chart-title.ts b/packages/devextreme-angular/src/ui/pie-chart/nested/pie-chart-title.ts
index 60943af17edc..dfa044b0a08b 100644
--- a/packages/devextreme-angular/src/ui/pie-chart/nested/pie-chart-title.ts
+++ b/packages/devextreme-angular/src/ui/pie-chart/nested/pie-chart-title.ts
@@ -65,18 +65,18 @@ export class DxoPieChartPieChartTitleComponent extends NestedOption implements O
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/polar-chart/index.ts b/packages/devextreme-angular/src/ui/polar-chart/index.ts
index 71d667461f54..c4f461b19e6e 100644
--- a/packages/devextreme-angular/src/ui/polar-chart/index.ts
+++ b/packages/devextreme-angular/src/ui/polar-chart/index.ts
@@ -660,10 +660,10 @@ export class DxPolarChartComponent extends DxComponent implements OnDestroy, OnC
     
      */
     @Input()
-    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
+    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
         return this._getOption('title');
     }
-    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
+    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
         this._setOption('title', value);
     }
 
@@ -1117,7 +1117,7 @@ export class DxPolarChartComponent extends DxComponent implements OnDestroy, OnC
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
+    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/polar-chart/nested/polar-chart-title-subtitle.ts b/packages/devextreme-angular/src/ui/polar-chart/nested/polar-chart-title-subtitle.ts
index eee8da73ad2c..531afa67a79d 100644
--- a/packages/devextreme-angular/src/ui/polar-chart/nested/polar-chart-title-subtitle.ts
+++ b/packages/devextreme-angular/src/ui/polar-chart/nested/polar-chart-title-subtitle.ts
@@ -48,10 +48,10 @@ export class DxoPolarChartPolarChartTitleSubtitleComponent extends NestedOption
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/polar-chart/nested/polar-chart-title.ts b/packages/devextreme-angular/src/ui/polar-chart/nested/polar-chart-title.ts
index da167d6a40cd..0da5847a4ffe 100644
--- a/packages/devextreme-angular/src/ui/polar-chart/nested/polar-chart-title.ts
+++ b/packages/devextreme-angular/src/ui/polar-chart/nested/polar-chart-title.ts
@@ -65,18 +65,18 @@ export class DxoPolarChartPolarChartTitleComponent extends NestedOption implemen
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/range-selector/index.ts b/packages/devextreme-angular/src/ui/range-selector/index.ts
index 8a9faeb095b7..df57da06a0fd 100644
--- a/packages/devextreme-angular/src/ui/range-selector/index.ts
+++ b/packages/devextreme-angular/src/ui/range-selector/index.ts
@@ -531,10 +531,10 @@ export class DxRangeSelectorComponent extends DxComponent implements OnDestroy,
     
      */
     @Input()
-    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
+    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
         return this._getOption('title');
     }
-    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
+    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
         this._setOption('title', value);
     }
 
@@ -789,7 +789,7 @@ export class DxRangeSelectorComponent extends DxComponent implements OnDestroy,
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
+    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/range-selector/nested/subtitle.ts b/packages/devextreme-angular/src/ui/range-selector/nested/subtitle.ts
index 1f7c64576164..e29376a99b31 100644
--- a/packages/devextreme-angular/src/ui/range-selector/nested/subtitle.ts
+++ b/packages/devextreme-angular/src/ui/range-selector/nested/subtitle.ts
@@ -48,10 +48,10 @@ export class DxoRangeSelectorSubtitleComponent extends NestedOption implements O
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/range-selector/nested/title.ts b/packages/devextreme-angular/src/ui/range-selector/nested/title.ts
index f879fc1a1d65..b3a5c79bef51 100644
--- a/packages/devextreme-angular/src/ui/range-selector/nested/title.ts
+++ b/packages/devextreme-angular/src/ui/range-selector/nested/title.ts
@@ -65,18 +65,18 @@ export class DxoRangeSelectorTitleComponent extends NestedOption implements OnDe
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/sankey/index.ts b/packages/devextreme-angular/src/ui/sankey/index.ts
index ef0efe8693f8..3e540d5063ce 100644
--- a/packages/devextreme-angular/src/ui/sankey/index.ts
+++ b/packages/devextreme-angular/src/ui/sankey/index.ts
@@ -391,10 +391,10 @@ export class DxSankeyComponent extends DxComponent implements OnDestroy, OnChang
     
      */
     @Input()
-    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
+    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
         return this._getOption('title');
     }
-    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
+    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
         this._setOption('title', value);
     }
 
@@ -679,7 +679,7 @@ export class DxSankeyComponent extends DxComponent implements OnDestroy, OnChang
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
+    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/sankey/nested/subtitle.ts b/packages/devextreme-angular/src/ui/sankey/nested/subtitle.ts
index 0e1faadfe844..8825e7877a41 100644
--- a/packages/devextreme-angular/src/ui/sankey/nested/subtitle.ts
+++ b/packages/devextreme-angular/src/ui/sankey/nested/subtitle.ts
@@ -48,10 +48,10 @@ export class DxoSankeySubtitleComponent extends NestedOption implements OnDestro
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/sankey/nested/title.ts b/packages/devextreme-angular/src/ui/sankey/nested/title.ts
index 22e36bd423c6..a8edd1504765 100644
--- a/packages/devextreme-angular/src/ui/sankey/nested/title.ts
+++ b/packages/devextreme-angular/src/ui/sankey/nested/title.ts
@@ -65,18 +65,18 @@ export class DxoSankeyTitleComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/scheduler/nested/form.ts b/packages/devextreme-angular/src/ui/scheduler/nested/form.ts
index 1c711da7d438..a01ad05395de 100644
--- a/packages/devextreme-angular/src/ui/scheduler/nested/form.ts
+++ b/packages/devextreme-angular/src/ui/scheduler/nested/form.ts
@@ -232,18 +232,18 @@ export class DxoSchedulerFormComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get onEditorEnterKey(): ((e: EditorEnterKeyEvent) => void) {
+    get onEditorEnterKey(): ((e: EditorEnterKeyEvent) => void) | null {
         return this._getOption('onEditorEnterKey');
     }
-    set onEditorEnterKey(value: ((e: EditorEnterKeyEvent) => void)) {
+    set onEditorEnterKey(value: ((e: EditorEnterKeyEvent) => void) | null) {
         this._setOption('onEditorEnterKey', value);
     }
 
     @Input()
-    get onFieldDataChanged(): ((e: FieldDataChangedEvent) => void) {
+    get onFieldDataChanged(): ((e: FieldDataChangedEvent) => void) | null {
         return this._getOption('onFieldDataChanged');
     }
-    set onFieldDataChanged(value: ((e: FieldDataChangedEvent) => void)) {
+    set onFieldDataChanged(value: ((e: FieldDataChangedEvent) => void) | null) {
         this._setOption('onFieldDataChanged', value);
     }
 
@@ -264,18 +264,18 @@ export class DxoSchedulerFormComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get onSmartPasted(): ((e: SmartPastedEvent) => void) {
+    get onSmartPasted(): ((e: SmartPastedEvent) => void) | null {
         return this._getOption('onSmartPasted');
     }
-    set onSmartPasted(value: ((e: SmartPastedEvent) => void)) {
+    set onSmartPasted(value: ((e: SmartPastedEvent) => void) | null) {
         this._setOption('onSmartPasted', value);
     }
 
     @Input()
-    get onSmartPasting(): ((e: SmartPastingEvent) => void) {
+    get onSmartPasting(): ((e: SmartPastingEvent) => void) | null {
         return this._getOption('onSmartPasting');
     }
-    set onSmartPasting(value: ((e: SmartPastingEvent) => void)) {
+    set onSmartPasting(value: ((e: SmartPastingEvent) => void) | null) {
         this._setOption('onSmartPasting', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tree-list/nested/form.ts b/packages/devextreme-angular/src/ui/tree-list/nested/form.ts
index 7b3ff5644dc5..88833a80898b 100644
--- a/packages/devextreme-angular/src/ui/tree-list/nested/form.ts
+++ b/packages/devextreme-angular/src/ui/tree-list/nested/form.ts
@@ -223,18 +223,18 @@ export class DxoTreeListFormComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get onEditorEnterKey(): ((e: EditorEnterKeyEvent) => void) {
+    get onEditorEnterKey(): ((e: EditorEnterKeyEvent) => void) | null {
         return this._getOption('onEditorEnterKey');
     }
-    set onEditorEnterKey(value: ((e: EditorEnterKeyEvent) => void)) {
+    set onEditorEnterKey(value: ((e: EditorEnterKeyEvent) => void) | null) {
         this._setOption('onEditorEnterKey', value);
     }
 
     @Input()
-    get onFieldDataChanged(): ((e: FieldDataChangedEvent) => void) {
+    get onFieldDataChanged(): ((e: FieldDataChangedEvent) => void) | null {
         return this._getOption('onFieldDataChanged');
     }
-    set onFieldDataChanged(value: ((e: FieldDataChangedEvent) => void)) {
+    set onFieldDataChanged(value: ((e: FieldDataChangedEvent) => void) | null) {
         this._setOption('onFieldDataChanged', value);
     }
 
@@ -255,18 +255,18 @@ export class DxoTreeListFormComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get onSmartPasted(): ((e: SmartPastedEvent) => void) {
+    get onSmartPasted(): ((e: SmartPastedEvent) => void) | null {
         return this._getOption('onSmartPasted');
     }
-    set onSmartPasted(value: ((e: SmartPastedEvent) => void)) {
+    set onSmartPasted(value: ((e: SmartPastedEvent) => void) | null) {
         this._setOption('onSmartPasted', value);
     }
 
     @Input()
-    get onSmartPasting(): ((e: SmartPastingEvent) => void) {
+    get onSmartPasting(): ((e: SmartPastingEvent) => void) | null {
         return this._getOption('onSmartPasting');
     }
-    set onSmartPasting(value: ((e: SmartPastingEvent) => void)) {
+    set onSmartPasting(value: ((e: SmartPastingEvent) => void) | null) {
         this._setOption('onSmartPasting', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tree-map/index.ts b/packages/devextreme-angular/src/ui/tree-map/index.ts
index 6f6d20c775a5..e63a889e15b4 100644
--- a/packages/devextreme-angular/src/ui/tree-map/index.ts
+++ b/packages/devextreme-angular/src/ui/tree-map/index.ts
@@ -419,10 +419,10 @@ export class DxTreeMapComponent extends DxComponent implements OnDestroy, OnChan
     
      */
     @Input()
-    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
+    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
         return this._getOption('title');
     }
-    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
+    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
         this._setOption('title', value);
     }
 
@@ -737,7 +737,7 @@ export class DxTreeMapComponent extends DxComponent implements OnDestroy, OnChan
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
+    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/tree-map/nested/subtitle.ts b/packages/devextreme-angular/src/ui/tree-map/nested/subtitle.ts
index c6a74b357591..cf0fbeda2531 100644
--- a/packages/devextreme-angular/src/ui/tree-map/nested/subtitle.ts
+++ b/packages/devextreme-angular/src/ui/tree-map/nested/subtitle.ts
@@ -48,10 +48,10 @@ export class DxoTreeMapSubtitleComponent extends NestedOption implements OnDestr
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tree-map/nested/title.ts b/packages/devextreme-angular/src/ui/tree-map/nested/title.ts
index 6a8d3b49e988..5e8a05cc17f8 100644
--- a/packages/devextreme-angular/src/ui/tree-map/nested/title.ts
+++ b/packages/devextreme-angular/src/ui/tree-map/nested/title.ts
@@ -65,18 +65,18 @@ export class DxoTreeMapTitleComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/vector-map/index.ts b/packages/devextreme-angular/src/ui/vector-map/index.ts
index 07a61f117b75..d009e97df54b 100644
--- a/packages/devextreme-angular/src/ui/vector-map/index.ts
+++ b/packages/devextreme-angular/src/ui/vector-map/index.ts
@@ -411,10 +411,10 @@ export class DxVectorMapComponent extends DxComponent implements OnDestroy, OnCh
     
      */
     @Input()
-    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
+    get title(): string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap } {
         return this._getOption('title');
     }
-    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
+    set title(value: string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }) {
         this._setOption('title', value);
     }
 
@@ -747,7 +747,7 @@ export class DxVectorMapComponent extends DxComponent implements OnDestroy, OnCh
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
+    @Output() titleChange: EventEmitter<string | { font?: Font, horizontalAlignment?: HorizontalAlignment, margin?: number | { bottom?: number, left?: number, right?: number, top?: number }, placeholderSize?: number | undefined, subtitle?: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }, text?: string | undefined, textOverflow?: TextOverflow, verticalAlignment?: VerticalEdge, wordWrap?: WordWrap }>;
 
     /**
     
diff --git a/packages/devextreme-angular/src/ui/vector-map/nested/vector-map-title-subtitle.ts b/packages/devextreme-angular/src/ui/vector-map/nested/vector-map-title-subtitle.ts
index 66de0fc86065..452cac6dca08 100644
--- a/packages/devextreme-angular/src/ui/vector-map/nested/vector-map-title-subtitle.ts
+++ b/packages/devextreme-angular/src/ui/vector-map/nested/vector-map-title-subtitle.ts
@@ -48,10 +48,10 @@ export class DxoVectorMapVectorMapTitleSubtitleComponent extends NestedOption im
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/vector-map/nested/vector-map-title.ts b/packages/devextreme-angular/src/ui/vector-map/nested/vector-map-title.ts
index 7a90f6a4a3d2..fa502477a3e6 100644
--- a/packages/devextreme-angular/src/ui/vector-map/nested/vector-map-title.ts
+++ b/packages/devextreme-angular/src/ui/vector-map/nested/vector-map-title.ts
@@ -65,18 +65,18 @@ export class DxoVectorMapVectorMapTitleComponent extends NestedOption implements
     }
 
     @Input()
-    get subtitle(): string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
+    get subtitle(): string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap } {
         return this._getOption('subtitle');
     }
-    set subtitle(value: string | { font?: Font, offset?: number, text?: string, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
+    set subtitle(value: string | { font?: Font, offset?: number, text?: string | undefined, textOverflow?: TextOverflow, wordWrap?: WordWrap }) {
         this._setOption('subtitle', value);
     }
 
     @Input()
-    get text(): string {
+    get text(): string | undefined {
         return this._getOption('text');
     }
-    set text(value: string) {
+    set text(value: string | undefined) {
         this._setOption('text', value);
     }
 
diff --git a/packages/devextreme-react/src/bar-gauge.ts b/packages/devextreme-react/src/bar-gauge.ts
index 99cdb7122718..e572011c3655 100644
--- a/packages/devextreme-react/src/bar-gauge.ts
+++ b/packages/devextreme-react/src/bar-gauge.ts
@@ -137,11 +137,11 @@ type IBarGaugeTitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
     textOverflow?: TextOverflow;
     wordWrap?: WordWrap;
   };
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   verticalAlignment?: VerticalEdge;
   wordWrap?: WordWrap;
@@ -170,7 +170,7 @@ const BarGaugeTitle = Object.assign<typeof _componentBarGaugeTitle, NestedCompon
 type IBarGaugeTitleSubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
 }>
diff --git a/packages/devextreme-react/src/card-view.ts b/packages/devextreme-react/src/card-view.ts
index 9c8211049d40..5a180c8834dc 100644
--- a/packages/devextreme-react/src/card-view.ts
+++ b/packages/devextreme-react/src/card-view.ts
@@ -1317,12 +1317,12 @@ type IFormProps = React.PropsWithChildren<{
   minColWidth?: number;
   onContentReady?: ((e: FormContentReadyEvent) => void);
   onDisposing?: ((e: FormDisposingEvent) => void);
-  onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void);
-  onFieldDataChanged?: ((e: FieldDataChangedEvent) => void);
+  onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void) | null;
+  onFieldDataChanged?: ((e: FieldDataChangedEvent) => void) | null;
   onInitialized?: ((e: FormInitializedEvent) => void);
   onOptionChanged?: ((e: FormOptionChangedEvent) => void);
-  onSmartPasted?: ((e: SmartPastedEvent) => void);
-  onSmartPasting?: ((e: SmartPastingEvent) => void);
+  onSmartPasted?: ((e: SmartPastedEvent) => void) | null;
+  onSmartPasting?: ((e: SmartPastingEvent) => void) | null;
   optionalMark?: string;
   readOnly?: boolean;
   requiredMark?: string;
diff --git a/packages/devextreme-react/src/chart.ts b/packages/devextreme-react/src/chart.ts
index 2cf14ad83d84..65e1242de340 100644
--- a/packages/devextreme-react/src/chart.ts
+++ b/packages/devextreme-react/src/chart.ts
@@ -851,11 +851,11 @@ type IChartTitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
     textOverflow?: TextOverflow;
     wordWrap?: WordWrap;
   };
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   verticalAlignment?: VerticalEdge;
   wordWrap?: WordWrap;
@@ -884,7 +884,7 @@ const ChartTitle = Object.assign<typeof _componentChartTitle, NestedComponentMet
 type IChartTitleSubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
 }>
diff --git a/packages/devextreme-react/src/circular-gauge.ts b/packages/devextreme-react/src/circular-gauge.ts
index 146a479d2fbd..8610e11f92e1 100644
--- a/packages/devextreme-react/src/circular-gauge.ts
+++ b/packages/devextreme-react/src/circular-gauge.ts
@@ -542,7 +542,7 @@ const Size = Object.assign<typeof _componentSize, NestedComponentMeta>(_componen
 type ISubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
 }>
@@ -670,11 +670,11 @@ type ITitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
     textOverflow?: TextOverflow;
     wordWrap?: WordWrap;
   };
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   verticalAlignment?: VerticalEdge;
   wordWrap?: WordWrap;
diff --git a/packages/devextreme-react/src/data-grid.ts b/packages/devextreme-react/src/data-grid.ts
index ac30ec0cf05b..d758dca58fb5 100644
--- a/packages/devextreme-react/src/data-grid.ts
+++ b/packages/devextreme-react/src/data-grid.ts
@@ -1905,12 +1905,12 @@ type IFormProps = React.PropsWithChildren<{
   minColWidth?: number;
   onContentReady?: ((e: FormContentReadyEvent) => void);
   onDisposing?: ((e: FormDisposingEvent) => void);
-  onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void);
-  onFieldDataChanged?: ((e: FieldDataChangedEvent) => void);
+  onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void) | null;
+  onFieldDataChanged?: ((e: FieldDataChangedEvent) => void) | null;
   onInitialized?: ((e: FormInitializedEvent) => void);
   onOptionChanged?: ((e: FormOptionChangedEvent) => void);
-  onSmartPasted?: ((e: SmartPastedEvent) => void);
-  onSmartPasting?: ((e: SmartPastingEvent) => void);
+  onSmartPasted?: ((e: SmartPastedEvent) => void) | null;
+  onSmartPasting?: ((e: SmartPastingEvent) => void) | null;
   optionalMark?: string;
   readOnly?: boolean;
   requiredMark?: string;
diff --git a/packages/devextreme-react/src/form.ts b/packages/devextreme-react/src/form.ts
index a24d55ef2291..b2abcf4341c8 100644
--- a/packages/devextreme-react/src/form.ts
+++ b/packages/devextreme-react/src/form.ts
@@ -27,10 +27,10 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 type IFormOptionsNarrowedEvents = {
   onContentReady?: ((e: ContentReadyEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
-  onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void);
+  onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void) | null;
   onInitialized?: ((e: InitializedEvent) => void);
-  onSmartPasted?: ((e: SmartPastedEvent) => void);
-  onSmartPasting?: ((e: SmartPastingEvent) => void);
+  onSmartPasted?: ((e: SmartPastedEvent) => void) | null;
+  onSmartPasting?: ((e: SmartPastingEvent) => void) | null;
 }
 
 type IFormOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IFormOptionsNarrowedEvents> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/funnel.ts b/packages/devextreme-react/src/funnel.ts
index 2310654e5eb5..3ea5469bb050 100644
--- a/packages/devextreme-react/src/funnel.ts
+++ b/packages/devextreme-react/src/funnel.ts
@@ -249,11 +249,11 @@ type IFunnelTitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
     textOverflow?: TextOverflow;
     wordWrap?: WordWrap;
   };
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   verticalAlignment?: VerticalEdge;
   wordWrap?: WordWrap;
@@ -282,7 +282,7 @@ const FunnelTitle = Object.assign<typeof _componentFunnelTitle, NestedComponentM
 type IFunnelTitleSubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
 }>
diff --git a/packages/devextreme-react/src/linear-gauge.ts b/packages/devextreme-react/src/linear-gauge.ts
index fe06ecb1a4c5..ad5c90c11afa 100644
--- a/packages/devextreme-react/src/linear-gauge.ts
+++ b/packages/devextreme-react/src/linear-gauge.ts
@@ -534,7 +534,7 @@ const Size = Object.assign<typeof _componentSize, NestedComponentMeta>(_componen
 type ISubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
 }>
@@ -662,11 +662,11 @@ type ITitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
     textOverflow?: TextOverflow;
     wordWrap?: WordWrap;
   };
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   verticalAlignment?: VerticalEdge;
   wordWrap?: WordWrap;
diff --git a/packages/devextreme-react/src/pie-chart.ts b/packages/devextreme-react/src/pie-chart.ts
index 0f164633a099..26da830023f8 100644
--- a/packages/devextreme-react/src/pie-chart.ts
+++ b/packages/devextreme-react/src/pie-chart.ts
@@ -967,11 +967,11 @@ type IPieChartTitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
     textOverflow?: TextOverflow;
     wordWrap?: WordWrap;
   };
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   verticalAlignment?: VerticalEdge;
   wordWrap?: WordWrap;
@@ -1000,7 +1000,7 @@ const PieChartTitle = Object.assign<typeof _componentPieChartTitle, NestedCompon
 type IPieChartTitleSubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
 }>
diff --git a/packages/devextreme-react/src/polar-chart.ts b/packages/devextreme-react/src/polar-chart.ts
index 7027c8efd654..318ca1ad6a84 100644
--- a/packages/devextreme-react/src/polar-chart.ts
+++ b/packages/devextreme-react/src/polar-chart.ts
@@ -1975,11 +1975,11 @@ type IPolarChartTitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
     textOverflow?: TextOverflow;
     wordWrap?: WordWrap;
   };
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   verticalAlignment?: VerticalEdge;
   wordWrap?: WordWrap;
@@ -2008,7 +2008,7 @@ const PolarChartTitle = Object.assign<typeof _componentPolarChartTitle, NestedCo
 type IPolarChartTitleSubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
 }>
diff --git a/packages/devextreme-react/src/range-selector.ts b/packages/devextreme-react/src/range-selector.ts
index 9683f6e1be1f..619ffeb648e9 100644
--- a/packages/devextreme-react/src/range-selector.ts
+++ b/packages/devextreme-react/src/range-selector.ts
@@ -2014,7 +2014,7 @@ const SliderMarker = Object.assign<typeof _componentSliderMarker, NestedComponen
 type ISubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
 }>
@@ -2095,11 +2095,11 @@ type ITitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
     textOverflow?: TextOverflow;
     wordWrap?: WordWrap;
   };
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   verticalAlignment?: VerticalEdge;
   wordWrap?: WordWrap;
diff --git a/packages/devextreme-react/src/sankey.ts b/packages/devextreme-react/src/sankey.ts
index 825ab791ffc8..0634ebb9c2ac 100644
--- a/packages/devextreme-react/src/sankey.ts
+++ b/packages/devextreme-react/src/sankey.ts
@@ -518,7 +518,7 @@ const Size = Object.assign<typeof _componentSize, NestedComponentMeta>(_componen
 type ISubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
 }>
@@ -553,11 +553,11 @@ type ITitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
     textOverflow?: TextOverflow;
     wordWrap?: WordWrap;
   };
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   verticalAlignment?: VerticalEdge;
   wordWrap?: WordWrap;
diff --git a/packages/devextreme-react/src/scheduler.ts b/packages/devextreme-react/src/scheduler.ts
index 2b5b5c174f56..7988d2c8a553 100644
--- a/packages/devextreme-react/src/scheduler.ts
+++ b/packages/devextreme-react/src/scheduler.ts
@@ -501,12 +501,12 @@ type IFormProps = React.PropsWithChildren<{
   minColWidth?: number;
   onContentReady?: ((e: FormContentReadyEvent) => void);
   onDisposing?: ((e: FormDisposingEvent) => void);
-  onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void);
-  onFieldDataChanged?: ((e: FieldDataChangedEvent) => void);
+  onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void) | null;
+  onFieldDataChanged?: ((e: FieldDataChangedEvent) => void) | null;
   onInitialized?: ((e: FormInitializedEvent) => void);
   onOptionChanged?: ((e: FormOptionChangedEvent) => void);
-  onSmartPasted?: ((e: SmartPastedEvent) => void);
-  onSmartPasting?: ((e: SmartPastingEvent) => void);
+  onSmartPasted?: ((e: SmartPastedEvent) => void) | null;
+  onSmartPasting?: ((e: SmartPastingEvent) => void) | null;
   optionalMark?: string;
   readOnly?: boolean;
   requiredMark?: string;
diff --git a/packages/devextreme-react/src/tree-list.ts b/packages/devextreme-react/src/tree-list.ts
index bd9797e4fc7b..e55652cbadd7 100644
--- a/packages/devextreme-react/src/tree-list.ts
+++ b/packages/devextreme-react/src/tree-list.ts
@@ -1674,12 +1674,12 @@ type IFormProps = React.PropsWithChildren<{
   minColWidth?: number;
   onContentReady?: ((e: FormContentReadyEvent) => void);
   onDisposing?: ((e: FormDisposingEvent) => void);
-  onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void);
-  onFieldDataChanged?: ((e: FieldDataChangedEvent) => void);
+  onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void) | null;
+  onFieldDataChanged?: ((e: FieldDataChangedEvent) => void) | null;
   onInitialized?: ((e: FormInitializedEvent) => void);
   onOptionChanged?: ((e: FormOptionChangedEvent) => void);
-  onSmartPasted?: ((e: SmartPastedEvent) => void);
-  onSmartPasting?: ((e: SmartPastingEvent) => void);
+  onSmartPasted?: ((e: SmartPastedEvent) => void) | null;
+  onSmartPasting?: ((e: SmartPastingEvent) => void) | null;
   optionalMark?: string;
   readOnly?: boolean;
   requiredMark?: string;
diff --git a/packages/devextreme-react/src/tree-map.ts b/packages/devextreme-react/src/tree-map.ts
index 5fb4515e219b..639891c08dee 100644
--- a/packages/devextreme-react/src/tree-map.ts
+++ b/packages/devextreme-react/src/tree-map.ts
@@ -461,7 +461,7 @@ const Size = Object.assign<typeof _componentSize, NestedComponentMeta>(_componen
 type ISubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
 }>
@@ -570,11 +570,11 @@ type ITitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
     textOverflow?: TextOverflow;
     wordWrap?: WordWrap;
   };
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   verticalAlignment?: VerticalEdge;
   wordWrap?: WordWrap;
diff --git a/packages/devextreme-react/src/vector-map.ts b/packages/devextreme-react/src/vector-map.ts
index d11b370329d3..bac7d1c81463 100644
--- a/packages/devextreme-react/src/vector-map.ts
+++ b/packages/devextreme-react/src/vector-map.ts
@@ -960,11 +960,11 @@ type IVectorMapTitleProps = React.PropsWithChildren<{
   subtitle?: Record<string, any> | string | {
     font?: ChartsFont;
     offset?: number;
-    text?: string;
+    text?: string | undefined;
     textOverflow?: TextOverflow;
     wordWrap?: WordWrap;
   };
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   verticalAlignment?: VerticalEdge;
   wordWrap?: WordWrap;
@@ -993,7 +993,7 @@ const VectorMapTitle = Object.assign<typeof _componentVectorMapTitle, NestedComp
 type IVectorMapTitleSubtitleProps = React.PropsWithChildren<{
   font?: ChartsFont;
   offset?: number;
-  text?: string;
+  text?: string | undefined;
   textOverflow?: TextOverflow;
   wordWrap?: WordWrap;
 }>
diff --git a/packages/devextreme/js/__internal/ui/form/form.layout_manager.ts b/packages/devextreme/js/__internal/ui/form/form.layout_manager.ts
index b39e20fe9e5e..9bf5bb485ac6 100644
--- a/packages/devextreme/js/__internal/ui/form/form.layout_manager.ts
+++ b/packages/devextreme/js/__internal/ui/form/form.layout_manager.ts
@@ -151,7 +151,6 @@ class LayoutManager extends Widget<LayoutManagerProperties> {
       labelLocation: 'left',
       // @ts-expect-error ts-error
       onFieldDataChanged: null,
-      // @ts-expect-error ts-error
       onEditorEnterKey: null,
       // @ts-expect-error ts-error
       customizeItem: null,
diff --git a/packages/devextreme/js/__internal/ui/form/form.ts b/packages/devextreme/js/__internal/ui/form/form.ts
index 6b4d70e9698f..79ecf17173dc 100644
--- a/packages/devextreme/js/__internal/ui/form/form.ts
+++ b/packages/devextreme/js/__internal/ui/form/form.ts
@@ -203,11 +203,9 @@ class Form extends Widget<FormProperties> {
       screenByWidth: defaultScreenFactorFunc,
       labelLocation: 'left',
       readOnly: false,
-      // @ts-expect-error ts-error
       onFieldDataChanged: null,
       // @ts-expect-error ts-error
       customizeItem: null,
-      // @ts-expect-error ts-error
       onEditorEnterKey: null,
       minColWidth: 200,
       alignItemLabels: true,
@@ -225,9 +223,7 @@ class Form extends Widget<FormProperties> {
       stylingMode: config().editorStylingMode,
       labelMode: 'outside',
       isDirty: false,
-      // @ts-expect-error ts-error
       onSmartPasting: null,
-      // @ts-expect-error ts-error
       onSmartPasted: null,
     };
   }
diff --git a/packages/devextreme/js/ui/form.d.ts b/packages/devextreme/js/ui/form.d.ts
index e7b46c29720a..308d93bd1a7d 100644
--- a/packages/devextreme/js/ui/form.d.ts
+++ b/packages/devextreme/js/ui/form.d.ts
@@ -273,7 +273,7 @@ export interface dxFormOptions extends WidgetOptions<dxForm> {
      * @action
      * @public
      */
-    onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void);
+     onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -281,7 +281,7 @@ export interface dxFormOptions extends WidgetOptions<dxForm> {
      * @action
      * @public
      */
-    onFieldDataChanged?: ((e: FieldDataChangedEvent) => void);
+     onFieldDataChanged?: ((e: FieldDataChangedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -289,7 +289,7 @@ export interface dxFormOptions extends WidgetOptions<dxForm> {
      * @action
      * @public
      */
-    onSmartPasting?: ((e: SmartPastingEvent) => void);
+     onSmartPasting?: ((e: SmartPastingEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -297,7 +297,7 @@ export interface dxFormOptions extends WidgetOptions<dxForm> {
      * @action
      * @public
      */
-    onSmartPasted?: ((e: SmartPastedEvent) => void);
+     onSmartPasted?: ((e: SmartPastedEvent) => void) | null;
     /**
      * @docid
      * @default "optional"
@@ -324,10 +324,9 @@ export interface dxFormOptions extends WidgetOptions<dxForm> {
     requiredMessage?: string;
     /**
      * @docid
-     * @default null
      * @public
      */
-    screenByWidth?: Function;
+     screenByWidth?: Function;
     /**
      * @docid
      * @default false
@@ -760,12 +759,11 @@ export interface dxFormSimpleItem {
      * @public
      */
     itemType?: FormItemType;
-    /**
-     * @docid
-     * @default undefined
-     * @public
-     */
-    label?: {
+     /**
+      * @docid
+      * @public
+      */
+     label?: {
       /**
        * @docid
        * @default "left"
@@ -812,12 +810,11 @@ export interface dxFormSimpleItem {
      * @public
      */
     template?: template | ((data: SimpleItemTemplateData, itemElement: DxElement) => string | UserDefinedElement);
-    /**
-     * @docid
-     * @default undefined
-     * @public
-     */
-    validationRules?: Array<RequiredRule | NumericRule | RangeRule | StringLengthRule | CustomRule | CompareRule | PatternRule | EmailRule | AsyncRule>;
+     /**
+      * @docid
+      * @public
+      */
+     validationRules?: Array<RequiredRule | NumericRule | RangeRule | StringLengthRule | CustomRule | CompareRule | PatternRule | EmailRule | AsyncRule>;
     /**
      * @docid
      * @default true
@@ -873,12 +870,11 @@ export interface dxFormTabbedItem {
      * @public
      */
     tabPanelOptions?: dxTabPanelOptions | undefined;
-    /**
-     * @docid
-     * @default undefined
-     * @public
-     */
-    tabs?: Array<{
+     /**
+      * @docid
+      * @public
+      */
+     tabs?: Array<{
       /**
        * @docid
        * @default true
diff --git a/packages/devextreme/js/viz/core/base_widget.d.ts b/packages/devextreme/js/viz/core/base_widget.d.ts
index 21b59a57d498..fb4109e565c7 100644
--- a/packages/devextreme/js/viz/core/base_widget.d.ts
+++ b/packages/devextreme/js/viz/core/base_widget.d.ts
@@ -112,47 +112,46 @@ export interface BaseWidgetOptions<TComponent> extends DOMComponentOptions<TComp
      * @public
      */
     margin?: BaseWidgetMargin;
-    /**
-     * @docid
-     * @default null
-     * @notUsedInTheme
-     * @action
-     * @public
-     */
-    onDrawn?: ((e: EventInfo<TComponent>) => void);
-    /**
-     * @docid
-     * @default null
-     * @action
-     * @public
-     */
-    onExported?: ((e: EventInfo<TComponent>) => void);
-    /**
-     * @docid
-     * @type_function_param1 e:object
-     * @type_function_param1_field component:this
-     * @default null
-     * @action
-     * @public
-     */
-    onExporting?: ((e: EventInfo<TComponent> & ExportInfo) => void);
-    /**
-     * @docid
-     * @type_function_param1 e:{viz/core/base_widget:FileSavingEventInfo}
-     * @default null
-     * @action
-     * @public
-     */
-    onFileSaving?: ((e: FileSavingEventInfo<TComponent>) => void);
-    /**
-     * @docid
-     * @default null
-     * @type_function_param1 e:object
-     * @type_function_param1_field component:this
-     * @action
-     * @public
-     */
-    onIncidentOccurred?: ((e: EventInfo<TComponent> & IncidentInfo) => void);
+     /**
+      * @docid
+      * @default undefined
+      * @notUsedInTheme
+      * @action
+      * @public
+      */
+     onDrawn?: ((e: EventInfo<TComponent>) => void) | undefined;
+     /**
+      * @docid
+      * @default undefined
+      * @action
+      * @public
+      */
+     onExported?: ((e: EventInfo<TComponent>) => void) | undefined;
+     /**
+      * @docid
+      * @type_function_param1 e:object
+      * @type_function_param1_field component:this
+      * @default undefined
+      * @action
+      * @public
+      */
+     onExporting?: ((e: EventInfo<TComponent> & ExportInfo) => void) | undefined;
+     /**
+      * @docid
+      * @type_function_param1 e:{viz/core/base_widget:FileSavingEventInfo}
+      * @default undefined
+      * @action
+      * @public
+      */
+     onFileSaving?: ((e: FileSavingEventInfo<TComponent>) => void) | undefined;
+     /**
+      * @docid
+      * @type_function_param1 e:object
+      * @type_function_param1_field component:this
+      * @action
+      * @public
+      */
+     onIncidentOccurred?: ((e: EventInfo<TComponent> & IncidentInfo) => void);
     /**
      * @docid
      * @default false
@@ -418,11 +417,11 @@ export interface BaseWidgetTitle {
        * @default 0
        */
       offset?: number;
-      /**
-       * @docid BaseWidgetOptions.title.subtitle.text
-       * @default null
-       */
-      text?: string;
+       /**
+        * @docid BaseWidgetOptions.title.subtitle.text
+        * @default undefined
+        */
+       text?: string | undefined;
       /**
        * @docid BaseWidgetOptions.title.subtitle.textOverflow
        * @default "ellipsis"
@@ -434,12 +433,12 @@ export interface BaseWidgetTitle {
        */
       wordWrap?: WordWrap;
     } | string;
-    /**
-     * @docid BaseWidgetOptions.title.text
-     * @default null
-     * @public
-     */
-    text?: string;
+     /**
+      * @docid BaseWidgetOptions.title.text
+      * @default undefined
+      * @public
+      */
+     text?: string | undefined;
     /**
      * @docid BaseWidgetOptions.title.textOverflow
      * @default "ellipsis"

From 8efe5214f3eabc4735b1c7dae69915f794919904 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:43 +0300
Subject: [PATCH 064/100] regenerate-all

---
 packages/devextreme/ts/dx.all.d.ts | 46 ++++++++++++++++++------------
 1 file changed, 27 insertions(+), 19 deletions(-)

diff --git a/packages/devextreme/ts/dx.all.d.ts b/packages/devextreme/ts/dx.all.d.ts
index 677214817445..9ca52bdaa46a 100644
--- a/packages/devextreme/ts/dx.all.d.ts
+++ b/packages/devextreme/ts/dx.all.d.ts
@@ -19618,21 +19618,25 @@ declare module DevExpress.ui {
     /**
      * [descr:dxFormOptions.onEditorEnterKey]
      */
-    onEditorEnterKey?: (e: DevExpress.ui.dxForm.EditorEnterKeyEvent) => void;
+    onEditorEnterKey?:
+      | ((e: DevExpress.ui.dxForm.EditorEnterKeyEvent) => void)
+      | null;
     /**
      * [descr:dxFormOptions.onFieldDataChanged]
      */
-    onFieldDataChanged?: (
-      e: DevExpress.ui.dxForm.FieldDataChangedEvent
-    ) => void;
+    onFieldDataChanged?:
+      | ((e: DevExpress.ui.dxForm.FieldDataChangedEvent) => void)
+      | null;
     /**
      * [descr:dxFormOptions.onSmartPasting]
      */
-    onSmartPasting?: (e: DevExpress.ui.dxForm.SmartPastingEvent) => void;
+    onSmartPasting?:
+      | ((e: DevExpress.ui.dxForm.SmartPastingEvent) => void)
+      | null;
     /**
      * [descr:dxFormOptions.onSmartPasted]
      */
-    onSmartPasted?: (e: DevExpress.ui.dxForm.SmartPastedEvent) => void;
+    onSmartPasted?: ((e: DevExpress.ui.dxForm.SmartPastedEvent) => void) | null;
     /**
      * [descr:dxFormOptions.optionalMark]
      */
@@ -36638,26 +36642,30 @@ declare module DevExpress.viz {
     /**
      * [descr:BaseWidgetOptions.onDrawn]
      */
-    onDrawn?: (e: DevExpress.common.core.events.EventInfo<TComponent>) => void;
+    onDrawn?:
+      | ((e: DevExpress.common.core.events.EventInfo<TComponent>) => void)
+      | undefined;
     /**
      * [descr:BaseWidgetOptions.onExported]
      */
-    onExported?: (
-      e: DevExpress.common.core.events.EventInfo<TComponent>
-    ) => void;
+    onExported?:
+      | ((e: DevExpress.common.core.events.EventInfo<TComponent>) => void)
+      | undefined;
     /**
      * [descr:BaseWidgetOptions.onExporting]
      */
-    onExporting?: (
-      e: DevExpress.common.core.events.EventInfo<TComponent> &
-        DevExpress.viz.BaseWidget.ExportInfo
-    ) => void;
+    onExporting?:
+      | ((
+          e: DevExpress.common.core.events.EventInfo<TComponent> &
+            DevExpress.viz.BaseWidget.ExportInfo
+        ) => void)
+      | undefined;
     /**
      * [descr:BaseWidgetOptions.onFileSaving]
      */
-    onFileSaving?: (
-      e: DevExpress.viz.BaseWidget.FileSavingEventInfo<TComponent>
-    ) => void;
+    onFileSaving?:
+      | ((e: DevExpress.viz.BaseWidget.FileSavingEventInfo<TComponent>) => void)
+      | undefined;
     /**
      * [descr:BaseWidgetOptions.onIncidentOccurred]
      */
@@ -36768,7 +36776,7 @@ declare module DevExpress.viz {
           /**
            * [descr:BaseWidgetOptions.title.subtitle.text]
            */
-          text?: string;
+          text?: string | undefined;
           /**
            * [descr:BaseWidgetOptions.title.subtitle.textOverflow]
            */
@@ -36782,7 +36790,7 @@ declare module DevExpress.viz {
     /**
      * [descr:BaseWidgetOptions.title.text]
      */
-    text?: string;
+    text?: string | undefined;
     /**
      * [descr:BaseWidgetOptions.title.textOverflow]
      */

From c43f9be0694a0d47514a6ff0afdd78400c6bde21 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:43 +0300
Subject: [PATCH 065/100] chore(nx-infra-plugin): format framework-handlers.ts

---
 .../src/executors/generate-components/framework-handlers.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/packages/nx-infra-plugin/src/executors/generate-components/framework-handlers.ts b/packages/nx-infra-plugin/src/executors/generate-components/framework-handlers.ts
index 56f64bdb1d4a..28632a59ecf6 100644
--- a/packages/nx-infra-plugin/src/executors/generate-components/framework-handlers.ts
+++ b/packages/nx-infra-plugin/src/executors/generate-components/framework-handlers.ts
@@ -55,7 +55,11 @@ function cleanVueMetadata(metaData: any): any {
 
   const cleanProp = (prop: any) => {
     if (prop && Array.isArray(prop.types)) {
-      const isFunction = /^on[A-Z]/.test(prop.name) || prop.types.some((t: any) => t && (t.type === 'Function' || t.acceptableValueType === 'Function'));
+      const isFunction =
+        /^on[A-Z]/.test(prop.name)
+        || prop.types.some(
+          (t: any) => t && (t.type === 'Function' || t.acceptableValueType === 'Function'),
+        );
       if (isFunction) {
         prop.types = prop.types.filter((t: any) => t && t.type !== 'Null');
       }

From d9040541501987f473fe0e48a3999d471e8d323d Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:44 +0300
Subject: [PATCH 066/100] fix extra spacing

---
 .../devextreme/js/viz/core/base_widget.d.ts   | 22 +++++++++----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/packages/devextreme/js/viz/core/base_widget.d.ts b/packages/devextreme/js/viz/core/base_widget.d.ts
index fb4109e565c7..49b11962993b 100644
--- a/packages/devextreme/js/viz/core/base_widget.d.ts
+++ b/packages/devextreme/js/viz/core/base_widget.d.ts
@@ -417,11 +417,11 @@ export interface BaseWidgetTitle {
        * @default 0
        */
       offset?: number;
-       /**
-        * @docid BaseWidgetOptions.title.subtitle.text
-        * @default undefined
-        */
-       text?: string | undefined;
+      /**
+      * @docid BaseWidgetOptions.title.subtitle.text
+      * @default undefined
+      */
+      text?: string | undefined;
       /**
        * @docid BaseWidgetOptions.title.subtitle.textOverflow
        * @default "ellipsis"
@@ -433,12 +433,12 @@ export interface BaseWidgetTitle {
        */
       wordWrap?: WordWrap;
     } | string;
-     /**
-      * @docid BaseWidgetOptions.title.text
-      * @default undefined
-      * @public
-      */
-     text?: string | undefined;
+    /**
+    * @docid BaseWidgetOptions.title.text
+    * @default undefined
+    * @public
+    */
+    text?: string | undefined;
     /**
      * @docid BaseWidgetOptions.title.textOverflow
      * @default "ellipsis"

From 7525bc8bd2ed547e94c82d08deba132592f46565 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:44 +0300
Subject: [PATCH 067/100] some fixex after review

---
 .../ui/date_box/m_date_box.strategy.date_view.ts     |  2 +-
 .../js/__internal/ui/html_editor/html_editor.ts      | 12 ++++--------
 packages/devextreme/js/__internal/ui/map/map.ts      |  4 +---
 packages/devextreme/js/ui/form.d.ts                  |  8 ++++----
 4 files changed, 10 insertions(+), 16 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.date_view.ts b/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.date_view.ts
index 781689a73ebe..23521c767da4 100644
--- a/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.date_view.ts
+++ b/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.date_view.ts
@@ -38,7 +38,7 @@ class DateViewStrategy extends DateBoxStrategy {
     };
   }
 
-  getDisplayFormat(displayFormat: Format | null | undefined): Format {
+  getDisplayFormat(displayFormat: Format | null): Format {
     const { type = 'date' } = this.dateBox.option();
     const globalFormat = type === 'date' || type === 'datetime'
       ? getGlobalFormatByDataType(type)
diff --git a/packages/devextreme/js/__internal/ui/html_editor/html_editor.ts b/packages/devextreme/js/__internal/ui/html_editor/html_editor.ts
index 6c7f8443201f..f39ca4d681a2 100644
--- a/packages/devextreme/js/__internal/ui/html_editor/html_editor.ts
+++ b/packages/devextreme/js/__internal/ui/html_editor/html_editor.ts
@@ -113,16 +113,12 @@ class HtmlEditor extends Editor<Properties> {
 
     return {
       ...super._getDefaultOptions(),
-      // @ts-expect-error undefined is not allowed
-      aiIntegration: null,
+      aiIntegration: undefined,
       allowSoftLineBreak: false,
-      // @ts-expect-error undefined is not allowed
-      converter: null,
-      // @ts-expect-error undefined is not allowed
-      customizeModules: null,
+      converter: undefined,
+      customizeModules: undefined,
       focusStateEnabled: true,
-      // @ts-expect-error undefined is not allowed
-      imageUpload: null,
+      imageUpload: undefined,
       mediaResizing: null,
       mentions: null,
       placeholder: '',
diff --git a/packages/devextreme/js/__internal/ui/map/map.ts b/packages/devextreme/js/__internal/ui/map/map.ts
index bc80c316c874..89fbbc07fda2 100644
--- a/packages/devextreme/js/__internal/ui/map/map.ts
+++ b/packages/devextreme/js/__internal/ui/map/map.ts
@@ -103,9 +103,7 @@ class Map extends Widget<MapProperties> {
       },
       controls: false,
       onReady: null,
-      // for internal use only
-      // @ts-expect-error ts-error
-      onUpdated: null,
+      onUpdated: undefined,
       onClick: null,
     };
   }
diff --git a/packages/devextreme/js/ui/form.d.ts b/packages/devextreme/js/ui/form.d.ts
index 308d93bd1a7d..618f1e3f51aa 100644
--- a/packages/devextreme/js/ui/form.d.ts
+++ b/packages/devextreme/js/ui/form.d.ts
@@ -273,7 +273,7 @@ export interface dxFormOptions extends WidgetOptions<dxForm> {
      * @action
      * @public
      */
-     onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void) | null;
+    onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -281,7 +281,7 @@ export interface dxFormOptions extends WidgetOptions<dxForm> {
      * @action
      * @public
      */
-     onFieldDataChanged?: ((e: FieldDataChangedEvent) => void) | null;
+    onFieldDataChanged?: ((e: FieldDataChangedEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -289,7 +289,7 @@ export interface dxFormOptions extends WidgetOptions<dxForm> {
      * @action
      * @public
      */
-     onSmartPasting?: ((e: SmartPastingEvent) => void) | null;
+    onSmartPasting?: ((e: SmartPastingEvent) => void) | null;
     /**
      * @docid
      * @default null
@@ -297,7 +297,7 @@ export interface dxFormOptions extends WidgetOptions<dxForm> {
      * @action
      * @public
      */
-     onSmartPasted?: ((e: SmartPastedEvent) => void) | null;
+    onSmartPasted?: ((e: SmartPastedEvent) => void) | null;
     /**
      * @docid
      * @default "optional"

From 96146f60cdf2fef411c9105e831f12c0fe048e86 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:45 +0300
Subject: [PATCH 068/100] remove some extra spacing and remove some ts-errors

---
 .../__internal/ui/form/form.layout_manager.ts |  9 +-
 .../devextreme/js/__internal/ui/form/form.ts  |  3 +-
 packages/devextreme/js/ui/form.d.ts           | 30 +++---
 .../devextreme/js/viz/core/base_widget.d.ts   | 94 +++++++++----------
 4 files changed, 66 insertions(+), 70 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/form/form.layout_manager.ts b/packages/devextreme/js/__internal/ui/form/form.layout_manager.ts
index 9bf5bb485ac6..936a79fb3770 100644
--- a/packages/devextreme/js/__internal/ui/form/form.layout_manager.ts
+++ b/packages/devextreme/js/__internal/ui/form/form.layout_manager.ts
@@ -149,16 +149,13 @@ class LayoutManager extends Widget<LayoutManagerProperties> {
       readOnly: false,
       colCount: 1,
       labelLocation: 'left',
-      // @ts-expect-error ts-error
-      onFieldDataChanged: null,
+      onFieldDataChanged: undefined,
       onEditorEnterKey: null,
-      // @ts-expect-error ts-error
-      customizeItem: null,
+      customizeItem: undefined,
       alignItemLabels: true,
       minColWidth: MIN_COLUMN_WIDTH,
       showRequiredMark: true,
-      // @ts-expect-error ts-error
-      screenByWidth: null,
+      screenByWidth: undefined,
       showOptionalMark: false,
       requiredMark: '*',
       labelMode: 'outside',
diff --git a/packages/devextreme/js/__internal/ui/form/form.ts b/packages/devextreme/js/__internal/ui/form/form.ts
index 79ecf17173dc..796dd6985ea8 100644
--- a/packages/devextreme/js/__internal/ui/form/form.ts
+++ b/packages/devextreme/js/__internal/ui/form/form.ts
@@ -204,8 +204,7 @@ class Form extends Widget<FormProperties> {
       labelLocation: 'left',
       readOnly: false,
       onFieldDataChanged: null,
-      // @ts-expect-error ts-error
-      customizeItem: null,
+      customizeItem: undefined,
       onEditorEnterKey: null,
       minColWidth: 200,
       alignItemLabels: true,
diff --git a/packages/devextreme/js/ui/form.d.ts b/packages/devextreme/js/ui/form.d.ts
index 618f1e3f51aa..0d95ec7e7c9a 100644
--- a/packages/devextreme/js/ui/form.d.ts
+++ b/packages/devextreme/js/ui/form.d.ts
@@ -759,11 +759,11 @@ export interface dxFormSimpleItem {
      * @public
      */
     itemType?: FormItemType;
-     /**
-      * @docid
-      * @public
-      */
-     label?: {
+    /**
+     * @docid
+     * @public
+     */
+    label?: {
       /**
        * @docid
        * @default "left"
@@ -810,11 +810,11 @@ export interface dxFormSimpleItem {
      * @public
      */
     template?: template | ((data: SimpleItemTemplateData, itemElement: DxElement) => string | UserDefinedElement);
-     /**
-      * @docid
-      * @public
-      */
-     validationRules?: Array<RequiredRule | NumericRule | RangeRule | StringLengthRule | CustomRule | CompareRule | PatternRule | EmailRule | AsyncRule>;
+    /**
+     * @docid
+     * @public
+     */
+    validationRules?: Array<RequiredRule | NumericRule | RangeRule | StringLengthRule | CustomRule | CompareRule | PatternRule | EmailRule | AsyncRule>;
     /**
      * @docid
      * @default true
@@ -870,11 +870,11 @@ export interface dxFormTabbedItem {
      * @public
      */
     tabPanelOptions?: dxTabPanelOptions | undefined;
-     /**
-      * @docid
-      * @public
-      */
-     tabs?: Array<{
+    /**
+     * @docid
+     * @public
+     */
+    tabs?: Array<{
       /**
        * @docid
        * @default true
diff --git a/packages/devextreme/js/viz/core/base_widget.d.ts b/packages/devextreme/js/viz/core/base_widget.d.ts
index 49b11962993b..b1de914aab3b 100644
--- a/packages/devextreme/js/viz/core/base_widget.d.ts
+++ b/packages/devextreme/js/viz/core/base_widget.d.ts
@@ -112,46 +112,46 @@ export interface BaseWidgetOptions<TComponent> extends DOMComponentOptions<TComp
      * @public
      */
     margin?: BaseWidgetMargin;
-     /**
-      * @docid
-      * @default undefined
-      * @notUsedInTheme
-      * @action
-      * @public
-      */
-     onDrawn?: ((e: EventInfo<TComponent>) => void) | undefined;
-     /**
-      * @docid
-      * @default undefined
-      * @action
-      * @public
-      */
-     onExported?: ((e: EventInfo<TComponent>) => void) | undefined;
-     /**
-      * @docid
-      * @type_function_param1 e:object
-      * @type_function_param1_field component:this
-      * @default undefined
-      * @action
-      * @public
-      */
-     onExporting?: ((e: EventInfo<TComponent> & ExportInfo) => void) | undefined;
-     /**
-      * @docid
-      * @type_function_param1 e:{viz/core/base_widget:FileSavingEventInfo}
-      * @default undefined
-      * @action
-      * @public
-      */
-     onFileSaving?: ((e: FileSavingEventInfo<TComponent>) => void) | undefined;
-     /**
-      * @docid
-      * @type_function_param1 e:object
-      * @type_function_param1_field component:this
-      * @action
-      * @public
-      */
-     onIncidentOccurred?: ((e: EventInfo<TComponent> & IncidentInfo) => void);
+    /**
+     * @docid
+     * @default undefined
+     * @notUsedInTheme
+     * @action
+     * @public
+     */
+    onDrawn?: ((e: EventInfo<TComponent>) => void) | undefined;
+    /**
+     * @docid
+     * @default undefined
+     * @action
+     * @public
+     */
+    onExported?: ((e: EventInfo<TComponent>) => void) | undefined;
+    /**
+     * @docid
+     * @type_function_param1 e:object
+     * @type_function_param1_field component:this
+     * @default undefined
+     * @action
+     * @public
+     */
+    onExporting?: ((e: EventInfo<TComponent> & ExportInfo) => void) | undefined;
+    /**
+     * @docid
+     * @type_function_param1 e:{viz/core/base_widget:FileSavingEventInfo}
+     * @default undefined
+     * @action
+     * @public
+     */
+    onFileSaving?: ((e: FileSavingEventInfo<TComponent>) => void) | undefined;
+    /**
+     * @docid
+     * @type_function_param1 e:object
+     * @type_function_param1_field component:this
+     * @action
+     * @public
+     */
+    onIncidentOccurred?: ((e: EventInfo<TComponent> & IncidentInfo) => void);
     /**
      * @docid
      * @default false
@@ -418,9 +418,9 @@ export interface BaseWidgetTitle {
        */
       offset?: number;
       /**
-      * @docid BaseWidgetOptions.title.subtitle.text
-      * @default undefined
-      */
+       * @docid BaseWidgetOptions.title.subtitle.text
+       * @default undefined
+       */
       text?: string | undefined;
       /**
        * @docid BaseWidgetOptions.title.subtitle.textOverflow
@@ -434,10 +434,10 @@ export interface BaseWidgetTitle {
       wordWrap?: WordWrap;
     } | string;
     /**
-    * @docid BaseWidgetOptions.title.text
-    * @default undefined
-    * @public
-    */
+     * @docid BaseWidgetOptions.title.text
+     * @default undefined
+     * @public
+     */
     text?: string | undefined;
     /**
      * @docid BaseWidgetOptions.title.textOverflow

From 86d301f643a42e3bad9fe11201832d104718ae0f Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:45 +0300
Subject: [PATCH 069/100] fix by review

---
 packages/devextreme/js/__internal/ui/list/list.edit.search.ts | 3 +--
 packages/devextreme/js/__internal/ui/map/map.ts               | 3 +--
 packages/devextreme/js/ui/form.d.ts                           | 2 +-
 3 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/list/list.edit.search.ts b/packages/devextreme/js/__internal/ui/list/list.edit.search.ts
index 9c71ea5a5f9f..f590d87d9e7f 100644
--- a/packages/devextreme/js/__internal/ui/list/list.edit.search.ts
+++ b/packages/devextreme/js/__internal/ui/list/list.edit.search.ts
@@ -36,8 +36,7 @@ class ListSearch extends ListEdit {
   _getDefaultOptions(): ListBaseProperties {
     return {
       ...super._getDefaultOptions(),
-      // @ts-expect-error ts-error
-      searchMode: '',
+      searchMode: undefined,
       searchExpr: null,
       searchValue: '',
       searchEnabled: false,
diff --git a/packages/devextreme/js/__internal/ui/map/map.ts b/packages/devextreme/js/__internal/ui/map/map.ts
index 89fbbc07fda2..8cc235559c25 100644
--- a/packages/devextreme/js/__internal/ui/map/map.ts
+++ b/packages/devextreme/js/__internal/ui/map/map.ts
@@ -85,8 +85,7 @@ class Map extends Widget<MapProperties> {
       provider: 'google',
       autoAdjust: true,
       markers: [],
-      // @ts-expect-error ts-error
-      markerIconSrc: null,
+      markerIconSrc: undefined,
       onMarkerAdded: null,
       onMarkerRemoved: null,
       routes: [],
diff --git a/packages/devextreme/js/ui/form.d.ts b/packages/devextreme/js/ui/form.d.ts
index 0d95ec7e7c9a..3286548c9d33 100644
--- a/packages/devextreme/js/ui/form.d.ts
+++ b/packages/devextreme/js/ui/form.d.ts
@@ -326,7 +326,7 @@ export interface dxFormOptions extends WidgetOptions<dxForm> {
      * @docid
      * @public
      */
-     screenByWidth?: Function;
+    screenByWidth?: Function;
     /**
      * @docid
      * @default false

From 258143c0a15de55f9546001b2f4130ce8278b0b8 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:46 +0300
Subject: [PATCH 070/100] update demos interface import for react

---
 apps/demos/Demos/DateRangeBox/Formatting/React/App.tsx | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/apps/demos/Demos/DateRangeBox/Formatting/React/App.tsx b/apps/demos/Demos/DateRangeBox/Formatting/React/App.tsx
index 4e8e838f875d..f98797229b69 100644
--- a/apps/demos/Demos/DateRangeBox/Formatting/React/App.tsx
+++ b/apps/demos/Demos/DateRangeBox/Formatting/React/App.tsx
@@ -1,13 +1,13 @@
 import React from 'react';
 import DateRangeBox from 'devextreme-react/date-range-box';
-import type { DateRangeBoxTypes } from 'devextreme-react/date-range-box';
+import type { IDateRangeBoxOptions } from 'devextreme-react/date-range-box';
 
 const msInDay = 1000 * 60 * 60 * 24;
 const now = new Date();
 const startDate = new Date(now.getTime() - msInDay * 3);
 const endDate = new Date(now.getTime() + msInDay * 3);
 
-const commonSettings: DateRangeBoxTypes.Properties = {
+const commonSettings: IDateRangeBoxOptions = {
   showClearButton: true,
   useMaskBehavior: true,
   openOnFieldClick: false,

From 67a8b7d24005517fc99a42ba151f6772a4d43c42 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:46 +0300
Subject: [PATCH 071/100] fix by review

---
 .../js/__internal/ui/date_box/m_date_box.strategy.ts           | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.ts b/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.ts
index 548f7dfaaa25..71c578489c08 100644
--- a/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.ts
+++ b/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.ts
@@ -63,8 +63,7 @@ class DateBoxStrategy extends (Class.inherit({}) as new() => {}) {
   }
 
   getDisplayFormat(displayFormat?: Format | null): Format {
-    // eslint-disable-next-line @typescript-eslint/prefer-nullish-coalescing
-    return displayFormat || 'shortdate';
+    return displayFormat ?? 'shortdate';
   }
 
   supportedKeys(): Record<string, (e: KeyboardEvent) => void> {

From 30f55d53e6a27f7f9a93bde9b8fbf3b9d26edc3b Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:46 +0300
Subject: [PATCH 072/100] fix by review

---
 .../devextreme/js/__internal/ui/date_box/m_date_box.strategy.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.ts b/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.ts
index 71c578489c08..74a3c9c27e85 100644
--- a/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.ts
+++ b/packages/devextreme/js/__internal/ui/date_box/m_date_box.strategy.ts
@@ -63,7 +63,7 @@ class DateBoxStrategy extends (Class.inherit({}) as new() => {}) {
   }
 
   getDisplayFormat(displayFormat?: Format | null): Format {
-    return displayFormat ?? 'shortdate';
+    return displayFormat || 'shortdate';
   }
 
   supportedKeys(): Record<string, (e: KeyboardEvent) => void> {

From 1b6883e978745c4fecb8c11aa5ad1fd6f511ae5b Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:47 +0300
Subject: [PATCH 073/100] revert frameworks generation

---
 .../generate-components/framework-handlers.ts | 47 +------------------
 1 file changed, 1 insertion(+), 46 deletions(-)

diff --git a/packages/nx-infra-plugin/src/executors/generate-components/framework-handlers.ts b/packages/nx-infra-plugin/src/executors/generate-components/framework-handlers.ts
index 28632a59ecf6..3d84e6161667 100644
--- a/packages/nx-infra-plugin/src/executors/generate-components/framework-handlers.ts
+++ b/packages/nx-infra-plugin/src/executors/generate-components/framework-handlers.ts
@@ -50,50 +50,6 @@ function createReactHandler(): FrameworkHandler {
   };
 }
 
-function cleanVueMetadata(metaData: any): any {
-  if (!metaData) return metaData;
-
-  const cleanProp = (prop: any) => {
-    if (prop && Array.isArray(prop.types)) {
-      const isFunction =
-        /^on[A-Z]/.test(prop.name)
-        || prop.types.some(
-          (t: any) => t && (t.type === 'Function' || t.acceptableValueType === 'Function'),
-        );
-      if (isFunction) {
-        prop.types = prop.types.filter((t: any) => t && t.type !== 'Null');
-      }
-    }
-    if (prop && Array.isArray(prop.props)) {
-      prop.props.forEach(cleanProp);
-    }
-  };
-
-  if (Array.isArray(metaData.widgets)) {
-    metaData.widgets.forEach((widget: any) => {
-      if (widget) {
-        if (Array.isArray(widget.options)) {
-          widget.options.forEach(cleanProp);
-        }
-        if (Array.isArray(widget.complexOptions)) {
-          widget.complexOptions.forEach((co: any) => {
-            if (co) {
-              if (Array.isArray(co.options)) {
-                co.options.forEach(cleanProp);
-              }
-              if (Array.isArray(co.props)) {
-                co.props.forEach(cleanProp);
-              }
-            }
-          });
-        }
-      }
-    });
-  }
-
-  return metaData;
-}
-
 function createVueHandler(): FrameworkHandler {
   return {
     getDefaults: () => ({
@@ -103,10 +59,9 @@ function createVueHandler(): FrameworkHandler {
 
     executeGeneration: async (generateFunction, config, metaData) => {
       const componentGeneratorTplConfig = config.componentGeneratorTplConfig || {};
-      const cleanedMetaData = cleanVueMetadata(JSON.parse(JSON.stringify(metaData)));
 
       await generateFunction(
-        cleanedMetaData,
+        metaData,
         componentGeneratorTplConfig,
         config.out,
         config.widgetsPackage,

From bc9ff687117c1279904947c2c4556c02ae8dea3b Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:47 +0300
Subject: [PATCH 074/100] fix onContentReady for Widget and SpeedDialAction

---
 packages/devextreme/js/__internal/core/widget/widget.ts       | 2 +-
 .../js/__internal/ui/speed_dial_action/m_speed_dial_action.ts | 2 +-
 packages/devextreme/js/ui/speed_dial_action.d.ts              | 4 ++--
 packages/devextreme/js/ui/widget/ui.widget.d.ts               | 4 ++--
 4 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/packages/devextreme/js/__internal/core/widget/widget.ts b/packages/devextreme/js/__internal/core/widget/widget.ts
index fa32c17fc460..daa60050fe2a 100644
--- a/packages/devextreme/js/__internal/core/widget/widget.ts
+++ b/packages/devextreme/js/__internal/core/widget/widget.ts
@@ -125,7 +125,7 @@ class Widget<
       visible: true,
       hint: undefined,
       activeStateEnabled: false,
-      onContentReady: null,
+      onContentReady: undefined,
       hoverStateEnabled: false,
       focusStateEnabled: false,
       tabIndex: 0,
diff --git a/packages/devextreme/js/__internal/ui/speed_dial_action/m_speed_dial_action.ts b/packages/devextreme/js/__internal/ui/speed_dial_action/m_speed_dial_action.ts
index db190fcc6b08..b39b1981781b 100644
--- a/packages/devextreme/js/__internal/ui/speed_dial_action/m_speed_dial_action.ts
+++ b/packages/devextreme/js/__internal/ui/speed_dial_action/m_speed_dial_action.ts
@@ -20,7 +20,7 @@ class SpeedDialAction extends Widget<Properties> {
       label: '',
       visible: true,
       index: 0,
-      onContentReady: null,
+      onContentReady: undefined,
       activeStateEnabled: true,
       hoverStateEnabled: true,
       animation: {
diff --git a/packages/devextreme/js/ui/speed_dial_action.d.ts b/packages/devextreme/js/ui/speed_dial_action.d.ts
index fa6402bb1783..0d9c9948350c 100644
--- a/packages/devextreme/js/ui/speed_dial_action.d.ts
+++ b/packages/devextreme/js/ui/speed_dial_action.d.ts
@@ -92,12 +92,12 @@ export interface dxSpeedDialActionOptions extends WidgetOptions<dxSpeedDialActio
     onClick?: ((e: ClickEvent) => void);
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/speed_dial_action:ContentReadyEvent}
      * @action
      * @public
      */
-    onContentReady?: ((e: ContentReadyEvent) => void) | null;
+    onContentReady?: ((e: ContentReadyEvent) => void) | undefined;
     /**
      * @docid
      * @public
diff --git a/packages/devextreme/js/ui/widget/ui.widget.d.ts b/packages/devextreme/js/ui/widget/ui.widget.d.ts
index 314ea2c6398e..473e39ee7fe4 100644
--- a/packages/devextreme/js/ui/widget/ui.widget.d.ts
+++ b/packages/devextreme/js/ui/widget/ui.widget.d.ts
@@ -51,11 +51,11 @@ export interface WidgetOptions<TComponent> extends DOMComponentOptions<TComponen
     hoverStateEnabled?: boolean;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @action
      * @public
      */
-    onContentReady?: ((e: EventInfo<TComponent>) => void) | null;
+    onContentReady?: ((e: EventInfo<TComponent>) => void) | undefined;
     /**
      * @docid
      * @default 0

From 8d12047b8a26bde5dfe0e0114274308e86a5795a Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:48 +0300
Subject: [PATCH 075/100] update onResize, onResizeStart, onResizeEnd,
 onTitleRendered for popup

---
 packages/devextreme/js/__internal/ui/lookup.ts   |  2 +-
 .../devextreme/js/__internal/ui/popup/popup.ts   |  8 ++++----
 packages/devextreme/js/ui/popup.d.ts             | 16 ++++++++--------
 3 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/lookup.ts b/packages/devextreme/js/__internal/ui/lookup.ts
index a5d7d7026400..e667f4103273 100644
--- a/packages/devextreme/js/__internal/ui/lookup.ts
+++ b/packages/devextreme/js/__internal/ui/lookup.ts
@@ -158,7 +158,7 @@ class Lookup extends DropDownList<LookupProperties> {
         animation: {},
         title: '',
         titleTemplate: 'title',
-        onTitleRendered: null,
+        onTitleRendered: undefined,
         fullScreen: false,
         maxHeight: '100vh',
       },
diff --git a/packages/devextreme/js/__internal/ui/popup/popup.ts b/packages/devextreme/js/__internal/ui/popup/popup.ts
index ad97b1deecf6..1b0d64db9f93 100644
--- a/packages/devextreme/js/__internal/ui/popup/popup.ts
+++ b/packages/devextreme/js/__internal/ui/popup/popup.ts
@@ -255,14 +255,14 @@ class Popup<
       title: '',
       showTitle: true,
       titleTemplate: 'title',
-      onTitleRendered: null,
+      onTitleRendered: undefined,
       dragOutsideBoundary: false,
       dragEnabled: false,
       enableBodyScroll: true,
       outsideDragFactor: 0,
-      onResizeStart: null,
-      onResize: null,
-      onResizeEnd: null,
+      onResizeStart: undefined,
+      onResize: undefined,
+      onResizeEnd: undefined,
       resizeEnabled: false,
       toolbarItems: [],
       showCloseButton: false,
diff --git a/packages/devextreme/js/ui/popup.d.ts b/packages/devextreme/js/ui/popup.d.ts
index 2532cec2c23c..62964378bc51 100644
--- a/packages/devextreme/js/ui/popup.d.ts
+++ b/packages/devextreme/js/ui/popup.d.ts
@@ -146,43 +146,43 @@ export interface dxPopupOptions<TComponent> extends dxOverlayOptions<TComponent>
     height?: number | string;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:object
      * @type_function_param1_field component:this
      * @type_function_param1_field event:event
      * @action
      * @public
      */
-    onResize?: ((e: ResizeEvent) => void) | null;
+    onResize?: ((e: ResizeEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:object
      * @type_function_param1_field component:this
      * @type_function_param1_field event:event
      * @action
      * @public
      */
-    onResizeEnd?: ((e: ResizeEndEvent) => void) | null;
+    onResizeEnd?: ((e: ResizeEndEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:object
      * @type_function_param1_field component:this
      * @type_function_param1_field event:event
      * @action
      * @public
      */
-    onResizeStart?: ((e: ResizeStartEvent) => void) | null;
+    onResizeStart?: ((e: ResizeStartEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:object
      * @type_function_param1_field component:this
      * @action
      * @public
      */
-    onTitleRendered?: ((e: EventInfo<TComponent> & TitleRenderedInfo) => void) | null;
+    onTitleRendered?: ((e: EventInfo<TComponent> & TitleRenderedInfo) => void) | undefined;
     /**
      * @docid
      * @public

From 9d3783e65fe4be4e7c3665e0ccbfc90b49389a23 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:48 +0300
Subject: [PATCH 076/100] ButtonGroup: onSelectionChanged and onItemClick

---
 packages/devextreme/js/__internal/ui/button_group.ts | 4 ++--
 packages/devextreme/js/ui/button_group.d.ts          | 8 ++++----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/button_group.ts b/packages/devextreme/js/__internal/ui/button_group.ts
index 69f083399605..a5a5ebd9e582 100644
--- a/packages/devextreme/js/__internal/ui/button_group.ts
+++ b/packages/devextreme/js/__internal/ui/button_group.ts
@@ -177,8 +177,8 @@ class ButtonGroup extends Widget<Properties> {
       keyExpr: 'text',
       items: [],
       buttonTemplate: 'content',
-      onSelectionChanged: null,
-      onItemClick: null,
+      onSelectionChanged: undefined,
+      onItemClick: undefined,
     };
   }
 
diff --git a/packages/devextreme/js/ui/button_group.d.ts b/packages/devextreme/js/ui/button_group.d.ts
index ae67c96f405a..d2ca8b3d354b 100644
--- a/packages/devextreme/js/ui/button_group.d.ts
+++ b/packages/devextreme/js/ui/button_group.d.ts
@@ -121,20 +121,20 @@ export interface dxButtonGroupOptions extends WidgetOptions<dxButtonGroup> {
     keyExpr?: string | ((item: any) => any);
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/button_group:ItemClickEvent}
      * @action
      * @public
      */
-    onItemClick?: ((e: ItemClickEvent) => void) | null;
+    onItemClick?: ((e: ItemClickEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/button_group:SelectionChangedEvent}
      * @action
      * @public
      */
-    onSelectionChanged?: ((e: SelectionChangedEvent) => void) | null;
+    onSelectionChanged?: ((e: SelectionChangedEvent) => void) | undefined;
     /**
      * @docid
      * @fires dxButtonGroupOptions.onSelectionChanged

From 46e79438b5bdb5b9f42177ed8781cf3b20546bec Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:48 +0300
Subject: [PATCH 077/100] FileUploader: onBeforeSend, onDropZoneEnter,
 onDropZoneLeave, onFilesUploaded, onProgress, onUploadAborted, onUploaded,
 onUploadError, onUploadStarted, onValueChanged

---
 .../ui/file_uploader/file_uploader.ts         | 18 ++++-----
 packages/devextreme/js/ui/file_uploader.d.ts  | 40 +++++++++----------
 2 files changed, 29 insertions(+), 29 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/file_uploader/file_uploader.ts b/packages/devextreme/js/__internal/ui/file_uploader/file_uploader.ts
index 813ef46d3855..470becfce690 100644
--- a/packages/devextreme/js/__internal/ui/file_uploader/file_uploader.ts
+++ b/packages/devextreme/js/__internal/ui/file_uploader/file_uploader.ts
@@ -206,16 +206,16 @@ class FileUploader extends Editor<FileUploaderProperties> {
         uploadMethod: 'POST',
         uploadHeaders: {},
         uploadCustomData: {},
-        onBeforeSend: null,
-        onUploadStarted: null,
-        onUploaded: null,
-        onFilesUploaded: null,
+        onBeforeSend: undefined,
+        onUploadStarted: undefined,
+        onUploaded: undefined,
+        onFilesUploaded: undefined,
         onFileValidationError: null,
-        onProgress: null,
-        onUploadError: null,
-        onUploadAborted: null,
-        onDropZoneEnter: null,
-        onDropZoneLeave: null,
+        onProgress: undefined,
+        onUploadError: undefined,
+        onUploadAborted: undefined,
+        onDropZoneEnter: undefined,
+        onDropZoneLeave: undefined,
         onCancelButtonClick: null,
         onFileLimitReached: undefined,
         allowedFileExtensions: [],
diff --git a/packages/devextreme/js/ui/file_uploader.d.ts b/packages/devextreme/js/ui/file_uploader.d.ts
index 45ba4bcc306b..db0c7a6e6b38 100644
--- a/packages/devextreme/js/ui/file_uploader.d.ts
+++ b/packages/devextreme/js/ui/file_uploader.d.ts
@@ -302,84 +302,84 @@ export interface dxFileUploaderOptions extends EditorOptions<dxFileUploader> {
     name?: string;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/file_uploader:BeforeSendEvent}
      * @action
      * @public
      */
-    onBeforeSend?: ((e: BeforeSendEvent) => void) | null;
+    onBeforeSend?: ((e: BeforeSendEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/file_uploader:DropZoneEnterEvent}
      * @action
      * @public
      */
-    onDropZoneEnter?: ((e: DropZoneEnterEvent) => void) | null;
+    onDropZoneEnter?: ((e: DropZoneEnterEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/file_uploader:DropZoneLeaveEvent}
      * @action
      * @public
      */
-    onDropZoneLeave?: ((e: DropZoneLeaveEvent) => void) | null;
+    onDropZoneLeave?: ((e: DropZoneLeaveEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/file_uploader:FilesUploadedEvent}
      * @action
      * @public
      */
-    onFilesUploaded?: ((e: FilesUploadedEvent) => void) | null;
+    onFilesUploaded?: ((e: FilesUploadedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/file_uploader:ProgressEvent}
      * @action
      * @public
      */
-    onProgress?: ((e: ProgressEvent) => void) | null;
+    onProgress?: ((e: ProgressEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/file_uploader:UploadAbortedEvent}
      * @action
      * @public
      */
-    onUploadAborted?: ((e: UploadAbortedEvent) => void) | null;
+    onUploadAborted?: ((e: UploadAbortedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/file_uploader:UploadErrorEvent}
      * @action
      * @public
      */
-    onUploadError?: ((e: UploadErrorEvent) => void) | null;
+    onUploadError?: ((e: UploadErrorEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/file_uploader:UploadStartedEvent}
      * @action
      * @public
      */
-    onUploadStarted?: ((e: UploadStartedEvent) => void) | null;
+    onUploadStarted?: ((e: UploadStartedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/file_uploader:UploadedEvent}
      * @action
      * @public
      */
-    onUploaded?: ((e: UploadedEvent) => void) | null;
+    onUploaded?: ((e: UploadedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/file_uploader:ValueChangedEvent}
      * @action
      * @public
      */
-    onValueChanged?: ((e: ValueChangedEvent) => void) | null;
+    onValueChanged?: ((e: ValueChangedEvent) => void) | undefined;
     /**
      * @docid
      * @default 0

From 0fdeeda9155af9a5a87d0b67c9d35d3f1c461e04 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:49 +0300
Subject: [PATCH 078/100] Form: onFieldDataChanged, onEditorEnterKey,
 onSmartPasting, onSmartPasted

---
 .../devextreme/js/__internal/ui/form/form.ts  |  8 ++--
 packages/devextreme/js/ui/form.d.ts           | 16 +++----
 packages/devextreme/ts/dx.all.d.ts            | 48 ++++++++++---------
 3 files changed, 38 insertions(+), 34 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/form/form.ts b/packages/devextreme/js/__internal/ui/form/form.ts
index 796dd6985ea8..6db99fccc810 100644
--- a/packages/devextreme/js/__internal/ui/form/form.ts
+++ b/packages/devextreme/js/__internal/ui/form/form.ts
@@ -203,9 +203,9 @@ class Form extends Widget<FormProperties> {
       screenByWidth: defaultScreenFactorFunc,
       labelLocation: 'left',
       readOnly: false,
-      onFieldDataChanged: null,
+      onFieldDataChanged: undefined,
       customizeItem: undefined,
-      onEditorEnterKey: null,
+      onEditorEnterKey: undefined,
       minColWidth: 200,
       alignItemLabels: true,
       alignItemLabelsInAllGroups: true,
@@ -222,8 +222,8 @@ class Form extends Widget<FormProperties> {
       stylingMode: config().editorStylingMode,
       labelMode: 'outside',
       isDirty: false,
-      onSmartPasting: null,
-      onSmartPasted: null,
+      onSmartPasting: undefined,
+      onSmartPasted: undefined,
     };
   }
 
diff --git a/packages/devextreme/js/ui/form.d.ts b/packages/devextreme/js/ui/form.d.ts
index 3286548c9d33..dc798d919d77 100644
--- a/packages/devextreme/js/ui/form.d.ts
+++ b/packages/devextreme/js/ui/form.d.ts
@@ -268,36 +268,36 @@ export interface dxFormOptions extends WidgetOptions<dxForm> {
     minColWidth?: number;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/form:EditorEnterKeyEvent}
      * @action
      * @public
      */
-    onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void) | null;
+    onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/form:FieldDataChangedEvent}
      * @action
      * @public
      */
-    onFieldDataChanged?: ((e: FieldDataChangedEvent) => void) | null;
+    onFieldDataChanged?: ((e: FieldDataChangedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/form:SmartPastingEvent}
      * @action
      * @public
      */
-    onSmartPasting?: ((e: SmartPastingEvent) => void) | null;
+    onSmartPasting?: ((e: SmartPastingEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/form:SmartPastedEvent}
      * @action
      * @public
      */
-    onSmartPasted?: ((e: SmartPastedEvent) => void) | null;
+    onSmartPasted?: ((e: SmartPastedEvent) => void) | undefined;
     /**
      * @docid
      * @default "optional"
diff --git a/packages/devextreme/ts/dx.all.d.ts b/packages/devextreme/ts/dx.all.d.ts
index 9ca52bdaa46a..885873a2417a 100644
--- a/packages/devextreme/ts/dx.all.d.ts
+++ b/packages/devextreme/ts/dx.all.d.ts
@@ -10261,13 +10261,13 @@ declare module DevExpress.ui {
      */
     onItemClick?:
       | ((e: DevExpress.ui.dxButtonGroup.ItemClickEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxButtonGroupOptions.onSelectionChanged]
      */
     onSelectionChanged?:
       | ((e: DevExpress.ui.dxButtonGroup.SelectionChangedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxButtonGroupOptions.selectedItemKeys]
      */
@@ -18638,61 +18638,61 @@ declare module DevExpress.ui {
      */
     onBeforeSend?:
       | ((e: DevExpress.ui.dxFileUploader.BeforeSendEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxFileUploaderOptions.onDropZoneEnter]
      */
     onDropZoneEnter?:
       | ((e: DevExpress.ui.dxFileUploader.DropZoneEnterEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxFileUploaderOptions.onDropZoneLeave]
      */
     onDropZoneLeave?:
       | ((e: DevExpress.ui.dxFileUploader.DropZoneLeaveEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxFileUploaderOptions.onFilesUploaded]
      */
     onFilesUploaded?:
       | ((e: DevExpress.ui.dxFileUploader.FilesUploadedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxFileUploaderOptions.onProgress]
      */
     onProgress?:
       | ((e: DevExpress.ui.dxFileUploader.ProgressEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxFileUploaderOptions.onUploadAborted]
      */
     onUploadAborted?:
       | ((e: DevExpress.ui.dxFileUploader.UploadAbortedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxFileUploaderOptions.onUploadError]
      */
     onUploadError?:
       | ((e: DevExpress.ui.dxFileUploader.UploadErrorEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxFileUploaderOptions.onUploadStarted]
      */
     onUploadStarted?:
       | ((e: DevExpress.ui.dxFileUploader.UploadStartedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxFileUploaderOptions.onUploaded]
      */
     onUploaded?:
       | ((e: DevExpress.ui.dxFileUploader.UploadedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxFileUploaderOptions.onValueChanged]
      */
     onValueChanged?:
       | ((e: DevExpress.ui.dxFileUploader.ValueChangedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxFileUploaderOptions.progress]
      */
@@ -19620,23 +19620,25 @@ declare module DevExpress.ui {
      */
     onEditorEnterKey?:
       | ((e: DevExpress.ui.dxForm.EditorEnterKeyEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxFormOptions.onFieldDataChanged]
      */
     onFieldDataChanged?:
       | ((e: DevExpress.ui.dxForm.FieldDataChangedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxFormOptions.onSmartPasting]
      */
     onSmartPasting?:
       | ((e: DevExpress.ui.dxForm.SmartPastingEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxFormOptions.onSmartPasted]
      */
-    onSmartPasted?: ((e: DevExpress.ui.dxForm.SmartPastedEvent) => void) | null;
+    onSmartPasted?:
+      | ((e: DevExpress.ui.dxForm.SmartPastedEvent) => void)
+      | undefined;
     /**
      * [descr:dxFormOptions.optionalMark]
      */
@@ -25715,17 +25717,19 @@ declare module DevExpress.ui {
     /**
      * [descr:dxPopupOptions.onResize]
      */
-    onResize?: ((e: DevExpress.ui.dxPopup.ResizeEvent) => void) | null;
+    onResize?: ((e: DevExpress.ui.dxPopup.ResizeEvent) => void) | undefined;
     /**
      * [descr:dxPopupOptions.onResizeEnd]
      */
-    onResizeEnd?: ((e: DevExpress.ui.dxPopup.ResizeEndEvent) => void) | null;
+    onResizeEnd?:
+      | ((e: DevExpress.ui.dxPopup.ResizeEndEvent) => void)
+      | undefined;
     /**
      * [descr:dxPopupOptions.onResizeStart]
      */
     onResizeStart?:
       | ((e: DevExpress.ui.dxPopup.ResizeStartEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxPopupOptions.onTitleRendered]
      */
@@ -25734,7 +25738,7 @@ declare module DevExpress.ui {
           e: DevExpress.common.core.events.EventInfo<TComponent> &
             DevExpress.ui.dxPopup.TitleRenderedInfo
         ) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxPopupOptions.position]
      */
@@ -28779,7 +28783,7 @@ declare module DevExpress.ui {
      */
     onContentReady?:
       | ((e: DevExpress.ui.dxSpeedDialAction.ContentReadyEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxSpeedDialActionOptions.visible]
      */
@@ -34121,7 +34125,7 @@ declare module DevExpress.ui {
      */
     onContentReady?:
       | ((e: DevExpress.common.core.events.EventInfo<TComponent>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:WidgetOptions.tabIndex]
      */

From dccc9d431eb936aa8ece0f6e497cd2aa790c6dd5 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:49 +0300
Subject: [PATCH 079/100] tabPanel: onTitleHold, onTitleRendered

---
 .../devextreme/js/__internal/ui/tab_panel/tab_panel.ts    | 4 ++--
 packages/devextreme/js/ui/tab_panel.d.ts                  | 8 ++++----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/tab_panel/tab_panel.ts b/packages/devextreme/js/__internal/ui/tab_panel/tab_panel.ts
index f37e5338b8c1..0022f9aa56d5 100644
--- a/packages/devextreme/js/__internal/ui/tab_panel/tab_panel.ts
+++ b/packages/devextreme/js/__internal/ui/tab_panel/tab_panel.ts
@@ -116,8 +116,8 @@ class TabPanel extends MultiView<TabPanelProperties> {
       iconPosition: ICON_POSITION.start,
       stylingMode: STYLING_MODE.primary,
       onTitleClick: null,
-      onTitleHold: null,
-      onTitleRendered: null,
+      onTitleHold: undefined,
+      onTitleRendered: undefined,
       badgeExpr(data: Item): string | undefined {
         return data?.badge;
       },
diff --git a/packages/devextreme/js/ui/tab_panel.d.ts b/packages/devextreme/js/ui/tab_panel.d.ts
index f40e4dd15d2c..1995ed1f7781 100644
--- a/packages/devextreme/js/ui/tab_panel.d.ts
+++ b/packages/devextreme/js/ui/tab_panel.d.ts
@@ -227,20 +227,20 @@ export interface dxTabPanelOptions<
     onTitleClick?: ((e: TitleClickEvent<TItem, TKey>) => void) | string | null;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/tab_panel:TitleHoldEvent}
      * @action
      * @public
      */
-    onTitleHold?: ((e: TitleHoldEvent<TItem, TKey>) => void) | null;
+    onTitleHold?: ((e: TitleHoldEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/tab_panel:TitleRenderedEvent}
      * @action
      * @public
      */
-    onTitleRendered?: ((e: TitleRenderedEvent<TItem, TKey>) => void) | null;
+    onTitleRendered?: ((e: TitleRenderedEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
      * @default false

From c4e8234b75b34cea8bdadbaf6daedd8d3479d61c Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:50 +0300
Subject: [PATCH 080/100] Menu: onSubmenuShowing, onSubmenuShown,
 onSubmenuHiding, onSubmenuHidden

---
 .../devextreme/js/__internal/ui/menu/menu.ts     |  8 ++++----
 packages/devextreme/js/ui/menu.d.ts              | 16 ++++++++--------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/packages/devextreme/js/__internal/ui/menu/menu.ts b/packages/devextreme/js/__internal/ui/menu/menu.ts
index 82cf2399bd78..89e96af91c79 100644
--- a/packages/devextreme/js/__internal/ui/menu/menu.ts
+++ b/packages/devextreme/js/__internal/ui/menu/menu.ts
@@ -166,10 +166,10 @@ class Menu extends MenuBase<MenuProperties> {
         },
       },
       hideSubmenuOnMouseLeave: false,
-      onSubmenuShowing: null,
-      onSubmenuShown: null,
-      onSubmenuHiding: null,
-      onSubmenuHidden: null,
+      onSubmenuShowing: undefined,
+      onSubmenuShown: undefined,
+      onSubmenuHiding: undefined,
+      onSubmenuHidden: undefined,
       adaptivityEnabled: false,
     };
   }
diff --git a/packages/devextreme/js/ui/menu.d.ts b/packages/devextreme/js/ui/menu.d.ts
index 564894640825..694a8f3994ac 100644
--- a/packages/devextreme/js/ui/menu.d.ts
+++ b/packages/devextreme/js/ui/menu.d.ts
@@ -210,36 +210,36 @@ export interface dxMenuOptions<
     items?: Array<TItem>;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/menu:SubmenuHiddenEvent}
      * @action
      * @public
      */
-    onSubmenuHidden?: ((e: SubmenuHiddenEvent<TItem, TKey>) => void) | null;
+    onSubmenuHidden?: ((e: SubmenuHiddenEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/menu:SubmenuHidingEvent}
      * @action
      * @public
      */
-    onSubmenuHiding?: ((e: SubmenuHidingEvent<TItem, TKey>) => void) | null;
+    onSubmenuHiding?: ((e: SubmenuHidingEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/menu:SubmenuShowingEvent}
      * @action
      * @public
      */
-    onSubmenuShowing?: ((e: SubmenuShowingEvent<TItem, TKey>) => void) | null;
+    onSubmenuShowing?: ((e: SubmenuShowingEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/menu:SubmenuShownEvent}
      * @action
      * @public
      */
-    onSubmenuShown?: ((e: SubmenuShownEvent<TItem, TKey>) => void) | null;
+    onSubmenuShown?: ((e: SubmenuShownEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
      * @default "horizontal"

From b93003116c462700c13cfa5c0e48bf4d281189c8 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 18:44:50 +0300
Subject: [PATCH 081/100] regenerate-all

---
 .../autocomplete/nested/drop-down-options.ts  | 20 +++----
 .../src/ui/card-view/nested/form.ts           | 16 +++---
 .../ui/card-view/nested/tab-panel-options.ts  |  8 +--
 .../ui/chat/nested/file-uploader-options.ts   | 40 +++++++-------
 .../src/ui/chat/nested/suggestions.ts         |  8 +--
 .../ui/color-box/nested/drop-down-options.ts  | 20 +++----
 .../data-grid/nested/filter-builder-popup.ts  | 20 +++----
 .../src/ui/data-grid/nested/form.ts           | 16 +++---
 .../src/ui/data-grid/nested/popup.ts          | 20 +++----
 .../ui/data-grid/nested/tab-panel-options.ts  |  8 +--
 .../ui/date-box/nested/drop-down-options.ts   | 20 +++----
 .../nested/drop-down-options.ts               | 20 +++----
 .../drop-down-box/nested/drop-down-options.ts | 20 +++----
 .../nested/drop-down-options.ts               | 20 +++----
 .../src/ui/form/nested/tab-panel-options.ts   |  8 +--
 .../nested/file-uploader-options.ts           | 40 +++++++-------
 .../src/ui/nested/base/popup-options.ts       | 20 +++----
 .../src/ui/scheduler/nested/form.ts           | 16 +++---
 .../src/ui/scheduler/nested/options.ts        |  8 +--
 .../ui/scheduler/nested/tab-panel-options.ts  |  8 +--
 .../ui/select-box/nested/drop-down-options.ts | 20 +++----
 .../ui/tag-box/nested/drop-down-options.ts    | 20 +++----
 .../tree-list/nested/filter-builder-popup.ts  | 20 +++----
 .../src/ui/tree-list/nested/form.ts           | 16 +++---
 .../src/ui/tree-list/nested/popup.ts          | 20 +++----
 .../ui/tree-list/nested/tab-panel-options.ts  |  8 +--
 packages/devextreme-react/src/autocomplete.ts | 10 ++--
 packages/devextreme-react/src/button-group.ts |  2 +-
 packages/devextreme-react/src/card-view.ts    | 12 ++---
 packages/devextreme-react/src/chat.ts         | 24 ++++-----
 packages/devextreme-react/src/color-box.ts    | 10 ++--
 packages/devextreme-react/src/data-grid.ts    | 32 +++++------
 packages/devextreme-react/src/date-box.ts     | 10 ++--
 .../devextreme-react/src/date-range-box.ts    | 10 ++--
 .../devextreme-react/src/drop-down-box.ts     | 10 ++--
 .../devextreme-react/src/drop-down-button.ts  | 10 ++--
 .../devextreme-react/src/file-uploader.ts     | 20 +++----
 packages/devextreme-react/src/form.ts         | 10 ++--
 packages/devextreme-react/src/html-editor.ts  | 20 +++----
 packages/devextreme-react/src/menu.ts         |  8 +--
 packages/devextreme-react/src/scheduler.ts    | 16 +++---
 packages/devextreme-react/src/select-box.ts   | 10 ++--
 .../devextreme-react/src/speed-dial-action.ts |  2 +-
 packages/devextreme-react/src/tab-panel.ts    |  4 +-
 packages/devextreme-react/src/tag-box.ts      | 10 ++--
 packages/devextreme-react/src/tree-list.ts    | 32 +++++------
 packages/devextreme-react/src/tree-view.ts    | 14 ++---
 packages/devextreme-vue/src/accordion.ts      |  2 +-
 packages/devextreme-vue/src/calendar.ts       |  2 +-
 packages/devextreme-vue/src/card-view.ts      |  4 +-
 packages/devextreme-vue/src/context-menu.ts   | 10 ++--
 packages/devextreme-vue/src/data-grid.ts      |  8 +--
 packages/devextreme-vue/src/date-box.ts       |  4 +-
 packages/devextreme-vue/src/date-range-box.ts |  2 +-
 packages/devextreme-vue/src/diagram.ts        | 10 ++--
 packages/devextreme-vue/src/gantt.ts          | 54 +++++++++----------
 packages/devextreme-vue/src/list.ts           | 24 ++++-----
 packages/devextreme-vue/src/lookup.ts         |  8 +--
 packages/devextreme-vue/src/map.ts            | 10 ++--
 packages/devextreme-vue/src/progress-bar.ts   |  2 +-
 packages/devextreme-vue/src/range-slider.ts   |  2 +-
 packages/devextreme-vue/src/responsive-box.ts |  2 +-
 packages/devextreme-vue/src/scroll-view.ts    |  4 +-
 packages/devextreme-vue/src/tabs.ts           |  2 +-
 packages/devextreme-vue/src/tag-box.ts        |  6 +--
 packages/devextreme-vue/src/tree-list.ts      |  8 +--
 packages/devextreme/js/ui/tree_view.d.ts      | 36 ++++++-------
 packages/devextreme/ts/dx.all.d.ts            | 30 +++++------
 68 files changed, 483 insertions(+), 483 deletions(-)

diff --git a/packages/devextreme-angular/src/ui/autocomplete/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/autocomplete/nested/drop-down-options.ts
index d2cce43ed6ce..f373d816e3b9 100644
--- a/packages/devextreme-angular/src/ui/autocomplete/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/autocomplete/nested/drop-down-options.ts
@@ -220,10 +220,10 @@ export class DxoAutocompleteDropDownOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) | null {
+    get onContentReady(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoAutocompleteDropDownOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoAutocompleteDropDownOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/card-view/nested/form.ts b/packages/devextreme-angular/src/ui/card-view/nested/form.ts
index 03be45a1c645..ac9f83c8805e 100644
--- a/packages/devextreme-angular/src/ui/card-view/nested/form.ts
+++ b/packages/devextreme-angular/src/ui/card-view/nested/form.ts
@@ -223,18 +223,18 @@ export class DxoCardViewFormComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get onEditorEnterKey(): ((e: EditorEnterKeyEvent) => void) | null {
+    get onEditorEnterKey(): ((e: EditorEnterKeyEvent) => void) | undefined {
         return this._getOption('onEditorEnterKey');
     }
-    set onEditorEnterKey(value: ((e: EditorEnterKeyEvent) => void) | null) {
+    set onEditorEnterKey(value: ((e: EditorEnterKeyEvent) => void) | undefined) {
         this._setOption('onEditorEnterKey', value);
     }
 
     @Input()
-    get onFieldDataChanged(): ((e: FieldDataChangedEvent) => void) | null {
+    get onFieldDataChanged(): ((e: FieldDataChangedEvent) => void) | undefined {
         return this._getOption('onFieldDataChanged');
     }
-    set onFieldDataChanged(value: ((e: FieldDataChangedEvent) => void) | null) {
+    set onFieldDataChanged(value: ((e: FieldDataChangedEvent) => void) | undefined) {
         this._setOption('onFieldDataChanged', value);
     }
 
@@ -255,18 +255,18 @@ export class DxoCardViewFormComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get onSmartPasted(): ((e: SmartPastedEvent) => void) | null {
+    get onSmartPasted(): ((e: SmartPastedEvent) => void) | undefined {
         return this._getOption('onSmartPasted');
     }
-    set onSmartPasted(value: ((e: SmartPastedEvent) => void) | null) {
+    set onSmartPasted(value: ((e: SmartPastedEvent) => void) | undefined) {
         this._setOption('onSmartPasted', value);
     }
 
     @Input()
-    get onSmartPasting(): ((e: SmartPastingEvent) => void) | null {
+    get onSmartPasting(): ((e: SmartPastingEvent) => void) | undefined {
         return this._getOption('onSmartPasting');
     }
-    set onSmartPasting(value: ((e: SmartPastingEvent) => void) | null) {
+    set onSmartPasting(value: ((e: SmartPastingEvent) => void) | undefined) {
         this._setOption('onSmartPasting', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/card-view/nested/tab-panel-options.ts b/packages/devextreme-angular/src/ui/card-view/nested/tab-panel-options.ts
index 652d10f863de..26ab26ff9f6f 100644
--- a/packages/devextreme-angular/src/ui/card-view/nested/tab-panel-options.ts
+++ b/packages/devextreme-angular/src/ui/card-view/nested/tab-panel-options.ts
@@ -288,18 +288,18 @@ export class DxoCardViewTabPanelOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onTitleHold(): ((e: TitleHoldEvent) => void) | null {
+    get onTitleHold(): ((e: TitleHoldEvent) => void) | undefined {
         return this._getOption('onTitleHold');
     }
-    set onTitleHold(value: ((e: TitleHoldEvent) => void) | null) {
+    set onTitleHold(value: ((e: TitleHoldEvent) => void) | undefined) {
         this._setOption('onTitleHold', value);
     }
 
     @Input()
-    get onTitleRendered(): ((e: TitleRenderedEvent) => void) | null {
+    get onTitleRendered(): ((e: TitleRenderedEvent) => void) | undefined {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: TitleRenderedEvent) => void) | null) {
+    set onTitleRendered(value: ((e: TitleRenderedEvent) => void) | undefined) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/chat/nested/file-uploader-options.ts b/packages/devextreme-angular/src/ui/chat/nested/file-uploader-options.ts
index d1628274a300..0cd0ea4af1ee 100644
--- a/packages/devextreme-angular/src/ui/chat/nested/file-uploader-options.ts
+++ b/packages/devextreme-angular/src/ui/chat/nested/file-uploader-options.ts
@@ -244,10 +244,10 @@ export class DxoChatFileUploaderOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onBeforeSend(): ((e: BeforeSendEvent) => void) | null {
+    get onBeforeSend(): ((e: BeforeSendEvent) => void) | undefined {
         return this._getOption('onBeforeSend');
     }
-    set onBeforeSend(value: ((e: BeforeSendEvent) => void) | null) {
+    set onBeforeSend(value: ((e: BeforeSendEvent) => void) | undefined) {
         this._setOption('onBeforeSend', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoChatFileUploaderOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onDropZoneEnter(): ((e: DropZoneEnterEvent) => void) | null {
+    get onDropZoneEnter(): ((e: DropZoneEnterEvent) => void) | undefined {
         return this._getOption('onDropZoneEnter');
     }
-    set onDropZoneEnter(value: ((e: DropZoneEnterEvent) => void) | null) {
+    set onDropZoneEnter(value: ((e: DropZoneEnterEvent) => void) | undefined) {
         this._setOption('onDropZoneEnter', value);
     }
 
     @Input()
-    get onDropZoneLeave(): ((e: DropZoneLeaveEvent) => void) | null {
+    get onDropZoneLeave(): ((e: DropZoneLeaveEvent) => void) | undefined {
         return this._getOption('onDropZoneLeave');
     }
-    set onDropZoneLeave(value: ((e: DropZoneLeaveEvent) => void) | null) {
+    set onDropZoneLeave(value: ((e: DropZoneLeaveEvent) => void) | undefined) {
         this._setOption('onDropZoneLeave', value);
     }
 
     @Input()
-    get onFilesUploaded(): ((e: FilesUploadedEvent) => void) | null {
+    get onFilesUploaded(): ((e: FilesUploadedEvent) => void) | undefined {
         return this._getOption('onFilesUploaded');
     }
-    set onFilesUploaded(value: ((e: FilesUploadedEvent) => void) | null) {
+    set onFilesUploaded(value: ((e: FilesUploadedEvent) => void) | undefined) {
         this._setOption('onFilesUploaded', value);
     }
 
@@ -308,50 +308,50 @@ export class DxoChatFileUploaderOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onProgress(): ((e: ProgressEvent) => void) | null {
+    get onProgress(): ((e: ProgressEvent) => void) | undefined {
         return this._getOption('onProgress');
     }
-    set onProgress(value: ((e: ProgressEvent) => void) | null) {
+    set onProgress(value: ((e: ProgressEvent) => void) | undefined) {
         this._setOption('onProgress', value);
     }
 
     @Input()
-    get onUploadAborted(): ((e: UploadAbortedEvent) => void) | null {
+    get onUploadAborted(): ((e: UploadAbortedEvent) => void) | undefined {
         return this._getOption('onUploadAborted');
     }
-    set onUploadAborted(value: ((e: UploadAbortedEvent) => void) | null) {
+    set onUploadAborted(value: ((e: UploadAbortedEvent) => void) | undefined) {
         this._setOption('onUploadAborted', value);
     }
 
     @Input()
-    get onUploaded(): ((e: UploadedEvent) => void) | null {
+    get onUploaded(): ((e: UploadedEvent) => void) | undefined {
         return this._getOption('onUploaded');
     }
-    set onUploaded(value: ((e: UploadedEvent) => void) | null) {
+    set onUploaded(value: ((e: UploadedEvent) => void) | undefined) {
         this._setOption('onUploaded', value);
     }
 
     @Input()
-    get onUploadError(): ((e: UploadErrorEvent) => void) | null {
+    get onUploadError(): ((e: UploadErrorEvent) => void) | undefined {
         return this._getOption('onUploadError');
     }
-    set onUploadError(value: ((e: UploadErrorEvent) => void) | null) {
+    set onUploadError(value: ((e: UploadErrorEvent) => void) | undefined) {
         this._setOption('onUploadError', value);
     }
 
     @Input()
-    get onUploadStarted(): ((e: UploadStartedEvent) => void) | null {
+    get onUploadStarted(): ((e: UploadStartedEvent) => void) | undefined {
         return this._getOption('onUploadStarted');
     }
-    set onUploadStarted(value: ((e: UploadStartedEvent) => void) | null) {
+    set onUploadStarted(value: ((e: UploadStartedEvent) => void) | undefined) {
         this._setOption('onUploadStarted', value);
     }
 
     @Input()
-    get onValueChanged(): ((e: ValueChangedEvent) => void) | null {
+    get onValueChanged(): ((e: ValueChangedEvent) => void) | undefined {
         return this._getOption('onValueChanged');
     }
-    set onValueChanged(value: ((e: ValueChangedEvent) => void) | null) {
+    set onValueChanged(value: ((e: ValueChangedEvent) => void) | undefined) {
         this._setOption('onValueChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/chat/nested/suggestions.ts b/packages/devextreme-angular/src/ui/chat/nested/suggestions.ts
index 75c682e08651..acd4ac4fd0b1 100644
--- a/packages/devextreme-angular/src/ui/chat/nested/suggestions.ts
+++ b/packages/devextreme-angular/src/ui/chat/nested/suggestions.ts
@@ -158,10 +158,10 @@ export class DxoChatSuggestionsComponent extends NestedOption implements OnDestr
     }
 
     @Input()
-    get onItemClick(): ((e: ItemClickEvent) => void) | null {
+    get onItemClick(): ((e: ItemClickEvent) => void) | undefined {
         return this._getOption('onItemClick');
     }
-    set onItemClick(value: ((e: ItemClickEvent) => void) | null) {
+    set onItemClick(value: ((e: ItemClickEvent) => void) | undefined) {
         this._setOption('onItemClick', value);
     }
 
@@ -174,10 +174,10 @@ export class DxoChatSuggestionsComponent extends NestedOption implements OnDestr
     }
 
     @Input()
-    get onSelectionChanged(): ((e: SelectionChangedEvent) => void) | null {
+    get onSelectionChanged(): ((e: SelectionChangedEvent) => void) | undefined {
         return this._getOption('onSelectionChanged');
     }
-    set onSelectionChanged(value: ((e: SelectionChangedEvent) => void) | null) {
+    set onSelectionChanged(value: ((e: SelectionChangedEvent) => void) | undefined) {
         this._setOption('onSelectionChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/color-box/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/color-box/nested/drop-down-options.ts
index a3b5b32236bb..9188425d78c5 100644
--- a/packages/devextreme-angular/src/ui/color-box/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/color-box/nested/drop-down-options.ts
@@ -220,10 +220,10 @@ export class DxoColorBoxDropDownOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) | null {
+    get onContentReady(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoColorBoxDropDownOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoColorBoxDropDownOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/data-grid/nested/filter-builder-popup.ts b/packages/devextreme-angular/src/ui/data-grid/nested/filter-builder-popup.ts
index 69e55be0d73b..860ae607769b 100644
--- a/packages/devextreme-angular/src/ui/data-grid/nested/filter-builder-popup.ts
+++ b/packages/devextreme-angular/src/ui/data-grid/nested/filter-builder-popup.ts
@@ -220,10 +220,10 @@ export class DxoDataGridFilterBuilderPopupComponent extends NestedOption impleme
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) | null {
+    get onContentReady(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoDataGridFilterBuilderPopupComponent extends NestedOption impleme
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoDataGridFilterBuilderPopupComponent extends NestedOption impleme
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/data-grid/nested/form.ts b/packages/devextreme-angular/src/ui/data-grid/nested/form.ts
index 6e17e7983365..020f2251913f 100644
--- a/packages/devextreme-angular/src/ui/data-grid/nested/form.ts
+++ b/packages/devextreme-angular/src/ui/data-grid/nested/form.ts
@@ -223,18 +223,18 @@ export class DxoDataGridFormComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get onEditorEnterKey(): ((e: EditorEnterKeyEvent) => void) | null {
+    get onEditorEnterKey(): ((e: EditorEnterKeyEvent) => void) | undefined {
         return this._getOption('onEditorEnterKey');
     }
-    set onEditorEnterKey(value: ((e: EditorEnterKeyEvent) => void) | null) {
+    set onEditorEnterKey(value: ((e: EditorEnterKeyEvent) => void) | undefined) {
         this._setOption('onEditorEnterKey', value);
     }
 
     @Input()
-    get onFieldDataChanged(): ((e: FieldDataChangedEvent) => void) | null {
+    get onFieldDataChanged(): ((e: FieldDataChangedEvent) => void) | undefined {
         return this._getOption('onFieldDataChanged');
     }
-    set onFieldDataChanged(value: ((e: FieldDataChangedEvent) => void) | null) {
+    set onFieldDataChanged(value: ((e: FieldDataChangedEvent) => void) | undefined) {
         this._setOption('onFieldDataChanged', value);
     }
 
@@ -255,18 +255,18 @@ export class DxoDataGridFormComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get onSmartPasted(): ((e: SmartPastedEvent) => void) | null {
+    get onSmartPasted(): ((e: SmartPastedEvent) => void) | undefined {
         return this._getOption('onSmartPasted');
     }
-    set onSmartPasted(value: ((e: SmartPastedEvent) => void) | null) {
+    set onSmartPasted(value: ((e: SmartPastedEvent) => void) | undefined) {
         this._setOption('onSmartPasted', value);
     }
 
     @Input()
-    get onSmartPasting(): ((e: SmartPastingEvent) => void) | null {
+    get onSmartPasting(): ((e: SmartPastingEvent) => void) | undefined {
         return this._getOption('onSmartPasting');
     }
-    set onSmartPasting(value: ((e: SmartPastingEvent) => void) | null) {
+    set onSmartPasting(value: ((e: SmartPastingEvent) => void) | undefined) {
         this._setOption('onSmartPasting', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/data-grid/nested/popup.ts b/packages/devextreme-angular/src/ui/data-grid/nested/popup.ts
index 96b0f4e18ae3..866f906cf9cd 100644
--- a/packages/devextreme-angular/src/ui/data-grid/nested/popup.ts
+++ b/packages/devextreme-angular/src/ui/data-grid/nested/popup.ts
@@ -220,10 +220,10 @@ export class DxoDataGridPopupComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) | null {
+    get onContentReady(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoDataGridPopupComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoDataGridPopupComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/data-grid/nested/tab-panel-options.ts b/packages/devextreme-angular/src/ui/data-grid/nested/tab-panel-options.ts
index 73d97410ec3e..13355696e2e2 100644
--- a/packages/devextreme-angular/src/ui/data-grid/nested/tab-panel-options.ts
+++ b/packages/devextreme-angular/src/ui/data-grid/nested/tab-panel-options.ts
@@ -288,18 +288,18 @@ export class DxoDataGridTabPanelOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onTitleHold(): ((e: TitleHoldEvent) => void) | null {
+    get onTitleHold(): ((e: TitleHoldEvent) => void) | undefined {
         return this._getOption('onTitleHold');
     }
-    set onTitleHold(value: ((e: TitleHoldEvent) => void) | null) {
+    set onTitleHold(value: ((e: TitleHoldEvent) => void) | undefined) {
         this._setOption('onTitleHold', value);
     }
 
     @Input()
-    get onTitleRendered(): ((e: TitleRenderedEvent) => void) | null {
+    get onTitleRendered(): ((e: TitleRenderedEvent) => void) | undefined {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: TitleRenderedEvent) => void) | null) {
+    set onTitleRendered(value: ((e: TitleRenderedEvent) => void) | undefined) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/date-box/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/date-box/nested/drop-down-options.ts
index 84febd31181e..a00457afd746 100644
--- a/packages/devextreme-angular/src/ui/date-box/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/date-box/nested/drop-down-options.ts
@@ -220,10 +220,10 @@ export class DxoDateBoxDropDownOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) | null {
+    get onContentReady(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoDateBoxDropDownOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoDateBoxDropDownOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/date-range-box/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/date-range-box/nested/drop-down-options.ts
index 356e06d41ea8..b07460197ac7 100644
--- a/packages/devextreme-angular/src/ui/date-range-box/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/date-range-box/nested/drop-down-options.ts
@@ -220,10 +220,10 @@ export class DxoDateRangeBoxDropDownOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) | null {
+    get onContentReady(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoDateRangeBoxDropDownOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoDateRangeBoxDropDownOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/drop-down-box/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/drop-down-box/nested/drop-down-options.ts
index a8df643dbbee..67ee792adf7a 100644
--- a/packages/devextreme-angular/src/ui/drop-down-box/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/drop-down-box/nested/drop-down-options.ts
@@ -220,10 +220,10 @@ export class DxoDropDownBoxDropDownOptionsComponent extends NestedOption impleme
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) | null {
+    get onContentReady(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoDropDownBoxDropDownOptionsComponent extends NestedOption impleme
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoDropDownBoxDropDownOptionsComponent extends NestedOption impleme
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/drop-down-button/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/drop-down-button/nested/drop-down-options.ts
index 6810980ba662..143b330d9079 100644
--- a/packages/devextreme-angular/src/ui/drop-down-button/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/drop-down-button/nested/drop-down-options.ts
@@ -220,10 +220,10 @@ export class DxoDropDownButtonDropDownOptionsComponent extends NestedOption impl
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) | null {
+    get onContentReady(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoDropDownButtonDropDownOptionsComponent extends NestedOption impl
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoDropDownButtonDropDownOptionsComponent extends NestedOption impl
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/form/nested/tab-panel-options.ts b/packages/devextreme-angular/src/ui/form/nested/tab-panel-options.ts
index 5467ca0481dd..512f929bb3bb 100644
--- a/packages/devextreme-angular/src/ui/form/nested/tab-panel-options.ts
+++ b/packages/devextreme-angular/src/ui/form/nested/tab-panel-options.ts
@@ -288,18 +288,18 @@ export class DxoFormTabPanelOptionsComponent extends NestedOption implements OnD
     }
 
     @Input()
-    get onTitleHold(): ((e: TitleHoldEvent) => void) | null {
+    get onTitleHold(): ((e: TitleHoldEvent) => void) | undefined {
         return this._getOption('onTitleHold');
     }
-    set onTitleHold(value: ((e: TitleHoldEvent) => void) | null) {
+    set onTitleHold(value: ((e: TitleHoldEvent) => void) | undefined) {
         this._setOption('onTitleHold', value);
     }
 
     @Input()
-    get onTitleRendered(): ((e: TitleRenderedEvent) => void) | null {
+    get onTitleRendered(): ((e: TitleRenderedEvent) => void) | undefined {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: TitleRenderedEvent) => void) | null) {
+    set onTitleRendered(value: ((e: TitleRenderedEvent) => void) | undefined) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/html-editor/nested/file-uploader-options.ts b/packages/devextreme-angular/src/ui/html-editor/nested/file-uploader-options.ts
index 8aa7fef9c9eb..e1414cd4c297 100644
--- a/packages/devextreme-angular/src/ui/html-editor/nested/file-uploader-options.ts
+++ b/packages/devextreme-angular/src/ui/html-editor/nested/file-uploader-options.ts
@@ -244,10 +244,10 @@ export class DxoHtmlEditorFileUploaderOptionsComponent extends NestedOption impl
     }
 
     @Input()
-    get onBeforeSend(): ((e: BeforeSendEvent) => void) | null {
+    get onBeforeSend(): ((e: BeforeSendEvent) => void) | undefined {
         return this._getOption('onBeforeSend');
     }
-    set onBeforeSend(value: ((e: BeforeSendEvent) => void) | null) {
+    set onBeforeSend(value: ((e: BeforeSendEvent) => void) | undefined) {
         this._setOption('onBeforeSend', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoHtmlEditorFileUploaderOptionsComponent extends NestedOption impl
     }
 
     @Input()
-    get onDropZoneEnter(): ((e: DropZoneEnterEvent) => void) | null {
+    get onDropZoneEnter(): ((e: DropZoneEnterEvent) => void) | undefined {
         return this._getOption('onDropZoneEnter');
     }
-    set onDropZoneEnter(value: ((e: DropZoneEnterEvent) => void) | null) {
+    set onDropZoneEnter(value: ((e: DropZoneEnterEvent) => void) | undefined) {
         this._setOption('onDropZoneEnter', value);
     }
 
     @Input()
-    get onDropZoneLeave(): ((e: DropZoneLeaveEvent) => void) | null {
+    get onDropZoneLeave(): ((e: DropZoneLeaveEvent) => void) | undefined {
         return this._getOption('onDropZoneLeave');
     }
-    set onDropZoneLeave(value: ((e: DropZoneLeaveEvent) => void) | null) {
+    set onDropZoneLeave(value: ((e: DropZoneLeaveEvent) => void) | undefined) {
         this._setOption('onDropZoneLeave', value);
     }
 
     @Input()
-    get onFilesUploaded(): ((e: FilesUploadedEvent) => void) | null {
+    get onFilesUploaded(): ((e: FilesUploadedEvent) => void) | undefined {
         return this._getOption('onFilesUploaded');
     }
-    set onFilesUploaded(value: ((e: FilesUploadedEvent) => void) | null) {
+    set onFilesUploaded(value: ((e: FilesUploadedEvent) => void) | undefined) {
         this._setOption('onFilesUploaded', value);
     }
 
@@ -308,50 +308,50 @@ export class DxoHtmlEditorFileUploaderOptionsComponent extends NestedOption impl
     }
 
     @Input()
-    get onProgress(): ((e: ProgressEvent) => void) | null {
+    get onProgress(): ((e: ProgressEvent) => void) | undefined {
         return this._getOption('onProgress');
     }
-    set onProgress(value: ((e: ProgressEvent) => void) | null) {
+    set onProgress(value: ((e: ProgressEvent) => void) | undefined) {
         this._setOption('onProgress', value);
     }
 
     @Input()
-    get onUploadAborted(): ((e: UploadAbortedEvent) => void) | null {
+    get onUploadAborted(): ((e: UploadAbortedEvent) => void) | undefined {
         return this._getOption('onUploadAborted');
     }
-    set onUploadAborted(value: ((e: UploadAbortedEvent) => void) | null) {
+    set onUploadAborted(value: ((e: UploadAbortedEvent) => void) | undefined) {
         this._setOption('onUploadAborted', value);
     }
 
     @Input()
-    get onUploaded(): ((e: UploadedEvent) => void) | null {
+    get onUploaded(): ((e: UploadedEvent) => void) | undefined {
         return this._getOption('onUploaded');
     }
-    set onUploaded(value: ((e: UploadedEvent) => void) | null) {
+    set onUploaded(value: ((e: UploadedEvent) => void) | undefined) {
         this._setOption('onUploaded', value);
     }
 
     @Input()
-    get onUploadError(): ((e: UploadErrorEvent) => void) | null {
+    get onUploadError(): ((e: UploadErrorEvent) => void) | undefined {
         return this._getOption('onUploadError');
     }
-    set onUploadError(value: ((e: UploadErrorEvent) => void) | null) {
+    set onUploadError(value: ((e: UploadErrorEvent) => void) | undefined) {
         this._setOption('onUploadError', value);
     }
 
     @Input()
-    get onUploadStarted(): ((e: UploadStartedEvent) => void) | null {
+    get onUploadStarted(): ((e: UploadStartedEvent) => void) | undefined {
         return this._getOption('onUploadStarted');
     }
-    set onUploadStarted(value: ((e: UploadStartedEvent) => void) | null) {
+    set onUploadStarted(value: ((e: UploadStartedEvent) => void) | undefined) {
         this._setOption('onUploadStarted', value);
     }
 
     @Input()
-    get onValueChanged(): ((e: ValueChangedEvent) => void) | null {
+    get onValueChanged(): ((e: ValueChangedEvent) => void) | undefined {
         return this._getOption('onValueChanged');
     }
-    set onValueChanged(value: ((e: ValueChangedEvent) => void) | null) {
+    set onValueChanged(value: ((e: ValueChangedEvent) => void) | undefined) {
         this._setOption('onValueChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/nested/base/popup-options.ts b/packages/devextreme-angular/src/ui/nested/base/popup-options.ts
index f15ce3f4706a..3246c4729b35 100644
--- a/packages/devextreme-angular/src/ui/nested/base/popup-options.ts
+++ b/packages/devextreme-angular/src/ui/nested/base/popup-options.ts
@@ -162,10 +162,10 @@ export abstract class DxoPopupOptions extends NestedOption {
         this._setOption('minWidth', value);
     }
 
-    get onContentReady(): Function | null {
+    get onContentReady(): Function | undefined {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: Function | null) {
+    set onContentReady(value: Function | undefined) {
         this._setOption('onContentReady', value);
     }
 
@@ -204,24 +204,24 @@ export abstract class DxoPopupOptions extends NestedOption {
         this._setOption('onOptionChanged', value);
     }
 
-    get onResize(): Function | null {
+    get onResize(): Function | undefined {
         return this._getOption('onResize');
     }
-    set onResize(value: Function | null) {
+    set onResize(value: Function | undefined) {
         this._setOption('onResize', value);
     }
 
-    get onResizeEnd(): Function | null {
+    get onResizeEnd(): Function | undefined {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: Function | null) {
+    set onResizeEnd(value: Function | undefined) {
         this._setOption('onResizeEnd', value);
     }
 
-    get onResizeStart(): Function | null {
+    get onResizeStart(): Function | undefined {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: Function | null) {
+    set onResizeStart(value: Function | undefined) {
         this._setOption('onResizeStart', value);
     }
 
@@ -239,10 +239,10 @@ export abstract class DxoPopupOptions extends NestedOption {
         this._setOption('onShown', value);
     }
 
-    get onTitleRendered(): Function | null {
+    get onTitleRendered(): Function | undefined {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: Function | null) {
+    set onTitleRendered(value: Function | undefined) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/scheduler/nested/form.ts b/packages/devextreme-angular/src/ui/scheduler/nested/form.ts
index a01ad05395de..7747daf6103d 100644
--- a/packages/devextreme-angular/src/ui/scheduler/nested/form.ts
+++ b/packages/devextreme-angular/src/ui/scheduler/nested/form.ts
@@ -232,18 +232,18 @@ export class DxoSchedulerFormComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get onEditorEnterKey(): ((e: EditorEnterKeyEvent) => void) | null {
+    get onEditorEnterKey(): ((e: EditorEnterKeyEvent) => void) | undefined {
         return this._getOption('onEditorEnterKey');
     }
-    set onEditorEnterKey(value: ((e: EditorEnterKeyEvent) => void) | null) {
+    set onEditorEnterKey(value: ((e: EditorEnterKeyEvent) => void) | undefined) {
         this._setOption('onEditorEnterKey', value);
     }
 
     @Input()
-    get onFieldDataChanged(): ((e: FieldDataChangedEvent) => void) | null {
+    get onFieldDataChanged(): ((e: FieldDataChangedEvent) => void) | undefined {
         return this._getOption('onFieldDataChanged');
     }
-    set onFieldDataChanged(value: ((e: FieldDataChangedEvent) => void) | null) {
+    set onFieldDataChanged(value: ((e: FieldDataChangedEvent) => void) | undefined) {
         this._setOption('onFieldDataChanged', value);
     }
 
@@ -264,18 +264,18 @@ export class DxoSchedulerFormComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get onSmartPasted(): ((e: SmartPastedEvent) => void) | null {
+    get onSmartPasted(): ((e: SmartPastedEvent) => void) | undefined {
         return this._getOption('onSmartPasted');
     }
-    set onSmartPasted(value: ((e: SmartPastedEvent) => void) | null) {
+    set onSmartPasted(value: ((e: SmartPastedEvent) => void) | undefined) {
         this._setOption('onSmartPasted', value);
     }
 
     @Input()
-    get onSmartPasting(): ((e: SmartPastingEvent) => void) | null {
+    get onSmartPasting(): ((e: SmartPastingEvent) => void) | undefined {
         return this._getOption('onSmartPasting');
     }
-    set onSmartPasting(value: ((e: SmartPastingEvent) => void) | null) {
+    set onSmartPasting(value: ((e: SmartPastingEvent) => void) | undefined) {
         this._setOption('onSmartPasting', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/scheduler/nested/options.ts b/packages/devextreme-angular/src/ui/scheduler/nested/options.ts
index 51f8efd5003d..23266f3b4e18 100644
--- a/packages/devextreme-angular/src/ui/scheduler/nested/options.ts
+++ b/packages/devextreme-angular/src/ui/scheduler/nested/options.ts
@@ -159,10 +159,10 @@ export class DxoSchedulerOptionsComponent extends NestedOption implements OnDest
     }
 
     @Input()
-    get onItemClick(): ((e: ItemClickEvent) => void) | null {
+    get onItemClick(): ((e: ItemClickEvent) => void) | undefined {
         return this._getOption('onItemClick');
     }
-    set onItemClick(value: ((e: ItemClickEvent) => void) | null) {
+    set onItemClick(value: ((e: ItemClickEvent) => void) | undefined) {
         this._setOption('onItemClick', value);
     }
 
@@ -175,10 +175,10 @@ export class DxoSchedulerOptionsComponent extends NestedOption implements OnDest
     }
 
     @Input()
-    get onSelectionChanged(): ((e: SelectionChangedEvent) => void) | null {
+    get onSelectionChanged(): ((e: SelectionChangedEvent) => void) | undefined {
         return this._getOption('onSelectionChanged');
     }
-    set onSelectionChanged(value: ((e: SelectionChangedEvent) => void) | null) {
+    set onSelectionChanged(value: ((e: SelectionChangedEvent) => void) | undefined) {
         this._setOption('onSelectionChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/scheduler/nested/tab-panel-options.ts b/packages/devextreme-angular/src/ui/scheduler/nested/tab-panel-options.ts
index dadb4e16751e..07ee7ab81a9f 100644
--- a/packages/devextreme-angular/src/ui/scheduler/nested/tab-panel-options.ts
+++ b/packages/devextreme-angular/src/ui/scheduler/nested/tab-panel-options.ts
@@ -288,18 +288,18 @@ export class DxoSchedulerTabPanelOptionsComponent extends NestedOption implement
     }
 
     @Input()
-    get onTitleHold(): ((e: TitleHoldEvent) => void) | null {
+    get onTitleHold(): ((e: TitleHoldEvent) => void) | undefined {
         return this._getOption('onTitleHold');
     }
-    set onTitleHold(value: ((e: TitleHoldEvent) => void) | null) {
+    set onTitleHold(value: ((e: TitleHoldEvent) => void) | undefined) {
         this._setOption('onTitleHold', value);
     }
 
     @Input()
-    get onTitleRendered(): ((e: TitleRenderedEvent) => void) | null {
+    get onTitleRendered(): ((e: TitleRenderedEvent) => void) | undefined {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: TitleRenderedEvent) => void) | null) {
+    set onTitleRendered(value: ((e: TitleRenderedEvent) => void) | undefined) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/select-box/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/select-box/nested/drop-down-options.ts
index 054229cff009..9eafaf145b84 100644
--- a/packages/devextreme-angular/src/ui/select-box/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/select-box/nested/drop-down-options.ts
@@ -220,10 +220,10 @@ export class DxoSelectBoxDropDownOptionsComponent extends NestedOption implement
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) | null {
+    get onContentReady(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoSelectBoxDropDownOptionsComponent extends NestedOption implement
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoSelectBoxDropDownOptionsComponent extends NestedOption implement
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tag-box/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/tag-box/nested/drop-down-options.ts
index 17bbac691caf..d6eadff61355 100644
--- a/packages/devextreme-angular/src/ui/tag-box/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/tag-box/nested/drop-down-options.ts
@@ -220,10 +220,10 @@ export class DxoTagBoxDropDownOptionsComponent extends NestedOption implements O
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) | null {
+    get onContentReady(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoTagBoxDropDownOptionsComponent extends NestedOption implements O
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoTagBoxDropDownOptionsComponent extends NestedOption implements O
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tree-list/nested/filter-builder-popup.ts b/packages/devextreme-angular/src/ui/tree-list/nested/filter-builder-popup.ts
index 8cd9f5ee8c22..77565658a7a4 100644
--- a/packages/devextreme-angular/src/ui/tree-list/nested/filter-builder-popup.ts
+++ b/packages/devextreme-angular/src/ui/tree-list/nested/filter-builder-popup.ts
@@ -220,10 +220,10 @@ export class DxoTreeListFilterBuilderPopupComponent extends NestedOption impleme
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) | null {
+    get onContentReady(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoTreeListFilterBuilderPopupComponent extends NestedOption impleme
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoTreeListFilterBuilderPopupComponent extends NestedOption impleme
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tree-list/nested/form.ts b/packages/devextreme-angular/src/ui/tree-list/nested/form.ts
index 88833a80898b..16895302efae 100644
--- a/packages/devextreme-angular/src/ui/tree-list/nested/form.ts
+++ b/packages/devextreme-angular/src/ui/tree-list/nested/form.ts
@@ -223,18 +223,18 @@ export class DxoTreeListFormComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get onEditorEnterKey(): ((e: EditorEnterKeyEvent) => void) | null {
+    get onEditorEnterKey(): ((e: EditorEnterKeyEvent) => void) | undefined {
         return this._getOption('onEditorEnterKey');
     }
-    set onEditorEnterKey(value: ((e: EditorEnterKeyEvent) => void) | null) {
+    set onEditorEnterKey(value: ((e: EditorEnterKeyEvent) => void) | undefined) {
         this._setOption('onEditorEnterKey', value);
     }
 
     @Input()
-    get onFieldDataChanged(): ((e: FieldDataChangedEvent) => void) | null {
+    get onFieldDataChanged(): ((e: FieldDataChangedEvent) => void) | undefined {
         return this._getOption('onFieldDataChanged');
     }
-    set onFieldDataChanged(value: ((e: FieldDataChangedEvent) => void) | null) {
+    set onFieldDataChanged(value: ((e: FieldDataChangedEvent) => void) | undefined) {
         this._setOption('onFieldDataChanged', value);
     }
 
@@ -255,18 +255,18 @@ export class DxoTreeListFormComponent extends NestedOption implements OnDestroy,
     }
 
     @Input()
-    get onSmartPasted(): ((e: SmartPastedEvent) => void) | null {
+    get onSmartPasted(): ((e: SmartPastedEvent) => void) | undefined {
         return this._getOption('onSmartPasted');
     }
-    set onSmartPasted(value: ((e: SmartPastedEvent) => void) | null) {
+    set onSmartPasted(value: ((e: SmartPastedEvent) => void) | undefined) {
         this._setOption('onSmartPasted', value);
     }
 
     @Input()
-    get onSmartPasting(): ((e: SmartPastingEvent) => void) | null {
+    get onSmartPasting(): ((e: SmartPastingEvent) => void) | undefined {
         return this._getOption('onSmartPasting');
     }
-    set onSmartPasting(value: ((e: SmartPastingEvent) => void) | null) {
+    set onSmartPasting(value: ((e: SmartPastingEvent) => void) | undefined) {
         this._setOption('onSmartPasting', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tree-list/nested/popup.ts b/packages/devextreme-angular/src/ui/tree-list/nested/popup.ts
index e4063caf8adb..b3df44382136 100644
--- a/packages/devextreme-angular/src/ui/tree-list/nested/popup.ts
+++ b/packages/devextreme-angular/src/ui/tree-list/nested/popup.ts
@@ -220,10 +220,10 @@ export class DxoTreeListPopupComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get onContentReady(): ((e: EventInfo<any>) => void) | null {
+    get onContentReady(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onContentReady');
     }
-    set onContentReady(value: ((e: EventInfo<any>) => void) | null) {
+    set onContentReady(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onContentReady', value);
     }
 
@@ -268,26 +268,26 @@ export class DxoTreeListPopupComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResize(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResize');
     }
-    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResize(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResize', value);
     }
 
     @Input()
-    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeEnd(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeEnd');
     }
-    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeEnd(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeEnd', value);
     }
 
     @Input()
-    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null {
+    get onResizeStart(): ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined {
         return this._getOption('onResizeStart');
     }
-    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null) {
+    set onResizeStart(value: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined) {
         this._setOption('onResizeStart', value);
     }
 
@@ -308,10 +308,10 @@ export class DxoTreeListPopupComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null {
+    get onTitleRendered(): ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null) {
+    set onTitleRendered(value: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tree-list/nested/tab-panel-options.ts b/packages/devextreme-angular/src/ui/tree-list/nested/tab-panel-options.ts
index fab94d6ff70b..781b37800df4 100644
--- a/packages/devextreme-angular/src/ui/tree-list/nested/tab-panel-options.ts
+++ b/packages/devextreme-angular/src/ui/tree-list/nested/tab-panel-options.ts
@@ -288,18 +288,18 @@ export class DxoTreeListTabPanelOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onTitleHold(): ((e: TitleHoldEvent) => void) | null {
+    get onTitleHold(): ((e: TitleHoldEvent) => void) | undefined {
         return this._getOption('onTitleHold');
     }
-    set onTitleHold(value: ((e: TitleHoldEvent) => void) | null) {
+    set onTitleHold(value: ((e: TitleHoldEvent) => void) | undefined) {
         this._setOption('onTitleHold', value);
     }
 
     @Input()
-    get onTitleRendered(): ((e: TitleRenderedEvent) => void) | null {
+    get onTitleRendered(): ((e: TitleRenderedEvent) => void) | undefined {
         return this._getOption('onTitleRendered');
     }
-    set onTitleRendered(value: ((e: TitleRenderedEvent) => void) | null) {
+    set onTitleRendered(value: ((e: TitleRenderedEvent) => void) | undefined) {
         this._setOption('onTitleRendered', value);
     }
 
diff --git a/packages/devextreme-react/src/autocomplete.ts b/packages/devextreme-react/src/autocomplete.ts
index 5d2382588216..2941db9899ea 100644
--- a/packages/devextreme-react/src/autocomplete.ts
+++ b/packages/devextreme-react/src/autocomplete.ts
@@ -257,18 +257,18 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void) | null;
+  onContentReady?: ((e: EventInfo<any>) => void) | undefined;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
diff --git a/packages/devextreme-react/src/button-group.ts b/packages/devextreme-react/src/button-group.ts
index 2118f31d4597..babe593d231b 100644
--- a/packages/devextreme-react/src/button-group.ts
+++ b/packages/devextreme-react/src/button-group.ts
@@ -20,7 +20,7 @@ type IButtonGroupOptionsNarrowedEvents = {
   onContentReady?: ((e: ContentReadyEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
-  onItemClick?: ((e: ItemClickEvent) => void) | null;
+  onItemClick?: ((e: ItemClickEvent) => void) | undefined;
 }
 
 type IButtonGroupOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IButtonGroupOptionsNarrowedEvents> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/card-view.ts b/packages/devextreme-react/src/card-view.ts
index 5a180c8834dc..f1553c20454e 100644
--- a/packages/devextreme-react/src/card-view.ts
+++ b/packages/devextreme-react/src/card-view.ts
@@ -1317,12 +1317,12 @@ type IFormProps = React.PropsWithChildren<{
   minColWidth?: number;
   onContentReady?: ((e: FormContentReadyEvent) => void);
   onDisposing?: ((e: FormDisposingEvent) => void);
-  onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void) | null;
-  onFieldDataChanged?: ((e: FieldDataChangedEvent) => void) | null;
+  onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void) | undefined;
+  onFieldDataChanged?: ((e: FieldDataChangedEvent) => void) | undefined;
   onInitialized?: ((e: FormInitializedEvent) => void);
   onOptionChanged?: ((e: FormOptionChangedEvent) => void);
-  onSmartPasted?: ((e: SmartPastedEvent) => void) | null;
-  onSmartPasting?: ((e: SmartPastingEvent) => void) | null;
+  onSmartPasted?: ((e: SmartPastedEvent) => void) | undefined;
+  onSmartPasting?: ((e: SmartPastingEvent) => void) | undefined;
   optionalMark?: string;
   readOnly?: boolean;
   requiredMark?: string;
@@ -2583,8 +2583,8 @@ type ITabPanelOptionsProps = React.PropsWithChildren<{
   onSelectionChanged?: ((e: SelectionChangedEvent) => void);
   onSelectionChanging?: ((e: SelectionChangingEvent) => void);
   onTitleClick?: ((e: TitleClickEvent) => void);
-  onTitleHold?: ((e: TitleHoldEvent) => void) | null;
-  onTitleRendered?: ((e: TitleRenderedEvent) => void) | null;
+  onTitleHold?: ((e: TitleHoldEvent) => void) | undefined;
+  onTitleRendered?: ((e: TitleRenderedEvent) => void) | undefined;
   repaintChangesOnly?: boolean;
   rtlEnabled?: boolean;
   scrollByContent?: boolean;
diff --git a/packages/devextreme-react/src/chat.ts b/packages/devextreme-react/src/chat.ts
index 2cc4726b1254..b536ca714887 100644
--- a/packages/devextreme-react/src/chat.ts
+++ b/packages/devextreme-react/src/chat.ts
@@ -297,20 +297,20 @@ type IFileUploaderOptionsProps = React.PropsWithChildren<{
   minFileSize?: number;
   multiple?: boolean;
   name?: string;
-  onBeforeSend?: ((e: BeforeSendEvent) => void) | null;
+  onBeforeSend?: ((e: BeforeSendEvent) => void) | undefined;
   onContentReady?: ((e: ContentReadyEvent) => void);
   onDisposing?: ((e: FileUploaderDisposingEvent) => void);
-  onDropZoneEnter?: ((e: DropZoneEnterEvent) => void) | null;
-  onDropZoneLeave?: ((e: DropZoneLeaveEvent) => void) | null;
-  onFilesUploaded?: ((e: FilesUploadedEvent) => void) | null;
+  onDropZoneEnter?: ((e: DropZoneEnterEvent) => void) | undefined;
+  onDropZoneLeave?: ((e: DropZoneLeaveEvent) => void) | undefined;
+  onFilesUploaded?: ((e: FilesUploadedEvent) => void) | undefined;
   onInitialized?: ((e: FileUploaderInitializedEvent) => void);
   onOptionChanged?: ((e: OptionChangedEvent) => void);
-  onProgress?: ((e: ProgressEvent) => void) | null;
-  onUploadAborted?: ((e: UploadAbortedEvent) => void) | null;
-  onUploaded?: ((e: UploadedEvent) => void) | null;
-  onUploadError?: ((e: UploadErrorEvent) => void) | null;
-  onUploadStarted?: ((e: UploadStartedEvent) => void) | null;
-  onValueChanged?: ((e: ValueChangedEvent) => void) | null;
+  onProgress?: ((e: ProgressEvent) => void) | undefined;
+  onUploadAborted?: ((e: UploadAbortedEvent) => void) | undefined;
+  onUploaded?: ((e: UploadedEvent) => void) | undefined;
+  onUploadError?: ((e: UploadErrorEvent) => void) | undefined;
+  onUploadStarted?: ((e: UploadStartedEvent) => void) | undefined;
+  onValueChanged?: ((e: ValueChangedEvent) => void) | undefined;
   progress?: number;
   readOnly?: boolean;
   readyToUploadMessage?: string;
@@ -532,9 +532,9 @@ type ISuggestionsProps = React.PropsWithChildren<{
   onContentReady?: ((e: ButtonGroupContentReadyEvent) => void);
   onDisposing?: ((e: ButtonGroupDisposingEvent) => void);
   onInitialized?: ((e: ButtonGroupInitializedEvent) => void);
-  onItemClick?: ((e: ItemClickEvent) => void) | null;
+  onItemClick?: ((e: ItemClickEvent) => void) | undefined;
   onOptionChanged?: ((e: ButtonGroupOptionChangedEvent) => void);
-  onSelectionChanged?: ((e: SelectionChangedEvent) => void) | null;
+  onSelectionChanged?: ((e: SelectionChangedEvent) => void) | undefined;
   rtlEnabled?: boolean;
   selectedItemKeys?: Array<any>;
   selectedItems?: Array<any>;
diff --git a/packages/devextreme-react/src/color-box.ts b/packages/devextreme-react/src/color-box.ts
index dca43459b314..eada7abebd0e 100644
--- a/packages/devextreme-react/src/color-box.ts
+++ b/packages/devextreme-react/src/color-box.ts
@@ -248,18 +248,18 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void) | null;
+  onContentReady?: ((e: EventInfo<any>) => void) | undefined;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
diff --git a/packages/devextreme-react/src/data-grid.ts b/packages/devextreme-react/src/data-grid.ts
index d758dca58fb5..0ae6af241406 100644
--- a/packages/devextreme-react/src/data-grid.ts
+++ b/packages/devextreme-react/src/data-grid.ts
@@ -1680,18 +1680,18 @@ type IFilterBuilderPopupProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void) | null;
+  onContentReady?: ((e: EventInfo<any>) => void) | undefined;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
@@ -1905,12 +1905,12 @@ type IFormProps = React.PropsWithChildren<{
   minColWidth?: number;
   onContentReady?: ((e: FormContentReadyEvent) => void);
   onDisposing?: ((e: FormDisposingEvent) => void);
-  onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void) | null;
-  onFieldDataChanged?: ((e: FieldDataChangedEvent) => void) | null;
+  onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void) | undefined;
+  onFieldDataChanged?: ((e: FieldDataChangedEvent) => void) | undefined;
   onInitialized?: ((e: FormInitializedEvent) => void);
   onOptionChanged?: ((e: FormOptionChangedEvent) => void);
-  onSmartPasted?: ((e: SmartPastedEvent) => void) | null;
-  onSmartPasting?: ((e: SmartPastingEvent) => void) | null;
+  onSmartPasted?: ((e: SmartPastedEvent) => void) | undefined;
+  onSmartPasting?: ((e: SmartPastingEvent) => void) | undefined;
   optionalMark?: string;
   readOnly?: boolean;
   requiredMark?: string;
@@ -2874,18 +2874,18 @@ type IPopupProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void) | null;
+  onContentReady?: ((e: EventInfo<any>) => void) | undefined;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
@@ -3645,8 +3645,8 @@ type ITabPanelOptionsProps = React.PropsWithChildren<{
   onSelectionChanged?: ((e: SelectionChangedEvent) => void);
   onSelectionChanging?: ((e: SelectionChangingEvent) => void);
   onTitleClick?: ((e: TitleClickEvent) => void);
-  onTitleHold?: ((e: TitleHoldEvent) => void) | null;
-  onTitleRendered?: ((e: TitleRenderedEvent) => void) | null;
+  onTitleHold?: ((e: TitleHoldEvent) => void) | undefined;
+  onTitleRendered?: ((e: TitleRenderedEvent) => void) | undefined;
   repaintChangesOnly?: boolean;
   rtlEnabled?: boolean;
   scrollByContent?: boolean;
diff --git a/packages/devextreme-react/src/date-box.ts b/packages/devextreme-react/src/date-box.ts
index 6fb214feab28..1cb3f096d02b 100644
--- a/packages/devextreme-react/src/date-box.ts
+++ b/packages/devextreme-react/src/date-box.ts
@@ -341,18 +341,18 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void) | null;
+  onContentReady?: ((e: EventInfo<any>) => void) | undefined;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
diff --git a/packages/devextreme-react/src/date-range-box.ts b/packages/devextreme-react/src/date-range-box.ts
index 36a47cf76269..dcc3dd7e3f9a 100644
--- a/packages/devextreme-react/src/date-range-box.ts
+++ b/packages/devextreme-react/src/date-range-box.ts
@@ -346,18 +346,18 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void) | null;
+  onContentReady?: ((e: EventInfo<any>) => void) | undefined;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
diff --git a/packages/devextreme-react/src/drop-down-box.ts b/packages/devextreme-react/src/drop-down-box.ts
index c50a3ed74754..4f3882b854da 100644
--- a/packages/devextreme-react/src/drop-down-box.ts
+++ b/packages/devextreme-react/src/drop-down-box.ts
@@ -252,18 +252,18 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void) | null;
+  onContentReady?: ((e: EventInfo<any>) => void) | undefined;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
diff --git a/packages/devextreme-react/src/drop-down-button.ts b/packages/devextreme-react/src/drop-down-button.ts
index e6996d09dd2e..e49389fab13e 100644
--- a/packages/devextreme-react/src/drop-down-button.ts
+++ b/packages/devextreme-react/src/drop-down-button.ts
@@ -207,18 +207,18 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void) | null;
+  onContentReady?: ((e: EventInfo<any>) => void) | undefined;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
diff --git a/packages/devextreme-react/src/file-uploader.ts b/packages/devextreme-react/src/file-uploader.ts
index 1c8904840549..a788653dfe8b 100644
--- a/packages/devextreme-react/src/file-uploader.ts
+++ b/packages/devextreme-react/src/file-uploader.ts
@@ -14,19 +14,19 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 }
 
 type IFileUploaderOptionsNarrowedEvents = {
-  onBeforeSend?: ((e: BeforeSendEvent) => void) | null;
+  onBeforeSend?: ((e: BeforeSendEvent) => void) | undefined;
   onContentReady?: ((e: ContentReadyEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
-  onDropZoneEnter?: ((e: DropZoneEnterEvent) => void) | null;
-  onDropZoneLeave?: ((e: DropZoneLeaveEvent) => void) | null;
-  onFilesUploaded?: ((e: FilesUploadedEvent) => void) | null;
+  onDropZoneEnter?: ((e: DropZoneEnterEvent) => void) | undefined;
+  onDropZoneLeave?: ((e: DropZoneLeaveEvent) => void) | undefined;
+  onFilesUploaded?: ((e: FilesUploadedEvent) => void) | undefined;
   onInitialized?: ((e: InitializedEvent) => void);
-  onProgress?: ((e: ProgressEvent) => void) | null;
-  onUploadAborted?: ((e: UploadAbortedEvent) => void) | null;
-  onUploaded?: ((e: UploadedEvent) => void) | null;
-  onUploadError?: ((e: UploadErrorEvent) => void) | null;
-  onUploadStarted?: ((e: UploadStartedEvent) => void) | null;
-  onValueChanged?: ((e: ValueChangedEvent) => void) | null;
+  onProgress?: ((e: ProgressEvent) => void) | undefined;
+  onUploadAborted?: ((e: UploadAbortedEvent) => void) | undefined;
+  onUploaded?: ((e: UploadedEvent) => void) | undefined;
+  onUploadError?: ((e: UploadErrorEvent) => void) | undefined;
+  onUploadStarted?: ((e: UploadStartedEvent) => void) | undefined;
+  onValueChanged?: ((e: ValueChangedEvent) => void) | undefined;
 }
 
 type IFileUploaderOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IFileUploaderOptionsNarrowedEvents> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/form.ts b/packages/devextreme-react/src/form.ts
index b2abcf4341c8..cee44697237f 100644
--- a/packages/devextreme-react/src/form.ts
+++ b/packages/devextreme-react/src/form.ts
@@ -27,10 +27,10 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 type IFormOptionsNarrowedEvents = {
   onContentReady?: ((e: ContentReadyEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
-  onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void) | null;
+  onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void) | undefined;
   onInitialized?: ((e: InitializedEvent) => void);
-  onSmartPasted?: ((e: SmartPastedEvent) => void) | null;
-  onSmartPasting?: ((e: SmartPastingEvent) => void) | null;
+  onSmartPasted?: ((e: SmartPastedEvent) => void) | undefined;
+  onSmartPasting?: ((e: SmartPastingEvent) => void) | undefined;
 }
 
 type IFormOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IFormOptionsNarrowedEvents> & IHtmlOptions & {
@@ -870,8 +870,8 @@ type ITabPanelOptionsProps = React.PropsWithChildren<{
   onSelectionChanged?: ((e: SelectionChangedEvent) => void);
   onSelectionChanging?: ((e: SelectionChangingEvent) => void);
   onTitleClick?: ((e: TitleClickEvent) => void);
-  onTitleHold?: ((e: TitleHoldEvent) => void) | null;
-  onTitleRendered?: ((e: TitleRenderedEvent) => void) | null;
+  onTitleHold?: ((e: TitleHoldEvent) => void) | undefined;
+  onTitleRendered?: ((e: TitleRenderedEvent) => void) | undefined;
   repaintChangesOnly?: boolean;
   rtlEnabled?: boolean;
   scrollByContent?: boolean;
diff --git a/packages/devextreme-react/src/html-editor.ts b/packages/devextreme-react/src/html-editor.ts
index eb39ab9a0fed..30bb958bd627 100644
--- a/packages/devextreme-react/src/html-editor.ts
+++ b/packages/devextreme-react/src/html-editor.ts
@@ -158,20 +158,20 @@ type IFileUploaderOptionsProps = React.PropsWithChildren<{
   minFileSize?: number;
   multiple?: boolean;
   name?: string;
-  onBeforeSend?: ((e: BeforeSendEvent) => void) | null;
+  onBeforeSend?: ((e: BeforeSendEvent) => void) | undefined;
   onContentReady?: ((e: FileUploaderContentReadyEvent) => void);
   onDisposing?: ((e: FileUploaderDisposingEvent) => void);
-  onDropZoneEnter?: ((e: DropZoneEnterEvent) => void) | null;
-  onDropZoneLeave?: ((e: DropZoneLeaveEvent) => void) | null;
-  onFilesUploaded?: ((e: FilesUploadedEvent) => void) | null;
+  onDropZoneEnter?: ((e: DropZoneEnterEvent) => void) | undefined;
+  onDropZoneLeave?: ((e: DropZoneLeaveEvent) => void) | undefined;
+  onFilesUploaded?: ((e: FilesUploadedEvent) => void) | undefined;
   onInitialized?: ((e: FileUploaderInitializedEvent) => void);
   onOptionChanged?: ((e: OptionChangedEvent) => void);
-  onProgress?: ((e: ProgressEvent) => void) | null;
-  onUploadAborted?: ((e: UploadAbortedEvent) => void) | null;
-  onUploaded?: ((e: UploadedEvent) => void) | null;
-  onUploadError?: ((e: UploadErrorEvent) => void) | null;
-  onUploadStarted?: ((e: UploadStartedEvent) => void) | null;
-  onValueChanged?: ((e: FileUploaderValueChangedEvent) => void) | null;
+  onProgress?: ((e: ProgressEvent) => void) | undefined;
+  onUploadAborted?: ((e: UploadAbortedEvent) => void) | undefined;
+  onUploaded?: ((e: UploadedEvent) => void) | undefined;
+  onUploadError?: ((e: UploadErrorEvent) => void) | undefined;
+  onUploadStarted?: ((e: UploadStartedEvent) => void) | undefined;
+  onValueChanged?: ((e: FileUploaderValueChangedEvent) => void) | undefined;
   progress?: number;
   readOnly?: boolean;
   readyToUploadMessage?: string;
diff --git a/packages/devextreme-react/src/menu.ts b/packages/devextreme-react/src/menu.ts
index 8954da19356f..a23f613b3181 100644
--- a/packages/devextreme-react/src/menu.ts
+++ b/packages/devextreme-react/src/menu.ts
@@ -25,10 +25,10 @@ type IMenuOptionsNarrowedEvents<TItem = any, TKey = any> = {
   onItemClick?: ((e: ItemClickEvent<TItem, TKey>) => void);
   onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void);
   onItemRendered?: ((e: ItemRenderedEvent<TItem, TKey>) => void);
-  onSubmenuHidden?: ((e: SubmenuHiddenEvent<TItem, TKey>) => void) | null;
-  onSubmenuHiding?: ((e: SubmenuHidingEvent<TItem, TKey>) => void) | null;
-  onSubmenuShowing?: ((e: SubmenuShowingEvent<TItem, TKey>) => void) | null;
-  onSubmenuShown?: ((e: SubmenuShownEvent<TItem, TKey>) => void) | null;
+  onSubmenuHidden?: ((e: SubmenuHiddenEvent<TItem, TKey>) => void) | undefined;
+  onSubmenuHiding?: ((e: SubmenuHidingEvent<TItem, TKey>) => void) | undefined;
+  onSubmenuShowing?: ((e: SubmenuShowingEvent<TItem, TKey>) => void) | undefined;
+  onSubmenuShown?: ((e: SubmenuShownEvent<TItem, TKey>) => void) | undefined;
 }
 
 type IMenuOptions<TItem = any, TKey = any> = React.PropsWithChildren<ReplaceFieldTypes<Properties<TItem, TKey>, IMenuOptionsNarrowedEvents<TItem, TKey>> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/scheduler.ts b/packages/devextreme-react/src/scheduler.ts
index 7988d2c8a553..59250c5beee0 100644
--- a/packages/devextreme-react/src/scheduler.ts
+++ b/packages/devextreme-react/src/scheduler.ts
@@ -501,12 +501,12 @@ type IFormProps = React.PropsWithChildren<{
   minColWidth?: number;
   onContentReady?: ((e: FormContentReadyEvent) => void);
   onDisposing?: ((e: FormDisposingEvent) => void);
-  onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void) | null;
-  onFieldDataChanged?: ((e: FieldDataChangedEvent) => void) | null;
+  onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void) | undefined;
+  onFieldDataChanged?: ((e: FieldDataChangedEvent) => void) | undefined;
   onInitialized?: ((e: FormInitializedEvent) => void);
   onOptionChanged?: ((e: FormOptionChangedEvent) => void);
-  onSmartPasted?: ((e: SmartPastedEvent) => void) | null;
-  onSmartPasting?: ((e: SmartPastingEvent) => void) | null;
+  onSmartPasted?: ((e: SmartPastedEvent) => void) | undefined;
+  onSmartPasting?: ((e: SmartPastingEvent) => void) | undefined;
   optionalMark?: string;
   readOnly?: boolean;
   requiredMark?: string;
@@ -814,9 +814,9 @@ type IOptionsProps = React.PropsWithChildren<{
   onContentReady?: ((e: ButtonGroupContentReadyEvent) => void);
   onDisposing?: ((e: ButtonGroupDisposingEvent) => void);
   onInitialized?: ((e: ButtonGroupInitializedEvent) => void);
-  onItemClick?: ((e: ItemClickEvent) => void) | null;
+  onItemClick?: ((e: ItemClickEvent) => void) | undefined;
   onOptionChanged?: ((e: ButtonGroupOptionChangedEvent) => void);
-  onSelectionChanged?: ((e: SelectionChangedEvent) => void) | null;
+  onSelectionChanged?: ((e: SelectionChangedEvent) => void) | undefined;
   rtlEnabled?: boolean;
   selectedItemKeys?: Array<any>;
   selectedItems?: Array<any>;
@@ -1238,8 +1238,8 @@ type ITabPanelOptionsProps = React.PropsWithChildren<{
   onSelectionChanged?: ((e: TabPanelSelectionChangedEvent) => void);
   onSelectionChanging?: ((e: SelectionChangingEvent) => void);
   onTitleClick?: ((e: TitleClickEvent) => void);
-  onTitleHold?: ((e: TitleHoldEvent) => void) | null;
-  onTitleRendered?: ((e: TitleRenderedEvent) => void) | null;
+  onTitleHold?: ((e: TitleHoldEvent) => void) | undefined;
+  onTitleRendered?: ((e: TitleRenderedEvent) => void) | undefined;
   repaintChangesOnly?: boolean;
   rtlEnabled?: boolean;
   scrollByContent?: boolean;
diff --git a/packages/devextreme-react/src/select-box.ts b/packages/devextreme-react/src/select-box.ts
index f5ccfa2c3b06..b17d3be9daf6 100644
--- a/packages/devextreme-react/src/select-box.ts
+++ b/packages/devextreme-react/src/select-box.ts
@@ -266,18 +266,18 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void) | null;
+  onContentReady?: ((e: EventInfo<any>) => void) | undefined;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
diff --git a/packages/devextreme-react/src/speed-dial-action.ts b/packages/devextreme-react/src/speed-dial-action.ts
index 617072d03ee8..cf073e2dcb47 100644
--- a/packages/devextreme-react/src/speed-dial-action.ts
+++ b/packages/devextreme-react/src/speed-dial-action.ts
@@ -15,7 +15,7 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 
 type ISpeedDialActionOptionsNarrowedEvents = {
   onClick?: ((e: ClickEvent) => void);
-  onContentReady?: ((e: ContentReadyEvent) => void) | null;
+  onContentReady?: ((e: ContentReadyEvent) => void) | undefined;
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
 }
diff --git a/packages/devextreme-react/src/tab-panel.ts b/packages/devextreme-react/src/tab-panel.ts
index 6df0bea7358e..92e6ba66247f 100644
--- a/packages/devextreme-react/src/tab-panel.ts
+++ b/packages/devextreme-react/src/tab-panel.ts
@@ -27,8 +27,8 @@ type ITabPanelOptionsNarrowedEvents<TItem = any, TKey = any> = {
   onItemRendered?: ((e: ItemRenderedEvent<TItem, TKey>) => void);
   onSelectionChanging?: ((e: SelectionChangingEvent<TItem, TKey>) => void);
   onTitleClick?: ((e: TitleClickEvent<TItem, TKey>) => void);
-  onTitleHold?: ((e: TitleHoldEvent<TItem, TKey>) => void) | null;
-  onTitleRendered?: ((e: TitleRenderedEvent<TItem, TKey>) => void) | null;
+  onTitleHold?: ((e: TitleHoldEvent<TItem, TKey>) => void) | undefined;
+  onTitleRendered?: ((e: TitleRenderedEvent<TItem, TKey>) => void) | undefined;
 }
 
 type ITabPanelOptions<TItem = any, TKey = any> = React.PropsWithChildren<ReplaceFieldTypes<Properties<TItem, TKey>, ITabPanelOptionsNarrowedEvents<TItem, TKey>> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/tag-box.ts b/packages/devextreme-react/src/tag-box.ts
index 14a4926bad8b..725621804869 100644
--- a/packages/devextreme-react/src/tag-box.ts
+++ b/packages/devextreme-react/src/tag-box.ts
@@ -272,18 +272,18 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void) | null;
+  onContentReady?: ((e: EventInfo<any>) => void) | undefined;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
diff --git a/packages/devextreme-react/src/tree-list.ts b/packages/devextreme-react/src/tree-list.ts
index e55652cbadd7..bcfbafee8f1c 100644
--- a/packages/devextreme-react/src/tree-list.ts
+++ b/packages/devextreme-react/src/tree-list.ts
@@ -1449,18 +1449,18 @@ type IFilterBuilderPopupProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void) | null;
+  onContentReady?: ((e: EventInfo<any>) => void) | undefined;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
@@ -1674,12 +1674,12 @@ type IFormProps = React.PropsWithChildren<{
   minColWidth?: number;
   onContentReady?: ((e: FormContentReadyEvent) => void);
   onDisposing?: ((e: FormDisposingEvent) => void);
-  onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void) | null;
-  onFieldDataChanged?: ((e: FieldDataChangedEvent) => void) | null;
+  onEditorEnterKey?: ((e: EditorEnterKeyEvent) => void) | undefined;
+  onFieldDataChanged?: ((e: FieldDataChangedEvent) => void) | undefined;
   onInitialized?: ((e: FormInitializedEvent) => void);
   onOptionChanged?: ((e: FormOptionChangedEvent) => void);
-  onSmartPasted?: ((e: SmartPastedEvent) => void) | null;
-  onSmartPasting?: ((e: SmartPastingEvent) => void) | null;
+  onSmartPasted?: ((e: SmartPastedEvent) => void) | undefined;
+  onSmartPasting?: ((e: SmartPastingEvent) => void) | undefined;
   optionalMark?: string;
   readOnly?: boolean;
   requiredMark?: string;
@@ -2506,18 +2506,18 @@ type IPopupProps = React.PropsWithChildren<{
   maxWidth?: number | string;
   minHeight?: number | string;
   minWidth?: number | string;
-  onContentReady?: ((e: EventInfo<any>) => void) | null;
+  onContentReady?: ((e: EventInfo<any>) => void) | undefined;
   onDisposing?: ((e: EventInfo<any>) => void);
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onInitialized?: ((e: { component: Component<any>, element: any }) => void);
   onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
-  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
-  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | null;
+  onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
+  onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onShowing?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
   onShown?: ((e: EventInfo<any>) => void);
-  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | null;
+  onTitleRendered?: ((e: { component: dxPopup, element: any, model: any, titleElement: any }) => void) | undefined;
   position?: (() => void) | PositionAlignment | PositionConfig;
   resizeEnabled?: boolean;
   restorePosition?: boolean;
@@ -3162,8 +3162,8 @@ type ITabPanelOptionsProps = React.PropsWithChildren<{
   onSelectionChanged?: ((e: SelectionChangedEvent) => void);
   onSelectionChanging?: ((e: SelectionChangingEvent) => void);
   onTitleClick?: ((e: TitleClickEvent) => void);
-  onTitleHold?: ((e: TitleHoldEvent) => void) | null;
-  onTitleRendered?: ((e: TitleRenderedEvent) => void) | null;
+  onTitleHold?: ((e: TitleHoldEvent) => void) | undefined;
+  onTitleRendered?: ((e: TitleRenderedEvent) => void) | undefined;
   repaintChangesOnly?: boolean;
   rtlEnabled?: boolean;
   scrollByContent?: boolean;
diff --git a/packages/devextreme-react/src/tree-view.ts b/packages/devextreme-react/src/tree-view.ts
index 555e492999b4..89b10b10c916 100644
--- a/packages/devextreme-react/src/tree-view.ts
+++ b/packages/devextreme-react/src/tree-view.ts
@@ -23,13 +23,13 @@ type ITreeViewOptionsNarrowedEvents<TItem = any, TKey = any> = {
   onContentReady?: ((e: ContentReadyEvent<TItem, TKey>) => void);
   onDisposing?: ((e: DisposingEvent<TItem, TKey>) => void);
   onInitialized?: ((e: InitializedEvent<TItem, TKey>) => void);
-  onItemClick?: ((e: ItemClickEvent<TItem, TKey>) => void) | null;
-  onItemCollapsed?: ((e: ItemCollapsedEvent<TItem, TKey>) => void) | null;
-  onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void) | null;
-  onItemExpanded?: ((e: ItemExpandedEvent<TItem, TKey>) => void) | null;
-  onItemHold?: ((e: ItemHoldEvent<TItem, TKey>) => void) | null;
-  onItemRendered?: ((e: ItemRenderedEvent<TItem, TKey>) => void) | null;
-  onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent<TItem, TKey>) => void) | null;
+  onItemClick?: ((e: ItemClickEvent<TItem, TKey>) => void) | undefined;
+  onItemCollapsed?: ((e: ItemCollapsedEvent<TItem, TKey>) => void) | undefined;
+  onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void) | undefined;
+  onItemExpanded?: ((e: ItemExpandedEvent<TItem, TKey>) => void) | undefined;
+  onItemHold?: ((e: ItemHoldEvent<TItem, TKey>) => void) | undefined;
+  onItemRendered?: ((e: ItemRenderedEvent<TItem, TKey>) => void) | undefined;
+  onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent<TItem, TKey>) => void) | undefined;
 }
 
 type ITreeViewOptions<TItem = any, TKey = any> = React.PropsWithChildren<ReplaceFieldTypes<Properties<TItem, TKey>, ITreeViewOptionsNarrowedEvents<TItem, TKey>> & IHtmlOptions & {
diff --git a/packages/devextreme-vue/src/accordion.ts b/packages/devextreme-vue/src/accordion.ts
index 93f0c6d35f9a..b26db562a4fe 100644
--- a/packages/devextreme-vue/src/accordion.ts
+++ b/packages/devextreme-vue/src/accordion.ts
@@ -88,7 +88,7 @@ const componentConfig = {
     items: Array as PropType<Array<any | dxAccordionItem | string>>,
     itemTemplate: {},
     itemTitleTemplate: {},
-    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | null | string>,
     multiple: Boolean,
     noDataText: String,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
diff --git a/packages/devextreme-vue/src/calendar.ts b/packages/devextreme-vue/src/calendar.ts
index 9d668d33a533..afc8fdd36268 100644
--- a/packages/devextreme-vue/src/calendar.ts
+++ b/packages/devextreme-vue/src/calendar.ts
@@ -74,7 +74,7 @@ const componentConfig = {
     cellTemplate: {},
     dateSerializationFormat: String,
     disabled: Boolean,
-    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: DisabledDate) => boolean))>,
+    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: DisabledDate) => boolean)) | null>,
     elementAttr: Object as PropType<Record<string, any>>,
     firstDayOfWeek: Number as PropType<DayOfWeek>,
     focusStateEnabled: Boolean,
diff --git a/packages/devextreme-vue/src/card-view.ts b/packages/devextreme-vue/src/card-view.ts
index ca1a100bacd8..972adc77da2d 100644
--- a/packages/devextreme-vue/src/card-view.ts
+++ b/packages/devextreme-vue/src/card-view.ts
@@ -1181,7 +1181,7 @@ const DxColumnHeaderFilterConfig = {
   props: {
     allowSearch: Boolean,
     allowSelectAll: Boolean,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | null | Store | Record<string, any>>,
     groupInterval: [Array, String, Number] as PropType<(Array<number | string>) | HeaderFilterGroupInterval | number>,
     height: [Number, String],
     search: Object as PropType<ColumnHeaderFilterSearchConfig | HeaderFilterSearchConfig | Record<string, any>>,
@@ -1994,7 +1994,7 @@ const DxHeaderFilterConfig = {
   props: {
     allowSearch: Boolean,
     allowSelectAll: Boolean,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | null | Store | Record<string, any>>,
     groupInterval: [Array, String, Number] as PropType<(Array<number | string>) | HeaderFilterGroupInterval | number>,
     height: [Number, String],
     search: Object as PropType<ColumnHeaderFilterSearchConfig | HeaderFilterSearchConfig | Record<string, any>>,
diff --git a/packages/devextreme-vue/src/context-menu.ts b/packages/devextreme-vue/src/context-menu.ts
index 710e286b64fc..b0c8a4fe7800 100644
--- a/packages/devextreme-vue/src/context-menu.ts
+++ b/packages/devextreme-vue/src/context-menu.ts
@@ -119,17 +119,17 @@ const componentConfig = {
     itemTemplate: {},
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
-    onHidden: Function as PropType<((e: HiddenEvent) => void)>,
-    onHiding: Function as PropType<((e: HidingEvent) => void)>,
+    onHidden: Function as PropType<(((e: HiddenEvent) => void)) | null>,
+    onHiding: Function as PropType<(((e: HidingEvent) => void)) | null>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
     onItemContextMenu: Function as PropType<((e: ItemContextMenuEvent) => void)>,
     onItemRendered: Function as PropType<((e: ItemRenderedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onPositioning: Function as PropType<((e: PositioningEvent) => void)>,
+    onPositioning: Function as PropType<(((e: PositioningEvent) => void)) | null>,
     onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
-    onShowing: Function as PropType<((e: ShowingEvent) => void)>,
-    onShown: Function as PropType<((e: ShownEvent) => void)>,
+    onShowing: Function as PropType<(((e: ShowingEvent) => void)) | null>,
+    onShown: Function as PropType<(((e: ShownEvent) => void)) | null>,
     position: Object as PropType<PositionConfig | Record<string, any>>,
     rtlEnabled: Boolean,
     selectByClick: Boolean,
diff --git a/packages/devextreme-vue/src/data-grid.ts b/packages/devextreme-vue/src/data-grid.ts
index 36058017ad2e..60de58e9c6cb 100644
--- a/packages/devextreme-vue/src/data-grid.ts
+++ b/packages/devextreme-vue/src/data-grid.ts
@@ -1438,7 +1438,7 @@ const DxColumnHeaderFilterConfig = {
   props: {
     allowSearch: Boolean,
     allowSelectAll: Boolean,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | null | Store | Record<string, any>>,
     groupInterval: [Array, String, Number] as PropType<(Array<number | string>) | HeaderFilterGroupInterval | number>,
     height: [Number, String],
     search: Object as PropType<ColumnHeaderFilterSearchConfig | HeaderFilterSearchConfig | Record<string, any>>,
@@ -1495,7 +1495,7 @@ const DxColumnLookupConfig = {
   props: {
     allowClearing: Boolean,
     calculateCellValue: Function as PropType<((rowData: any) => any)>,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { data: Record<string, any>, key: any }) => Array<any> | Store | DataSourceOptions)) | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { data: Record<string, any>, key: any }) => Array<any> | Store | DataSourceOptions)) | null | Store | Record<string, any>>,
     displayExpr: [Function, String] as PropType<(((data: any) => string)) | string>,
     valueExpr: String
   }
@@ -2931,7 +2931,7 @@ const DxHeaderFilterConfig = {
   props: {
     allowSearch: Boolean,
     allowSelectAll: Boolean,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | null | Store | Record<string, any>>,
     groupInterval: [Array, String, Number] as PropType<(Array<number | string>) | HeaderFilterGroupInterval | number>,
     height: [Number, String],
     search: Object as PropType<ColumnHeaderFilterSearchConfig | HeaderFilterSearchConfig | Record<string, any>>,
@@ -3254,7 +3254,7 @@ const DxLookupConfig = {
   props: {
     allowClearing: Boolean,
     calculateCellValue: Function as PropType<((rowData: any) => any)>,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { data: Record<string, any>, key: any }) => Array<any> | Store | DataSourceOptions)) | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { data: Record<string, any>, key: any }) => Array<any> | Store | DataSourceOptions)) | null | Store | Record<string, any>>,
     displayExpr: [Function, String] as PropType<(((data: any) => string)) | string>,
     valueExpr: [String, Function] as PropType<string | (((data: any) => string | number | boolean))>
   }
diff --git a/packages/devextreme-vue/src/date-box.ts b/packages/devextreme-vue/src/date-box.ts
index 91ebdf640f70..a5f4ceb804db 100644
--- a/packages/devextreme-vue/src/date-box.ts
+++ b/packages/devextreme-vue/src/date-box.ts
@@ -198,7 +198,7 @@ const componentConfig = {
     dateSerializationFormat: String,
     deferRendering: Boolean,
     disabled: Boolean,
-    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: { component: dxDateBox, date: Date, view: string }) => boolean))>,
+    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: { component: dxDateBox, date: Date, view: string }) => boolean)) | null>,
     displayFormat: [Object, String, Function] as PropType<Format | null | CommonFormat | (((value: number | Date) => string)) | Record<string, any> | string>,
     dropDownButtonTemplate: {},
     dropDownOptions: Object as PropType<dxPopupOptions<any> | Record<string, any>>,
@@ -501,7 +501,7 @@ const DxCalendarOptionsConfig = {
     cellTemplate: {},
     dateSerializationFormat: String,
     disabled: Boolean,
-    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: DisabledDate) => boolean))>,
+    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: DisabledDate) => boolean)) | null>,
     elementAttr: Object as PropType<Record<string, any>>,
     firstDayOfWeek: Number as PropType<DayOfWeek>,
     focusStateEnabled: Boolean,
diff --git a/packages/devextreme-vue/src/date-range-box.ts b/packages/devextreme-vue/src/date-range-box.ts
index 3523cdfbd031..a5b641516aca 100644
--- a/packages/devextreme-vue/src/date-range-box.ts
+++ b/packages/devextreme-vue/src/date-range-box.ts
@@ -510,7 +510,7 @@ const DxCalendarOptionsConfig = {
     cellTemplate: {},
     dateSerializationFormat: String,
     disabled: Boolean,
-    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: DisabledDate) => boolean))>,
+    disabledDates: [Array, Function] as PropType<Array<Date> | (((data: DisabledDate) => boolean)) | null>,
     elementAttr: Object as PropType<Record<string, any>>,
     firstDayOfWeek: Number as PropType<DayOfWeek>,
     focusStateEnabled: Boolean,
diff --git a/packages/devextreme-vue/src/diagram.ts b/packages/devextreme-vue/src/diagram.ts
index 551fe1416c39..255da3bb1fb7 100644
--- a/packages/devextreme-vue/src/diagram.ts
+++ b/packages/devextreme-vue/src/diagram.ts
@@ -117,12 +117,12 @@ const componentConfig = {
     onCustomCommand: Function as PropType<((e: CustomCommandEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
-    onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
-    onItemDblClick: Function as PropType<((e: ItemDblClickEvent) => void)>,
+    onItemClick: Function as PropType<(((e: ItemClickEvent) => void)) | null>,
+    onItemDblClick: Function as PropType<(((e: ItemDblClickEvent) => void)) | null>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onRequestEditOperation: Function as PropType<((e: RequestEditOperationEvent) => void)>,
-    onRequestLayoutUpdate: Function as PropType<((e: RequestLayoutUpdateEvent) => void)>,
-    onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
+    onRequestEditOperation: Function as PropType<(((e: RequestEditOperationEvent) => void)) | null>,
+    onRequestLayoutUpdate: Function as PropType<(((e: RequestLayoutUpdateEvent) => void)) | null>,
+    onSelectionChanged: Function as PropType<(((e: SelectionChangedEvent) => void)) | null>,
     pageColor: String,
     pageOrientation: String as PropType<PageOrientation>,
     pageSize: Object as PropType<Record<string, any>>,
diff --git a/packages/devextreme-vue/src/gantt.ts b/packages/devextreme-vue/src/gantt.ts
index cb7ad274abb9..d8863f598c4b 100644
--- a/packages/devextreme-vue/src/gantt.ts
+++ b/packages/devextreme-vue/src/gantt.ts
@@ -188,36 +188,36 @@ const componentConfig = {
     hint: String,
     hoverStateEnabled: Boolean,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
-    onContextMenuPreparing: Function as PropType<((e: ContextMenuPreparingEvent) => void)>,
-    onCustomCommand: Function as PropType<((e: CustomCommandEvent) => void)>,
-    onDependencyDeleted: Function as PropType<((e: DependencyDeletedEvent) => void)>,
-    onDependencyDeleting: Function as PropType<((e: DependencyDeletingEvent) => void)>,
-    onDependencyInserted: Function as PropType<((e: DependencyInsertedEvent) => void)>,
-    onDependencyInserting: Function as PropType<((e: DependencyInsertingEvent) => void)>,
+    onContextMenuPreparing: Function as PropType<(((e: ContextMenuPreparingEvent) => void)) | null>,
+    onCustomCommand: Function as PropType<(((e: CustomCommandEvent) => void)) | null>,
+    onDependencyDeleted: Function as PropType<(((e: DependencyDeletedEvent) => void)) | null>,
+    onDependencyDeleting: Function as PropType<(((e: DependencyDeletingEvent) => void)) | null>,
+    onDependencyInserted: Function as PropType<(((e: DependencyInsertedEvent) => void)) | null>,
+    onDependencyInserting: Function as PropType<(((e: DependencyInsertingEvent) => void)) | null>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onResourceAssigned: Function as PropType<((e: ResourceAssignedEvent) => void)>,
-    onResourceAssigning: Function as PropType<((e: ResourceAssigningEvent) => void)>,
-    onResourceDeleted: Function as PropType<((e: ResourceDeletedEvent) => void)>,
-    onResourceDeleting: Function as PropType<((e: ResourceDeletingEvent) => void)>,
-    onResourceInserted: Function as PropType<((e: ResourceInsertedEvent) => void)>,
-    onResourceInserting: Function as PropType<((e: ResourceInsertingEvent) => void)>,
+    onResourceAssigned: Function as PropType<(((e: ResourceAssignedEvent) => void)) | null>,
+    onResourceAssigning: Function as PropType<(((e: ResourceAssigningEvent) => void)) | null>,
+    onResourceDeleted: Function as PropType<(((e: ResourceDeletedEvent) => void)) | null>,
+    onResourceDeleting: Function as PropType<(((e: ResourceDeletingEvent) => void)) | null>,
+    onResourceInserted: Function as PropType<(((e: ResourceInsertedEvent) => void)) | null>,
+    onResourceInserting: Function as PropType<(((e: ResourceInsertingEvent) => void)) | null>,
     onResourceManagerDialogShowing: Function as PropType<((e: ResourceManagerDialogShowingEvent) => void)>,
-    onResourceUnassigned: Function as PropType<((e: ResourceUnassignedEvent) => void)>,
-    onResourceUnassigning: Function as PropType<((e: ResourceUnassigningEvent) => void)>,
+    onResourceUnassigned: Function as PropType<(((e: ResourceUnassignedEvent) => void)) | null>,
+    onResourceUnassigning: Function as PropType<(((e: ResourceUnassigningEvent) => void)) | null>,
     onScaleCellPrepared: Function as PropType<((e: ScaleCellPreparedEvent) => void)>,
-    onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
-    onTaskClick: Function as PropType<((e: TaskClickEvent) => void)>,
-    onTaskDblClick: Function as PropType<((e: TaskDblClickEvent) => void)>,
-    onTaskDeleted: Function as PropType<((e: TaskDeletedEvent) => void)>,
-    onTaskDeleting: Function as PropType<((e: TaskDeletingEvent) => void)>,
-    onTaskEditDialogShowing: Function as PropType<((e: TaskEditDialogShowingEvent) => void)>,
-    onTaskInserted: Function as PropType<((e: TaskInsertedEvent) => void)>,
-    onTaskInserting: Function as PropType<((e: TaskInsertingEvent) => void)>,
-    onTaskMoving: Function as PropType<((e: TaskMovingEvent) => void)>,
-    onTaskUpdated: Function as PropType<((e: TaskUpdatedEvent) => void)>,
-    onTaskUpdating: Function as PropType<((e: TaskUpdatingEvent) => void)>,
+    onSelectionChanged: Function as PropType<(((e: SelectionChangedEvent) => void)) | null>,
+    onTaskClick: Function as PropType<(((e: TaskClickEvent) => void)) | null>,
+    onTaskDblClick: Function as PropType<(((e: TaskDblClickEvent) => void)) | null>,
+    onTaskDeleted: Function as PropType<(((e: TaskDeletedEvent) => void)) | null>,
+    onTaskDeleting: Function as PropType<(((e: TaskDeletingEvent) => void)) | null>,
+    onTaskEditDialogShowing: Function as PropType<(((e: TaskEditDialogShowingEvent) => void)) | null>,
+    onTaskInserted: Function as PropType<(((e: TaskInsertedEvent) => void)) | null>,
+    onTaskInserting: Function as PropType<(((e: TaskInsertingEvent) => void)) | null>,
+    onTaskMoving: Function as PropType<(((e: TaskMovingEvent) => void)) | null>,
+    onTaskUpdated: Function as PropType<(((e: TaskUpdatedEvent) => void)) | null>,
+    onTaskUpdating: Function as PropType<(((e: TaskUpdatingEvent) => void)) | null>,
     resourceAssignments: Object as PropType<Record<string, any>>,
     resources: Object as PropType<Record<string, any>>,
     rootValue: {},
@@ -453,7 +453,7 @@ const DxColumnHeaderFilterConfig = {
   props: {
     allowSearch: Boolean,
     allowSelectAll: Boolean,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | null | Store | Record<string, any>>,
     groupInterval: [Array, String, Number] as PropType<(Array<number | string>) | HeaderFilterGroupInterval | number>,
     height: [Number, String],
     search: Object as PropType<ColumnHeaderFilterSearchConfig | HeaderFilterSearchConfig | Record<string, any>>,
@@ -795,7 +795,7 @@ const DxHeaderFilterConfig = {
   props: {
     allowSearch: Boolean,
     allowSelectAll: Boolean,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | null | Store | Record<string, any>>,
     groupInterval: [Array, String, Number] as PropType<(Array<number | string>) | HeaderFilterGroupInterval | number>,
     height: [Number, String],
     search: Object as PropType<ColumnHeaderFilterSearchConfig | HeaderFilterSearchConfig | Record<string, any>>,
diff --git a/packages/devextreme-vue/src/list.ts b/packages/devextreme-vue/src/list.ts
index aa72c04ed9e5..e7f9a04a8a09 100644
--- a/packages/devextreme-vue/src/list.ts
+++ b/packages/devextreme-vue/src/list.ts
@@ -201,28 +201,28 @@ const componentConfig = {
     itemHoldTimeout: Number,
     items: Array as PropType<Array<any | dxListItem | string>>,
     itemTemplate: {},
-    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | null | string>,
     menuItems: Array as PropType<Array<Record<string, any>>>,
     menuMode: String as PropType<ListMenuMode>,
     nextButtonText: String,
     noDataText: String,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
-    onGroupRendered: Function as PropType<((e: GroupRenderedEvent) => void)>,
+    onGroupRendered: Function as PropType<(((e: GroupRenderedEvent) => void)) | null>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
-    onItemContextMenu: Function as PropType<((e: ItemContextMenuEvent) => void)>,
-    onItemDeleted: Function as PropType<((e: ItemDeletedEvent) => void)>,
-    onItemDeleting: Function as PropType<((e: ItemDeletingEvent) => void)>,
-    onItemHold: Function as PropType<((e: ItemHoldEvent) => void)>,
+    onItemContextMenu: Function as PropType<(((e: ItemContextMenuEvent) => void)) | null>,
+    onItemDeleted: Function as PropType<(((e: ItemDeletedEvent) => void)) | null>,
+    onItemDeleting: Function as PropType<(((e: ItemDeletingEvent) => void)) | null>,
+    onItemHold: Function as PropType<(((e: ItemHoldEvent) => void)) | null>,
     onItemRendered: Function as PropType<((e: ItemRenderedEvent) => void)>,
-    onItemReordered: Function as PropType<((e: ItemReorderedEvent) => void)>,
-    onItemSwipe: Function as PropType<((e: ItemSwipeEvent) => void)>,
+    onItemReordered: Function as PropType<(((e: ItemReorderedEvent) => void)) | null>,
+    onItemSwipe: Function as PropType<(((e: ItemSwipeEvent) => void)) | null>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onPageLoading: Function as PropType<((e: PageLoadingEvent) => void)>,
-    onPullRefresh: Function as PropType<((e: PullRefreshEvent) => void)>,
-    onScroll: Function as PropType<((e: ScrollEvent) => void)>,
-    onSelectAllValueChanged: Function as PropType<((e: SelectAllValueChangedEvent) => void)>,
+    onPageLoading: Function as PropType<(((e: PageLoadingEvent) => void)) | null>,
+    onPullRefresh: Function as PropType<(((e: PullRefreshEvent) => void)) | null>,
+    onScroll: Function as PropType<(((e: ScrollEvent) => void)) | null>,
+    onSelectAllValueChanged: Function as PropType<(((e: SelectAllValueChangedEvent) => void)) | null>,
     onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
     onSelectionChanging: Function as PropType<((e: SelectionChangingEvent) => void)>,
     pageLoadingText: String,
diff --git a/packages/devextreme-vue/src/lookup.ts b/packages/devextreme-vue/src/lookup.ts
index c1c59b98423f..79d2bdeb479a 100644
--- a/packages/devextreme-vue/src/lookup.ts
+++ b/packages/devextreme-vue/src/lookup.ts
@@ -206,11 +206,11 @@ const componentConfig = {
     onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
     onOpened: Function as PropType<((e: OpenedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onPageLoading: Function as PropType<((e: PageLoadingEvent) => void)>,
-    onPullRefresh: Function as PropType<((e: PullRefreshEvent) => void)>,
-    onScroll: Function as PropType<((e: ScrollEvent) => void)>,
+    onPageLoading: Function as PropType<(((e: PageLoadingEvent) => void)) | null>,
+    onPullRefresh: Function as PropType<(((e: PullRefreshEvent) => void)) | null>,
+    onScroll: Function as PropType<(((e: ScrollEvent) => void)) | null>,
     onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
-    onValueChanged: Function as PropType<((e: ValueChangedEvent) => void)>,
+    onValueChanged: Function as PropType<(((e: ValueChangedEvent) => void)) | null>,
     opened: Boolean,
     pageLoadingText: String,
     pageLoadMode: String as PropType<PageLoadMode>,
diff --git a/packages/devextreme-vue/src/map.ts b/packages/devextreme-vue/src/map.ts
index 7e1c8fecdc49..470e92f22630 100644
--- a/packages/devextreme-vue/src/map.ts
+++ b/packages/devextreme-vue/src/map.ts
@@ -76,12 +76,12 @@ const componentConfig = {
     onClick: Function as PropType<((e: ClickEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
-    onMarkerAdded: Function as PropType<((e: MarkerAddedEvent) => void)>,
-    onMarkerRemoved: Function as PropType<((e: MarkerRemovedEvent) => void)>,
+    onMarkerAdded: Function as PropType<(((e: MarkerAddedEvent) => void)) | null>,
+    onMarkerRemoved: Function as PropType<(((e: MarkerRemovedEvent) => void)) | null>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onReady: Function as PropType<((e: ReadyEvent) => void)>,
-    onRouteAdded: Function as PropType<((e: RouteAddedEvent) => void)>,
-    onRouteRemoved: Function as PropType<((e: RouteRemovedEvent) => void)>,
+    onReady: Function as PropType<(((e: ReadyEvent) => void)) | null>,
+    onRouteAdded: Function as PropType<(((e: RouteAddedEvent) => void)) | null>,
+    onRouteRemoved: Function as PropType<(((e: RouteRemovedEvent) => void)) | null>,
     provider: String as PropType<MapProvider>,
     providerConfig: Object as PropType<Record<string, any>>,
     routes: Array as PropType<Array<Record<string, any>>>,
diff --git a/packages/devextreme-vue/src/progress-bar.ts b/packages/devextreme-vue/src/progress-bar.ts
index f927ac46a684..0e7f4b00695e 100644
--- a/packages/devextreme-vue/src/progress-bar.ts
+++ b/packages/devextreme-vue/src/progress-bar.ts
@@ -61,7 +61,7 @@ const componentConfig = {
     isValid: Boolean,
     max: Number,
     min: Number,
-    onComplete: Function as PropType<((e: CompleteEvent) => void)>,
+    onComplete: Function as PropType<(((e: CompleteEvent) => void)) | null>,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
diff --git a/packages/devextreme-vue/src/range-slider.ts b/packages/devextreme-vue/src/range-slider.ts
index eff249b51b3d..61e9b2a28db2 100644
--- a/packages/devextreme-vue/src/range-slider.ts
+++ b/packages/devextreme-vue/src/range-slider.ts
@@ -90,7 +90,7 @@ const componentConfig = {
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onValueChanged: Function as PropType<((e: ValueChangedEvent) => void)>,
+    onValueChanged: Function as PropType<(((e: ValueChangedEvent) => void)) | null>,
     readOnly: Boolean,
     rtlEnabled: Boolean,
     showRange: Boolean,
diff --git a/packages/devextreme-vue/src/responsive-box.ts b/packages/devextreme-vue/src/responsive-box.ts
index 1ae0d3be4154..86a26760a0c9 100644
--- a/packages/devextreme-vue/src/responsive-box.ts
+++ b/packages/devextreme-vue/src/responsive-box.ts
@@ -74,7 +74,7 @@ const componentConfig = {
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
     rows: Array as PropType<Array<Record<string, any>>>,
     rtlEnabled: Boolean,
-    screenByWidth: Function as PropType<(() => void)>,
+    screenByWidth: Function as PropType<((() => void)) | null>,
     singleColumnScreen: String,
     visible: Boolean,
     width: [Number, String]
diff --git a/packages/devextreme-vue/src/scroll-view.ts b/packages/devextreme-vue/src/scroll-view.ts
index a1403de5bf91..612944df11b5 100644
--- a/packages/devextreme-vue/src/scroll-view.ts
+++ b/packages/devextreme-vue/src/scroll-view.ts
@@ -54,8 +54,8 @@ const componentConfig = {
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onPullDown: Function as PropType<((e: PullDownEvent) => void)>,
-    onReachBottom: Function as PropType<((e: ReachBottomEvent) => void)>,
+    onPullDown: Function as PropType<(((e: PullDownEvent) => void)) | null>,
+    onReachBottom: Function as PropType<(((e: ReachBottomEvent) => void)) | null>,
     onScroll: Function as PropType<((e: ScrollEvent) => void)>,
     onUpdated: Function as PropType<((e: UpdatedEvent) => void)>,
     pulledDownText: String,
diff --git a/packages/devextreme-vue/src/tabs.ts b/packages/devextreme-vue/src/tabs.ts
index 17e7999dbda8..557e5a83e587 100644
--- a/packages/devextreme-vue/src/tabs.ts
+++ b/packages/devextreme-vue/src/tabs.ts
@@ -91,7 +91,7 @@ const componentConfig = {
     itemHoldTimeout: Number,
     items: Array as PropType<Array<any | dxTabsItem | string>>,
     itemTemplate: {},
-    keyExpr: [Function, String] as PropType<(((item: any) => any)) | string>,
+    keyExpr: [Function, String] as PropType<(((item: any) => any)) | null | string>,
     noDataText: String,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
diff --git a/packages/devextreme-vue/src/tag-box.ts b/packages/devextreme-vue/src/tag-box.ts
index a8a1fdd821dd..65ea9032e3be 100644
--- a/packages/devextreme-vue/src/tag-box.ts
+++ b/packages/devextreme-vue/src/tag-box.ts
@@ -243,11 +243,11 @@ const componentConfig = {
     onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
     onKeyDown: Function as PropType<((e: KeyDownEvent) => void)>,
     onKeyUp: Function as PropType<((e: KeyUpEvent) => void)>,
-    onMultiTagPreparing: Function as PropType<((e: MultiTagPreparingEvent) => void)>,
+    onMultiTagPreparing: Function as PropType<(((e: MultiTagPreparingEvent) => void)) | null>,
     onOpened: Function as PropType<((e: OpenedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onSelectAllValueChanged: Function as PropType<((e: SelectAllValueChangedEvent) => void)>,
-    onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
+    onSelectAllValueChanged: Function as PropType<(((e: SelectAllValueChangedEvent) => void)) | null>,
+    onSelectionChanged: Function as PropType<(((e: SelectionChangedEvent) => void)) | null>,
     onValueChanged: Function as PropType<((e: ValueChangedEvent) => void)>,
     opened: Boolean,
     openOnFieldClick: Boolean,
diff --git a/packages/devextreme-vue/src/tree-list.ts b/packages/devextreme-vue/src/tree-list.ts
index 4c5a044e0f15..5fcbda89e67f 100644
--- a/packages/devextreme-vue/src/tree-list.ts
+++ b/packages/devextreme-vue/src/tree-list.ts
@@ -1413,7 +1413,7 @@ const DxColumnHeaderFilterConfig = {
   props: {
     allowSearch: Boolean,
     allowSelectAll: Boolean,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | null | Store | Record<string, any>>,
     groupInterval: [Array, String, Number] as PropType<(Array<number | string>) | HeaderFilterGroupInterval | number>,
     height: [Number, String],
     search: Object as PropType<ColumnHeaderFilterSearchConfig | HeaderFilterSearchConfig | Record<string, any>>,
@@ -1470,7 +1470,7 @@ const DxColumnLookupConfig = {
   props: {
     allowClearing: Boolean,
     calculateCellValue: Function as PropType<((rowData: any) => any)>,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { data: Record<string, any>, key: any }) => Array<any> | Store | DataSourceOptions)) | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { data: Record<string, any>, key: any }) => Array<any> | Store | DataSourceOptions)) | null | Store | Record<string, any>>,
     displayExpr: [Function, String] as PropType<(((data: any) => string)) | string>,
     valueExpr: String
   }
@@ -2594,7 +2594,7 @@ const DxHeaderFilterConfig = {
   props: {
     allowSearch: Boolean,
     allowSelectAll: Boolean,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { component: Record<string, any>, dataSource: DataSourceOptions | null }) => void)) | null | Store | Record<string, any>>,
     groupInterval: [Array, String, Number] as PropType<(Array<number | string>) | HeaderFilterGroupInterval | number>,
     height: [Number, String],
     search: Object as PropType<ColumnHeaderFilterSearchConfig | HeaderFilterSearchConfig | Record<string, any>>,
@@ -2917,7 +2917,7 @@ const DxLookupConfig = {
   props: {
     allowClearing: Boolean,
     calculateCellValue: Function as PropType<((rowData: any) => any)>,
-    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { data: Record<string, any>, key: any }) => Array<any> | Store | DataSourceOptions)) | Store | Record<string, any>>,
+    dataSource: [Array, Object, Function] as PropType<Array<any> | DataSourceOptions | (((options: { data: Record<string, any>, key: any }) => Array<any> | Store | DataSourceOptions)) | null | Store | Record<string, any>>,
     displayExpr: [Function, String] as PropType<(((data: any) => string)) | string>,
     valueExpr: [String, Function] as PropType<string | (((data: any) => string | number | boolean))>
   }
diff --git a/packages/devextreme/js/ui/tree_view.d.ts b/packages/devextreme/js/ui/tree_view.d.ts
index 42ef190071fa..eed9cc5d926a 100644
--- a/packages/devextreme/js/ui/tree_view.d.ts
+++ b/packages/devextreme/js/ui/tree_view.d.ts
@@ -257,78 +257,78 @@ export interface dxTreeViewOptions<TItem extends ItemLike = any, TKey = any>
     items?: Array<TItem>;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/tree_view:ItemClickEvent}
 
      * @action
      * @public
      */
-    onItemClick?: ((e: ItemClickEvent<TItem, TKey>) => void) | null;
+    onItemClick?: ((e: ItemClickEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/tree_view:ItemCollapsedEvent}
      * @action
      * @public
      */
-    onItemCollapsed?: ((e: ItemCollapsedEvent<TItem, TKey>) => void) | null;
+    onItemCollapsed?: ((e: ItemCollapsedEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/tree_view:ItemContextMenuEvent}
      * @action
      * @public
      */
-    onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void) | null;
+    onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/tree_view:ItemExpandedEvent}
      * @action
      * @public
      */
-    onItemExpanded?: ((e: ItemExpandedEvent<TItem, TKey>) => void) | null;
+    onItemExpanded?: ((e: ItemExpandedEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/tree_view:ItemHoldEvent}
      * @action
      * @public
      */
-    onItemHold?: ((e: ItemHoldEvent<TItem, TKey>) => void) | null;
+    onItemHold?: ((e: ItemHoldEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/tree_view:ItemRenderedEvent}
      * @action
      * @public
      */
-    onItemRendered?: ((e: ItemRenderedEvent<TItem, TKey>) => void) | null;
+    onItemRendered?: ((e: ItemRenderedEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/tree_view:ItemSelectionChangedEvent}
      * @action
      * @public
      */
-    onItemSelectionChanged?: ((e: ItemSelectionChangedEvent<TItem, TKey>) => void) | null;
+    onItemSelectionChanged?: ((e: ItemSelectionChangedEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/tree_view:SelectAllValueChangedEvent}
      * @action
      * @public
      */
-    onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent<TItem, TKey>) => void) | null;
+    onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/tree_view:SelectionChangedEvent}
      * @action
      * @public
      * @override
      */
-    onSelectionChanged?: ((e: SelectionChangedEvent<TItem, TKey>) => void) | null;
+    onSelectionChanged?: ((e: SelectionChangedEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
      * @default 'parentId'
diff --git a/packages/devextreme/ts/dx.all.d.ts b/packages/devextreme/ts/dx.all.d.ts
index 885873a2417a..0ab20f12f810 100644
--- a/packages/devextreme/ts/dx.all.d.ts
+++ b/packages/devextreme/ts/dx.all.d.ts
@@ -23964,25 +23964,25 @@ declare module DevExpress.ui {
      */
     onSubmenuHidden?:
       | ((e: DevExpress.ui.dxMenu.SubmenuHiddenEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxMenuOptions.onSubmenuHiding]
      */
     onSubmenuHiding?:
       | ((e: DevExpress.ui.dxMenu.SubmenuHidingEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxMenuOptions.onSubmenuShowing]
      */
     onSubmenuShowing?:
       | ((e: DevExpress.ui.dxMenu.SubmenuShowingEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxMenuOptions.onSubmenuShown]
      */
     onSubmenuShown?:
       | ((e: DevExpress.ui.dxMenu.SubmenuShownEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxMenuOptions.orientation]
      */
@@ -29536,13 +29536,13 @@ declare module DevExpress.ui {
      */
     onTitleHold?:
       | ((e: DevExpress.ui.dxTabPanel.TitleHoldEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxTabPanelOptions.onTitleRendered]
      */
     onTitleRendered?:
       | ((e: DevExpress.ui.dxTabPanel.TitleRenderedEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxTabPanelOptions.repaintChangesOnly]
      */
@@ -33264,13 +33264,13 @@ declare module DevExpress.ui {
      */
     onItemClick?:
       | ((e: DevExpress.ui.dxTreeView.ItemClickEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxTreeViewOptions.onItemCollapsed]
      */
     onItemCollapsed?:
       | ((e: DevExpress.ui.dxTreeView.ItemCollapsedEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxTreeViewOptions.onItemContextMenu]
      */
@@ -33278,25 +33278,25 @@ declare module DevExpress.ui {
       | ((
           e: DevExpress.ui.dxTreeView.ItemContextMenuEvent<TItem, TKey>
         ) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxTreeViewOptions.onItemExpanded]
      */
     onItemExpanded?:
       | ((e: DevExpress.ui.dxTreeView.ItemExpandedEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxTreeViewOptions.onItemHold]
      */
     onItemHold?:
       | ((e: DevExpress.ui.dxTreeView.ItemHoldEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxTreeViewOptions.onItemRendered]
      */
     onItemRendered?:
       | ((e: DevExpress.ui.dxTreeView.ItemRenderedEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxTreeViewOptions.onItemSelectionChanged]
      */
@@ -33304,7 +33304,7 @@ declare module DevExpress.ui {
       | ((
           e: DevExpress.ui.dxTreeView.ItemSelectionChangedEvent<TItem, TKey>
         ) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxTreeViewOptions.onSelectAllValueChanged]
      */
@@ -33312,7 +33312,7 @@ declare module DevExpress.ui {
       | ((
           e: DevExpress.ui.dxTreeView.SelectAllValueChangedEvent<TItem, TKey>
         ) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxTreeViewOptions.onSelectionChanged]
      */
@@ -33320,7 +33320,7 @@ declare module DevExpress.ui {
       | ((
           e: DevExpress.ui.dxTreeView.SelectionChangedEvent<TItem, TKey>
         ) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxTreeViewOptions.parentIdExpr]
      */

From c8807c50748a1029afc30699d3b848d4b29a5098 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 19:06:22 +0300
Subject: [PATCH 082/100] Form: fix runtime onEditorEnterKey

---
 .../devextreme/js/__internal/ui/form/form.layout_manager.ts     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/devextreme/js/__internal/ui/form/form.layout_manager.ts b/packages/devextreme/js/__internal/ui/form/form.layout_manager.ts
index 936a79fb3770..22ae328b1a44 100644
--- a/packages/devextreme/js/__internal/ui/form/form.layout_manager.ts
+++ b/packages/devextreme/js/__internal/ui/form/form.layout_manager.ts
@@ -150,7 +150,7 @@ class LayoutManager extends Widget<LayoutManagerProperties> {
       colCount: 1,
       labelLocation: 'left',
       onFieldDataChanged: undefined,
-      onEditorEnterKey: null,
+      onEditorEnterKey: undefined,
       customizeItem: undefined,
       alignItemLabels: true,
       minColWidth: MIN_COLUMN_WIDTH,

From 80a71e1f30dfd57c8bd5e342298fa2772e42b532 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 19:15:05 +0300
Subject: [PATCH 083/100] Component: onInitialized, onOptionChanged,
 onDisposing

---
 .../js/__internal/core/widget/component.ts           |  6 +++---
 packages/devextreme/js/core/component.d.ts           | 12 ++++++------
 2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/packages/devextreme/js/__internal/core/widget/component.ts b/packages/devextreme/js/__internal/core/widget/component.ts
index e13f3f9f47af..ac0cf9abd18f 100644
--- a/packages/devextreme/js/__internal/core/widget/component.ts
+++ b/packages/devextreme/js/__internal/core/widget/component.ts
@@ -123,9 +123,9 @@ export class Component<
 
   _getDefaultOptions(): TProperties {
     return {
-      onInitialized: null,
-      onOptionChanged: null,
-      onDisposing: null,
+      onInitialized: undefined,
+      onOptionChanged: undefined,
+      onDisposing: undefined,
 
       defaultOptionsRules: null,
     } as unknown as TProperties;
diff --git a/packages/devextreme/js/core/component.d.ts b/packages/devextreme/js/core/component.d.ts
index d2cfd21921fb..22d7e9ced235 100644
--- a/packages/devextreme/js/core/component.d.ts
+++ b/packages/devextreme/js/core/component.d.ts
@@ -8,21 +8,21 @@ export interface ComponentOptions<TDisposingEvent, TInitializedEvent, TOptionCha
    * @docid
    * @type_function_param1 e:object
    * @type_function_param1_field component:this
-   * @default null
+   * @default undefined
    * @action
    * @public
    */
-  onDisposing?: ((e: TDisposingEvent) => void);
+  onDisposing?: ((e: TDisposingEvent) => void) | undefined;
   /**
    * @docid
    * @type_function_param1 e:object
    * @type_function_param1_field component:this
    * @type_function_param1_field element:DxElement
-   * @default null
+   * @default undefined
    * @action
    * @public
    */
-  onInitialized?: ((e: TInitializedEvent) => void);
+  onInitialized?: ((e: TInitializedEvent) => void) | undefined;
   /**
    * @docid
    * @type_function_param1 e:object
@@ -30,11 +30,11 @@ export interface ComponentOptions<TDisposingEvent, TInitializedEvent, TOptionCha
    * @type_function_param1_field name:string
    * @type_function_param1_field fullName:string
    * @type_function_param1_field value:any
-   * @default null
+   * @default undefined
    * @action
    * @public
    */
-  onOptionChanged?: ((e: TOptionChangedEvent) => void);
+  onOptionChanged?: ((e: TOptionChangedEvent) => void) | undefined;
 }
 /**
  * @docid Component

From bf589dccc7f8379b54d61499cd619271e20011d6 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 19:21:44 +0300
Subject: [PATCH 084/100] DOMComponent: onOptionChanged, onDisposing

---
 packages/devextreme/js/core/dom_component.d.ts | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/packages/devextreme/js/core/dom_component.d.ts b/packages/devextreme/js/core/dom_component.d.ts
index 8ab611de3705..1be32f99cc9d 100644
--- a/packages/devextreme/js/core/dom_component.d.ts
+++ b/packages/devextreme/js/core/dom_component.d.ts
@@ -48,19 +48,19 @@ export interface DOMComponentOptions<TComponent> extends ComponentOptions<
     /**
      * @docid
      * @action
-     * @default null
+     * @default undefined
      * @public
      */
-    onDisposing?: ((e: EventInfo<TComponent>) => void);
+    onDisposing?: ((e: EventInfo<TComponent>) => void) | undefined;
     /**
      * @docid
      * @action
-     * @default null
+     * @default undefined
      * @type_function_param1 e:object
      * @type_function_param1_field component:<DOMComponent>
      * @public
      */
-    onOptionChanged?: ((e: OptionChangedEventInfo<TComponent>) => void);
+    onOptionChanged?: ((e: OptionChangedEventInfo<TComponent>) => void) | undefined;
     /**
      * @docid
      * @default false

From 199b8b02efd262f54456c82aff493884ef91f3e9 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 19:22:12 +0300
Subject: [PATCH 085/100] regenerate-all

---
 .../autocomplete/nested/drop-down-options.ts  | 12 +++++------
 .../ui/color-box/nested/drop-down-options.ts  | 12 +++++------
 .../data-grid/nested/filter-builder-popup.ts  | 12 +++++------
 .../src/ui/data-grid/nested/popup.ts          | 12 +++++------
 .../ui/date-box/nested/drop-down-options.ts   | 12 +++++------
 .../nested/drop-down-options.ts               | 12 +++++------
 .../drop-down-box/nested/drop-down-options.ts | 12 +++++------
 .../nested/drop-down-options.ts               | 12 +++++------
 .../src/ui/nested/base/popup-options.ts       | 12 +++++------
 .../ui/select-box/nested/drop-down-options.ts | 12 +++++------
 .../ui/tag-box/nested/drop-down-options.ts    | 12 +++++------
 .../tree-list/nested/filter-builder-popup.ts  | 12 +++++------
 .../src/ui/tree-list/nested/popup.ts          | 12 +++++------
 packages/devextreme-react/src/autocomplete.ts |  6 +++---
 packages/devextreme-react/src/color-box.ts    |  6 +++---
 packages/devextreme-react/src/data-grid.ts    | 12 +++++------
 packages/devextreme-react/src/date-box.ts     |  6 +++---
 .../devextreme-react/src/date-range-box.ts    |  6 +++---
 .../devextreme-react/src/drop-down-box.ts     |  6 +++---
 .../devextreme-react/src/drop-down-button.ts  |  6 +++---
 packages/devextreme-react/src/select-box.ts   |  6 +++---
 packages/devextreme-react/src/tag-box.ts      |  6 +++---
 packages/devextreme-react/src/tree-list.ts    | 12 +++++------
 packages/devextreme/ts/dx.all.d.ts            | 20 ++++++++++---------
 24 files changed, 125 insertions(+), 123 deletions(-)

diff --git a/packages/devextreme-angular/src/ui/autocomplete/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/autocomplete/nested/drop-down-options.ts
index f373d816e3b9..72c75fc26d78 100644
--- a/packages/devextreme-angular/src/ui/autocomplete/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/autocomplete/nested/drop-down-options.ts
@@ -228,10 +228,10 @@ export class DxoAutocompleteDropDownOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get onDisposing(): ((e: EventInfo<any>) => void) {
+    get onDisposing(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onDisposing');
     }
-    set onDisposing(value: ((e: EventInfo<any>) => void)) {
+    set onDisposing(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onDisposing', value);
     }
 
@@ -252,18 +252,18 @@ export class DxoAutocompleteDropDownOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) {
+    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) | undefined {
         return this._getOption('onInitialized');
     }
-    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void)) {
+    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void) | undefined) {
         this._setOption('onInitialized', value);
     }
 
     @Input()
-    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) {
+    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined {
         return this._getOption('onOptionChanged');
     }
-    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)) {
+    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined) {
         this._setOption('onOptionChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/color-box/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/color-box/nested/drop-down-options.ts
index 9188425d78c5..6c85fcf886f5 100644
--- a/packages/devextreme-angular/src/ui/color-box/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/color-box/nested/drop-down-options.ts
@@ -228,10 +228,10 @@ export class DxoColorBoxDropDownOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onDisposing(): ((e: EventInfo<any>) => void) {
+    get onDisposing(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onDisposing');
     }
-    set onDisposing(value: ((e: EventInfo<any>) => void)) {
+    set onDisposing(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onDisposing', value);
     }
 
@@ -252,18 +252,18 @@ export class DxoColorBoxDropDownOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) {
+    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) | undefined {
         return this._getOption('onInitialized');
     }
-    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void)) {
+    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void) | undefined) {
         this._setOption('onInitialized', value);
     }
 
     @Input()
-    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) {
+    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined {
         return this._getOption('onOptionChanged');
     }
-    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)) {
+    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined) {
         this._setOption('onOptionChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/data-grid/nested/filter-builder-popup.ts b/packages/devextreme-angular/src/ui/data-grid/nested/filter-builder-popup.ts
index 860ae607769b..a0b1e1170848 100644
--- a/packages/devextreme-angular/src/ui/data-grid/nested/filter-builder-popup.ts
+++ b/packages/devextreme-angular/src/ui/data-grid/nested/filter-builder-popup.ts
@@ -228,10 +228,10 @@ export class DxoDataGridFilterBuilderPopupComponent extends NestedOption impleme
     }
 
     @Input()
-    get onDisposing(): ((e: EventInfo<any>) => void) {
+    get onDisposing(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onDisposing');
     }
-    set onDisposing(value: ((e: EventInfo<any>) => void)) {
+    set onDisposing(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onDisposing', value);
     }
 
@@ -252,18 +252,18 @@ export class DxoDataGridFilterBuilderPopupComponent extends NestedOption impleme
     }
 
     @Input()
-    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) {
+    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) | undefined {
         return this._getOption('onInitialized');
     }
-    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void)) {
+    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void) | undefined) {
         this._setOption('onInitialized', value);
     }
 
     @Input()
-    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) {
+    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined {
         return this._getOption('onOptionChanged');
     }
-    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)) {
+    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined) {
         this._setOption('onOptionChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/data-grid/nested/popup.ts b/packages/devextreme-angular/src/ui/data-grid/nested/popup.ts
index 866f906cf9cd..7c9c3e5f9971 100644
--- a/packages/devextreme-angular/src/ui/data-grid/nested/popup.ts
+++ b/packages/devextreme-angular/src/ui/data-grid/nested/popup.ts
@@ -228,10 +228,10 @@ export class DxoDataGridPopupComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get onDisposing(): ((e: EventInfo<any>) => void) {
+    get onDisposing(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onDisposing');
     }
-    set onDisposing(value: ((e: EventInfo<any>) => void)) {
+    set onDisposing(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onDisposing', value);
     }
 
@@ -252,18 +252,18 @@ export class DxoDataGridPopupComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) {
+    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) | undefined {
         return this._getOption('onInitialized');
     }
-    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void)) {
+    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void) | undefined) {
         this._setOption('onInitialized', value);
     }
 
     @Input()
-    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) {
+    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined {
         return this._getOption('onOptionChanged');
     }
-    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)) {
+    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined) {
         this._setOption('onOptionChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/date-box/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/date-box/nested/drop-down-options.ts
index a00457afd746..a34e30d591b0 100644
--- a/packages/devextreme-angular/src/ui/date-box/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/date-box/nested/drop-down-options.ts
@@ -228,10 +228,10 @@ export class DxoDateBoxDropDownOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onDisposing(): ((e: EventInfo<any>) => void) {
+    get onDisposing(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onDisposing');
     }
-    set onDisposing(value: ((e: EventInfo<any>) => void)) {
+    set onDisposing(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onDisposing', value);
     }
 
@@ -252,18 +252,18 @@ export class DxoDateBoxDropDownOptionsComponent extends NestedOption implements
     }
 
     @Input()
-    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) {
+    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) | undefined {
         return this._getOption('onInitialized');
     }
-    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void)) {
+    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void) | undefined) {
         this._setOption('onInitialized', value);
     }
 
     @Input()
-    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) {
+    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined {
         return this._getOption('onOptionChanged');
     }
-    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)) {
+    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined) {
         this._setOption('onOptionChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/date-range-box/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/date-range-box/nested/drop-down-options.ts
index b07460197ac7..90e889bf0e38 100644
--- a/packages/devextreme-angular/src/ui/date-range-box/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/date-range-box/nested/drop-down-options.ts
@@ -228,10 +228,10 @@ export class DxoDateRangeBoxDropDownOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get onDisposing(): ((e: EventInfo<any>) => void) {
+    get onDisposing(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onDisposing');
     }
-    set onDisposing(value: ((e: EventInfo<any>) => void)) {
+    set onDisposing(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onDisposing', value);
     }
 
@@ -252,18 +252,18 @@ export class DxoDateRangeBoxDropDownOptionsComponent extends NestedOption implem
     }
 
     @Input()
-    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) {
+    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) | undefined {
         return this._getOption('onInitialized');
     }
-    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void)) {
+    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void) | undefined) {
         this._setOption('onInitialized', value);
     }
 
     @Input()
-    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) {
+    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined {
         return this._getOption('onOptionChanged');
     }
-    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)) {
+    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined) {
         this._setOption('onOptionChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/drop-down-box/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/drop-down-box/nested/drop-down-options.ts
index 67ee792adf7a..a4140ed75beb 100644
--- a/packages/devextreme-angular/src/ui/drop-down-box/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/drop-down-box/nested/drop-down-options.ts
@@ -228,10 +228,10 @@ export class DxoDropDownBoxDropDownOptionsComponent extends NestedOption impleme
     }
 
     @Input()
-    get onDisposing(): ((e: EventInfo<any>) => void) {
+    get onDisposing(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onDisposing');
     }
-    set onDisposing(value: ((e: EventInfo<any>) => void)) {
+    set onDisposing(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onDisposing', value);
     }
 
@@ -252,18 +252,18 @@ export class DxoDropDownBoxDropDownOptionsComponent extends NestedOption impleme
     }
 
     @Input()
-    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) {
+    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) | undefined {
         return this._getOption('onInitialized');
     }
-    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void)) {
+    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void) | undefined) {
         this._setOption('onInitialized', value);
     }
 
     @Input()
-    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) {
+    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined {
         return this._getOption('onOptionChanged');
     }
-    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)) {
+    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined) {
         this._setOption('onOptionChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/drop-down-button/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/drop-down-button/nested/drop-down-options.ts
index 143b330d9079..9a9ed959eb1d 100644
--- a/packages/devextreme-angular/src/ui/drop-down-button/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/drop-down-button/nested/drop-down-options.ts
@@ -228,10 +228,10 @@ export class DxoDropDownButtonDropDownOptionsComponent extends NestedOption impl
     }
 
     @Input()
-    get onDisposing(): ((e: EventInfo<any>) => void) {
+    get onDisposing(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onDisposing');
     }
-    set onDisposing(value: ((e: EventInfo<any>) => void)) {
+    set onDisposing(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onDisposing', value);
     }
 
@@ -252,18 +252,18 @@ export class DxoDropDownButtonDropDownOptionsComponent extends NestedOption impl
     }
 
     @Input()
-    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) {
+    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) | undefined {
         return this._getOption('onInitialized');
     }
-    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void)) {
+    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void) | undefined) {
         this._setOption('onInitialized', value);
     }
 
     @Input()
-    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) {
+    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined {
         return this._getOption('onOptionChanged');
     }
-    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)) {
+    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined) {
         this._setOption('onOptionChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/nested/base/popup-options.ts b/packages/devextreme-angular/src/ui/nested/base/popup-options.ts
index 3246c4729b35..35831bc83034 100644
--- a/packages/devextreme-angular/src/ui/nested/base/popup-options.ts
+++ b/packages/devextreme-angular/src/ui/nested/base/popup-options.ts
@@ -169,10 +169,10 @@ export abstract class DxoPopupOptions extends NestedOption {
         this._setOption('onContentReady', value);
     }
 
-    get onDisposing(): Function {
+    get onDisposing(): Function | undefined {
         return this._getOption('onDisposing');
     }
-    set onDisposing(value: Function) {
+    set onDisposing(value: Function | undefined) {
         this._setOption('onDisposing', value);
     }
 
@@ -190,17 +190,17 @@ export abstract class DxoPopupOptions extends NestedOption {
         this._setOption('onHiding', value);
     }
 
-    get onInitialized(): Function {
+    get onInitialized(): Function | undefined {
         return this._getOption('onInitialized');
     }
-    set onInitialized(value: Function) {
+    set onInitialized(value: Function | undefined) {
         this._setOption('onInitialized', value);
     }
 
-    get onOptionChanged(): Function {
+    get onOptionChanged(): Function | undefined {
         return this._getOption('onOptionChanged');
     }
-    set onOptionChanged(value: Function) {
+    set onOptionChanged(value: Function | undefined) {
         this._setOption('onOptionChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/select-box/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/select-box/nested/drop-down-options.ts
index 9eafaf145b84..d9c39e668dee 100644
--- a/packages/devextreme-angular/src/ui/select-box/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/select-box/nested/drop-down-options.ts
@@ -228,10 +228,10 @@ export class DxoSelectBoxDropDownOptionsComponent extends NestedOption implement
     }
 
     @Input()
-    get onDisposing(): ((e: EventInfo<any>) => void) {
+    get onDisposing(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onDisposing');
     }
-    set onDisposing(value: ((e: EventInfo<any>) => void)) {
+    set onDisposing(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onDisposing', value);
     }
 
@@ -252,18 +252,18 @@ export class DxoSelectBoxDropDownOptionsComponent extends NestedOption implement
     }
 
     @Input()
-    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) {
+    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) | undefined {
         return this._getOption('onInitialized');
     }
-    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void)) {
+    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void) | undefined) {
         this._setOption('onInitialized', value);
     }
 
     @Input()
-    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) {
+    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined {
         return this._getOption('onOptionChanged');
     }
-    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)) {
+    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined) {
         this._setOption('onOptionChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tag-box/nested/drop-down-options.ts b/packages/devextreme-angular/src/ui/tag-box/nested/drop-down-options.ts
index d6eadff61355..235f1bbefb48 100644
--- a/packages/devextreme-angular/src/ui/tag-box/nested/drop-down-options.ts
+++ b/packages/devextreme-angular/src/ui/tag-box/nested/drop-down-options.ts
@@ -228,10 +228,10 @@ export class DxoTagBoxDropDownOptionsComponent extends NestedOption implements O
     }
 
     @Input()
-    get onDisposing(): ((e: EventInfo<any>) => void) {
+    get onDisposing(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onDisposing');
     }
-    set onDisposing(value: ((e: EventInfo<any>) => void)) {
+    set onDisposing(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onDisposing', value);
     }
 
@@ -252,18 +252,18 @@ export class DxoTagBoxDropDownOptionsComponent extends NestedOption implements O
     }
 
     @Input()
-    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) {
+    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) | undefined {
         return this._getOption('onInitialized');
     }
-    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void)) {
+    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void) | undefined) {
         this._setOption('onInitialized', value);
     }
 
     @Input()
-    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) {
+    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined {
         return this._getOption('onOptionChanged');
     }
-    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)) {
+    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined) {
         this._setOption('onOptionChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tree-list/nested/filter-builder-popup.ts b/packages/devextreme-angular/src/ui/tree-list/nested/filter-builder-popup.ts
index 77565658a7a4..148c8fad9e0e 100644
--- a/packages/devextreme-angular/src/ui/tree-list/nested/filter-builder-popup.ts
+++ b/packages/devextreme-angular/src/ui/tree-list/nested/filter-builder-popup.ts
@@ -228,10 +228,10 @@ export class DxoTreeListFilterBuilderPopupComponent extends NestedOption impleme
     }
 
     @Input()
-    get onDisposing(): ((e: EventInfo<any>) => void) {
+    get onDisposing(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onDisposing');
     }
-    set onDisposing(value: ((e: EventInfo<any>) => void)) {
+    set onDisposing(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onDisposing', value);
     }
 
@@ -252,18 +252,18 @@ export class DxoTreeListFilterBuilderPopupComponent extends NestedOption impleme
     }
 
     @Input()
-    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) {
+    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) | undefined {
         return this._getOption('onInitialized');
     }
-    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void)) {
+    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void) | undefined) {
         this._setOption('onInitialized', value);
     }
 
     @Input()
-    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) {
+    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined {
         return this._getOption('onOptionChanged');
     }
-    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)) {
+    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined) {
         this._setOption('onOptionChanged', value);
     }
 
diff --git a/packages/devextreme-angular/src/ui/tree-list/nested/popup.ts b/packages/devextreme-angular/src/ui/tree-list/nested/popup.ts
index b3df44382136..f8759ac785a0 100644
--- a/packages/devextreme-angular/src/ui/tree-list/nested/popup.ts
+++ b/packages/devextreme-angular/src/ui/tree-list/nested/popup.ts
@@ -228,10 +228,10 @@ export class DxoTreeListPopupComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get onDisposing(): ((e: EventInfo<any>) => void) {
+    get onDisposing(): ((e: EventInfo<any>) => void) | undefined {
         return this._getOption('onDisposing');
     }
-    set onDisposing(value: ((e: EventInfo<any>) => void)) {
+    set onDisposing(value: ((e: EventInfo<any>) => void) | undefined) {
         this._setOption('onDisposing', value);
     }
 
@@ -252,18 +252,18 @@ export class DxoTreeListPopupComponent extends NestedOption implements OnDestroy
     }
 
     @Input()
-    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) {
+    get onInitialized(): ((e: { component: CoreComponent<any>, element: any }) => void) | undefined {
         return this._getOption('onInitialized');
     }
-    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void)) {
+    set onInitialized(value: ((e: { component: CoreComponent<any>, element: any }) => void) | undefined) {
         this._setOption('onInitialized', value);
     }
 
     @Input()
-    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) {
+    get onOptionChanged(): ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined {
         return this._getOption('onOptionChanged');
     }
-    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void)) {
+    set onOptionChanged(value: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined) {
         this._setOption('onOptionChanged', value);
     }
 
diff --git a/packages/devextreme-react/src/autocomplete.ts b/packages/devextreme-react/src/autocomplete.ts
index 2941db9899ea..48637530768f 100644
--- a/packages/devextreme-react/src/autocomplete.ts
+++ b/packages/devextreme-react/src/autocomplete.ts
@@ -258,11 +258,11 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   minHeight?: number | string;
   minWidth?: number | string;
   onContentReady?: ((e: EventInfo<any>) => void) | undefined;
-  onDisposing?: ((e: EventInfo<any>) => void);
+  onDisposing?: ((e: EventInfo<any>) => void) | undefined;
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
-  onInitialized?: ((e: { component: Component<any>, element: any }) => void);
-  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
+  onInitialized?: ((e: { component: Component<any>, element: any }) => void) | undefined;
+  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined;
   onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
diff --git a/packages/devextreme-react/src/color-box.ts b/packages/devextreme-react/src/color-box.ts
index eada7abebd0e..8f2a589509b7 100644
--- a/packages/devextreme-react/src/color-box.ts
+++ b/packages/devextreme-react/src/color-box.ts
@@ -249,11 +249,11 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   minHeight?: number | string;
   minWidth?: number | string;
   onContentReady?: ((e: EventInfo<any>) => void) | undefined;
-  onDisposing?: ((e: EventInfo<any>) => void);
+  onDisposing?: ((e: EventInfo<any>) => void) | undefined;
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
-  onInitialized?: ((e: { component: Component<any>, element: any }) => void);
-  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
+  onInitialized?: ((e: { component: Component<any>, element: any }) => void) | undefined;
+  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined;
   onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
diff --git a/packages/devextreme-react/src/data-grid.ts b/packages/devextreme-react/src/data-grid.ts
index 0ae6af241406..f8c169f9288b 100644
--- a/packages/devextreme-react/src/data-grid.ts
+++ b/packages/devextreme-react/src/data-grid.ts
@@ -1681,11 +1681,11 @@ type IFilterBuilderPopupProps = React.PropsWithChildren<{
   minHeight?: number | string;
   minWidth?: number | string;
   onContentReady?: ((e: EventInfo<any>) => void) | undefined;
-  onDisposing?: ((e: EventInfo<any>) => void);
+  onDisposing?: ((e: EventInfo<any>) => void) | undefined;
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
-  onInitialized?: ((e: { component: Component<any>, element: any }) => void);
-  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
+  onInitialized?: ((e: { component: Component<any>, element: any }) => void) | undefined;
+  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined;
   onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
@@ -2875,11 +2875,11 @@ type IPopupProps = React.PropsWithChildren<{
   minHeight?: number | string;
   minWidth?: number | string;
   onContentReady?: ((e: EventInfo<any>) => void) | undefined;
-  onDisposing?: ((e: EventInfo<any>) => void);
+  onDisposing?: ((e: EventInfo<any>) => void) | undefined;
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
-  onInitialized?: ((e: { component: Component<any>, element: any }) => void);
-  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
+  onInitialized?: ((e: { component: Component<any>, element: any }) => void) | undefined;
+  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined;
   onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
diff --git a/packages/devextreme-react/src/date-box.ts b/packages/devextreme-react/src/date-box.ts
index 1cb3f096d02b..565ccdbb3504 100644
--- a/packages/devextreme-react/src/date-box.ts
+++ b/packages/devextreme-react/src/date-box.ts
@@ -342,11 +342,11 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   minHeight?: number | string;
   minWidth?: number | string;
   onContentReady?: ((e: EventInfo<any>) => void) | undefined;
-  onDisposing?: ((e: EventInfo<any>) => void);
+  onDisposing?: ((e: EventInfo<any>) => void) | undefined;
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
-  onInitialized?: ((e: { component: Component<any>, element: any }) => void);
-  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
+  onInitialized?: ((e: { component: Component<any>, element: any }) => void) | undefined;
+  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined;
   onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
diff --git a/packages/devextreme-react/src/date-range-box.ts b/packages/devextreme-react/src/date-range-box.ts
index dcc3dd7e3f9a..a52af5e8f715 100644
--- a/packages/devextreme-react/src/date-range-box.ts
+++ b/packages/devextreme-react/src/date-range-box.ts
@@ -347,11 +347,11 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   minHeight?: number | string;
   minWidth?: number | string;
   onContentReady?: ((e: EventInfo<any>) => void) | undefined;
-  onDisposing?: ((e: EventInfo<any>) => void);
+  onDisposing?: ((e: EventInfo<any>) => void) | undefined;
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
-  onInitialized?: ((e: { component: Component<any>, element: any }) => void);
-  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
+  onInitialized?: ((e: { component: Component<any>, element: any }) => void) | undefined;
+  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined;
   onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
diff --git a/packages/devextreme-react/src/drop-down-box.ts b/packages/devextreme-react/src/drop-down-box.ts
index 4f3882b854da..25d37db6e3b2 100644
--- a/packages/devextreme-react/src/drop-down-box.ts
+++ b/packages/devextreme-react/src/drop-down-box.ts
@@ -253,11 +253,11 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   minHeight?: number | string;
   minWidth?: number | string;
   onContentReady?: ((e: EventInfo<any>) => void) | undefined;
-  onDisposing?: ((e: EventInfo<any>) => void);
+  onDisposing?: ((e: EventInfo<any>) => void) | undefined;
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
-  onInitialized?: ((e: { component: Component<any>, element: any }) => void);
-  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
+  onInitialized?: ((e: { component: Component<any>, element: any }) => void) | undefined;
+  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined;
   onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
diff --git a/packages/devextreme-react/src/drop-down-button.ts b/packages/devextreme-react/src/drop-down-button.ts
index e49389fab13e..bf41717ebb69 100644
--- a/packages/devextreme-react/src/drop-down-button.ts
+++ b/packages/devextreme-react/src/drop-down-button.ts
@@ -208,11 +208,11 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   minHeight?: number | string;
   minWidth?: number | string;
   onContentReady?: ((e: EventInfo<any>) => void) | undefined;
-  onDisposing?: ((e: EventInfo<any>) => void);
+  onDisposing?: ((e: EventInfo<any>) => void) | undefined;
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
-  onInitialized?: ((e: { component: Component<any>, element: any }) => void);
-  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
+  onInitialized?: ((e: { component: Component<any>, element: any }) => void) | undefined;
+  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined;
   onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
diff --git a/packages/devextreme-react/src/select-box.ts b/packages/devextreme-react/src/select-box.ts
index b17d3be9daf6..3b46b048be9b 100644
--- a/packages/devextreme-react/src/select-box.ts
+++ b/packages/devextreme-react/src/select-box.ts
@@ -267,11 +267,11 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   minHeight?: number | string;
   minWidth?: number | string;
   onContentReady?: ((e: EventInfo<any>) => void) | undefined;
-  onDisposing?: ((e: EventInfo<any>) => void);
+  onDisposing?: ((e: EventInfo<any>) => void) | undefined;
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
-  onInitialized?: ((e: { component: Component<any>, element: any }) => void);
-  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
+  onInitialized?: ((e: { component: Component<any>, element: any }) => void) | undefined;
+  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined;
   onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
diff --git a/packages/devextreme-react/src/tag-box.ts b/packages/devextreme-react/src/tag-box.ts
index 725621804869..a7b48f31be58 100644
--- a/packages/devextreme-react/src/tag-box.ts
+++ b/packages/devextreme-react/src/tag-box.ts
@@ -273,11 +273,11 @@ type IDropDownOptionsProps = React.PropsWithChildren<{
   minHeight?: number | string;
   minWidth?: number | string;
   onContentReady?: ((e: EventInfo<any>) => void) | undefined;
-  onDisposing?: ((e: EventInfo<any>) => void);
+  onDisposing?: ((e: EventInfo<any>) => void) | undefined;
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
-  onInitialized?: ((e: { component: Component<any>, element: any }) => void);
-  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
+  onInitialized?: ((e: { component: Component<any>, element: any }) => void) | undefined;
+  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined;
   onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
diff --git a/packages/devextreme-react/src/tree-list.ts b/packages/devextreme-react/src/tree-list.ts
index bcfbafee8f1c..22f2ead911b0 100644
--- a/packages/devextreme-react/src/tree-list.ts
+++ b/packages/devextreme-react/src/tree-list.ts
@@ -1450,11 +1450,11 @@ type IFilterBuilderPopupProps = React.PropsWithChildren<{
   minHeight?: number | string;
   minWidth?: number | string;
   onContentReady?: ((e: EventInfo<any>) => void) | undefined;
-  onDisposing?: ((e: EventInfo<any>) => void);
+  onDisposing?: ((e: EventInfo<any>) => void) | undefined;
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
-  onInitialized?: ((e: { component: Component<any>, element: any }) => void);
-  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
+  onInitialized?: ((e: { component: Component<any>, element: any }) => void) | undefined;
+  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined;
   onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
@@ -2507,11 +2507,11 @@ type IPopupProps = React.PropsWithChildren<{
   minHeight?: number | string;
   minWidth?: number | string;
   onContentReady?: ((e: EventInfo<any>) => void) | undefined;
-  onDisposing?: ((e: EventInfo<any>) => void);
+  onDisposing?: ((e: EventInfo<any>) => void) | undefined;
   onHidden?: ((e: EventInfo<any>) => void);
   onHiding?: ((e: { cancel: boolean | any, component: dxOverlay<any>, element: any, model: any }) => void);
-  onInitialized?: ((e: { component: Component<any>, element: any }) => void);
-  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void);
+  onInitialized?: ((e: { component: Component<any>, element: any }) => void) | undefined;
+  onOptionChanged?: ((e: { component: DOMComponent, element: any, fullName: string, model: any, name: string, previousValue: any, value: any }) => void) | undefined;
   onResize?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeEnd?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
   onResizeStart?: ((e: { component: dxPopup, element: any, event: event, height: number, model: any, width: number }) => void) | undefined;
diff --git a/packages/devextreme/ts/dx.all.d.ts b/packages/devextreme/ts/dx.all.d.ts
index 0ab20f12f810..780ef1b9e7ad 100644
--- a/packages/devextreme/ts/dx.all.d.ts
+++ b/packages/devextreme/ts/dx.all.d.ts
@@ -587,15 +587,15 @@ declare module DevExpress {
     /**
      * [descr:ComponentOptions.onDisposing]
      */
-    onDisposing?: (e: TDisposingEvent) => void;
+    onDisposing?: ((e: TDisposingEvent) => void) | undefined;
     /**
      * [descr:ComponentOptions.onInitialized]
      */
-    onInitialized?: (e: TInitializedEvent) => void;
+    onInitialized?: ((e: TInitializedEvent) => void) | undefined;
     /**
      * [descr:ComponentOptions.onOptionChanged]
      */
-    onOptionChanged?: (e: TOptionChangedEvent) => void;
+    onOptionChanged?: ((e: TOptionChangedEvent) => void) | undefined;
   }
   /**
    * [descr:config()]
@@ -714,15 +714,17 @@ declare module DevExpress {
     /**
      * [descr:DOMComponentOptions.onDisposing]
      */
-    onDisposing?: (
-      e: DevExpress.common.core.events.EventInfo<TComponent>
-    ) => void;
+    onDisposing?:
+      | ((e: DevExpress.common.core.events.EventInfo<TComponent>) => void)
+      | undefined;
     /**
      * [descr:DOMComponentOptions.onOptionChanged]
      */
-    onOptionChanged?: (
-      e: DevExpress.DOMComponent.OptionChangedEventInfo<TComponent>
-    ) => void;
+    onOptionChanged?:
+      | ((
+          e: DevExpress.DOMComponent.OptionChangedEventInfo<TComponent>
+        ) => void)
+      | undefined;
     /**
      * [descr:DOMComponentOptions.rtlEnabled]
      */

From 85efa637c3b81a0b21761953c4abdcbe0aaa0296 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 19:37:46 +0300
Subject: [PATCH 086/100] ContextMenu: onHidden, onHiding, onPositioning,
 onShowing, onShown

---
 packages/devextreme-vue/src/context-menu.ts   | 10 +++++-----
 .../ui/context_menu/context_menu.ts           | 10 +++++-----
 packages/devextreme/js/ui/context_menu.d.ts   | 20 +++++++++----------
 3 files changed, 20 insertions(+), 20 deletions(-)

diff --git a/packages/devextreme-vue/src/context-menu.ts b/packages/devextreme-vue/src/context-menu.ts
index b0c8a4fe7800..710e286b64fc 100644
--- a/packages/devextreme-vue/src/context-menu.ts
+++ b/packages/devextreme-vue/src/context-menu.ts
@@ -119,17 +119,17 @@ const componentConfig = {
     itemTemplate: {},
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
-    onHidden: Function as PropType<(((e: HiddenEvent) => void)) | null>,
-    onHiding: Function as PropType<(((e: HidingEvent) => void)) | null>,
+    onHidden: Function as PropType<((e: HiddenEvent) => void)>,
+    onHiding: Function as PropType<((e: HidingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
     onItemContextMenu: Function as PropType<((e: ItemContextMenuEvent) => void)>,
     onItemRendered: Function as PropType<((e: ItemRenderedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onPositioning: Function as PropType<(((e: PositioningEvent) => void)) | null>,
+    onPositioning: Function as PropType<((e: PositioningEvent) => void)>,
     onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
-    onShowing: Function as PropType<(((e: ShowingEvent) => void)) | null>,
-    onShown: Function as PropType<(((e: ShownEvent) => void)) | null>,
+    onShowing: Function as PropType<((e: ShowingEvent) => void)>,
+    onShown: Function as PropType<((e: ShownEvent) => void)>,
     position: Object as PropType<PositionConfig | Record<string, any>>,
     rtlEnabled: Boolean,
     selectByClick: Boolean,
diff --git a/packages/devextreme/js/__internal/ui/context_menu/context_menu.ts b/packages/devextreme/js/__internal/ui/context_menu/context_menu.ts
index 5adf0be26435..35b88009a7ed 100644
--- a/packages/devextreme/js/__internal/ui/context_menu/context_menu.ts
+++ b/packages/devextreme/js/__internal/ui/context_menu/context_menu.ts
@@ -183,12 +183,12 @@ class ContextMenu<
         at: 'top left',
         my: 'top left',
       },
-      onShowing: null,
-      onShown: null,
+      onShowing: undefined,
+      onShown: undefined,
       onSubmenuCreated: null,
-      onHiding: null,
-      onHidden: null,
-      onPositioning: null,
+      onHiding: undefined,
+      onHidden: undefined,
+      onPositioning: undefined,
       submenuDirection: 'auto',
       visible: false,
       target: undefined,
diff --git a/packages/devextreme/js/ui/context_menu.d.ts b/packages/devextreme/js/ui/context_menu.d.ts
index 3840582c6ad5..ed081696a6c0 100644
--- a/packages/devextreme/js/ui/context_menu.d.ts
+++ b/packages/devextreme/js/ui/context_menu.d.ts
@@ -179,44 +179,44 @@ export interface dxContextMenuOptions<
     items?: Array<TItem>;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/context_menu:HiddenEvent}
      * @action
      * @public
      */
-    onHidden?: ((e: HiddenEvent<TItem, TKey>) => void) | null;
+    onHidden?: ((e: HiddenEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/context_menu:HidingEvent}
      * @action
      * @public
      */
-    onHiding?: ((e: HidingEvent<TItem, TKey>) => void) | null;
+    onHiding?: ((e: HidingEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/context_menu:PositioningEvent}
      * @action
      * @public
      */
-    onPositioning?: ((e: PositioningEvent<TItem, TKey>) => void) | null;
+    onPositioning?: ((e: PositioningEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/context_menu:ShowingEvent}
      * @action
      * @public
      */
-    onShowing?: ((e: ShowingEvent<TItem, TKey>) => void) | null;
+    onShowing?: ((e: ShowingEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/context_menu:ShownEvent}
      * @action
      * @public
      */
-    onShown?: ((e: ShownEvent<TItem, TKey>) => void) | null;
+    onShown?: ((e: ShownEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
      * @default { my: 'top left', at: 'top left' }

From 47fd15f24c063ceb72690bf4d9e42c8c27423b95 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 19:38:36 +0300
Subject: [PATCH 087/100] Diagram: onItemClick, onItemDblClick,
 onSelectionChanged, onRequestEditOperation

---
 packages/devextreme-vue/src/diagram.ts        | 10 +++++-----
 .../js/__internal/ui/diagram/ui.diagram.ts    | 10 +++++-----
 packages/devextreme/js/ui/diagram.d.ts        | 20 +++++++++----------
 3 files changed, 20 insertions(+), 20 deletions(-)

diff --git a/packages/devextreme-vue/src/diagram.ts b/packages/devextreme-vue/src/diagram.ts
index 255da3bb1fb7..551fe1416c39 100644
--- a/packages/devextreme-vue/src/diagram.ts
+++ b/packages/devextreme-vue/src/diagram.ts
@@ -117,12 +117,12 @@ const componentConfig = {
     onCustomCommand: Function as PropType<((e: CustomCommandEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
-    onItemClick: Function as PropType<(((e: ItemClickEvent) => void)) | null>,
-    onItemDblClick: Function as PropType<(((e: ItemDblClickEvent) => void)) | null>,
+    onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
+    onItemDblClick: Function as PropType<((e: ItemDblClickEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onRequestEditOperation: Function as PropType<(((e: RequestEditOperationEvent) => void)) | null>,
-    onRequestLayoutUpdate: Function as PropType<(((e: RequestLayoutUpdateEvent) => void)) | null>,
-    onSelectionChanged: Function as PropType<(((e: SelectionChangedEvent) => void)) | null>,
+    onRequestEditOperation: Function as PropType<((e: RequestEditOperationEvent) => void)>,
+    onRequestLayoutUpdate: Function as PropType<((e: RequestLayoutUpdateEvent) => void)>,
+    onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
     pageColor: String,
     pageOrientation: String as PropType<PageOrientation>,
     pageSize: Object as PropType<Record<string, any>>,
diff --git a/packages/devextreme/js/__internal/ui/diagram/ui.diagram.ts b/packages/devextreme/js/__internal/ui/diagram/ui.diagram.ts
index 4da7b2fc7823..9c264445de99 100644
--- a/packages/devextreme/js/__internal/ui/diagram/ui.diagram.ts
+++ b/packages/devextreme/js/__internal/ui/diagram/ui.diagram.ts
@@ -2311,15 +2311,15 @@ class Diagram extends Widget<Properties> {
         fileName: 'Diagram',
       },
 
-      onItemClick: null,
+      onItemClick: undefined,
 
-      onItemDblClick: null,
+      onItemDblClick: undefined,
 
-      onSelectionChanged: null,
+      onSelectionChanged: undefined,
 
-      onRequestEditOperation: null,
+      onRequestEditOperation: undefined,
 
-      onRequestLayoutUpdate: null,
+      onRequestLayoutUpdate: undefined,
     });
   }
 
diff --git a/packages/devextreme/js/ui/diagram.d.ts b/packages/devextreme/js/ui/diagram.d.ts
index 90a87a50ce96..efbb5bdeb6f9 100644
--- a/packages/devextreme/js/ui/diagram.d.ts
+++ b/packages/devextreme/js/ui/diagram.d.ts
@@ -835,44 +835,44 @@ export interface dxDiagramOptions extends WidgetOptions<dxDiagram> {
     hasChanges?: boolean;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/diagram:ItemClickEvent}
      * @action
      * @public
      */
-    onItemClick?: ((e: ItemClickEvent) => void) | null;
+    onItemClick?: ((e: ItemClickEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/diagram:ItemDblClickEvent}
      * @action
      * @public
      */
-    onItemDblClick?: ((e: ItemDblClickEvent) => void) | null;
+    onItemDblClick?: ((e: ItemDblClickEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/diagram:SelectionChangedEvent}
      * @action
      * @public
      */
-    onSelectionChanged?: ((e: SelectionChangedEvent) => void) | null;
+    onSelectionChanged?: ((e: SelectionChangedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/diagram:RequestEditOperationEvent}
      * @action
      * @public
      */
-    onRequestEditOperation?: ((e: RequestEditOperationEvent) => void) | null;
+    onRequestEditOperation?: ((e: RequestEditOperationEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/diagram:RequestLayoutUpdateEvent}
      * @action
      * @public
      */
-    onRequestLayoutUpdate?: ((e: RequestLayoutUpdateEvent) => void) | null;
+    onRequestLayoutUpdate?: ((e: RequestLayoutUpdateEvent) => void) | undefined;
     /**
      * @docid
      * @default "white"

From 273128ee7e73ac97ff4db8968e29631befb51476 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 19:42:03 +0300
Subject: [PATCH 088/100] Gantt: onSelectionChanged, onCustomCommand,
 onContextMenuPreparing, onTaskInserting, onTaskInserted, onTaskDeleting,
 onTaskDeleted, onTaskUpdating, onTaskUpdated, onTaskMoving,
 onTaskEditDialogShowing, onResourceManagerDialogShowing,
 onDependencyInserting, onDependencyInserted, onDependencyDeleting,
 onDependencyDeleted, onResourceInserting, onResourceInserted,
 onResourceDeleting, onResourceDeleted, onResourceAssigning,
 onResourceAssigned, onResourceUnassigning, onResourceUnassigned, onTaskClick,
 onTaskDblClick

---
 packages/devextreme-vue/src/gantt.ts          |  50 ++++-----
 .../js/__internal/ui/gantt/ui.gantt.helper.ts |  54 +++++-----
 packages/devextreme/js/ui/gantt.d.ts          | 100 +++++++++---------
 3 files changed, 102 insertions(+), 102 deletions(-)

diff --git a/packages/devextreme-vue/src/gantt.ts b/packages/devextreme-vue/src/gantt.ts
index d8863f598c4b..4c9a89fc2091 100644
--- a/packages/devextreme-vue/src/gantt.ts
+++ b/packages/devextreme-vue/src/gantt.ts
@@ -188,36 +188,36 @@ const componentConfig = {
     hint: String,
     hoverStateEnabled: Boolean,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
-    onContextMenuPreparing: Function as PropType<(((e: ContextMenuPreparingEvent) => void)) | null>,
-    onCustomCommand: Function as PropType<(((e: CustomCommandEvent) => void)) | null>,
-    onDependencyDeleted: Function as PropType<(((e: DependencyDeletedEvent) => void)) | null>,
-    onDependencyDeleting: Function as PropType<(((e: DependencyDeletingEvent) => void)) | null>,
-    onDependencyInserted: Function as PropType<(((e: DependencyInsertedEvent) => void)) | null>,
-    onDependencyInserting: Function as PropType<(((e: DependencyInsertingEvent) => void)) | null>,
+    onContextMenuPreparing: Function as PropType<((e: ContextMenuPreparingEvent) => void)>,
+    onCustomCommand: Function as PropType<((e: CustomCommandEvent) => void)>,
+    onDependencyDeleted: Function as PropType<((e: DependencyDeletedEvent) => void)>,
+    onDependencyDeleting: Function as PropType<((e: DependencyDeletingEvent) => void)>,
+    onDependencyInserted: Function as PropType<((e: DependencyInsertedEvent) => void)>,
+    onDependencyInserting: Function as PropType<((e: DependencyInsertingEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onResourceAssigned: Function as PropType<(((e: ResourceAssignedEvent) => void)) | null>,
-    onResourceAssigning: Function as PropType<(((e: ResourceAssigningEvent) => void)) | null>,
-    onResourceDeleted: Function as PropType<(((e: ResourceDeletedEvent) => void)) | null>,
-    onResourceDeleting: Function as PropType<(((e: ResourceDeletingEvent) => void)) | null>,
-    onResourceInserted: Function as PropType<(((e: ResourceInsertedEvent) => void)) | null>,
-    onResourceInserting: Function as PropType<(((e: ResourceInsertingEvent) => void)) | null>,
+    onResourceAssigned: Function as PropType<((e: ResourceAssignedEvent) => void)>,
+    onResourceAssigning: Function as PropType<((e: ResourceAssigningEvent) => void)>,
+    onResourceDeleted: Function as PropType<((e: ResourceDeletedEvent) => void)>,
+    onResourceDeleting: Function as PropType<((e: ResourceDeletingEvent) => void)>,
+    onResourceInserted: Function as PropType<((e: ResourceInsertedEvent) => void)>,
+    onResourceInserting: Function as PropType<((e: ResourceInsertingEvent) => void)>,
     onResourceManagerDialogShowing: Function as PropType<((e: ResourceManagerDialogShowingEvent) => void)>,
-    onResourceUnassigned: Function as PropType<(((e: ResourceUnassignedEvent) => void)) | null>,
-    onResourceUnassigning: Function as PropType<(((e: ResourceUnassigningEvent) => void)) | null>,
+    onResourceUnassigned: Function as PropType<((e: ResourceUnassignedEvent) => void)>,
+    onResourceUnassigning: Function as PropType<((e: ResourceUnassigningEvent) => void)>,
     onScaleCellPrepared: Function as PropType<((e: ScaleCellPreparedEvent) => void)>,
-    onSelectionChanged: Function as PropType<(((e: SelectionChangedEvent) => void)) | null>,
-    onTaskClick: Function as PropType<(((e: TaskClickEvent) => void)) | null>,
-    onTaskDblClick: Function as PropType<(((e: TaskDblClickEvent) => void)) | null>,
-    onTaskDeleted: Function as PropType<(((e: TaskDeletedEvent) => void)) | null>,
-    onTaskDeleting: Function as PropType<(((e: TaskDeletingEvent) => void)) | null>,
-    onTaskEditDialogShowing: Function as PropType<(((e: TaskEditDialogShowingEvent) => void)) | null>,
-    onTaskInserted: Function as PropType<(((e: TaskInsertedEvent) => void)) | null>,
-    onTaskInserting: Function as PropType<(((e: TaskInsertingEvent) => void)) | null>,
-    onTaskMoving: Function as PropType<(((e: TaskMovingEvent) => void)) | null>,
-    onTaskUpdated: Function as PropType<(((e: TaskUpdatedEvent) => void)) | null>,
-    onTaskUpdating: Function as PropType<(((e: TaskUpdatingEvent) => void)) | null>,
+    onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
+    onTaskClick: Function as PropType<((e: TaskClickEvent) => void)>,
+    onTaskDblClick: Function as PropType<((e: TaskDblClickEvent) => void)>,
+    onTaskDeleted: Function as PropType<((e: TaskDeletedEvent) => void)>,
+    onTaskDeleting: Function as PropType<((e: TaskDeletingEvent) => void)>,
+    onTaskEditDialogShowing: Function as PropType<((e: TaskEditDialogShowingEvent) => void)>,
+    onTaskInserted: Function as PropType<((e: TaskInsertedEvent) => void)>,
+    onTaskInserting: Function as PropType<((e: TaskInsertingEvent) => void)>,
+    onTaskMoving: Function as PropType<((e: TaskMovingEvent) => void)>,
+    onTaskUpdated: Function as PropType<((e: TaskUpdatedEvent) => void)>,
+    onTaskUpdating: Function as PropType<((e: TaskUpdatingEvent) => void)>,
     resourceAssignments: Object as PropType<Record<string, any>>,
     resources: Object as PropType<Record<string, any>>,
     rootValue: {},
diff --git a/packages/devextreme/js/__internal/ui/gantt/ui.gantt.helper.ts b/packages/devextreme/js/__internal/ui/gantt/ui.gantt.helper.ts
index 490c9010e4c8..f15e51fd5393 100644
--- a/packages/devextreme/js/__internal/ui/gantt/ui.gantt.helper.ts
+++ b/packages/devextreme/js/__internal/ui/gantt/ui.gantt.helper.ts
@@ -157,33 +157,33 @@ export const GanttHelper = {
       taskTitlePosition: 'inside',
       firstDayOfWeek: undefined,
       selectedRowKey: undefined,
-      onSelectionChanged: null,
-      onTaskClick: null,
-      onTaskDblClick: null,
-      onTaskInserting: null,
-      onTaskInserted: null,
-      onTaskDeleting: null,
-      onTaskDeleted: null,
-      onTaskUpdating: null,
-      onTaskUpdated: null,
-      onTaskMoving: null,
-      onTaskEditDialogShowing: null,
-      onDependencyInserting: null,
-      onDependencyInserted: null,
-      onDependencyDeleting: null,
-      onDependencyDeleted: null,
-      onResourceInserting: null,
-      onResourceInserted: null,
-      onResourceDeleting: null,
-      onResourceDeleted: null,
-      onResourceAssigning: null,
-      onResourceAssigned: null,
-
-      onResourceUnassigning: null,
-
-      onResourceUnassigned: null,
-      onCustomCommand: null,
-      onContextMenuPreparing: null,
+      onSelectionChanged: undefined,
+      onTaskClick: undefined,
+      onTaskDblClick: undefined,
+      onTaskInserting: undefined,
+      onTaskInserted: undefined,
+      onTaskDeleting: undefined,
+      onTaskDeleted: undefined,
+      onTaskUpdating: undefined,
+      onTaskUpdated: undefined,
+      onTaskMoving: undefined,
+      onTaskEditDialogShowing: undefined,
+      onDependencyInserting: undefined,
+      onDependencyInserted: undefined,
+      onDependencyDeleting: undefined,
+      onDependencyDeleted: undefined,
+      onResourceInserting: undefined,
+      onResourceInserted: undefined,
+      onResourceDeleting: undefined,
+      onResourceDeleted: undefined,
+      onResourceAssigning: undefined,
+      onResourceAssigned: undefined,
+
+      onResourceUnassigning: undefined,
+
+      onResourceUnassigned: undefined,
+      onCustomCommand: undefined,
+      onContextMenuPreparing: undefined,
       allowSelection: true,
       showRowLines: true,
       stripLines: undefined,
diff --git a/packages/devextreme/js/ui/gantt.d.ts b/packages/devextreme/js/ui/gantt.d.ts
index 7c605450ae67..e593d25571b5 100644
--- a/packages/devextreme/js/ui/gantt.d.ts
+++ b/packages/devextreme/js/ui/gantt.d.ts
@@ -643,92 +643,92 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
      headerFilter?: dxGanttHeaderFilter;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:SelectionChangedEvent}
      * @action
      * @public
      */
-    onSelectionChanged?: ((e: SelectionChangedEvent) => void) | null;
+    onSelectionChanged?: ((e: SelectionChangedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:CustomCommandEvent}
      * @action
      * @public
      */
-    onCustomCommand?: ((e: CustomCommandEvent) => void) | null;
+    onCustomCommand?: ((e: CustomCommandEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:ContextMenuPreparingEvent}
      * @action
      * @public
      */
-    onContextMenuPreparing?: ((e: ContextMenuPreparingEvent) => void) | null;
+    onContextMenuPreparing?: ((e: ContextMenuPreparingEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:TaskInsertingEvent}
      * @action
      * @public
      */
-    onTaskInserting?: ((e: TaskInsertingEvent) => void) | null;
+    onTaskInserting?: ((e: TaskInsertingEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:TaskInsertedEvent}
      * @action
      * @public
      */
-    onTaskInserted?: ((e: TaskInsertedEvent) => void) | null;
+    onTaskInserted?: ((e: TaskInsertedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:TaskDeletingEvent}
      * @action
      * @public
      */
-    onTaskDeleting?: ((e: TaskDeletingEvent) => void) | null;
+    onTaskDeleting?: ((e: TaskDeletingEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:TaskDeletedEvent}
      * @action
      * @public
      */
-    onTaskDeleted?: ((e: TaskDeletedEvent) => void) | null;
+    onTaskDeleted?: ((e: TaskDeletedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:TaskUpdatingEvent}
      * @action
      * @public
      */
-    onTaskUpdating?: ((e: TaskUpdatingEvent) => void) | null;
+    onTaskUpdating?: ((e: TaskUpdatingEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:TaskUpdatedEvent}
      * @action
      * @public
      */
-    onTaskUpdated?: ((e: TaskUpdatedEvent) => void) | null;
+    onTaskUpdated?: ((e: TaskUpdatedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:TaskMovingEvent}
      * @action
      * @public
      */
-    onTaskMoving?: ((e: TaskMovingEvent) => void) | null;
+    onTaskMoving?: ((e: TaskMovingEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:TaskEditDialogShowingEvent}
      * @action
      * @public
      */
-    onTaskEditDialogShowing?: ((e: TaskEditDialogShowingEvent) => void) | null;
+    onTaskEditDialogShowing?: ((e: TaskEditDialogShowingEvent) => void) | undefined;
     /**
      * @docid
      * @default undefined
@@ -739,116 +739,116 @@ export interface dxGanttOptions extends WidgetOptions<dxGantt> {
     onResourceManagerDialogShowing?: ((e: ResourceManagerDialogShowingEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:DependencyInsertingEvent}
      * @action
      * @public
      */
-    onDependencyInserting?: ((e: DependencyInsertingEvent) => void) | null;
+    onDependencyInserting?: ((e: DependencyInsertingEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:DependencyInsertedEvent}
      * @action
      * @public
      */
-    onDependencyInserted?: ((e: DependencyInsertedEvent) => void) | null;
+    onDependencyInserted?: ((e: DependencyInsertedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:DependencyDeletingEvent}
      * @action
      * @public
      */
-    onDependencyDeleting?: ((e: DependencyDeletingEvent) => void) | null;
+    onDependencyDeleting?: ((e: DependencyDeletingEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:DependencyDeletedEvent}
      * @action
      * @public
      */
-    onDependencyDeleted?: ((e: DependencyDeletedEvent) => void) | null;
+    onDependencyDeleted?: ((e: DependencyDeletedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:ResourceInsertingEvent}
      * @action
      * @public
      */
-    onResourceInserting?: ((e: ResourceInsertingEvent) => void) | null;
+    onResourceInserting?: ((e: ResourceInsertingEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:ResourceInsertedEvent}
      * @action
      * @public
      */
-    onResourceInserted?: ((e: ResourceInsertedEvent) => void) | null;
+    onResourceInserted?: ((e: ResourceInsertedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:ResourceDeletingEvent}
      * @action
      * @public
      */
-    onResourceDeleting?: ((e: ResourceDeletingEvent) => void) | null;
+    onResourceDeleting?: ((e: ResourceDeletingEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:ResourceDeletedEvent}
      * @action
      * @public
      */
-    onResourceDeleted?: ((e: ResourceDeletedEvent) => void) | null;
+    onResourceDeleted?: ((e: ResourceDeletedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:ResourceAssigningEvent}
      * @action
      * @public
      */
-    onResourceAssigning?: ((e: ResourceAssigningEvent) => void) | null;
+    onResourceAssigning?: ((e: ResourceAssigningEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:ResourceAssignedEvent}
      * @action
      * @public
      */
-    onResourceAssigned?: ((e: ResourceAssignedEvent) => void) | null;
+    onResourceAssigned?: ((e: ResourceAssignedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:ResourceUnassigningEvent}
      * @action
      * @public
      */
-    onResourceUnassigning?: ((e: ResourceUnassigningEvent) => void) | null;
+    onResourceUnassigning?: ((e: ResourceUnassigningEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:ResourceUnassignedEvent}
      * @action
      * @public
      */
-    onResourceUnassigned?: ((e: ResourceUnassignedEvent) => void) | null;
+    onResourceUnassigned?: ((e: ResourceUnassignedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:TaskClickEvent}
      * @action
      * @public
      */
-    onTaskClick?: ((e: TaskClickEvent) => void) | null;
+    onTaskClick?: ((e: TaskClickEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/gantt:TaskDblClickEvent}
      * @action
      * @public
      */
-    onTaskDblClick?: ((e: TaskDblClickEvent) => void) | null;
+    onTaskDblClick?: ((e: TaskDblClickEvent) => void) | undefined;
     /**
      * @docid
      * @default undefined

From 45ff0be71261913efd9567dde3829d6677607fb0 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 19:44:23 +0300
Subject: [PATCH 089/100] List: onGroupRendered, onItemContextMenu,
 onItemDeleted, onItemDeleting, onItemHold, onItemReordered, onItemSwipe,
 onPageLoading, onPullRefresh, onScroll, onSelectAllValueChanged

---
 packages/devextreme-vue/src/list.ts           | 22 +++++-----
 .../ui/collection/collection_widget.base.ts   | 10 ++---
 .../ui/collection/collection_widget.edit.ts   | 10 ++---
 .../js/__internal/ui/list/list.base.ts        | 10 ++---
 .../js/__internal/ui/list/list.edit.ts        |  2 +-
 packages/devextreme/js/ui/list.d.ts           | 44 +++++++++----------
 6 files changed, 49 insertions(+), 49 deletions(-)

diff --git a/packages/devextreme-vue/src/list.ts b/packages/devextreme-vue/src/list.ts
index e7f9a04a8a09..13deec187046 100644
--- a/packages/devextreme-vue/src/list.ts
+++ b/packages/devextreme-vue/src/list.ts
@@ -208,21 +208,21 @@ const componentConfig = {
     noDataText: String,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
-    onGroupRendered: Function as PropType<(((e: GroupRenderedEvent) => void)) | null>,
+    onGroupRendered: Function as PropType<((e: GroupRenderedEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
-    onItemContextMenu: Function as PropType<(((e: ItemContextMenuEvent) => void)) | null>,
-    onItemDeleted: Function as PropType<(((e: ItemDeletedEvent) => void)) | null>,
-    onItemDeleting: Function as PropType<(((e: ItemDeletingEvent) => void)) | null>,
-    onItemHold: Function as PropType<(((e: ItemHoldEvent) => void)) | null>,
+    onItemContextMenu: Function as PropType<((e: ItemContextMenuEvent) => void)>,
+    onItemDeleted: Function as PropType<((e: ItemDeletedEvent) => void)>,
+    onItemDeleting: Function as PropType<((e: ItemDeletingEvent) => void)>,
+    onItemHold: Function as PropType<((e: ItemHoldEvent) => void)>,
     onItemRendered: Function as PropType<((e: ItemRenderedEvent) => void)>,
-    onItemReordered: Function as PropType<(((e: ItemReorderedEvent) => void)) | null>,
-    onItemSwipe: Function as PropType<(((e: ItemSwipeEvent) => void)) | null>,
+    onItemReordered: Function as PropType<((e: ItemReorderedEvent) => void)>,
+    onItemSwipe: Function as PropType<((e: ItemSwipeEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onPageLoading: Function as PropType<(((e: PageLoadingEvent) => void)) | null>,
-    onPullRefresh: Function as PropType<(((e: PullRefreshEvent) => void)) | null>,
-    onScroll: Function as PropType<(((e: ScrollEvent) => void)) | null>,
-    onSelectAllValueChanged: Function as PropType<(((e: SelectAllValueChangedEvent) => void)) | null>,
+    onPageLoading: Function as PropType<((e: PageLoadingEvent) => void)>,
+    onPullRefresh: Function as PropType<((e: PullRefreshEvent) => void)>,
+    onScroll: Function as PropType<((e: ScrollEvent) => void)>,
+    onSelectAllValueChanged: Function as PropType<((e: SelectAllValueChangedEvent) => void)>,
     onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
     onSelectionChanging: Function as PropType<((e: SelectionChangingEvent) => void)>,
     pageLoadingText: String,
diff --git a/packages/devextreme/js/__internal/ui/collection/collection_widget.base.ts b/packages/devextreme/js/__internal/ui/collection/collection_widget.base.ts
index 2a4bdfa737f8..5e7b3b98d00d 100644
--- a/packages/devextreme/js/__internal/ui/collection/collection_widget.base.ts
+++ b/packages/devextreme/js/__internal/ui/collection/collection_widget.base.ts
@@ -255,12 +255,12 @@ class CollectionWidget<
       loopItemFocus: true,
       items: [],
       itemTemplate: 'item',
-      onItemRendered: null,
-      onItemClick: null,
-      onItemHold: null,
+      onItemRendered: undefined,
+      onItemClick: undefined,
+      onItemHold: undefined,
       itemHoldTimeout: 750,
-      onItemContextMenu: null,
-      onFocusedItemChanged: null,
+      onItemContextMenu: undefined,
+      onFocusedItemChanged: undefined,
       noDataText: messageLocalization.format('dxCollectionWidget-noDataText'),
       encodeNoDataText: false,
       dataSource: null,
diff --git a/packages/devextreme/js/__internal/ui/collection/collection_widget.edit.ts b/packages/devextreme/js/__internal/ui/collection/collection_widget.edit.ts
index 405d7e379b92..06d89a472973 100644
--- a/packages/devextreme/js/__internal/ui/collection/collection_widget.edit.ts
+++ b/packages/devextreme/js/__internal/ui/collection/collection_widget.edit.ts
@@ -118,11 +118,11 @@ class CollectionWidget<
       selectedIndex: NOT_EXISTING_INDEX,
       focusOnSelectedItem: true,
       selectedItem: null,
-      onSelectionChanging: null,
-      onSelectionChanged: null,
-      onItemReordered: null,
-      onItemDeleting: null,
-      onItemDeleted: null,
+      onSelectionChanging: undefined,
+      onSelectionChanged: undefined,
+      onItemReordered: undefined,
+      onItemDeleting: undefined,
+      onItemDeleted: undefined,
     };
   }
 
diff --git a/packages/devextreme/js/__internal/ui/list/list.base.ts b/packages/devextreme/js/__internal/ui/list/list.base.ts
index 69163d01a13e..5c0999ba971d 100644
--- a/packages/devextreme/js/__internal/ui/list/list.base.ts
+++ b/packages/devextreme/js/__internal/ui/list/list.base.ts
@@ -275,14 +275,14 @@ export class ListBase extends CollectionWidget<ListBaseProperties, Item> {
       pulledDownText: messageLocalization.format('dxList-pulledDownText'),
       refreshingText: messageLocalization.format('dxList-refreshingText'),
       pageLoadingText: messageLocalization.format('dxList-pageLoadingText'),
-      onScroll: null,
-      onPullRefresh: null,
-      onPageLoading: null,
+      onScroll: undefined,
+      onPullRefresh: undefined,
+      onPageLoading: undefined,
       pageLoadMode: 'scrollBottom',
       nextButtonText: messageLocalization.format('dxList-nextButtonText'),
-      onItemSwipe: null,
+      onItemSwipe: undefined,
       grouped: false,
-      onGroupRendered: null,
+      onGroupRendered: undefined,
       collapsibleGroups: false,
       groupTemplate: 'group',
       indicateLoading: true,
diff --git a/packages/devextreme/js/__internal/ui/list/list.edit.ts b/packages/devextreme/js/__internal/ui/list/list.edit.ts
index 8e548da5e045..8dee8715ff69 100644
--- a/packages/devextreme/js/__internal/ui/list/list.edit.ts
+++ b/packages/devextreme/js/__internal/ui/list/list.edit.ts
@@ -155,7 +155,7 @@ class ListEdit extends ListBase {
       showSelectionControls: false,
       selectionMode: 'none',
       selectAllMode: 'page',
-      onSelectAllValueChanged: null,
+      onSelectAllValueChanged: undefined,
       selectAllText: localizationMessage.format('dxList-selectAll'),
       menuItems: [],
       menuMode: 'context',
diff --git a/packages/devextreme/js/ui/list.d.ts b/packages/devextreme/js/ui/list.d.ts
index 4a0e233d8133..59ce5f2cf804 100644
--- a/packages/devextreme/js/ui/list.d.ts
+++ b/packages/devextreme/js/ui/list.d.ts
@@ -401,12 +401,12 @@ export interface dxListOptions<
     nextButtonText?: string;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/list:GroupRenderedEvent}
      * @action
      * @public
      */
-    onGroupRendered?: ((e: GroupRenderedEvent<TItem, TKey>) => void) | null;
+    onGroupRendered?: ((e: GroupRenderedEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
      * @default null
@@ -418,87 +418,87 @@ export interface dxListOptions<
     onItemClick?: ((e: ItemClickEvent<TItem, TKey>) => void) | string | null;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/list:ItemContextMenuEvent}
      * @action
      * @public
      */
-    onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void) | null;
+    onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/list:ItemDeletedEvent}
      * @action
      * @hidden false
      * @public
      */
-    onItemDeleted?: ((e: ItemDeletedEvent<TItem, TKey>) => void) | null;
+    onItemDeleted?: ((e: ItemDeletedEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/list:ItemDeletingEvent}
      * @action
      * @hidden false
      * @public
      */
-    onItemDeleting?: ((e: ItemDeletingEvent<TItem, TKey>) => void) | null;
+    onItemDeleting?: ((e: ItemDeletingEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/list:ItemHoldEvent}
      * @action
      * @public
      */
-    onItemHold?: ((e: ItemHoldEvent<TItem, TKey>) => void) | null;
+    onItemHold?: ((e: ItemHoldEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/list:ItemReorderedEvent}
      * @action
      * @hidden false
      * @public
      */
-    onItemReordered?: ((e: ItemReorderedEvent<TItem, TKey>) => void) | null;
+    onItemReordered?: ((e: ItemReorderedEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/list:ItemSwipeEvent}
      * @action
      * @public
      */
-    onItemSwipe?: ((e: ItemSwipeEvent<TItem, TKey>) => void) | null;
+    onItemSwipe?: ((e: ItemSwipeEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/list:PageLoadingEvent}
      * @action
      * @public
      */
-    onPageLoading?: ((e: PageLoadingEvent<TItem, TKey>) => void) | null;
+    onPageLoading?: ((e: PageLoadingEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/list:PullRefreshEvent}
      * @action
      * @public
      */
-    onPullRefresh?: ((e: PullRefreshEvent<TItem, TKey>) => void) | null;
+    onPullRefresh?: ((e: PullRefreshEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/list:ScrollEvent}
      * @action
      * @public
      */
-    onScroll?: ((e: ScrollEvent<TItem, TKey>) => void) | null;
+    onScroll?: ((e: ScrollEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/list:SelectAllValueChangedEvent}
      * @action
      * @public
      */
-    onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent<TItem, TKey>) => void) | null;
+    onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent<TItem, TKey>) => void) | undefined;
     /**
      * @docid
      * @default "scrollBottom"

From 9f83ddc4f33c89e0bd275f7e2ddcb8f3b5a9438d Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 19:46:45 +0300
Subject: [PATCH 090/100] Lookup: onPageLoading, onPullRefresh, onScroll,
 onValueChanged

---
 packages/devextreme-vue/src/lookup.ts            |  8 ++++----
 .../ui/date_range_box/m_date_range_box.ts        |  2 +-
 .../devextreme/js/__internal/ui/editor/editor.ts |  2 +-
 packages/devextreme/js/__internal/ui/lookup.ts   |  6 +++---
 packages/devextreme/js/ui/lookup.d.ts            | 16 ++++++++--------
 5 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/packages/devextreme-vue/src/lookup.ts b/packages/devextreme-vue/src/lookup.ts
index 79d2bdeb479a..c1c59b98423f 100644
--- a/packages/devextreme-vue/src/lookup.ts
+++ b/packages/devextreme-vue/src/lookup.ts
@@ -206,11 +206,11 @@ const componentConfig = {
     onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
     onOpened: Function as PropType<((e: OpenedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onPageLoading: Function as PropType<(((e: PageLoadingEvent) => void)) | null>,
-    onPullRefresh: Function as PropType<(((e: PullRefreshEvent) => void)) | null>,
-    onScroll: Function as PropType<(((e: ScrollEvent) => void)) | null>,
+    onPageLoading: Function as PropType<((e: PageLoadingEvent) => void)>,
+    onPullRefresh: Function as PropType<((e: PullRefreshEvent) => void)>,
+    onScroll: Function as PropType<((e: ScrollEvent) => void)>,
     onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
-    onValueChanged: Function as PropType<(((e: ValueChangedEvent) => void)) | null>,
+    onValueChanged: Function as PropType<((e: ValueChangedEvent) => void)>,
     opened: Boolean,
     pageLoadingText: String,
     pageLoadMode: String as PropType<PageLoadMode>,
diff --git a/packages/devextreme/js/__internal/ui/date_range_box/m_date_range_box.ts b/packages/devextreme/js/__internal/ui/date_range_box/m_date_range_box.ts
index 419c27fa56a0..b1940dd493d0 100644
--- a/packages/devextreme/js/__internal/ui/date_range_box/m_date_range_box.ts
+++ b/packages/devextreme/js/__internal/ui/date_range_box/m_date_range_box.ts
@@ -122,7 +122,7 @@ class DateRangeBox extends Editor<Properties> {
       onKeyUp: null,
       onOpened: null,
       onPaste: null,
-      onValueChanged: null,
+      onValueChanged: undefined,
       openOnFieldClick: true,
       opened: false,
       pickerType: 'calendar',
diff --git a/packages/devextreme/js/__internal/ui/editor/editor.ts b/packages/devextreme/js/__internal/ui/editor/editor.ts
index 3c0b5eb5b2f7..d51319178a2f 100644
--- a/packages/devextreme/js/__internal/ui/editor/editor.ts
+++ b/packages/devextreme/js/__internal/ui/editor/editor.ts
@@ -117,7 +117,7 @@ class Editor<
       ...super._getDefaultOptions(),
       value: null,
       name: '',
-      onValueChanged: null,
+      onValueChanged: undefined,
       readOnly: false,
       isValid: true,
       validationError: null,
diff --git a/packages/devextreme/js/__internal/ui/lookup.ts b/packages/devextreme/js/__internal/ui/lookup.ts
index e667f4103273..461a78405986 100644
--- a/packages/devextreme/js/__internal/ui/lookup.ts
+++ b/packages/devextreme/js/__internal/ui/lookup.ts
@@ -135,9 +135,9 @@ class Lookup extends DropDownList<LookupProperties> {
       pulledDownText: messageLocalization.format('dxList-pulledDownText'),
       refreshingText: messageLocalization.format('dxList-refreshingText'),
       pageLoadingText: messageLocalization.format('dxList-pageLoadingText'),
-      onScroll: null,
-      onPullRefresh: null,
-      onPageLoading: null,
+      onScroll: undefined,
+      onPullRefresh: undefined,
+      onPageLoading: undefined,
       pageLoadMode: 'scrollBottom',
       nextButtonText: messageLocalization.format('dxList-nextButtonText'),
       grouped: false,
diff --git a/packages/devextreme/js/ui/lookup.d.ts b/packages/devextreme/js/ui/lookup.d.ts
index 9ef4398d7654..9ed5daabce80 100644
--- a/packages/devextreme/js/ui/lookup.d.ts
+++ b/packages/devextreme/js/ui/lookup.d.ts
@@ -215,36 +215,36 @@ export interface dxLookupOptions extends dxDropDownListOptions<dxLookup> {
     nextButtonText?: string;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/lookup:PageLoadingEvent}
      * @action
      * @public
      */
-    onPageLoading?: ((e: PageLoadingEvent) => void) | null;
+    onPageLoading?: ((e: PageLoadingEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/lookup:PullRefreshEvent}
      * @action
      * @public
      */
-    onPullRefresh?: ((e: PullRefreshEvent) => void) | null;
+    onPullRefresh?: ((e: PullRefreshEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/lookup:ScrollEvent}
      * @action
      * @public
      */
-    onScroll?: ((e: ScrollEvent) => void) | null;
+    onScroll?: ((e: ScrollEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/lookup:ValueChangedEvent}
      * @action
      * @public
      */
-    onValueChanged?: ((e: ValueChangedEvent) => void) | null;
+    onValueChanged?: ((e: ValueChangedEvent) => void) | undefined;
     /**
      * @docid
      * @default "scrollBottom"

From 590f6debd6161f22f25f3dc889e9387a127495fb Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 19:48:27 +0300
Subject: [PATCH 091/100] Map: onMarkerAdded

---
 packages/devextreme-vue/src/map.ts            | 10 +++++-----
 .../devextreme/js/__internal/ui/map/map.ts    | 10 +++++-----
 packages/devextreme/js/ui/map.d.ts            | 20 +++++++++----------
 3 files changed, 20 insertions(+), 20 deletions(-)

diff --git a/packages/devextreme-vue/src/map.ts b/packages/devextreme-vue/src/map.ts
index 470e92f22630..7e1c8fecdc49 100644
--- a/packages/devextreme-vue/src/map.ts
+++ b/packages/devextreme-vue/src/map.ts
@@ -76,12 +76,12 @@ const componentConfig = {
     onClick: Function as PropType<((e: ClickEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
-    onMarkerAdded: Function as PropType<(((e: MarkerAddedEvent) => void)) | null>,
-    onMarkerRemoved: Function as PropType<(((e: MarkerRemovedEvent) => void)) | null>,
+    onMarkerAdded: Function as PropType<((e: MarkerAddedEvent) => void)>,
+    onMarkerRemoved: Function as PropType<((e: MarkerRemovedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onReady: Function as PropType<(((e: ReadyEvent) => void)) | null>,
-    onRouteAdded: Function as PropType<(((e: RouteAddedEvent) => void)) | null>,
-    onRouteRemoved: Function as PropType<(((e: RouteRemovedEvent) => void)) | null>,
+    onReady: Function as PropType<((e: ReadyEvent) => void)>,
+    onRouteAdded: Function as PropType<((e: RouteAddedEvent) => void)>,
+    onRouteRemoved: Function as PropType<((e: RouteRemovedEvent) => void)>,
     provider: String as PropType<MapProvider>,
     providerConfig: Object as PropType<Record<string, any>>,
     routes: Array as PropType<Array<Record<string, any>>>,
diff --git a/packages/devextreme/js/__internal/ui/map/map.ts b/packages/devextreme/js/__internal/ui/map/map.ts
index 8cc235559c25..a57e5a94fa36 100644
--- a/packages/devextreme/js/__internal/ui/map/map.ts
+++ b/packages/devextreme/js/__internal/ui/map/map.ts
@@ -86,11 +86,11 @@ class Map extends Widget<MapProperties> {
       autoAdjust: true,
       markers: [],
       markerIconSrc: undefined,
-      onMarkerAdded: null,
-      onMarkerRemoved: null,
+      onMarkerAdded: undefined,
+      onMarkerRemoved: undefined,
       routes: [],
-      onRouteAdded: null,
-      onRouteRemoved: null,
+      onRouteAdded: undefined,
+      onRouteRemoved: undefined,
       apiKey: {
         bing: '',
         google: '',
@@ -101,7 +101,7 @@ class Map extends Widget<MapProperties> {
         useAdvancedMarkers: true,
       },
       controls: false,
-      onReady: null,
+      onReady: undefined,
       onUpdated: undefined,
       onClick: null,
     };
diff --git a/packages/devextreme/js/ui/map.d.ts b/packages/devextreme/js/ui/map.d.ts
index 04342d12321a..3114984ba144 100644
--- a/packages/devextreme/js/ui/map.d.ts
+++ b/packages/devextreme/js/ui/map.d.ts
@@ -273,44 +273,44 @@ export interface dxMapOptions extends WidgetOptions<dxMap> {
     onClick?: ((e: ClickEvent) => void) | string | null;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/map:MarkerAddedEvent}
      * @action
      * @public
      */
-    onMarkerAdded?: ((e: MarkerAddedEvent) => void) | null;
+    onMarkerAdded?: ((e: MarkerAddedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/map:MarkerRemovedEvent}
      * @action
      * @public
      */
-    onMarkerRemoved?: ((e: MarkerRemovedEvent) => void) | null;
+    onMarkerRemoved?: ((e: MarkerRemovedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/map:ReadyEvent}
      * @action
      * @public
      */
-    onReady?: ((e: ReadyEvent) => void) | null;
+    onReady?: ((e: ReadyEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/map:RouteAddedEvent}
      * @action
      * @public
      */
-    onRouteAdded?: ((e: RouteAddedEvent) => void) | null;
+    onRouteAdded?: ((e: RouteAddedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/map:RouteRemovedEvent}
      * @action
      * @public
      */
-    onRouteRemoved?: ((e: RouteRemovedEvent) => void) | null;
+    onRouteRemoved?: ((e: RouteRemovedEvent) => void) | undefined;
     /**
      * @docid
      * @default "google"

From 1d0e2220d92aa870b16ea746695c5b3ea4bc2f1f Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 19:49:07 +0300
Subject: [PATCH 092/100] ProgressBar: onComplete

---
 packages/devextreme-vue/src/progress-bar.ts            | 2 +-
 packages/devextreme/js/__internal/ui/m_progress_bar.ts | 2 +-
 packages/devextreme/js/ui/progress_bar.d.ts            | 4 ++--
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/packages/devextreme-vue/src/progress-bar.ts b/packages/devextreme-vue/src/progress-bar.ts
index 0e7f4b00695e..f927ac46a684 100644
--- a/packages/devextreme-vue/src/progress-bar.ts
+++ b/packages/devextreme-vue/src/progress-bar.ts
@@ -61,7 +61,7 @@ const componentConfig = {
     isValid: Boolean,
     max: Number,
     min: Number,
-    onComplete: Function as PropType<(((e: CompleteEvent) => void)) | null>,
+    onComplete: Function as PropType<((e: CompleteEvent) => void)>,
     onContentReady: Function as PropType<((e: ContentReadyEvent) => void)>,
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
diff --git a/packages/devextreme/js/__internal/ui/m_progress_bar.ts b/packages/devextreme/js/__internal/ui/m_progress_bar.ts
index 12d8dfe63e51..78ed7106d04d 100644
--- a/packages/devextreme/js/__internal/ui/m_progress_bar.ts
+++ b/packages/devextreme/js/__internal/ui/m_progress_bar.ts
@@ -43,7 +43,7 @@ class ProgressBar extends TrackBar<ProgressBarProperties> {
         return `Progress: ${Math.round(ratio * 100)}%`;
       },
       showStatus: true,
-      onComplete: null,
+      onComplete: undefined,
       activeStateEnabled: false,
       statusPosition: 'bottom left',
       _animatingSegmentCount: 0,
diff --git a/packages/devextreme/js/ui/progress_bar.d.ts b/packages/devextreme/js/ui/progress_bar.d.ts
index 087eaac6451f..b5c0d526afcf 100644
--- a/packages/devextreme/js/ui/progress_bar.d.ts
+++ b/packages/devextreme/js/ui/progress_bar.d.ts
@@ -69,12 +69,12 @@ export type ValueChangedEvent = NativeEventInfo<dxProgressBar> & ValueChangedInf
 export interface dxProgressBarOptions extends dxTrackBarOptions<dxProgressBar> {
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/progress_bar:CompleteEvent}
      * @action
      * @public
      */
-    onComplete?: ((e: CompleteEvent) => void) | null;
+    onComplete?: ((e: CompleteEvent) => void) | undefined;
     /**
      * @docid
      * @default true

From 2a74cf1367e71107aa78dce57f8a17c0135ff694 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 19:49:43 +0300
Subject: [PATCH 093/100] RangeSlider: onValueChanged

---
 packages/devextreme-vue/src/range-slider.ts | 2 +-
 packages/devextreme/js/ui/range_slider.d.ts | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/devextreme-vue/src/range-slider.ts b/packages/devextreme-vue/src/range-slider.ts
index 61e9b2a28db2..eff249b51b3d 100644
--- a/packages/devextreme-vue/src/range-slider.ts
+++ b/packages/devextreme-vue/src/range-slider.ts
@@ -90,7 +90,7 @@ const componentConfig = {
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onValueChanged: Function as PropType<(((e: ValueChangedEvent) => void)) | null>,
+    onValueChanged: Function as PropType<((e: ValueChangedEvent) => void)>,
     readOnly: Boolean,
     rtlEnabled: Boolean,
     showRange: Boolean,
diff --git a/packages/devextreme/js/ui/range_slider.d.ts b/packages/devextreme/js/ui/range_slider.d.ts
index a69c113eb215..4af528982147 100644
--- a/packages/devextreme/js/ui/range_slider.d.ts
+++ b/packages/devextreme/js/ui/range_slider.d.ts
@@ -85,10 +85,10 @@ export interface dxRangeSliderOptions extends dxSliderBaseOptions<dxRangeSlider>
      * @docid
      * @type_function_param1 e:{ui/range_slider:ValueChangedEvent}
      * @action
-     * @default null
+     * @default undefined
      * @public
      */
-    onValueChanged?: ((e: ValueChangedEvent) => void) | null;
+    onValueChanged?: ((e: ValueChangedEvent) => void) | undefined;
     /**
      * @docid
      * @default 40

From 99a5b1dcef2e4faca067b33db96b7ed96c3fff4a Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 19:51:32 +0300
Subject: [PATCH 094/100] RespociveBox: screenByWidth

---
 packages/devextreme-vue/src/responsive-box.ts          | 2 +-
 packages/devextreme/js/__internal/ui/responsive_box.ts | 2 +-
 packages/devextreme/js/ui/responsive_box.d.ts          | 4 ++--
 3 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/packages/devextreme-vue/src/responsive-box.ts b/packages/devextreme-vue/src/responsive-box.ts
index 86a26760a0c9..1ae0d3be4154 100644
--- a/packages/devextreme-vue/src/responsive-box.ts
+++ b/packages/devextreme-vue/src/responsive-box.ts
@@ -74,7 +74,7 @@ const componentConfig = {
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
     rows: Array as PropType<Array<Record<string, any>>>,
     rtlEnabled: Boolean,
-    screenByWidth: Function as PropType<((() => void)) | null>,
+    screenByWidth: Function as PropType<(() => void)>,
     singleColumnScreen: String,
     visible: Boolean,
     width: [Number, String]
diff --git a/packages/devextreme/js/__internal/ui/responsive_box.ts b/packages/devextreme/js/__internal/ui/responsive_box.ts
index dfd30d63c41e..bf35b9bc5421 100644
--- a/packages/devextreme/js/__internal/ui/responsive_box.ts
+++ b/packages/devextreme/js/__internal/ui/responsive_box.ts
@@ -97,7 +97,7 @@ class ResponsiveBox extends CollectionWidget<ResponsiveBoxProperties> {
       rows: [],
       cols: [],
       singleColumnScreen: '',
-      screenByWidth: null,
+      screenByWidth: undefined,
       height: '100%',
       width: '100%',
       activeStateEnabled: false,
diff --git a/packages/devextreme/js/ui/responsive_box.d.ts b/packages/devextreme/js/ui/responsive_box.d.ts
index 4982d9b86560..0e13c2a8292d 100644
--- a/packages/devextreme/js/ui/responsive_box.d.ts
+++ b/packages/devextreme/js/ui/responsive_box.d.ts
@@ -172,10 +172,10 @@ export interface dxResponsiveBoxOptions<
     }>;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @public
      */
-    screenByWidth?: Function | null;
+    screenByWidth?: Function | undefined;
     /**
      * @docid
      * @default ""

From b15d845de0cfc1ca598849e7b86f957e368faecd Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 19:52:50 +0300
Subject: [PATCH 095/100] ScrollView: onPullDown, onReachBottom

---
 packages/devextreme-vue/src/scroll-view.ts                | 4 ++--
 .../js/__internal/ui/scroll_view/scroll_view.ts           | 4 ++--
 packages/devextreme/js/ui/scroll_view.d.ts                | 8 ++++----
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/packages/devextreme-vue/src/scroll-view.ts b/packages/devextreme-vue/src/scroll-view.ts
index 612944df11b5..a1403de5bf91 100644
--- a/packages/devextreme-vue/src/scroll-view.ts
+++ b/packages/devextreme-vue/src/scroll-view.ts
@@ -54,8 +54,8 @@ const componentConfig = {
     onDisposing: Function as PropType<((e: DisposingEvent) => void)>,
     onInitialized: Function as PropType<((e: InitializedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onPullDown: Function as PropType<(((e: PullDownEvent) => void)) | null>,
-    onReachBottom: Function as PropType<(((e: ReachBottomEvent) => void)) | null>,
+    onPullDown: Function as PropType<((e: PullDownEvent) => void)>,
+    onReachBottom: Function as PropType<((e: ReachBottomEvent) => void)>,
     onScroll: Function as PropType<((e: ScrollEvent) => void)>,
     onUpdated: Function as PropType<((e: UpdatedEvent) => void)>,
     pulledDownText: String,
diff --git a/packages/devextreme/js/__internal/ui/scroll_view/scroll_view.ts b/packages/devextreme/js/__internal/ui/scroll_view/scroll_view.ts
index a939cc0def14..4d449f18c91a 100644
--- a/packages/devextreme/js/__internal/ui/scroll_view/scroll_view.ts
+++ b/packages/devextreme/js/__internal/ui/scroll_view/scroll_view.ts
@@ -105,8 +105,8 @@ export class ScrollView extends Scrollable<ScrollViewProperties> {
       pulledDownText: messageLocalization.format('dxScrollView-pulledDownText'),
       refreshingText: messageLocalization.format('dxScrollView-refreshingText'),
       reachBottomText: messageLocalization.format('dxScrollView-reachBottomText'),
-      onPullDown: null,
-      onReachBottom: null,
+      onPullDown: undefined,
+      onReachBottom: undefined,
       refreshStrategy: 'pullDown',
     };
   }
diff --git a/packages/devextreme/js/ui/scroll_view.d.ts b/packages/devextreme/js/ui/scroll_view.d.ts
index 5719919008c9..0149bd31b422 100644
--- a/packages/devextreme/js/ui/scroll_view.d.ts
+++ b/packages/devextreme/js/ui/scroll_view.d.ts
@@ -77,20 +77,20 @@ export type UpdatedEvent = ScrollEventInfo<dxScrollView>;
 export interface dxScrollViewOptions extends dxScrollableOptions<dxScrollView> {
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/scroll_view:PullDownEvent}
      * @action
      * @public
      */
-    onPullDown?: ((e: PullDownEvent) => void) | null;
+    onPullDown?: ((e: PullDownEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/scroll_view:ReachBottomEvent}
      * @action
      * @public
      */
-    onReachBottom?: ((e: ReachBottomEvent) => void) | null;
+    onReachBottom?: ((e: ReachBottomEvent) => void) | undefined;
     /**
      * @docid
      * @default "Release to refresh..."

From 876e843146f159395ab52b4ddf43ecb187f81c98 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 19:54:38 +0300
Subject: [PATCH 096/100] TagBox: onMultiTagPreparing

---
 packages/devextreme-vue/src/tag-box.ts          |  6 +++---
 packages/devextreme/js/__internal/ui/tag_box.ts |  4 ++--
 packages/devextreme/js/ui/tag_box.d.ts          | 12 ++++++------
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/packages/devextreme-vue/src/tag-box.ts b/packages/devextreme-vue/src/tag-box.ts
index 65ea9032e3be..a8a1fdd821dd 100644
--- a/packages/devextreme-vue/src/tag-box.ts
+++ b/packages/devextreme-vue/src/tag-box.ts
@@ -243,11 +243,11 @@ const componentConfig = {
     onItemClick: Function as PropType<((e: ItemClickEvent) => void)>,
     onKeyDown: Function as PropType<((e: KeyDownEvent) => void)>,
     onKeyUp: Function as PropType<((e: KeyUpEvent) => void)>,
-    onMultiTagPreparing: Function as PropType<(((e: MultiTagPreparingEvent) => void)) | null>,
+    onMultiTagPreparing: Function as PropType<((e: MultiTagPreparingEvent) => void)>,
     onOpened: Function as PropType<((e: OpenedEvent) => void)>,
     onOptionChanged: Function as PropType<((e: OptionChangedEvent) => void)>,
-    onSelectAllValueChanged: Function as PropType<(((e: SelectAllValueChangedEvent) => void)) | null>,
-    onSelectionChanged: Function as PropType<(((e: SelectionChangedEvent) => void)) | null>,
+    onSelectAllValueChanged: Function as PropType<((e: SelectAllValueChangedEvent) => void)>,
+    onSelectionChanged: Function as PropType<((e: SelectionChangedEvent) => void)>,
     onValueChanged: Function as PropType<((e: ValueChangedEvent) => void)>,
     opened: Boolean,
     openOnFieldClick: Boolean,
diff --git a/packages/devextreme/js/__internal/ui/tag_box.ts b/packages/devextreme/js/__internal/ui/tag_box.ts
index 6fd3eb91e9e3..fcf746bd0215 100644
--- a/packages/devextreme/js/__internal/ui/tag_box.ts
+++ b/packages/devextreme/js/__internal/ui/tag_box.ts
@@ -426,13 +426,13 @@ class TagBox<
 
       selectAllMode: 'page',
 
-      onSelectAllValueChanged: null,
+      onSelectAllValueChanged: undefined,
 
       maxDisplayedTags: undefined,
 
       showMultiTagOnly: true,
 
-      onMultiTagPreparing: null,
+      onMultiTagPreparing: undefined,
 
       multiline: true,
 
diff --git a/packages/devextreme/js/ui/tag_box.d.ts b/packages/devextreme/js/ui/tag_box.d.ts
index 90c880be7daa..4bbc497bb6ee 100644
--- a/packages/devextreme/js/ui/tag_box.d.ts
+++ b/packages/devextreme/js/ui/tag_box.d.ts
@@ -238,28 +238,28 @@ export interface dxTagBoxOptions extends Pick<dxSelectBoxOptions<dxTagBox>, Excl
     multiline?: boolean;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/tag_box:MultiTagPreparingEvent}
      * @action
      * @public
      */
-    onMultiTagPreparing?: ((e: MultiTagPreparingEvent) => void) | null;
+    onMultiTagPreparing?: ((e: MultiTagPreparingEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/tag_box:SelectAllValueChangedEvent}
      * @action
      * @public
      */
-    onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent) => void) | null;
+    onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent) => void) | undefined;
     /**
      * @docid
-     * @default null
+     * @default undefined
      * @type_function_param1 e:{ui/tag_box:SelectionChangedEvent}
      * @action
      * @public
      */
-    onSelectionChanged?: ((e: SelectionChangedEvent) => void) | null;
+    onSelectionChanged?: ((e: SelectionChangedEvent) => void) | undefined;
     /**
      * @docid
      * @default 'page'

From 600a35b5e4efad73385514789b217751533d00a9 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Mon, 13 Jul 2026 19:59:43 +0300
Subject: [PATCH 097/100] regenerate-all

---
 .../src/ui/responsive-box/index.ts            |   6 +-
 packages/devextreme-react/src/context-menu.ts |  10 +-
 packages/devextreme-react/src/diagram.ts      |   8 +-
 packages/devextreme-react/src/gantt.ts        |  48 +++---
 packages/devextreme-react/src/list.ts         |  22 +--
 packages/devextreme-react/src/lookup.ts       |   8 +-
 packages/devextreme-react/src/map.ts          |  10 +-
 packages/devextreme-react/src/progress-bar.ts |   2 +-
 packages/devextreme-react/src/range-slider.ts |   2 +-
 packages/devextreme-react/src/scroll-view.ts  |   4 +-
 packages/devextreme-react/src/tag-box.ts      |   4 +-
 .../js/__internal/ui/list/list.base.ts        |   4 +-
 packages/devextreme/ts/dx.all.d.ts            | 138 ++++++++++--------
 13 files changed, 139 insertions(+), 127 deletions(-)

diff --git a/packages/devextreme-angular/src/ui/responsive-box/index.ts b/packages/devextreme-angular/src/ui/responsive-box/index.ts
index 61c2f3309913..1d0e3a0e49a6 100644
--- a/packages/devextreme-angular/src/ui/responsive-box/index.ts
+++ b/packages/devextreme-angular/src/ui/responsive-box/index.ts
@@ -246,10 +246,10 @@ export class DxResponsiveBoxComponent<TItem = any, TKey = any> extends DxCompone
     
      */
     @Input()
-    get screenByWidth(): Function | null {
+    get screenByWidth(): Function | undefined {
         return this._getOption('screenByWidth');
     }
-    set screenByWidth(value: Function | null) {
+    set screenByWidth(value: Function | undefined) {
         this._setOption('screenByWidth', value);
     }
 
@@ -438,7 +438,7 @@ export class DxResponsiveBoxComponent<TItem = any, TKey = any> extends DxCompone
      * This member supports the internal infrastructure and is not intended to be used directly from your code.
     
      */
-    @Output() screenByWidthChange: EventEmitter<Function | null>;
+    @Output() screenByWidthChange: EventEmitter<Function | undefined>;
 
     /**
     
diff --git a/packages/devextreme-react/src/context-menu.ts b/packages/devextreme-react/src/context-menu.ts
index 478b93938a0a..469f61ea34ae 100644
--- a/packages/devextreme-react/src/context-menu.ts
+++ b/packages/devextreme-react/src/context-menu.ts
@@ -21,15 +21,15 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 type IContextMenuOptionsNarrowedEvents<TItem = any, TKey = any> = {
   onContentReady?: ((e: ContentReadyEvent<TItem, TKey>) => void);
   onDisposing?: ((e: DisposingEvent<TItem, TKey>) => void);
-  onHidden?: ((e: HiddenEvent<TItem, TKey>) => void) | null;
-  onHiding?: ((e: HidingEvent<TItem, TKey>) => void) | null;
+  onHidden?: ((e: HiddenEvent<TItem, TKey>) => void) | undefined;
+  onHiding?: ((e: HidingEvent<TItem, TKey>) => void) | undefined;
   onInitialized?: ((e: InitializedEvent<TItem, TKey>) => void);
   onItemClick?: ((e: ItemClickEvent<TItem, TKey>) => void);
   onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void);
   onItemRendered?: ((e: ItemRenderedEvent<TItem, TKey>) => void);
-  onPositioning?: ((e: PositioningEvent<TItem, TKey>) => void) | null;
-  onShowing?: ((e: ShowingEvent<TItem, TKey>) => void) | null;
-  onShown?: ((e: ShownEvent<TItem, TKey>) => void) | null;
+  onPositioning?: ((e: PositioningEvent<TItem, TKey>) => void) | undefined;
+  onShowing?: ((e: ShowingEvent<TItem, TKey>) => void) | undefined;
+  onShown?: ((e: ShownEvent<TItem, TKey>) => void) | undefined;
 }
 
 type IContextMenuOptions<TItem = any, TKey = any> = React.PropsWithChildren<ReplaceFieldTypes<Properties<TItem, TKey>, IContextMenuOptionsNarrowedEvents<TItem, TKey>> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/diagram.ts b/packages/devextreme-react/src/diagram.ts
index 56a2eac4c2fd..0adfd2e87f50 100644
--- a/packages/devextreme-react/src/diagram.ts
+++ b/packages/devextreme-react/src/diagram.ts
@@ -25,10 +25,10 @@ type IDiagramOptionsNarrowedEvents = {
   onCustomCommand?: ((e: CustomCommandEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
-  onItemClick?: ((e: ItemClickEvent) => void) | null;
-  onItemDblClick?: ((e: ItemDblClickEvent) => void) | null;
-  onRequestEditOperation?: ((e: RequestEditOperationEvent) => void) | null;
-  onRequestLayoutUpdate?: ((e: RequestLayoutUpdateEvent) => void) | null;
+  onItemClick?: ((e: ItemClickEvent) => void) | undefined;
+  onItemDblClick?: ((e: ItemDblClickEvent) => void) | undefined;
+  onRequestEditOperation?: ((e: RequestEditOperationEvent) => void) | undefined;
+  onRequestLayoutUpdate?: ((e: RequestLayoutUpdateEvent) => void) | undefined;
 }
 
 type IDiagramOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IDiagramOptionsNarrowedEvents> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/gantt.ts b/packages/devextreme-react/src/gantt.ts
index ff7d7f7b4051..dc2cdff0e864 100644
--- a/packages/devextreme-react/src/gantt.ts
+++ b/packages/devextreme-react/src/gantt.ts
@@ -28,34 +28,34 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 
 type IGanttOptionsNarrowedEvents = {
   onContentReady?: ((e: ContentReadyEvent) => void);
-  onContextMenuPreparing?: ((e: ContextMenuPreparingEvent) => void) | null;
-  onCustomCommand?: ((e: CustomCommandEvent) => void) | null;
-  onDependencyDeleted?: ((e: DependencyDeletedEvent) => void) | null;
-  onDependencyDeleting?: ((e: DependencyDeletingEvent) => void) | null;
-  onDependencyInserted?: ((e: DependencyInsertedEvent) => void) | null;
-  onDependencyInserting?: ((e: DependencyInsertingEvent) => void) | null;
+  onContextMenuPreparing?: ((e: ContextMenuPreparingEvent) => void) | undefined;
+  onCustomCommand?: ((e: CustomCommandEvent) => void) | undefined;
+  onDependencyDeleted?: ((e: DependencyDeletedEvent) => void) | undefined;
+  onDependencyDeleting?: ((e: DependencyDeletingEvent) => void) | undefined;
+  onDependencyInserted?: ((e: DependencyInsertedEvent) => void) | undefined;
+  onDependencyInserting?: ((e: DependencyInsertingEvent) => void) | undefined;
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
-  onResourceAssigned?: ((e: ResourceAssignedEvent) => void) | null;
-  onResourceAssigning?: ((e: ResourceAssigningEvent) => void) | null;
-  onResourceDeleted?: ((e: ResourceDeletedEvent) => void) | null;
-  onResourceDeleting?: ((e: ResourceDeletingEvent) => void) | null;
-  onResourceInserted?: ((e: ResourceInsertedEvent) => void) | null;
-  onResourceInserting?: ((e: ResourceInsertingEvent) => void) | null;
+  onResourceAssigned?: ((e: ResourceAssignedEvent) => void) | undefined;
+  onResourceAssigning?: ((e: ResourceAssigningEvent) => void) | undefined;
+  onResourceDeleted?: ((e: ResourceDeletedEvent) => void) | undefined;
+  onResourceDeleting?: ((e: ResourceDeletingEvent) => void) | undefined;
+  onResourceInserted?: ((e: ResourceInsertedEvent) => void) | undefined;
+  onResourceInserting?: ((e: ResourceInsertingEvent) => void) | undefined;
   onResourceManagerDialogShowing?: ((e: ResourceManagerDialogShowingEvent) => void) | undefined;
-  onResourceUnassigned?: ((e: ResourceUnassignedEvent) => void) | null;
-  onResourceUnassigning?: ((e: ResourceUnassigningEvent) => void) | null;
+  onResourceUnassigned?: ((e: ResourceUnassignedEvent) => void) | undefined;
+  onResourceUnassigning?: ((e: ResourceUnassigningEvent) => void) | undefined;
   onScaleCellPrepared?: ((e: ScaleCellPreparedEvent) => void) | undefined;
-  onTaskClick?: ((e: TaskClickEvent) => void) | null;
-  onTaskDblClick?: ((e: TaskDblClickEvent) => void) | null;
-  onTaskDeleted?: ((e: TaskDeletedEvent) => void) | null;
-  onTaskDeleting?: ((e: TaskDeletingEvent) => void) | null;
-  onTaskEditDialogShowing?: ((e: TaskEditDialogShowingEvent) => void) | null;
-  onTaskInserted?: ((e: TaskInsertedEvent) => void) | null;
-  onTaskInserting?: ((e: TaskInsertingEvent) => void) | null;
-  onTaskMoving?: ((e: TaskMovingEvent) => void) | null;
-  onTaskUpdated?: ((e: TaskUpdatedEvent) => void) | null;
-  onTaskUpdating?: ((e: TaskUpdatingEvent) => void) | null;
+  onTaskClick?: ((e: TaskClickEvent) => void) | undefined;
+  onTaskDblClick?: ((e: TaskDblClickEvent) => void) | undefined;
+  onTaskDeleted?: ((e: TaskDeletedEvent) => void) | undefined;
+  onTaskDeleting?: ((e: TaskDeletingEvent) => void) | undefined;
+  onTaskEditDialogShowing?: ((e: TaskEditDialogShowingEvent) => void) | undefined;
+  onTaskInserted?: ((e: TaskInsertedEvent) => void) | undefined;
+  onTaskInserting?: ((e: TaskInsertingEvent) => void) | undefined;
+  onTaskMoving?: ((e: TaskMovingEvent) => void) | undefined;
+  onTaskUpdated?: ((e: TaskUpdatedEvent) => void) | undefined;
+  onTaskUpdating?: ((e: TaskUpdatingEvent) => void) | undefined;
 }
 
 type IGanttOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IGanttOptionsNarrowedEvents> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/list.ts b/packages/devextreme-react/src/list.ts
index 83d13440fe7c..1176645d0eb4 100644
--- a/packages/devextreme-react/src/list.ts
+++ b/packages/devextreme-react/src/list.ts
@@ -23,20 +23,20 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 type IListOptionsNarrowedEvents<TItem = any, TKey = any> = {
   onContentReady?: ((e: ContentReadyEvent<TItem, TKey>) => void);
   onDisposing?: ((e: DisposingEvent<TItem, TKey>) => void);
-  onGroupRendered?: ((e: GroupRenderedEvent<TItem, TKey>) => void) | null;
+  onGroupRendered?: ((e: GroupRenderedEvent<TItem, TKey>) => void) | undefined;
   onInitialized?: ((e: InitializedEvent<TItem, TKey>) => void);
   onItemClick?: ((e: ItemClickEvent<TItem, TKey>) => void);
-  onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void) | null;
-  onItemDeleted?: ((e: ItemDeletedEvent<TItem, TKey>) => void) | null;
-  onItemDeleting?: ((e: ItemDeletingEvent<TItem, TKey>) => void) | null;
-  onItemHold?: ((e: ItemHoldEvent<TItem, TKey>) => void) | null;
+  onItemContextMenu?: ((e: ItemContextMenuEvent<TItem, TKey>) => void) | undefined;
+  onItemDeleted?: ((e: ItemDeletedEvent<TItem, TKey>) => void) | undefined;
+  onItemDeleting?: ((e: ItemDeletingEvent<TItem, TKey>) => void) | undefined;
+  onItemHold?: ((e: ItemHoldEvent<TItem, TKey>) => void) | undefined;
   onItemRendered?: ((e: ItemRenderedEvent<TItem, TKey>) => void);
-  onItemReordered?: ((e: ItemReorderedEvent<TItem, TKey>) => void) | null;
-  onItemSwipe?: ((e: ItemSwipeEvent<TItem, TKey>) => void) | null;
-  onPageLoading?: ((e: PageLoadingEvent<TItem, TKey>) => void) | null;
-  onPullRefresh?: ((e: PullRefreshEvent<TItem, TKey>) => void) | null;
-  onScroll?: ((e: ScrollEvent<TItem, TKey>) => void) | null;
-  onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent<TItem, TKey>) => void) | null;
+  onItemReordered?: ((e: ItemReorderedEvent<TItem, TKey>) => void) | undefined;
+  onItemSwipe?: ((e: ItemSwipeEvent<TItem, TKey>) => void) | undefined;
+  onPageLoading?: ((e: PageLoadingEvent<TItem, TKey>) => void) | undefined;
+  onPullRefresh?: ((e: PullRefreshEvent<TItem, TKey>) => void) | undefined;
+  onScroll?: ((e: ScrollEvent<TItem, TKey>) => void) | undefined;
+  onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent<TItem, TKey>) => void) | undefined;
   onSelectionChanging?: ((e: SelectionChangingEvent<TItem, TKey>) => void);
 }
 
diff --git a/packages/devextreme-react/src/lookup.ts b/packages/devextreme-react/src/lookup.ts
index 2795468da226..558857410e04 100644
--- a/packages/devextreme-react/src/lookup.ts
+++ b/packages/devextreme-react/src/lookup.ts
@@ -28,10 +28,10 @@ type ILookupOptionsNarrowedEvents = {
   onInitialized?: ((e: InitializedEvent) => void);
   onItemClick?: ((e: ItemClickEvent) => void);
   onOpened?: ((e: OpenedEvent) => void);
-  onPageLoading?: ((e: PageLoadingEvent) => void) | null;
-  onPullRefresh?: ((e: PullRefreshEvent) => void) | null;
-  onScroll?: ((e: ScrollEvent) => void) | null;
-  onValueChanged?: ((e: ValueChangedEvent) => void) | null;
+  onPageLoading?: ((e: PageLoadingEvent) => void) | undefined;
+  onPullRefresh?: ((e: PullRefreshEvent) => void) | undefined;
+  onScroll?: ((e: ScrollEvent) => void) | undefined;
+  onValueChanged?: ((e: ValueChangedEvent) => void) | undefined;
 }
 
 type ILookupOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, ILookupOptionsNarrowedEvents> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/map.ts b/packages/devextreme-react/src/map.ts
index 57067d2a5510..0a2d1462543d 100644
--- a/packages/devextreme-react/src/map.ts
+++ b/packages/devextreme-react/src/map.ts
@@ -18,11 +18,11 @@ type IMapOptionsNarrowedEvents = {
   onClick?: ((e: ClickEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
-  onMarkerAdded?: ((e: MarkerAddedEvent) => void) | null;
-  onMarkerRemoved?: ((e: MarkerRemovedEvent) => void) | null;
-  onReady?: ((e: ReadyEvent) => void) | null;
-  onRouteAdded?: ((e: RouteAddedEvent) => void) | null;
-  onRouteRemoved?: ((e: RouteRemovedEvent) => void) | null;
+  onMarkerAdded?: ((e: MarkerAddedEvent) => void) | undefined;
+  onMarkerRemoved?: ((e: MarkerRemovedEvent) => void) | undefined;
+  onReady?: ((e: ReadyEvent) => void) | undefined;
+  onRouteAdded?: ((e: RouteAddedEvent) => void) | undefined;
+  onRouteRemoved?: ((e: RouteRemovedEvent) => void) | undefined;
 }
 
 type IMapOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IMapOptionsNarrowedEvents> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/progress-bar.ts b/packages/devextreme-react/src/progress-bar.ts
index d17c414e34cd..1581707a5979 100644
--- a/packages/devextreme-react/src/progress-bar.ts
+++ b/packages/devextreme-react/src/progress-bar.ts
@@ -14,7 +14,7 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 }
 
 type IProgressBarOptionsNarrowedEvents = {
-  onComplete?: ((e: CompleteEvent) => void) | null;
+  onComplete?: ((e: CompleteEvent) => void) | undefined;
   onContentReady?: ((e: ContentReadyEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
diff --git a/packages/devextreme-react/src/range-slider.ts b/packages/devextreme-react/src/range-slider.ts
index f13c7f180417..694b80b22c12 100644
--- a/packages/devextreme-react/src/range-slider.ts
+++ b/packages/devextreme-react/src/range-slider.ts
@@ -20,7 +20,7 @@ type IRangeSliderOptionsNarrowedEvents = {
   onContentReady?: ((e: ContentReadyEvent) => void);
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
-  onValueChanged?: ((e: ValueChangedEvent) => void) | null;
+  onValueChanged?: ((e: ValueChangedEvent) => void) | undefined;
 }
 
 type IRangeSliderOptions = React.PropsWithChildren<ReplaceFieldTypes<Properties, IRangeSliderOptionsNarrowedEvents> & IHtmlOptions & {
diff --git a/packages/devextreme-react/src/scroll-view.ts b/packages/devextreme-react/src/scroll-view.ts
index 0c4f8990042b..108daead3b35 100644
--- a/packages/devextreme-react/src/scroll-view.ts
+++ b/packages/devextreme-react/src/scroll-view.ts
@@ -16,8 +16,8 @@ type ReplaceFieldTypes<TSource, TReplacement> = {
 type IScrollViewOptionsNarrowedEvents = {
   onDisposing?: ((e: DisposingEvent) => void);
   onInitialized?: ((e: InitializedEvent) => void);
-  onPullDown?: ((e: PullDownEvent) => void) | null;
-  onReachBottom?: ((e: ReachBottomEvent) => void) | null;
+  onPullDown?: ((e: PullDownEvent) => void) | undefined;
+  onReachBottom?: ((e: ReachBottomEvent) => void) | undefined;
   onScroll?: ((e: ScrollEvent) => void);
   onUpdated?: ((e: UpdatedEvent) => void);
 }
diff --git a/packages/devextreme-react/src/tag-box.ts b/packages/devextreme-react/src/tag-box.ts
index a7b48f31be58..4486cacad69e 100644
--- a/packages/devextreme-react/src/tag-box.ts
+++ b/packages/devextreme-react/src/tag-box.ts
@@ -41,9 +41,9 @@ type ITagBoxOptionsNarrowedEvents = {
   onItemClick?: ((e: ItemClickEvent) => void);
   onKeyDown?: ((e: KeyDownEvent) => void);
   onKeyUp?: ((e: KeyUpEvent) => void);
-  onMultiTagPreparing?: ((e: MultiTagPreparingEvent) => void) | null;
+  onMultiTagPreparing?: ((e: MultiTagPreparingEvent) => void) | undefined;
   onOpened?: ((e: OpenedEvent) => void);
-  onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent) => void) | null;
+  onSelectAllValueChanged?: ((e: SelectAllValueChangedEvent) => void) | undefined;
   onValueChanged?: ((e: ValueChangedEvent) => void);
 }
 
diff --git a/packages/devextreme/js/__internal/ui/list/list.base.ts b/packages/devextreme/js/__internal/ui/list/list.base.ts
index 5c0999ba971d..4bcf638d67db 100644
--- a/packages/devextreme/js/__internal/ui/list/list.base.ts
+++ b/packages/devextreme/js/__internal/ui/list/list.base.ts
@@ -593,9 +593,9 @@ export class ListBase extends CollectionWidget<ListBaseProperties, Item> {
       onScroll: (e: ScrollEvent): void => {
         this._scrollHandler(e);
       },
-      onPullDown: isPullRefreshEnabled ? this._pullDownHandler.bind(this) : null,
+      onPullDown: isPullRefreshEnabled ? this._pullDownHandler.bind(this) : undefined,
       // @ts-expect-error ts-error
-      onReachBottom: autoPagingEnabled ? this._scrollBottomHandler.bind(this) : null,
+      onReachBottom: autoPagingEnabled ? this._scrollBottomHandler.bind(this) : undefined,
       showScrollbar,
       useNative: useNativeScrolling,
       bounceEnabled,
diff --git a/packages/devextreme/ts/dx.all.d.ts b/packages/devextreme/ts/dx.all.d.ts
index 780ef1b9e7ad..a7b5c56c9330 100644
--- a/packages/devextreme/ts/dx.all.d.ts
+++ b/packages/devextreme/ts/dx.all.d.ts
@@ -12345,31 +12345,31 @@ declare module DevExpress.ui {
      */
     onHidden?:
       | ((e: DevExpress.ui.dxContextMenu.HiddenEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxContextMenuOptions.onHiding]
      */
     onHiding?:
       | ((e: DevExpress.ui.dxContextMenu.HidingEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxContextMenuOptions.onPositioning]
      */
     onPositioning?:
       | ((e: DevExpress.ui.dxContextMenu.PositioningEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxContextMenuOptions.onShowing]
      */
     onShowing?:
       | ((e: DevExpress.ui.dxContextMenu.ShowingEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxContextMenuOptions.onShown]
      */
     onShown?:
       | ((e: DevExpress.ui.dxContextMenu.ShownEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxContextMenuOptions.position]
      */
@@ -16209,31 +16209,33 @@ declare module DevExpress.ui {
     /**
      * [descr:dxDiagramOptions.onItemClick]
      */
-    onItemClick?: ((e: DevExpress.ui.dxDiagram.ItemClickEvent) => void) | null;
+    onItemClick?:
+      | ((e: DevExpress.ui.dxDiagram.ItemClickEvent) => void)
+      | undefined;
     /**
      * [descr:dxDiagramOptions.onItemDblClick]
      */
     onItemDblClick?:
       | ((e: DevExpress.ui.dxDiagram.ItemDblClickEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxDiagramOptions.onSelectionChanged]
      */
     onSelectionChanged?:
       | ((e: DevExpress.ui.dxDiagram.SelectionChangedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxDiagramOptions.onRequestEditOperation]
      */
     onRequestEditOperation?:
       | ((e: DevExpress.ui.dxDiagram.RequestEditOperationEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxDiagramOptions.onRequestLayoutUpdate]
      */
     onRequestLayoutUpdate?:
       | ((e: DevExpress.ui.dxDiagram.RequestLayoutUpdateEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxDiagramOptions.pageColor]
      */
@@ -21209,65 +21211,67 @@ declare module DevExpress.ui {
      */
     onSelectionChanged?:
       | ((e: DevExpress.ui.dxGantt.SelectionChangedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onCustomCommand]
      */
     onCustomCommand?:
       | ((e: DevExpress.ui.dxGantt.CustomCommandEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onContextMenuPreparing]
      */
     onContextMenuPreparing?:
       | ((e: DevExpress.ui.dxGantt.ContextMenuPreparingEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onTaskInserting]
      */
     onTaskInserting?:
       | ((e: DevExpress.ui.dxGantt.TaskInsertingEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onTaskInserted]
      */
     onTaskInserted?:
       | ((e: DevExpress.ui.dxGantt.TaskInsertedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onTaskDeleting]
      */
     onTaskDeleting?:
       | ((e: DevExpress.ui.dxGantt.TaskDeletingEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onTaskDeleted]
      */
     onTaskDeleted?:
       | ((e: DevExpress.ui.dxGantt.TaskDeletedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onTaskUpdating]
      */
     onTaskUpdating?:
       | ((e: DevExpress.ui.dxGantt.TaskUpdatingEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onTaskUpdated]
      */
     onTaskUpdated?:
       | ((e: DevExpress.ui.dxGantt.TaskUpdatedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onTaskMoving]
      */
-    onTaskMoving?: ((e: DevExpress.ui.dxGantt.TaskMovingEvent) => void) | null;
+    onTaskMoving?:
+      | ((e: DevExpress.ui.dxGantt.TaskMovingEvent) => void)
+      | undefined;
     /**
      * [descr:dxGanttOptions.onTaskEditDialogShowing]
      */
     onTaskEditDialogShowing?:
       | ((e: DevExpress.ui.dxGantt.TaskEditDialogShowingEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onResourceManagerDialogShowing]
      */
@@ -21279,83 +21283,85 @@ declare module DevExpress.ui {
      */
     onDependencyInserting?:
       | ((e: DevExpress.ui.dxGantt.DependencyInsertingEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onDependencyInserted]
      */
     onDependencyInserted?:
       | ((e: DevExpress.ui.dxGantt.DependencyInsertedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onDependencyDeleting]
      */
     onDependencyDeleting?:
       | ((e: DevExpress.ui.dxGantt.DependencyDeletingEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onDependencyDeleted]
      */
     onDependencyDeleted?:
       | ((e: DevExpress.ui.dxGantt.DependencyDeletedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onResourceInserting]
      */
     onResourceInserting?:
       | ((e: DevExpress.ui.dxGantt.ResourceInsertingEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onResourceInserted]
      */
     onResourceInserted?:
       | ((e: DevExpress.ui.dxGantt.ResourceInsertedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onResourceDeleting]
      */
     onResourceDeleting?:
       | ((e: DevExpress.ui.dxGantt.ResourceDeletingEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onResourceDeleted]
      */
     onResourceDeleted?:
       | ((e: DevExpress.ui.dxGantt.ResourceDeletedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onResourceAssigning]
      */
     onResourceAssigning?:
       | ((e: DevExpress.ui.dxGantt.ResourceAssigningEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onResourceAssigned]
      */
     onResourceAssigned?:
       | ((e: DevExpress.ui.dxGantt.ResourceAssignedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onResourceUnassigning]
      */
     onResourceUnassigning?:
       | ((e: DevExpress.ui.dxGantt.ResourceUnassigningEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onResourceUnassigned]
      */
     onResourceUnassigned?:
       | ((e: DevExpress.ui.dxGantt.ResourceUnassignedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onTaskClick]
      */
-    onTaskClick?: ((e: DevExpress.ui.dxGantt.TaskClickEvent) => void) | null;
+    onTaskClick?:
+      | ((e: DevExpress.ui.dxGantt.TaskClickEvent) => void)
+      | undefined;
     /**
      * [descr:dxGanttOptions.onTaskDblClick]
      */
     onTaskDblClick?:
       | ((e: DevExpress.ui.dxGantt.TaskDblClickEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxGanttOptions.onScaleCellPrepared]
      */
@@ -22740,7 +22746,7 @@ declare module DevExpress.ui {
      */
     onGroupRendered?:
       | ((e: DevExpress.ui.dxList.GroupRenderedEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxListOptions.onItemClick]
      */
@@ -22753,55 +22759,55 @@ declare module DevExpress.ui {
      */
     onItemContextMenu?:
       | ((e: DevExpress.ui.dxList.ItemContextMenuEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxListOptions.onItemDeleted]
      */
     onItemDeleted?:
       | ((e: DevExpress.ui.dxList.ItemDeletedEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxListOptions.onItemDeleting]
      */
     onItemDeleting?:
       | ((e: DevExpress.ui.dxList.ItemDeletingEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxListOptions.onItemHold]
      */
     onItemHold?:
       | ((e: DevExpress.ui.dxList.ItemHoldEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxListOptions.onItemReordered]
      */
     onItemReordered?:
       | ((e: DevExpress.ui.dxList.ItemReorderedEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxListOptions.onItemSwipe]
      */
     onItemSwipe?:
       | ((e: DevExpress.ui.dxList.ItemSwipeEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxListOptions.onPageLoading]
      */
     onPageLoading?:
       | ((e: DevExpress.ui.dxList.PageLoadingEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxListOptions.onPullRefresh]
      */
     onPullRefresh?:
       | ((e: DevExpress.ui.dxList.PullRefreshEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxListOptions.onScroll]
      */
     onScroll?:
       | ((e: DevExpress.ui.dxList.ScrollEvent<TItem, TKey>) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxListOptions.onSelectAllValueChanged]
      */
@@ -22809,7 +22815,7 @@ declare module DevExpress.ui {
       | ((
           e: DevExpress.ui.dxList.SelectAllValueChangedEvent<TItem, TKey>
         ) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxListOptions.pageLoadMode]
      */
@@ -23221,23 +23227,23 @@ declare module DevExpress.ui {
      */
     onPageLoading?:
       | ((e: DevExpress.ui.dxLookup.PageLoadingEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxLookupOptions.onPullRefresh]
      */
     onPullRefresh?:
       | ((e: DevExpress.ui.dxLookup.PullRefreshEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxLookupOptions.onScroll]
      */
-    onScroll?: ((e: DevExpress.ui.dxLookup.ScrollEvent) => void) | null;
+    onScroll?: ((e: DevExpress.ui.dxLookup.ScrollEvent) => void) | undefined;
     /**
      * [descr:dxLookupOptions.onValueChanged]
      */
     onValueChanged?:
       | ((e: DevExpress.ui.dxLookup.ValueChangedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxLookupOptions.pageLoadMode]
      */
@@ -23513,27 +23519,31 @@ declare module DevExpress.ui {
     /**
      * [descr:dxMapOptions.onMarkerAdded]
      */
-    onMarkerAdded?: ((e: DevExpress.ui.dxMap.MarkerAddedEvent) => void) | null;
+    onMarkerAdded?:
+      | ((e: DevExpress.ui.dxMap.MarkerAddedEvent) => void)
+      | undefined;
     /**
      * [descr:dxMapOptions.onMarkerRemoved]
      */
     onMarkerRemoved?:
       | ((e: DevExpress.ui.dxMap.MarkerRemovedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxMapOptions.onReady]
      */
-    onReady?: ((e: DevExpress.ui.dxMap.ReadyEvent) => void) | null;
+    onReady?: ((e: DevExpress.ui.dxMap.ReadyEvent) => void) | undefined;
     /**
      * [descr:dxMapOptions.onRouteAdded]
      */
-    onRouteAdded?: ((e: DevExpress.ui.dxMap.RouteAddedEvent) => void) | null;
+    onRouteAdded?:
+      | ((e: DevExpress.ui.dxMap.RouteAddedEvent) => void)
+      | undefined;
     /**
      * [descr:dxMapOptions.onRouteRemoved]
      */
     onRouteRemoved?:
       | ((e: DevExpress.ui.dxMap.RouteRemovedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxMapOptions.provider]
      */
@@ -25849,7 +25859,7 @@ declare module DevExpress.ui {
      */
     onComplete?:
       | ((e: DevExpress.ui.dxProgressBar.CompleteEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxProgressBarOptions.showStatus]
      */
@@ -26010,7 +26020,7 @@ declare module DevExpress.ui {
      */
     onValueChanged?:
       | ((e: DevExpress.ui.dxRangeSlider.ValueChangedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxRangeSliderOptions.start]
      */
@@ -26354,7 +26364,7 @@ declare module DevExpress.ui {
     /**
      * [descr:dxResponsiveBoxOptions.screenByWidth]
      */
-    screenByWidth?: Function | null;
+    screenByWidth?: Function | undefined;
     /**
      * [descr:dxResponsiveBoxOptions.singleColumnScreen]
      */
@@ -27758,13 +27768,15 @@ declare module DevExpress.ui {
     /**
      * [descr:dxScrollViewOptions.onPullDown]
      */
-    onPullDown?: ((e: DevExpress.ui.dxScrollView.PullDownEvent) => void) | null;
+    onPullDown?:
+      | ((e: DevExpress.ui.dxScrollView.PullDownEvent) => void)
+      | undefined;
     /**
      * [descr:dxScrollViewOptions.onReachBottom]
      */
     onReachBottom?:
       | ((e: DevExpress.ui.dxScrollView.ReachBottomEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxScrollViewOptions.pulledDownText]
      */
@@ -29961,19 +29973,19 @@ declare module DevExpress.ui {
      */
     onMultiTagPreparing?:
       | ((e: DevExpress.ui.dxTagBox.MultiTagPreparingEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxTagBoxOptions.onSelectAllValueChanged]
      */
     onSelectAllValueChanged?:
       | ((e: DevExpress.ui.dxTagBox.SelectAllValueChangedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxTagBoxOptions.onSelectionChanged]
      */
     onSelectionChanged?:
       | ((e: DevExpress.ui.dxTagBox.SelectionChangedEvent) => void)
-      | null;
+      | undefined;
     /**
      * [descr:dxTagBoxOptions.selectAllMode]
      */

From f8985491d2400967e80d3f7723151a45a0f7efd3 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Tue, 14 Jul 2026 11:22:38 +0300
Subject: [PATCH 098/100] fix tests for default options

---
 .../devextreme/testing/helpers/dropDownOptions.js  | 14 +++++++-------
 .../buttonGroup.markup.tests.js                    |  2 +-
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/packages/devextreme/testing/helpers/dropDownOptions.js b/packages/devextreme/testing/helpers/dropDownOptions.js
index cc0d5a116c54..5063600d9012 100644
--- a/packages/devextreme/testing/helpers/dropDownOptions.js
+++ b/packages/devextreme/testing/helpers/dropDownOptions.js
@@ -30,18 +30,18 @@ const defaultDropDownOptions = {
     maxWidth: null,
     minHeight: null,
     minWidth: null,
-    onContentReady: null,
-    onDisposing: null,
+    onContentReady: undefined,
+    onDisposing: undefined,
     onHidden: null,
     onHiding: null,
     onInitialized: null,
-    onOptionChanged: null,
-    onResize: null,
-    onResizeEnd: null,
-    onResizeStart: null,
+    onOptionChanged: undefined,
+    onResize: undefined,
+    onResizeEnd: undefined,
+    onResizeStart: undefined,
     onShowing: null,
     onShown: null,
-    onTitleRendered: null,
+    onTitleRendered: undefined,
     position: null,
     resizeEnabled: false,
     rtlEnabled: false,
diff --git a/packages/devextreme/testing/tests/DevExpress.ui.widgets/buttonGroup.markup.tests.js b/packages/devextreme/testing/tests/DevExpress.ui.widgets/buttonGroup.markup.tests.js
index 78b8e736cf35..8d15f83c3c15 100644
--- a/packages/devextreme/testing/tests/DevExpress.ui.widgets/buttonGroup.markup.tests.js
+++ b/packages/devextreme/testing/tests/DevExpress.ui.widgets/buttonGroup.markup.tests.js
@@ -50,7 +50,7 @@ QUnit.module('default', {
         assert.strictEqual(getOptionValue('keyExpr'), 'text', 'keyExpr');
         assert.deepEqual(getOptionValue('items'), [], 'items');
         assert.strictEqual(getOptionValue('buttonTemplate'), 'content', 'buttonTemplate');
-        assert.strictEqual(getOptionValue('onSelectionChanged'), null, 'onSelectionChanged');
+        assert.strictEqual(getOptionValue('onSelectionChanged'), undefined, 'onSelectionChanged');
         assert.strictEqual(getOptionValue('stylingMode'), 'contained', 'stylingMode');
     });
 

From d4477f3cdcbd44dceba028c45635ec32f6a01ce4 Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Tue, 14 Jul 2026 11:40:04 +0300
Subject: [PATCH 099/100] fix tests for default options

---
 packages/devextreme/testing/helpers/dropDownOptions.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/devextreme/testing/helpers/dropDownOptions.js b/packages/devextreme/testing/helpers/dropDownOptions.js
index 5063600d9012..cd8295a3be24 100644
--- a/packages/devextreme/testing/helpers/dropDownOptions.js
+++ b/packages/devextreme/testing/helpers/dropDownOptions.js
@@ -34,7 +34,7 @@ const defaultDropDownOptions = {
     onDisposing: undefined,
     onHidden: null,
     onHiding: null,
-    onInitialized: null,
+    onInitialized: undefined,
     onOptionChanged: undefined,
     onResize: undefined,
     onResizeEnd: undefined,

From 05e7c8d2e5e490c5705075e220c8958b73bd0d7c Mon Sep 17 00:00:00 2001
From: dmlvr <dmitrii.lavrinovich@devexpress.com>
Date: Tue, 14 Jul 2026 12:58:25 +0300
Subject: [PATCH 100/100] update one more test

---
 .../DevExpress.ui.widgets.editors/lookup.tests.js    | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/packages/devextreme/testing/tests/DevExpress.ui.widgets.editors/lookup.tests.js b/packages/devextreme/testing/tests/DevExpress.ui.widgets.editors/lookup.tests.js
index 68edb2bdae39..076f033dfa29 100644
--- a/packages/devextreme/testing/tests/DevExpress.ui.widgets.editors/lookup.tests.js
+++ b/packages/devextreme/testing/tests/DevExpress.ui.widgets.editors/lookup.tests.js
@@ -2511,12 +2511,22 @@ QUnit.module('popup options', {
         const lookup = $('#lookup').dxLookup({ }).dxLookup('instance');
         const dropDownOptionsAfterInit = { ... lookup.option('dropDownOptions') };
 
+        const normalizeOptions = (options) => {
+            const filteredEntries = Object.entries(options).filter(([key, value]) => {
+                return value !== undefined;
+            });
+            return Object.fromEntries(filteredEntries);
+        };
+
         lookup.open();
         lookup.option('dropDownOptions.width', 123);
 
         const { _cached_dropDownOptions } = lookup.option();
 
-        assert.deepEqual(_cached_dropDownOptions, { ...dropDownOptionsAfterInit, width: 123 }, 'updated part of dropDownOptions is cached in _cached_dropDownOptions');
+        assert.deepEqual(
+            normalizeOptions(_cached_dropDownOptions),
+            normalizeOptions({ ...dropDownOptionsAfterInit, width: 123 }),
+            'updated part of dropDownOptions is cached in _cached_dropDownOptions');
     });
 
     [