Convert Group blocks to beehiiv sections

includes/Editor/Meta.php

@@ -72,6 +72,15 @@ final class Meta {
 	 */
 	public const BEEHIIV_POST_ID = '_beehiiv_post_id';
 
+	/**
+	 * Set when the post was first synced with Group blocks converted to beehiiv sections.
+	 *
+	 * Posts synced before section support lack it and keep omitting Group blocks on re-sync.
+	 *
+	 * @since x.x.x
+	 */
+	public const BEEHIIV_GROUP_SECTIONS = '_beehiiv_group_sections';
+
 	/**
 	 * UTC ISO 8601 datetime last synced to beehiiv `scheduled_at` for a linked post.
 	 *

includes/Newsletter/BlockConverter.php

@@ -11,6 +11,7 @@
 use Beehiiv\API\Resources\AdvertisementOpportunities;
 use Beehiiv\Editor\Meta;
 use Beehiiv\Newsletter\Converters\ColumnsBlockConverter;
+use Beehiiv\Newsletter\Converters\GroupBlockConverter;
 use Beehiiv\Newsletter\Converters\MediaTextBlockConverter;
 use Beehiiv\Newsletter\Converters\TableBlockConverter;
 use Beehiiv\Newsletter\Converters\ListBlockConverter;
@@ -38,7 +39,12 @@
  * - `core/more` — snippet newsletters only; beehiiv Read More `button` via `convert_more_block()`
  * - `beehiiv/advertisement` — beehiiv `advertisement` block via `convert_advertisement_block()`
  *
- * Layout blocks (`core/group`, `core/columns`, etc.) are skipped at the top level.
+ * - `core/group` — `convert_group_block()` (beehiiv `section` block holding the converted inner
+ *   blocks; only for posts whose first sync used sections, see `PostSettingsBuilder`; a Group
+ *   inside a Group is omitted because beehiiv sections cannot hold sections)
+ *
+ * Other layout blocks (`core/columns`, etc.) are skipped at the top level, and so is
+ * `core/group` for posts first synced before section support.
  * `convert_columns_block()` exists for internal reuse (e.g. `core/media-text`) and is
  * not wired into the main block walk yet. Snippet mode stops at `core/more`.
  *
@@ -49,11 +55,13 @@ final class BlockConverter {
 	/**
 	 * Convert a WordPress post's blocks to beehiiv blocks.
 	 *
-	 * @param WP_Post $post_object Post object.
+	 * @param WP_Post $post_object   Post object.
+	 * @param bool    $convert_groups Whether `core/group` blocks become beehiiv sections. When false,
+	 *                                Group blocks are omitted.
 	 * @return array<int, array<string, mixed>>
 	 * @since 1.0.0
 	 */
-	public static function convert_supported_blocks( WP_Post $post_object ): array {
+	public static function convert_supported_blocks( WP_Post $post_object, bool $convert_groups = false ): array {
 		$beehiiv_blocks = [];
 		$wp_blocks      = parse_blocks( $post_object->post_content );
 
@@ -73,7 +81,8 @@ public static function convert_supported_blocks( WP_Post $post_object ): array {
 		$converted_blocks = self::convert_blocks(
 			$wp_blocks,
 			$post_object,
-			$is_send_newsletter_snippet
+			$is_send_newsletter_snippet,
+			$convert_groups
 		);
 
 		return array_values(
@@ -89,13 +98,15 @@ public static function convert_supported_blocks( WP_Post $post_object ): array {
 	 * @param array<int, array<string, mixed>> $wp_blocks                  Parsed blocks.
 	 * @param WP_Post                          $post_object                Post object.
 	 * @param bool                             $is_send_newsletter_snippet Whether snippet mode is enabled.
+	 * @param bool                             $convert_groups             Whether Group blocks become sections.
 	 * @return array<int, array<string, mixed>>
 	 * @since 1.0.0
 	 */
 	private static function convert_blocks(
 		array $wp_blocks,
 		WP_Post $post_object,
-		bool $is_send_newsletter_snippet
+		bool $is_send_newsletter_snippet,
+		bool $convert_groups = false
 	): array {
 		$beehiiv_blocks = [];
 
@@ -111,6 +122,16 @@ private static function convert_blocks(
 				break;
 			}
 
+			if ( 'core/group' === $block_name ) {
+				$section_block = $convert_groups ? self::convert_group_block( $wp_block, $post_object ) : [];
+
+				if ( ! empty( $section_block ) ) {
+					$beehiiv_blocks[] = $section_block;
+				}
+
+				continue;
+			}
+
 			if ( ! SupportedBlocks::is_supported( $block_name, $is_send_newsletter_snippet ) ) {
 				continue;
 			}
@@ -137,6 +158,48 @@ private static function convert_blocks(
 		return $beehiiv_blocks;
 	}
 
+	/**
+	 * Convert a core/group block to a beehiiv section block.
+	 *
+	 * The Group's inner blocks are converted with the same rules as top-level blocks and
+	 * placed in the section in their original order. A Group nested inside a Group is
+	 * omitted with its inner blocks, because a beehiiv section cannot hold another section
+	 * and sending one makes beehiiv reject the whole post. The Group's background colour, text
+	 * colour, padding, margin and border go in the section's `visual_settings`; every other setting is
+	 * left at beehiiv defaults. Returns an empty array when no inner block converts, so no empty section
+	 * is sent. Snippet-only blocks are omitted inside a section.
+	 *
+	 * @param array<string, mixed> $wp_block    Parsed core/group block.
+	 * @param WP_Post              $post_object Post object.
+	 * @return array<string, mixed>
+	 * @since x.x.x
+	 */
+	private static function convert_group_block( array $wp_block, WP_Post $post_object ): array {
+		$inner_blocks = self::convert_blocks(
+			$wp_block['innerBlocks'] ?? [],
+			$post_object,
+			false,
+			false
+		);
+
+		if ( empty( $inner_blocks ) ) {
+			return [];
+		}
+
+		$section = [
+			'type'   => 'section',
+			'blocks' => $inner_blocks,
+		];
+
+		$visual_settings = GroupBlockConverter::build_visual_settings( $wp_block );
+
+		if ( ! empty( $visual_settings ) ) {
+			$section['visual_settings'] = $visual_settings;
+		}
+
+		return $section;
+	}
+
 	/**
 	 * Convert a single supported WordPress block.
 	 *