LifecycleCollector

This library provides you convenience extension functions to easier collect Kotlin Flows lifecycle-aware from an Android component, such as Activity or Fragments. It gives you a more convenient way to collect Flows in LiveData-fashion.

Examples

class MainActivity : AppCompatActivity() {

    override fun onCreate() {
        ...
        viewModel.someStateFlow.collectWhenStarted(owner = this) {
            binding.someTextView.text = it
        }
    }
}

viewModel.someFlow.collectWhenResumed(owner = viewLifecycleOwner) {
    Log.d("Collected item:", it)
}

Note: To recreate the same behaviour as with LiveData, use collectWhenStarted().

Setup

allprojects {
    repositories {
        ...
        maven { url 'https://jitpack.io' }
    }
}

dependencies {
    implementation 'com.github.sebschaef:LifecycleCollector:1.0.0'
}

How it works

It uses the androidx.lifecycle:lifecycle-runtime-ktx under the hood, which supports the repeatOnLifecycle() functionality to restart a flow collection after it left the wanted lifecycle scope and re-enters it.

The convenience functions are no suspend functions and will handle the launch of a Coroutine themselves. They will launch it in the lifecycleScope of the current LifecycleOwner and only collect the given flow inside the specific scope (CREATED, STARTED, RESUMED). When the scope is left, the collection is canceled. If the LifecycleOwner re-enters the scope, the collection is restarted.

See the demo application for more details:

License

Copyright 2021 Sebastian Schäf

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.