Lifecycle

Lifecycle-aware components perform actions in response to a change in the lifecycle status of another component, such as activities and fragments. These components help you produce better-organized, and often lighter-weight code, that is easier to maintain.

This table lists all the artifacts in the androidx.lifecycle group.

Artifact	Stable Release	Release Candidate	Beta Release	Alpha Release
lifecycle-*	2.9.1	-	-	-
lifecycle-viewmodel-navigation3	-	-	-	1.0.0-alpha03

This library was last updated on: July 2, 2025

Declaring dependencies

To add a dependency on Lifecycle, you must add the Google Maven repository to your project. Read Google's Maven repository for more information.

Add the dependencies for the artifacts you need in the build.gradle file for your app or module:

The APIs in lifecycle-extensions have been deprecated. Instead, add dependencies for the specific Lifecycle artifacts you need.

Kotlin

Groovy

    dependencies {
        def lifecycle_version = "2.9.1"
        def arch_version = "2.2.0"

        // ViewModel
        implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version"
        // ViewModel utilities for Compose
        implementation "androidx.lifecycle:lifecycle-viewmodel-compose:$lifecycle_version"
        // LiveData
        implementation "androidx.lifecycle:lifecycle-livedata-ktx:$lifecycle_version"
        // Lifecycles only (without ViewModel or LiveData)
        implementation "androidx.lifecycle:lifecycle-runtime-ktx:$lifecycle_version"
        // Lifecycle utilities for Compose
        implementation "androidx.lifecycle:lifecycle-runtime-compose:$lifecycle_version"

        // Saved state module for ViewModel
        implementation "androidx.lifecycle:lifecycle-viewmodel-savedstate:$lifecycle_version"

        // ViewModel integration with Navigation3
        implementation "androidx.lifecycle:lifecycle-viewmodel-navigation3:1.0.0-alpha03"

        // Annotation processor
        kapt "androidx.lifecycle:lifecycle-compiler:$lifecycle_version"
        // alternately - if using Java8, use the following instead of lifecycle-compiler
        implementation "androidx.lifecycle:lifecycle-common-java8:$lifecycle_version"

        // optional - helpers for implementing LifecycleOwner in a Service
        implementation "androidx.lifecycle:lifecycle-service:$lifecycle_version"

        // optional - ProcessLifecycleOwner provides a lifecycle for the whole application process
        implementation "androidx.lifecycle:lifecycle-process:$lifecycle_version"

        // optional - ReactiveStreams support for LiveData
        implementation "androidx.lifecycle:lifecycle-reactivestreams-ktx:$lifecycle_version"

        // optional - Test helpers for LiveData
        testImplementation "androidx.arch.core:core-testing:$arch_version"

        // optional - Test helpers for Lifecycle runtime
        testImplementation "androidx.lifecycle:lifecycle-runtime-testing:$lifecycle_version"
    }

Kotlin

    dependencies {
        val lifecycle_version = "2.9.1"
        val arch_version = "2.2.0"

        // ViewModel
        implementation("androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version")
        // ViewModel utilities for Compose
        implementation("androidx.lifecycle:lifecycle-viewmodel-compose:$lifecycle_version")
        // LiveData
        implementation("androidx.lifecycle:lifecycle-livedata-ktx:$lifecycle_version")
        // Lifecycles only (without ViewModel or LiveData)
        implementation("androidx.lifecycle:lifecycle-runtime-ktx:$lifecycle_version")
        // Lifecycle utilities for Compose
        implementation("androidx.lifecycle:lifecycle-runtime-compose:$lifecycle_version")

        // Saved state module for ViewModel
        implementation("androidx.lifecycle:lifecycle-viewmodel-savedstate:$lifecycle_version")

        // ViewModel integration with Navigation3
        implementation("androidx.lifecycle:lifecycle-viewmodel-navigation3:1.0.0-alpha03")

        // Annotation processor
        kapt("androidx.lifecycle:lifecycle-compiler:$lifecycle_version")
        // alternately - if using Java8, use the following instead of lifecycle-compiler
        implementation("androidx.lifecycle:lifecycle-common-java8:$lifecycle_version")

        // optional - helpers for implementing LifecycleOwner in a Service
        implementation("androidx.lifecycle:lifecycle-service:$lifecycle_version")

        // optional - ProcessLifecycleOwner provides a lifecycle for the whole application process
        implementation("androidx.lifecycle:lifecycle-process:$lifecycle_version")

        // optional - ReactiveStreams support for LiveData
        implementation("androidx.lifecycle:lifecycle-reactivestreams-ktx:$lifecycle_version")

        // optional - Test helpers for LiveData
        testImplementation("androidx.arch.core:core-testing:$arch_version")

        // optional - Test helpers for Lifecycle runtime
        testImplementation ("androidx.lifecycle:lifecycle-runtime-testing:$lifecycle_version")
    }

Java

Groovy

    dependencies {
        def lifecycle_version = "2.9.1"
        def arch_version = "2.2.0"

        // ViewModel
        implementation "androidx.lifecycle:lifecycle-viewmodel:$lifecycle_version"
        // LiveData
        implementation "androidx.lifecycle:lifecycle-livedata:$lifecycle_version"
        // Lifecycles only (without ViewModel or LiveData)
        implementation "androidx.lifecycle:lifecycle-runtime:$lifecycle_version"

        // Saved state module for ViewModel
        implementation "androidx.lifecycle:lifecycle-viewmodel-savedstate:$lifecycle_version"

        // Annotation processor
        annotationProcessor "androidx.lifecycle:lifecycle-compiler:$lifecycle_version"
        // alternately - if using Java8, use the following instead of lifecycle-compiler
        implementation "androidx.lifecycle:lifecycle-common-java8:$lifecycle_version"

        // optional - helpers for implementing LifecycleOwner in a Service
        implementation "androidx.lifecycle:lifecycle-service:$lifecycle_version"

        // optional - ProcessLifecycleOwner provides a lifecycle for the whole application process
        implementation "androidx.lifecycle:lifecycle-process:$lifecycle_version"

        // optional - ReactiveStreams support for LiveData
        implementation "androidx.lifecycle:lifecycle-reactivestreams:$lifecycle_version"

        // optional - Test helpers for LiveData
        testImplementation "androidx.arch.core:core-testing:$arch_version"

        // optional - Test helpers for Lifecycle runtime
        testImplementation "androidx.lifecycle:lifecycle-runtime-testing:$lifecycle_version"
    }

Kotlin

    dependencies {
        val lifecycle_version = "2.9.1"
        val arch_version = "2.2.0"

        // ViewModel
        implementation("androidx.lifecycle:lifecycle-viewmodel:$lifecycle_version")
        // LiveData
        implementation("androidx.lifecycle:lifecycle-livedata:$lifecycle_version")
        // Lifecycles only (without ViewModel or LiveData)
        implementation("androidx.lifecycle:lifecycle-runtime:$lifecycle_version")

        // Saved state module for ViewModel
        implementation("androidx.lifecycle:lifecycle-viewmodel-savedstate:$lifecycle_version")

        // Annotation processor
        annotationProcessor("androidx.lifecycle:lifecycle-compiler:$lifecycle_version")
        // alternately - if using Java8, use the following instead of lifecycle-compiler
        implementation("androidx.lifecycle:lifecycle-common-java8:$lifecycle_version")

        // optional - helpers for implementing LifecycleOwner in a Service
        implementation("androidx.lifecycle:lifecycle-service:$lifecycle_version")

        // optional - ProcessLifecycleOwner provides a lifecycle for the whole application process
        implementation("androidx.lifecycle:lifecycle-process:$lifecycle_version")

        // optional - ReactiveStreams support for LiveData
        implementation("androidx.lifecycle:lifecycle-reactivestreams:$lifecycle_version")

        // optional - Test helpers for LiveData
        testImplementation("androidx.arch.core:core-testing:$arch_version")

        // optional - Test helpers for Lifecycle runtime
        testImplementation("androidx.lifecycle:lifecycle-runtime-testing:$lifecycle_version")
    }

For more information about dependencies, see Add Build Dependencies.

Feedback

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Create a new issue

See the Issue Tracker documentation for more information.

Lifecycle ViewModel Navigation3 Version 1.0.0

Version 1.0.0-alpha03

July 2, 2025

androidx.lifecycle:lifecycle-viewmodel-navigation3:1.0.0-alpha03 and androidx.lifecycle:lifecycle-viewmodel-navigation3-android:1.0.0-alpha03 are released. Version 1.0.0-alpha03 contains these commits.

Dependency Changes

Lifecycle ViewModel Navigation 3 now depends on Navigation3 Alpha05

Version 1.0.0-alpha02

June 18, 2025

androidx.lifecycle:lifecycle-viewmodel-navigation3:1.0.0-alpha02 and androidx.lifecycle:lifecycle-viewmodel-navigation3-android:1.0.0-alpha02 are released. Version 1.0.0-alpha02 contains these commits.

Dependency Updates

Lifecycle ViewModel Navigation3 1.0.0-alpha02 is dependent on changes in Navigation3 1.0.0-alpha04. (Icd0fd, b/420991203)

Version 1.0.0-alpha01

May 23, 2025

androidx.lifecycle:lifecycle-viewmodel-navigation3:1.0.0-alpha01 is released. Version 1.0.0-alpha01 contains these commits.

New Features

Lifecycle ViewModel Navigation3 is a new library built alongside Navigation3 to provide integrations with ViewModels. The androidx.lifecycle:lifecycle-viewmodel-navigation3 artifact provides the ViewModelStoreNavEntryDecorator which provides a unique ViewModelStoreOwner to the content of each NavEntry. It also provides a rememberViewModelStoreNavEntryDecorator() to ensure that the decorator is properly handled by config changes.

val viewModelDecorator = rememberViewModelStoreNavEntryDecorator()

NavDisplay(
  …,
  entryDecorators =
  listOf(
    rememberSceneSetupNavEntryDecorator(),
    rememberSavedStateNavEntryDecorator(),
    viewModelDecorator
  )
)

Version 2.9

Version 2.9.1

June 4, 2025

androidx.lifecycle:lifecycle-*:2.9.1 is released. Version 2.9.1 contains these commits.

Bug Fixes

Fix SavedStateHandle.remove(key) not clearing SavedStateHandle.getMutableStateFlow(key) states. (d5f939, b/418746333)

Version 2.9.0

May 7, 2025

androidx.lifecycle:lifecycle-*:2.9.0 is released. Version 2.9.0 contains these commits.

Important changes since 2.8.0

A new androidx.lifecycle:lifecycle-viewmodel-testing KMP artifact is available that provides a ViewModelScenario class for testing ViewModels in isolation, with support for onCleared and SavedStateHandle as well as testing process death and recreation via recreate().
Add getMutableStateFlow to SavedStateHandle to return a MutableStateFlow. This new function is key-exclusive and cannot be used with getLiveData. An exception will be thrown if you try to use both to access the same state.
CreationExtras now includes map-like operator overloads to enable idiomatic manipulation of content in Kotlin. It allows the use of in, +=, and + with CreationExtras.

KotlinX Serialization Support

With the support of KotlinX Serialization added in SavedState 1.3.0, we have introduced saved, a lazy property delegate, to make it easy to store @Serializable classes in a SavedStateHandle and have those classes automatically be restored across process death and recreation. Please note the saved delegate is lazy and will not call the init lambda or save anything into the SavedStateHandle until it is accessed.
```
@Serializable
data class Person(val firstName: String, val lastName: String)

class MyViewModel(handle: SavedStateHandle) : ViewModel() {
    var person by handle.saved { Person("John", "Doe") }

    fun onPersonChanged(person: Person) {
        this.person = person
    }
}
```

Kotlin Multiplatform

The lifecycle-testing module is now KMP compatible including APIs like TestLifecycleOwner.
The lifecycle-viewmodel-savedstate module is now KMP compatible including APIs like SavedStateHandle.
The androidx.compose.ui.platform.LocalLifecycleOwner is now available in the common source set.
NewInstanceFactory is now available on JVM Desktop and Android targets.

Behavior Changes

The Lifecycle.DESTROYED state is terminal, and any attempt to move a Lifecycle from it to any other state will now result in an IllegalStateException.
SavedStateHandle no longer includes any SavedStateProvider.saveState() where the returned Bundle is empty.

Version 2.9.0-rc01

April 23, 2025

androidx.lifecycle:lifecycle-*:2.9.0-rc01 is released. Version 2.9.0-rc01 contains these commits.

Version 2.9.0-beta01

April 9, 2025

androidx.lifecycle:lifecycle-*:2.9.0-beta01 is released. Version 2.9.0-beta01 contains these commits.

API Changes

Lifecycle ViewModel Compose now uses the same Kotlin Multiplatform setup as Compose Runtime 1.7.1 and higher - the -desktop artifacts are now removed and -jvmStubs and -linuxx64Stubs artifacts have been added. None of these targets are meant to be used, they are placeholders to help Jetbrains Compose efforts. (I5cb14, b/406592090)

Dependency Updates

This library now targets Kotlin 2.0 language level and requires KGP 2.0.0 or newer. (Idb6b5)
Lifecycle ViewModel Compose now depends on Compose 1.7.8. (I5cb14, b/406592090)

Version 2.9.0-alpha13

March 26, 2025

androidx.lifecycle:lifecycle-*:2.9.0-alpha13 is released with no notable public changes. Version 2.9.0-alpha13 contains these commits.

Version 2.9.0-alpha12

March 12, 2025

androidx.lifecycle:lifecycle-*:2.9.0-alpha12 is released. Version 2.9.0-alpha12 contains these commits.

API Changes

Add @MainThread annotation to ViewModelProvider.get in all supported KMP platforms. (I7e8dd, b/397736115)
Rename SavedState*Delegates to SavedState*Delegate. (I8589b, b/399629301)

Version 2.9.0-alpha11

February 26, 2025

androidx.lifecycle:lifecycle-*:2.9.0-alpha11 is released. Version 2.9.0-alpha11 contains these commits.

API Changes

Add SavedStateConfig parameter to saved() delegates (I39b3a)

Version 2.9.0-alpha10

February 12, 2025

androidx.lifecycle:lifecycle-*:2.9.0-alpha10 is released. Version 2.9.0-alpha10 contains these commits.

API Changes

Move MutableStateSerializer to savedstate-compose from lifecycle-viewmodel-compose. (I4f690, b/378895074)

External Contribution

Adds a new Lint issue for calling Lifecycle::currentState in composition, instead suggesting using currentStateAsalue().value to ensure that changes in the Lifecycle state correctly cause recomposition. Thanks Steven Schoen! (Iad484)

Version 2.9.0-alpha09

January 29, 2025

androidx.lifecycle:lifecycle-*:2.9.0-alpha09 is released. Version 2.9.0-alpha09 contains these commits.

New Features

Add MutableStateSerializer for serializing androidx.compose.runtime.MutableState. (Idfc48, b/378895074)

API Changes

Replace overloaded SavedStateHandle.saved() delegate functions with default parameters (Icd1c1)
AbstractSavedStateViewModelFactory is deprecated as it creates a SavedStateHandle for every ViewModel, causing unnecessary overhead. Use ViewModelProvider.Factory with CreationExtras.createSavedStateHandle instead for more efficient ViewModel creation. (Ia920b, b/388590327)

Version 2.9.0-alpha08

December 11, 2024

androidx.lifecycle:lifecycle-*:2.9.0-alpha08 is released. Version 2.9.0-alpha08 contains these commits.

New Features

Add ViewModelScenario.recreate to simulate a System Process Death recreating the ViewModel under test and all associated components. (Id6a69, b/381063087)
LifecycleOwner and ViewModelStoreOwner instances retrieved via their respective findViewTree APIs can now be resolved through disjoint parents of a view, such as a ViewOverlay. See the release notes of core or the documentation in ViewTree.setViewTreeDisjointParent for more information on disjoint view parents. (I800f4)

API Changes

Make the namings and package organization more consistent with SavedStateRegistryOwnerDelegate (I8c135, b/376026744)

Bug Fixes

This library now uses JSpecify nullness annotations, which are type-use. Kotlin developers should use the following compiler argument to enforce correct usage: -Xjspecify-annotations=strict (this is the default starting with version 2.1.0 of the Kotlin compiler). (Ie4340, b/326456246)
Document ViewModel.onCleared clearing sequence. (I586c7, b/363984116)

Version 2.9.0-alpha07

November 13, 2024

androidx.lifecycle:lifecycle-*:2.9.0-alpha07 is released. Version 2.9.0-alpha07 contains these commits.

Kotlin Multiplatform Compatibility

Lifecycle ViewModel SavedState is now KMP compatible. This allows you to use SavedStateHandle in common code. (Ib6394, b/334076622)

KotlinX Serialization Support

With the support of KotlinX Serialization added in SavedState 1.3.0-alpha05, we have introduced saved, a lazy property delegate, to make it easy to store @Serializable classes in a SavedStateHandle and have those classes automatically be restored across process death and recreation. Please note the saved delegate is lazy and will not call the init lambda or save anything into the SavedStateHandle until it is accessed. (I47a88, b/376026744)
```
@Serializable
data class Person(val firstName: String, val lastName: String)

class MyViewModel(handle: SavedStateHandle) : ViewModel() {
    var person by handle.saved { Person("John", "Doe") }

    fun onPersonChanged(person: Person) {
        this.person = person
    }
}
```

API Changes

Add getMutableStateFlow to SavedStateHandle to return a MutableStateFlow. This new function is key-exclusive and cannot be used with getLiveData. An exception will be thrown if you try to use both to access the same state. (I04a4f, b/375408415)

Version 2.9.0-alpha06

October 30, 2024

androidx.lifecycle:lifecycle-*:2.9.0-alpha06 is released. Version 2.9.0-alpha06 contains these commits.

Behavior Changes

The Lifecycle.DESTROYED state is terminal, and any attempt to move a Lifecycle from it to any other state will now result in an IllegalStateException. (I116c4, b/370577987)
SavedStateHandle no longer includes any SavedStateProvider.saveState() where the returned Bundle is empty. (I910b5, b/370577987)

Bug Fixes

Lifecycle.eventFlow now correctly complete when Lifecycle is DESTROYED (I293b2, b/374043130)

Version 2.9.0-alpha05

October 16, 2024

androidx.lifecycle:lifecycle-*:2.9.0-alpha05 is released with no notable changes. Version 2.9.0-alpha05 contains these commits.

Version 2.9.0-alpha04

October 2, 2024

androidx.lifecycle:lifecycle-*:2.9.0-alpha04 is released. Version 2.9.0-alpha04 contains these commits.

Kotlin Multiplatform

The lifecycle-viewmodel-savedstate module is now configured to be KMP compatible in preparation for APIs like SavedStateHandle being made available in the common source set in a future release. (I503ed, I48764, b/334076622)

Version 2.9.0-alpha03

September 18, 2024

androidx.lifecycle:lifecycle-*:2.9.0-alpha03 is released. Version 2.9.0-alpha03 contains these commits.

Bug Fixes

From Lifecycle 2.8.6: The NullSafeMutableLiveData Lint error has improved support for smart casts, avoiding false positives. (85fed6, b/181042665)

Dependency Updates

From Lifecycle 2.8.6: Lifecycle Runtime Compose now depends on Compose Runtime 1.7.1
Lifecycle Runtime now depends on ProfileInstaller 1.4.0

Version 2.9.0-alpha02

September 4, 2024

androidx.lifecycle:lifecycle-*:2.9.0-alpha02 is released. Version 2.9.0-alpha02 contains these commits.

Bug Fixes

From Lifecycle 2.8.5: Update the androidx.lifecycle.ReportFragment ProGuard rules to allow obfuscation . (ff898e1)

External Contribution

Move androidx.compose.ui.platform.LocalLifecycleOwner to common source set (KMP). Thanks Ivan Matkov from JetBrains for the contribution. (8cd5d03)
From Lifecycle 2.8.5: SavedStateHandle.saveable` extension delegate now supports nullable values. Thanks Roman Kalukiewicz for the contribution. (0d78ea6)

Version 2.9.0-alpha01

August 7, 2024

androidx.lifecycle:lifecycle-*:2.9.0-alpha01 is released. Version 2.9.0-alpha01 contains these commits.

Kotlin Multiplatform

lifecycle-testing is now KMP compatible. (Iea41e)
Add support for linuxArm64 kotlin multiplatform target (I139d3, b/338268719)

New Features

A new androidx.lifecycle:lifecycle-viewmodel-testing KMP artifact is available that provides a ViewModelScenario class for testing ViewModels in isolation, with support for onCleared (all platforms) and SavedStateHandle (Android only). (337f68d, c9b3409, 9799a95c, b/264602919)
Creating a ViewModel with ViewModelProvider is now thread safe; @MainThread annotations have been removed. (Ifd978, b/237006831)

API Changes

Add the CreationExtras.Key() factory function to simplify the creation of anonymous CreationExtras.Key objects. (I970ee)
CreationExtras now includes map-like operator overloads to enable idiomatic manipulation of content in Kotlin. It allows the use of in, +=, and + with CreationExtras. (Ib4353)
CreationExtras now implements equals, hashCode, and toString methods. (Ib4353)
NewInstanceFactory is now available on JVM Desktop and Android targets. (d3d0892)
Inline extension property to expose underlying Application safely in Kotlin language version 2.0 (I39df2)

Bug Fixes

Removed manual outlining of access to new platform APIs since this happens automatically via API modeling when using R8 with AGP 7.3 or later (e.g. R8 version 3.3) and for all builds when using AGP 8.1 or later (e.g. D8 version 8.1). Clients who are not using AGP are advised to update to D8 version 8.1 or later. See this article for more details. (If6b4c, b/345472586)

Version 2.8

Version 2.8.7

October 30, 2024

androidx.lifecycle:lifecycle-*:2.8.7 is released. Version 2.8.7 contains these commits.

API Changes

androidx.compose.ui.platform.LocalLifecycleOwner is now available in the common source set (KMP). (6a3f5b3)
lifecycle-runtime-compose: desktop artifacts were removed and -jvmStubs and -linuxx64Stubs artifacts were added. None of these targets are meant to be used, they are placeholders to help Jetbrains Compose efforts. (6a3f5b3)

Version 2.8.6

September 18, 2024

androidx.lifecycle:lifecycle-*:2.8.6 is released. Version 2.8.6 contains these commits.

Bug Fixes

The NullSafeMutableLiveData Lint error has improved support for smart casts, avoiding false positives. (85fed6, b/181042665)

Dependency Updates

Lifecycle Runtime Compose now depends on Compose Runtime 1.7.1

Version 2.8.5

September 4, 2024

androidx.lifecycle:lifecycle-*:2.8.5 is released. Version 2.8.5 contains these commits.

Bug Fixes

Update the androidx.lifecycle.ReportFragment ProGuard rules to allow obfuscation . (ff898e1)

External Contribution

SavedStateHandle.saveable extension delegate now supports nullable values. Thanks Roman Kalukiewicz for the contribution. (0d78ea6)

Version 2.8.4

July 24, 2024

androidx.lifecycle:lifecycle-*:2.8.4 is released. Version 2.8.4 contains these commits.

Bug Fixes

LiveData.asFlow() now correctly handles cases where the returned Flow is immediately completed after receiving a value already set on the LiveData (for example, when using take(1)). (I9c566)
Lifecycle*Effect completion is now idempotent (i.e., if the onStopOrDispose was called because of the Lifecycle being stopped, it won’t be called a second time upon disposal unless the Lifecycle goes back up to STARTED again). (I5f607, b/352364595)

Version 2.8.3

July 1, 2024

androidx.lifecycle:lifecycle-*:2.8.3 is released. Version 2.8.3 contains these commits.

Bug Fixes

Fixed an issue with Lifecycle 2.8’s backward compatibility with Compose 1.6.0 and lower when using code shrinking. (aosp/3133056, b/346808608)

Version 2.8.2

June 12, 2024

androidx.lifecycle:lifecycle-*:2.8.2 is released. Version 2.8.2 contains these commits.

Bug Fixes

Fixed CompositionLocal LocalLifecycleOwner not present errors when using Lifecycle 2.8.X with Compose 1.6.X or earlier - you can now use Lifecycle 2.8.2 with any version of Compose without any workarounds required. (aosp/3105647, b/336842920)
ViewModelProvider will no longer crash when mixing previous versions of compileOnly Lifecycle dependencies with versions 2.8+, fixing issues with libraries such as LeakCanary. (I80383, b/341792251)

Version 2.8.1

May 29, 2024

androidx.lifecycle:lifecycle-*:2.8.1 is released. Version 2.8.1 contains these commits.

Bug Fixes

lifecycle-viewmodel-compose now only has a common dependency on compose-runtime, removing its common dependency on compose-ui. The Android artifact retains its compose-ui for compatibility. (aosp/3079334, b/339562627)
ViewModel’s saveable integration using property delegates now uses the class name as part of the auto-generated key, avoiding conflicts if multiple classes use the same SavedStateHandle. (aosp/3063463)

Version 2.8.0

May 14, 2024

androidx.lifecycle:lifecycle-*:2.8.0 is released. Version 2.8.0 contains these commits.

Important changes since 2.7.0

LocalLifecycleOwner has been moved from Compose UI to lifecycle-runtime-compose so that its Compose-based helper APIs can be used outside of Compose UI.
The lifecycle-runtime-compose artifact now contains the dropUnlessResumed and dropUnlessStarted APIs which allow you to drop click or other events that occur even after the LifecycleOwner has dropped below the given Lifecycle.State. For example, this can be used with Navigation Compose to avoid handling click events after a transition to another screen has already begun: onClick: () -> Unit = dropUnlessResumed { navController.navigate(NEW_SCREEN) }

ViewModel.viewModelScope is now an overridable constructor parameter, allowing you to inject your own dispatcher and SupervisorJob() or to override the default by using the backgroundScope available within runTest. (I2817c, b/264598574)

class MyViewModel(
  // Make Dispatchers.Main the default, rather than Dispatchers.Main.immediate
  viewModelScope: CoroutineScope = Dispatchers.Main + SupervisorJob()
) : ViewModel(viewModelScope) {
  // Use viewModelScope as before, without any code changes
}

// Allows overriding the viewModelScope in a test
fun Test() = runTest {
  val viewModel = MyViewModel(backgroundScope)
}

ViewModel has been rewritten in Kotlin and now uses AutoClosable instead of Closeable. It now supports adding AutoCloseable objects with a key that allows retrieving them via getCloseable().
Calling LifecycleStartEffect and LifecycleResumeEffect without a key is now an error, following the same convention as the DisposableEffect API that these APIs mirror.
Deprecated LiveDataReactiveStreams.toPublisher(lifecycleOwner, liveData) in favor of LiveData.toPublisher(lifecycleOwner).
The lifecycle-livedata-core-ktx kotlin extensions have now been moved to the lifecycle-livedata-core module.
The NullSafeMutableLiveData has been refactored to avoid many false positives.

Lifecycle Kotlin Multiplatform Compatibility

The core Lifecycle APIs in Lifecycle, LifecycleOwner, LifecycleObserver, Lifecycle.State, Lifecycle.Event, and LifecycleRegistry are now shipped in artifacts compatible with Kotlin Multiplatform.

Artifacts impacted:

lifecycle-common moves most APIs to common and supports jvm and iOS in addition to Android.
lifecycle-runtime moves most APIs to common and supports jvm and iOS in addition to Android.
lifecycle-runtime-ktx is now empty, with all APIs being moved into lifecycle-runtime.
lifecycle-runtime-compose moves all APIs to common and ships an Android artifact, matching the multiplatform support of androidx.compose.

ViewModel Kotlin Multiplatform Compatibility

The lifecycle-viewmodel artifact and APIs like ViewModel, ViewModelStore, ViewModelStoreOwner, and ViewModelProvider are now shipped in artifacts compatible with Kotlin Multiplatform.

To accommodate this change, methods such as those on ViewModelProvider that took a java.lang.Class<T> now have an equivalent method that takes a kotlin.reflect.KClass<T>.

Binary compatibility on Android has been maintained, but there are a few notable changes when comparing the Android API surface to the common API surface:

Constructing a ViewModelProvider instance is now done through the ViewModelProvider.create() methods rather than directly calling its constructor.
ViewModelProvider.NewInstanceFactory and ViewModelProvider.AndroidViewModelFactory are only available on Android.
- Custom Factories are recommended to extend from ViewModelProvider.Factory and use the create method that takes a CreationExtras or use the viewModelFactory Kotlin DSL.
Using ViewModelProvider without a custom factory on non-JVM platforms will result in an UnsupportedOperationException. On JVM platforms, compatibility is preserved by using the no-args ViewModel constructor if a custom factory is not provided.
viewModelScope will fallback to an EmptyCoroutineContext in platforms where Dispatchers.Main is not available (e.g., Linux).

Artifacts impacted:

lifecycle-viewmodel moves most APIs to common and supports jvm and iOS in addition to Android.
lifecycle-viewmodel-ktx is now empty, with all APIs being moved into lifecycle-viewmodel.
lifecycle-viewmodel-compose moves all APIs to common and ships an Android artifact, matching the multiplatform support of androidx.compose.

Behavior Changes

InitializerViewModelFactory (including viewModelFactory builder function) will now throw an IllegalArgumentException if a initializer with the same clazz: KClass<VM : ViewModel> has already been added. (Ic3a36)

Known Issues

lifecycle-*:2.8.0 requires a minimum Compose version of 1.7.0-alpha05 (b/336842920).

Version 2.8.0-rc01

May 1, 2024

androidx.lifecycle:lifecycle-*:2.8.0-rc01 is released. Version 2.8.0-rc01 contains these commits.

Bug Fixes

Fixed an issue where the Baseline Profile for lifecycle-common classes was not properly packaged. These are now packaged in the lifecycle-runtime AAR. (aosp/3038274, b/322382422)
Fixed an unintentional ordering change in how AutoCloseable instances attached to a ViewModel are cleared - the previous order of addCloseable(String, AutoCloseable), then addClosable(AutoCloseable), then onCleared() has been restored. (aosp/3041632)
Improve the default creation behavior for viewModelScope for native and JVM Desktop environments. (aosp/3039221)

External Contribution

Thanks Victor Kropp for improving the checking for the main thread on JVM Desktop. (aosp/3037116)

Version 2.8.0-beta01

April 17, 2024

androidx.lifecycle:lifecycle-*:2.8.0-beta01 is released. Version 2.8.0-beta01 contains these commits.

New Features

The lifecycle-runtime-compose artifact is now compatible with Kotlin Multiplatform, moving its code to common and ships an Android artifact, matching the multiplatform support for androidx.compose. (If7a71, I4f4a0, b/331769623)

Version 2.8.0-alpha04

April 3, 2024

androidx.lifecycle:lifecycle-*:2.8.0-alpha04 is released. Version 2.8.0-alpha04 contains these commits.

New Features

The lifecycle-viewmodel-compose artifact is now compatible with Kotlin Multiplatform, moving its code to common and ships an Android artifact, matching the multiplatform support of androidx.compose. The accommodate this change, the Composable viewModel method now accepts a KClass in addition to a java.lang.Class. (b/330323282)

Bug Fixes

The NullSafeMutableLiveData has been refactored to avoid many false positives. (I2d8c1, Iafb18, I03463, I7ecef)

Dependency update

The lifecycle-viewmodel-compose artifact now depends on Compose 1.6.0.
Lifecycle now depends on Profile Installer 1.3.1.

Version 2.8.0-alpha03

March 20, 2024

androidx.lifecycle:lifecycle-*:2.8.0-alpha03 is released. Version 2.8.0-alpha03 contains these commits.

New Features

class MyViewModel(
  // Make Dispatchers.Main the default, rather than Dispatchers.Main.immediate
  viewModelScope: CoroutineScope = Dispatchers.Main + SupervisorJob()
) : ViewModel(viewModelScope) {
  // Use viewModelScope as before, without any code changes
}

// Allows overriding the viewModelScope in a test
fun Test() = runTest {
  val viewModel = MyViewModel(backgroundScope)
}

Kotlin Multiplatform Compatibility

The lifecycle-viewmodel artifact and APIs like ViewModel, ViewModelStore, ViewModelStoreOwner, and ViewModelProvider are now shipped in artifacts compatible with Kotlin Multiplatform. (b/214568825)

To accommodate this change, methods such as those on ViewModelProvider that took a java.lang.Class<T> now have an equivalent method that takes a kotlin.reflect.KClass<T>.

Binary compatibility on Android has been maintained, but there are a few notable changes when comparing the Android API surface to the common API surface:

Constructing a ViewModelProvider instance is now done through the ViewModelProvider.create() methods rather than directly calling its constructor.
ViewModelProvider.NewInstanceFactory and ViewModelProvider.AndroidViewModelFactory are only available on Android.
- Custom Factories are recommended to extend from ViewModelProvider.Factory and use the create method that takes a CreationExtras or use the viewModelFactory Kotlin DSL.
Using ViewModelProvider without a custom factory on non-JVM platforms will result in an UnsupportedOperationException. On JVM platforms, compatibility is preserved by using the no-args ViewModel constructor if a custom factory is not provided.
viewModelScope will fallback to an EmptyCoroutineContext in platforms where Dispatchers.Main is not available (e.g., Linux).

Behavior Changes

InitializerViewModelFactory (including viewModelFactory builder function) will now throw an IllegalArgumentException if a initializer with the same clazz: KClass<VM : ViewModel> has already been added. (Ic3a36)

Bug Fixes

ViewModel.getCloseable now handles duplicated keys: if the key already has an AutoCloseable resource associated with it, the old resource will be replaced and closed immediately. (Ibeb67)
Accessing the viewModelScope of a ViewModel is now thread safe. (If4766, b/322407038)

External Contribution

LocalLifecycleOwner moved from Compose UI to lifecycle-runtime-compose so that its Compose-based helper APIs can be used outside of Compose UI. Thanks Jake Wharton for the contribution. (I6c41b, b/328263448)

Version 2.8.0-alpha02

February 21, 2024

androidx.lifecycle:lifecycle-*:2.8.0-alpha02 is released. Version 2.8.0-alpha02 contains these commits.

New Features

The dropUnlessResumed and dropUnlessStarted APIs have been added which allow you to drop click or other events that occur even after the LifecycleOwner has dropped below the given Lifecycle.State. For example, this can be used with Navigation Compose to avoid handling click events after a transition to another screen has already begun: onClick: () -> Unit = dropUnlessResumed { navController.navigate(NEW_SCREEN) } (Icba83, b/317230685)

Kotlin Conversions

ViewModel is now written in Kotlin (I16f26, b/214568825)
The lifecycle-viewmodel-ktx kotlin extensions have now been moved to the base lifecycle module. (Id787b, b/274800183)
The lifecycle-runtime-ktx kotlin extensions have now been moved to the base lifecycle module. (Ic3686, b/274800183)
The lifecycle-livedata-core-ktx kotlin extensions have now been moved to the base lifecycle module. (I54a3d, b/274800183)

Kotlin Multiplatform Compatibility

The core Lifecycle APIs in Lifecycle, LifecycleOwner, LifecycleObserver, Lifecycle.State, Lifecycle.Event, and LifecycleRegistry are now shipped in artifacts compatible with Kotlin Multiplatform. (b/317249252)

API Changes

Calling LifecycleStartEffect and LifecycleResumeEffect without a key is now an error, following the same convention as the DisposableEffect API that these APIs mirror. (Ib0e0c, b/323518079)
ViewModel now uses AutoCloseable instead of Closeable. That is a backward compatible change. (I27f8e, b/214568825)
Deprecated LiveDataReactiveStreams.toPublisher(lifecycleOwner, liveData) in favor of LiveData.toPublisher(lifecycleOwner). (Iabe29, b/262623005)

External Contribution

Thanks Ivan Matkov from Jetbrains for helping move Lifecycle to Kotlin Multiplatform. (aosp/2926690, I0c5ac, If445d)

Version 2.8.0-alpha01

January 24, 2024

androidx.lifecycle:lifecycle-*:2.8.0-alpha01 is released. Version 2.8.0-alpha01 contains these commits.

New Features

ViewModel now supports adding Closeable objects with a key that allows retrieving them via getCloseable(). (I3cf63)

Version 2.7

Version 2.7.0

January 10, 2024

androidx.lifecycle:lifecycle-*:2.7.0 is released. Version 2.7.0 contains these commits.

Important changes since 2.6.0

TestLifecycleOwner now includes a suspending function setCurrentState() which ensures that the state change and all LifecycleObserver callbacks are completed before returning. Notably, unlike setting the currentState property directly, this does not use runBlocking, making it safe to use within a coroutine such as one provided by runTest.
The LiveData extensions of map and switchMap now mirror the behavior of distinctUntilChanged - if the LiveData has a value set, the map/switchMap function will be immediately called to populate the value of the returned LiveData. This ensures that the initial value will be set as part of the first composition (when used with observeAsState()), but does not change the observation behavior - updates values from the source LiveData will still only apply once you start observing the LiveData.
This release fixes an issue where SavedStateHandle would not properly restore custom Parcelable classes after process death and recreation. Due to type information that is lost by the Android framework, arrays of custom Parcelables require additional work (manually creating a typed array of the right type) and the documentation on get, getLiveData, and getStateFlow now specifically calls this limitation out.
The proguard keep rules associated with LifecycleObserver have been removed. This means that proguarded code that wishes to use APIs via reflection (such as using the long since deprecated @OnLifecycleEvent annotation) will need to provide their own keep rules for their specific use case.

Lifecycle Event Observability

As an alternative to using a LifecycleEventObserver, you can now observe a Flow of Lifecycle.Event via the Lifecycle.asFlow() extension method.
Jetpack Compose users can now use LifecycleEventEffect to run Compose side effects based on Lifecycle.Event.

@Composable
fun HomeScreen(viewModel: HomeViewModel = viewModel()) {
  LifecycleEventEffect(Lifecycle.Event.ON_RESUME) {
    viewModel.refreshData()
  }
  // …
}

Jetpack Compose users can use LifecycleStartEffect and LifecycleResumeEffect to handle pairs of events - started to stopped and resumed to paused, respectively. This API mirrors the one found in DisposableEffect and is suitable for cases where the change being made when the state is going up needs to be reversed when going back down.

fun HomeScreen(viewModel: HomeViewModel = viewModel()) {
  LifecycleStartEffect(viewModel) {
    val timeTracking = viewModel.startTrackingTimeOnScreen()
    onStopOrDispose {
      timeTracking.stopTrackingTimeOnScreen()
    }
  }
  // …
}

See Run code on lifecycle events for more information.

Lifecycle State Observability

The current Lifecycle.State can now be observed via the Lifecycle.currentStateFlow property, which returns a StateFlow where the value is the current Lifecycle.State.
Jetpack Compose users can use the Lifecycle.currentStateAsState() extension to directly expose Lifecycle.State as Compose State. This is equivalent (and a shorter alternative) to lifecycle.currentStateFlow.collectAsState().

See Collect lifecycle state with flows for more information.

Version 2.7.0-rc02

December 13, 2023

androidx.lifecycle:lifecycle-*:2.7.0-rc02 is released. Version 2.7.0-rc02 contains these commits.

Bug Fixes

Fixed an issue where SavedStateHandle would not properly restore custom Parcelable classes after process death and recreation. Due to type information that is lost by the Android framework, arrays of custom Parcelables require additional work (manually creating a typed array of the right type) and the documentation on get, getLiveData, and getStateFlow now specifically calls this limitation out. (I0b55a)

Version 2.7.0-rc01

November 15, 2023

androidx.lifecycle:lifecycle-*:2.7.0-rc01 is released. Version 2.7.0-rc01 contains these commits.

Bug Fixes

LifecycleStartEffect and LifecycleResumeEffect now correctly dispose and recreate the effect block if the LifecycleOwner is changed. (Ia25c6)

Version 2.7.0-beta01

November 1, 2023

androidx.lifecycle:lifecycle-*:2.7.0-beta01 is released with no changes. Version 2.7.0-beta01 contains these commits.

A beta version bump, no major changes to this release version.

Version 2.7.0-alpha03

October 18, 2023

androidx.lifecycle:lifecycle-*:2.7.0-alpha03 is released. Version 2.7.0-alpha03 contains these commits.

New Features

lifecycle-runtime-testing now contains a new Lint check to avoid setting the Lifecycle.State of the TestLifecycleOwner by using the currentState field when inside of a coroutine. The Lint check now suggests the suspending setCurrentState which allows setting the Lifecycle.State without blocking. (Icf728, b/297880630)

Bug Fixes

Fixed an issue with LiveData.switchMap where returning the same LiveData instance both on the initial call and a subsequent call would prevent the LiveData instance from being added as a source. (Ibedcba7)

Version 2.7.0-alpha02

September 6, 2023

androidx.lifecycle:lifecycle-*:2.7.0-alpha02 is released. Version 2.7.0-alpha02 contains these commits.

New Features

TestLifecycleOwner now includes the suspending function setCurrentState() to give users the option of using TestLifecycleOwner from within a coroutine such as one provided by runTest. (I329de, b/259344129)

API Changes

All files from the lifecycle-livedata-ktx modules have been moved into the main lifecycle-livedata module. (I10c6f, b/274800183)

Behavior Changes

The LiveData.map() and LiveData.switchMap() extensions now sets the value of the returned LiveData if the previous LiveData has had a value set on it, ensuring that using the resulting LiveData in Jetpack Compose has the right state on the initial composition. (I91d2b, b/269479952)
ViewModel's addCloseable() now immediately closes the Closeable if the ViewModel has already received a call to onCleared(). (I4712e, b/280294730)

Bug Fixes

From Lifecycle 2.6.2: Fixed an issue where SavedStateHandle would not correctly be restored after process death if the state was restored, save() was called without actually saving the state in the parent SavedStateRegistry, and then the state was restored again. This fixes the interaction between rememberSaveable and Navigation Compose’s NavHost. (aosp/2729289)

Version 2.7.0-alpha01

July 26, 2023

androidx.lifecycle:lifecycle-*:2.7.0-alpha01 is released. Version 2.7.0-alpha01 contains these commits.

API Changes

Lifecycle.State is now Compose-observable via Lifecycle.currentStateFlow, which returns a StateFlow where the value is the current Lifecycle.State. (Ib212d, b/209684871)
Lifecycle.Events can now able to be observed as a Flow with Lifecycle.asFlow(). (If2c0f, b/176311030)
LifecycleResumeEffect API has been added to run Compose SideEffects based on both Lifecycle.Event.ON_RESUME and Lifecycle.Event.ON_PAUSE event callbacks. (I60386, b/235529345)
LifecycleStartEffect API has been added to run Compose SideEffects based on Lifecycle.Event.ON_START and Lifecycle.Event.ON_STOP event callbacks. (I5a8d1, b/235529345)
LifecycleEventEffect API has been added to run Compose SideEffects based on Lifecycle.Event. (Ic9794, b/235529345)
Lifecycle.collectAsState() extension has been added to directly expose Lifecycle.State as Compose State. This is equivalent (and a shorter alternative) to lifecycle.currentStateFlow.collectAsState(). (I11015, b/235529345)

Bug Fixes

The LiveData.distinctUntilChanged() extension now sets the value of the returned LiveData if the previous LiveData has had a value set on it. This does not change the observation behavior - updated values from the source LiveData will still only apply once you start observing the LiveData returned from distinctUntilChanged(). (Ib482f)
The proguard keep rules associated with LifecycleObserver have been removed. This means that proguarded code that wishes to use APIs via reflection will need to provide their own keep rules for their specific use case. (Ia12fd)

Version 2.6

Version 2.6.2

September 6, 2023

androidx.lifecycle:lifecycle-*:2.6.2 is released. Version 2.6.2 contains these commits.

Bug Fixes

Fixed an issue where SavedStateHandle would not correctly be restored after process death if the state was restored, save() was called without actually saving the state in the parent SavedStateRegistry, and then the state was restored again. This fixes the interaction between rememberSaveable and Navigation Compose’s NavHost. (aosp/2729289)

Version 2.6.1

March 22, 2023

androidx.lifecycle:lifecycle-*:2.6.1 is released. Version 2.6.1 contains these commits.

Dependency Updates

lifecycle-viewmodel-savedstate now depends on SavedState 1.2.1. (cd7251)
Lifecycle now depends on ProfileInstaller 1.3.0. (f9d30b)

Version 2.6.0

March 8, 2023

androidx.lifecycle:lifecycle-*:2.6.0 is released. Version 2.6.0 contains these commits.

Important changes since 2.5.0

LiveData now includes a new isInitialized property that indicates whether an explicit value has ever been set on the LiveData, allowing you to distinguish between liveData.value returning null because no value has ever been set or an explicit null value.
MediatorLiveData now includes a constructor to set an initial value.
Added a new extension on StateFlow and Flow of collectAsStateWithLifecycle() that collect from flows and represents its latest value as Compose State in a lifecycle-aware manner.
Lifecycle.launchWhenX methods and Lifecycle.whenX methods have been deprecated as the use of a pausing dispatcher can lead to wasted resources in some cases. It is recommended to use Lifecycle.repeatOnLifecycle. For more information about one-time suspending work, please see this explanation on why this is inherently unsafe.
Kotlin Conversion - A large number of Lifecycle classes have been converted to Kotlin. All converted classes still retain their binary compatibility with previous versions. The following classes have source incompatible changes for classes written in Kotlin: ViewTreeLifecycleOwner, LiveDataReactiveStreams, HasDefaultViewModelProviderFactory, ViewTreeViewModelStoreOwner, Transformations, ViewModelStoreOwner, LifecycleOwner

The table below provides the source conversions for the new version of lifecycle.

Lifecycle 2.5	Lifecycle 2.5 (KTX)	Lifecycle 2.6
`Transformations.switchMap(liveData) {...}`	`liveData.switchMap {...}`	`liveData.switchMap {...}`
`Transformations.map(liveData) {...}`	`liveData.map {...}`	`liveData.map {...}`
`Transformations.distinctUntilChanged(liveData) {...}`	`liveData.distinctUntilChanged{...}`	`liveData.distinctUntilChanged{...}`
`LiveDataReactiveStreams.fromPublisher(publisher)`	`publisher.toLiveData()`	`publisher.toLiveData()`
`LiveDataReactiveStreams.toPublisher(lifecycleOwner, liveData)`	`liveData.toPublisher(lifecycleOwner)`	`liveData.toPublisher(lifecycleOwner)`
`override fun getDefaultViewModelProviderFactory(): ViewModelProvider.Factory = factory`	`override fun getDefaultViewModelProviderFactory(): ViewModelProvider.Factory = factory`	`override val defaultViewModelProviderFactory = factory`
`override fun getDefaultViewModelCreationExtras(): CreationExtras = extras`	`override fun getDefaultViewModelCreationExtras(): CreationExtras = extras`	`override val defaultViewModelProviderCreationExtras = extras`
`ViewTreeLifecycleOwner.set(view, owner)`	`ViewTreeLifecycleOwner.set(view, owner)`	`view.setViewTreeLifecycleOwner(owner)`
`ViewTreeLifecycleOwner.get(view)`	`view.findViewTreeLifecycleOwner()`	`view.findViewTreeLifecycleOwner()`
`override fun getViewModelStore(): ViewModelStore = store`	`override fun getViewModelStore(): ViewModelStore = store`	`override val viewModelStore: ViewModelStore = store`
`override fun getLifecycle(): Lifecycle = registry`	`override fun getLifecycle(): Lifecycle = registry`	`override val lifecycle: Lifecycle get() = registry`

The nullability of the onChanged method of a Observer created in Kotlin now matches the nullability of the generic type. If you want Observer.onChanged() to accept a nullable type, you must instantiate the Observer with a nullable type.
These classes were also converted to Kotlin, but remain source compatible: DefaultLifecycleObserver, LifecycleEventObserver, Lifecycle, LifecycleRegistry, LifecycleObserver, ViewModelStore, AndroidViewModel, AbstractSavedStateViewModelFactory, LifecycleService, ServiceLifecycleDispatcher, and ProcessLifecycleOwner

Version 2.6.0-rc01

February 22, 2023

androidx.lifecycle:lifecycle-*:2.6.0-rc01 is released. Version 2.6.0-rc01 contains these commits.

Bug Fixes

The LiveData.distinctUntilChanged() extension now sets the value of the returned LiveData if the previous LiveData has had a value set on it. This does not change the observation behavior - updated values from the source LiveData will still only apply once you start observing the LiveData returned from distinctUntilChanged(). (Ib482f)

Version 2.6.0-beta01

February 8, 2023

androidx.lifecycle:lifecycle-*:2.6.0-beta01 is released. Version 2.6.0-beta01 contains these commits.

Kotlin Conversions

LifecycleOwner is now written in Kotlin. This is a source incompatible change for classes written in Kotlin - they must now override the lifecycle property rather than implementing the previous getLifecycle() function. (I75b4b, b/240298691)
ViewModelStoreOwner is now in Kotlin. This is a source incompatible change for classes written in Kotlin - they must now override the viewModelStore property rather than implementing the previous getViewModelStore() function. (I86409, b/240298691)
The Kotlin extension on LifecycleOwner that provides the lifecycleScope field has been moved to the lifecycle-common artifact from lifecycle-runtime-ktx. (I41d78, b/240298691)
The Kotlin extension on Lifecycle that provides the coroutineScope field has been moved to the lifecycle-common artifact from lifecycle-runtime-ktx. (Iabb91, b/240298691)

Version 2.6.0-alpha05

January 25, 2023

androidx.lifecycle:lifecycle-*:2.6.0-alpha05 is released. Version 2.6.0-alpha05 contains these commits.

Kotlin Conversions

Transformations is now written in Kotlin. This is a source incompatible change for those classes written in Kotlin that were directly using syntax such as Transformations.map - Kotlin code must now use the Kotlin extension method syntax that was previously only available when using lifecycle-livedata-ktx. When using the Java programming language, the versions of these methods that take an androidx.arch.core.util.Function method are deprecated and replaced with the versions that take a Kotlin Function1. This change maintains binary compatibility. (I8e14f)
ViewTreeViewModelStoreOwner is now written in Kotlin. This is a source incompatible change for those classes written in Kotlin - you must now directly import and use the Kotlin extension methods on View of androidx.lifecycle.setViewTreeViewModelStoreOwner and androidx.lifecycle.findViewTreeViewModelStoreOwner to set and find a previously set owner. This is binary compatible and remains source compatible for implementations written in the Java programming language. (Ia06d8, Ib22d8, b/240298691)
The HasDefaultViewModelProviderFactory interface is now written in Kotlin. This is a source incompatible change for classes written in Kotlin - they must now override the defaultViewModelProviderFactory and defaultViewModelCreationExtras properties rather than implementing the previous corresponding functions. (Iaed9c, b/240298691)
Observer is now written in Kotlin. Its onChanged() method now uses the name value for its parameter. (Iffef2, I4995e, b/240298691)
AndroidViewModel, AbstractSavedStateViewModelFactory, LifecycleService, ServiceLifecycleDispatcher, and ProcessLifecycleOwner are now written in Kotlin (I2e771, Ibae40, I160d7, I08884, I1cda7, b/240298691)

Version 2.6.0-alpha04

January 11, 2023

androidx.lifecycle:lifecycle-*:2.6.0-alpha04 is released. Version 2.6.0-alpha04 contains these commits.

New Features

LiveData now includes a new isInitialized property that indicates whether an explicit value has ever been set on the LiveData, allowing you to distinguish between liveData.value returning null because no value has ever been set or an explicit null value. (Ibd018)

API Changes

The collectAsStateWithLifecycle() APIs of lifecycle-runtime-compose are no longer in experimental status. (I09d42, b/258835424)
Lifecycle.launchWhenX methods and Lifecycle.whenX methods have been deprecated as the use of a pausing dispatcher can lead to wasted resources in some cases. It is recommended to use Lifecycle.repeatOnLifecycle. (Iafc54, b/248302832)

Kotlin Conversions

ViewTreeLifecycleOwner is now written in Kotlin. This is a source incompatible change for those classes written in Kotlin - you must now directly import and use the Kotlin extension methods on View of androidx.lifecycle.setViewTreeLifecycleOwner and androidx.lifecycle.findViewTreeLifecycleOwner to set and find a previously set owner. This replaces the previous Kotlin extension in lifecycle-runtime-ktx. This is binary compatible and remains source compatible for implementations written in the Java programming language. (I8a77a, I5234e, b/240298691)
LiveDataReactiveStreams is now written in Kotlin. The Kotlin extensions previously in lifecycle-reactivestreams-ktx have been moved into the lifecycle-reactivestreams module and have become the primary surface for code written in Kotlin. This is a source incompatible change for code written in Kotlin if you were not already using the Kotlin extension method APIs. (I2b1b9, I95d22, b/240298691)
DefaultLifecycleObserver, LifecycleEventObserver, Lifecycle, LifecycleRegistry, LifecycleObserver, and ViewModelStore are now written in Kotlin (Iadffd, (I60034, I8c52c, I9593d, I01fe1, I59a23, b/240298691)

Bug Fixes

SavedStateHandle no longer crashes with a ClassCastException when calling get() with the incorrect class type. (I6ae7c)

Version 2.6.0-alpha03

October 24, 2022

androidx.lifecycle:lifecycle-*:2.6.0-alpha03 is released. Version 2.6.0-alpha03 contains these commits.

Bug Fixes

Fixed an issue with constraints between different Lifecycle modules not working as intended. (I18d0d, b/249686765)
Errors thrown by LifecycleRegistry.moveToState() now include a more helpful error messaging that informs developers of the component causing the error. (Idf4b2, b/244910446)

Version 2.6.0-alpha02

September 7, 2022

androidx.lifecycle:lifecycle-*:2.6.0-alpha02 is released. Version 2.6.0-alpha02 contains these commits.

API Changes

MediatorLiveData now includes a constructor to set an initial value. (Ib6cc5, b/151244085)

Bug Fixes

Lifecycle artifacts now include constraints that ensure that all inter-dependent Lifecycle artifacts use the same version, automatically upgrading other dependencies when one is upgraded. b/242871265
FlowLiveData.asFlow() now creates a callbackFlow rather than using its own Channel implementation to ensure thread-safety and context preservation. (I4a8b2, b/200596935)
FlowLiveData's asLiveData function will now preserve the initial value of a StateFlow when creating the new LiveData object. (I3f530, b/157380488)
From Lifecycle 2.5.1: Custom implementations of AndroidViewModelFactory now correctly calls the create(modelClass) function when using the stateful constructor with Lifecycle 2.4+ (I5b315, b/238011621)

Version 2.6.0-alpha01

June 29, 2022

androidx.lifecycle:lifecycle-*:2.6.0-alpha01 is released. Version 2.6.0-alpha01 contains these commits.

New Features

Added a new extension on StateFlow and Flow of collectAsStateWithLifecycle that collect from flows and represents its latest value as Compose State in a lifecycle-aware manner. The flow is collected and the new emission is set to the State's value when the lifecycle is at least in a certain Lifecycle.State. When the lifecycle falls below that Lifecycle.State, the flow collection stops and the State's value is not updated. (I1856e, b/230557927)

Version 2.5

Version 2.5.1

July 27, 2022

androidx.lifecycle:lifecycle-*:2.5.1 is released. Version 2.5.1 contains these commits.

Bug Fixes

Custom implementations of AndroidViewModelFactory now correctly call the create(modelClass) function when using the stateful AndroidViewModelFactory constructor with Lifecycle 2.4+. (I5b315, b/238011621)

Version 2.5.0

June 29, 2022

androidx.lifecycle:lifecycle-*:2.5.0 is released. Version 2.5.0 contains these commits.

Important changes since 2.4.0

SavedStateHandle now offers a getStateFlow() API that returns a Kotlin StateFlow for monitoring value changes as an alternative to using LiveData.

ViewModel CreationExtras - when writing a custom ViewModelProvider.Factory, it is no longer required to extend AndroidViewModelFactory or AbstractSavedStateViewModelFactory to gain access to an Application or SavedStateHandle, respectively. Instead, these fields are provided to every ViewModelProvider.Factory subclass as CreationExtras via the new overload of create: create(Class<T>, CreationExtras). These extras are provided automatically by your Activity or Fragment when using Activity 1.5.0 and Fragment 1.5.0, respectively.

class CustomFactory : ViewModelProvider.Factory {
    override fun <T : ViewModel> create(modelClass: Class<T>, extras: CreationExtras): T {
        return when (modelClass) {
            HomeViewModel::class -> {
                // Get the Application object from extras
                val application = checkNotNull(extras[ViewModelProvider.AndroidViewModelFactory.APPLICATION_KEY])
                // Pass it directly to HomeViewModel
                HomeViewModel(application)
            }
            DetailViewModel::class -> {
                // Create a SavedStateHandle for this ViewModel from extras
                val savedStateHandle = extras.createSavedStateHandle()
                DetailViewModel(savedStateHandle)
            }
            else -> throw IllegalArgumentException("Unknown class $modelClass")
        } as T
    }
}

lifecycle-viewmodel now provides a viewModelFactory Kotlin DSL that allows you define your ViewModelProvider.Factory in terms of one or more lambda initializers, one for each particular ViewModel class your custom factory supports, using CreationExtras as the primary data source.

val customFactory = viewModelFactory {
    // The return type of the lambda automatically sets what class this lambda handles
    initializer {
        // Get the Application object from extras provided to the lambda
        val application = checkNotNull(get(ViewModelProvider.AndroidViewModelFactory.APPLICATION_KEY))
        HomeViewModel(application)
    }
    initializer {
        val savedStateHandle = createSavedStateHandle()
        DetailViewModel(savedStateHandle)
    }
}

lifecycle-viewmodel-compose now offers a viewModel() API that takes a lambda factory for creating a ViewModel instance without requiring the creation of a custom ViewModelProvider.Factory.

// Within a @Composable, you can now skip writing a custom Factory
// and instead write a lambda to do the initialization of your ViewModel
val detailViewModel = viewModel {
  // This lambda is only called the first time the ViewModel is created
  // and all CreationExtras are available inside the lambda
  val savedStateHandle = createSavedStateHandle()
  DetailViewModel(savedStateHandle)
}

SavedStateHandle Compose Saver Integration - the lifecycle-viewmodel-compose artifact now contains new experimental APIs in SavedStateHandle.saveable that allow rememberSaveable like behavior backed by the SavedStateHandle of a `ViewModel.

class ListScreenViewModel(handle: SavedStateHandle): ViewModel() {
    // This value survives both configuration changes and process death and recreation
    val editMode by handle.saveable { mutableStateOf(false) }
}

Added an addCloseable() API and a new constructor overload that allow you to add one or more Closeable objects to the ViewModel that will be closed when the ViewModel is cleared without requiring any manual work in onCleared().

For instance, to create a coroutine scope that you can inject into a ViewModel, but control via testing, you can create a CoroutineScope that implements Closeable:

class CloseableCoroutineScope(
    context: CoroutineContext = SupervisorJob() + Dispatchers.Main.immediate
) : Closeable, CoroutineScope {
    override val coroutineContext: CoroutineContext = context
    override fun close() {
        coroutineContext.cancel()
   }
}

Which can then be used in your ViewModel constructor while maintaining the same lifetime as viewModelScope:

class TestScopeViewModel(
    val customScope: CloseableCoroutineScope = CloseableCoroutineScope()
) : ViewModel(customScope) {
    // You can now use customScope in the same way as viewModelScope
}

Behavior changes

Attempting to move the Lifecycle.State from INITIALIZED to DESTROYED will now always throw an IllegalStateException regardless of whether the Lifecycle has an attached observer.
LifecycleRegistry will now clear their observers when they reach the DESTROYED state.

Version 2.5.0-rc02

June 15, 2022

androidx.lifecycle:lifecycle-*:2.5.0-rc02 is released. Version 2.5.0-rc02 contains these commits.

Bug Fixes

ViewModelProvider will no longer crash when mixing previous versions of compileOnly Lifecycle dependencies with versions 2.5+. (I81a66, b/230454566)

Version 2.5.0-rc01

May 11, 2022

androidx.lifecycle:lifecycle-*:2.5.0-rc01 is released. Version 2.5.0-rc01 contains these commits.

Bug Fixes

MediatorLiveData.addSource() now throws a NullPointerException when passed a null source instead of propagating the null source to observers.(Ibd0fb, b/123085232)

Version 2.5.0-beta01

April 20, 2022

androidx.lifecycle:lifecycle-*:2.5.0-beta01 is released. Version 2.5.0-beta01 contains these commits.

API Changes

Added SavedStateHandle.saveable property delegates to use property names as keys for persisting state into the SavedStateHandle (I8bb86, b/225014345)

Bug Fixes

Fixed an issue where nesting one NavHost within another NavHost in a non-primary bottom navigation tab would lead to an IllegalStateException when using multiple back stacks. (I11bd5, b/228865698)

Version 2.5.0-alpha06

April 6, 2022

androidx.lifecycle:lifecycle-*:2.5.0-alpha06 is released. Version 2.5.0-alpha06 contains these commits.

New Features

Add experimental MutableState overload to SavedStateHandle.saveable for parity with rememberSaveable (I38cfe, b/224565154)

API Changes

CreationExtras is now abstract instead of sealed. (Ib8a7a)

Bug Fixes

Fixed an IllegalStateException: Already attached to lifecycleOwner error caused by SavedStateHandleController. (I7ea47, b/215406268)

Version 2.5.0-alpha05

March 23, 2022

androidx.lifecycle:lifecycle-*:2.5.0-alpha05 is released. Version 2.5.0-alpha05 contains these commits.

New Features

The lifecycle-viewmodel-compose module now provides SavedStateHandleSaver, an experimental API that ensures values in a SavedStateHandle are integrated correctly with the same saved instance state that rememberSaveable uses. (Ia88b7, b/195689777)

API Changes

Fixed a compatibility issue with Lifecycle 2.3 and newer Lifecycle versions in Java. (I52c8a, b/219545060)

Bug Fixes

SavedStateViewFactory now supports using CreationExtras even when it was initialized with a SavedStateRegistryOwner. If extras are provided, the initialized arguments are ignored. (I6c43b, b/224844583)

Version 2.5.0-alpha04

March 9, 2022

androidx.lifecycle:lifecycle-*:2.5.0-alpha04 is released. Version 2.5.0-alpha04 contains these commits.

API Changes

SavedStateHandle now offers a getStateFlow() API that returns a Kotlin StateFlow for monitoring value changes as an alternative to using LiveData. (Iad3ab, b/178037961)

Version 2.5.0-alpha03

February 23, 2022

androidx.lifecycle:lifecycle-*:2.5.0-alpha03 is released. Version 2.5.0-alpha03 contains these commits.

New Features

Added an addCloseable() API and a new constructor overload that allow you to add one or more Closeable objects to the ViewModel that will be closed when the ViewModel is cleared without requiring any manual work in onCleared(). (I55ea0)
lifecycle-viewmodel now provides an InitializerViewModelFactory that allows you to add lambda for handling particular ViewModel classes, using CreationExtras as the primary data source. (If58fc, b/216687549)
lifecycle-viewmodel-compose now offers a viewModel() API that takes a lambda factory for creating a ViewModel instance without requiring the creation of a custom ViewModelProvider.Factory. (I97fbb, b/216688927)

API Changes

You can now create a ViewModel with CreationExtras via lifecycle-viewmodel-compose. (I08887, b/216688927)

Behavior changes

Attempting to move the Lifecycle.State from INITIALIZED to DESTROYED will now always throw an IllegalStateException regardless of whether the Lifecycle has an attached observer. (I7c390, b/177924329)
LifecycleRegistry will now clear their observers when they reach the DESTROYED state. (I4f8dd, b/142925860)

Version 2.5.0-alpha02

February 9, 2022

androidx.lifecycle:lifecycle-*:2.5.0-alpha02 is released. Version 2.5.0-alpha02 contains these commits.

API Changes

SavedStateHandle and SavedStateViewModelFactory have been converted to Kotlin. This has improved the nullability of the generics in both classes. (Ib6ce2, b/216168263, I9647a, b/177667711)
The LiveData switchMap function parameter can now have a nullable output. (I40396, b/132923666)
The LiveData -ktx extensions are now annotated with @CheckResult to enforce that the result is used when calling these functions. (Ia0f05, b/207325134)

Behavior changes

SavedStateHandle now properly stores the defaultValue when no value for the specified key exists. (I1c6ce, b/178510877)

Bug Fixes

From Lifecycle 2.4.1: Updated lifecycle-process to depend on Startup 1.1.1 to ensure that fixes that prevent ProcessLifecycleInitializer from throwing a StartupException are available by default. (Ib01df, b/216490724)
There is now an improved error message when custom AndroidViewModel classes have parameters in the wrong order and attempt to create a ViewModel. (I340f7, b/177667711)
You can now create a view model via CreationExtras using the AndroidViewModelFactory without setting an application. (I6ebef, b/217271656)

Version 2.5.0-alpha01

January 26, 2022

androidx.lifecycle:lifecycle-*:2.5.0-alpha01 is released. Version 2.5.0-alpha01 contains these commits.

ViewModel CreationExtras

With this release, we are laying the groundwork for restructuring how a ViewModel is constructed. Instead of a rigid set of subclasses of ViewModelProvider.Factory that each add additional functionality (allowing an Application constructor parameter via AndroidViewModelFactory, allowing a SavedStateHandle constructor parameter via SavedStateViewModelFactory and AbstractSavedStateViewModelFactory, etc.), we are moving to a world of stateless factories that rely on a new concept, CreationExtras. (Ia7343, b/188691010, b/188541057)

With this change, ViewModelProvider no longer makes direct calls into the previous create(Class<T>) method of ViewModelProvider.Factory. Instead, it calls into a new overload of create: create(Class<T>, CreationExtras). This means that any direct implementation of the ViewModelProvider.Factory instance now has access to each of these new CreationExtras:

ViewModelProvider.NewInstanceFactory.VIEW_MODEL_KEY: this String provides access to the custom key you passed to ViewModelProvider.get().
ViewModelProvider.AndroidViewModelFactory.APPLICATION_KEY provides access to the Application class.
SavedStateHandleSupport.SAVED_STATE_REGISTRY_OWNER_KEY provides access to the SavedStateRegistryOwner that is being used to construct this ViewModel.
SavedStateHandleSupport.VIEW_MODEL_STORE_OWNER_KEY provides access to the ViewModelStoreOwner that is being used to construct this ViewModel.
SavedStateHandleSupport.DEFAULT_ARGS_KEY provides access to the Bundle of arguments that should be used to construct a SavedStateHandle.

These extras are provided by default when using Activity 1.5.0-alpha01, Fragment 1.5.0-alpha01, and Navigation 2.5.0-alpha01. If you use an earlier version of those libraries, your CreationExtras will be empty - all of the existing subclasses of ViewModelProvider.Factory have been rewritten to support both the legacy creation path used by earlier versions of those libraries and the CreationExtras path which will be used going forward.

These CreationExtras allow you to construct a ViewModelProvider.Factory that passes just the information you need to each ViewModel without relying on a strict hierarchy of Factory subclasses:

class CustomFactory : ViewModelProvider.Factory {
    override fun <T : ViewModel> create(modelClass: Class<T>, extras: CreationExtras): T {
        return when (modelClass) {
            HomeViewModel::class -> {
                // Get the Application object from extras
                val application = checkNotNull(extras[ViewModelProvider.AndroidViewModelFactory.APPLICATION_KEY])
                // Pass it directly to HomeViewModel
                HomeViewModel(application)
            }
            DetailViewModel::class -> {
                // Create a SavedStateHandle for this ViewModel from extras
                val savedStateHandle = extras.createSavedStateHandle()
                DetailViewModel(savedStateHandle)
            }
            else -> throw IllegalArgumentException("Unknown class $modelClass")
        } as T
    }
}

We use the createSavedStateHandle() Kotlin extension function on CreationExtras from SavedStateHandleSupport to construct a SavedStateHandle only for the one ViewModel that needs it. (Ia6654, b/188541057)

Custom CreationExtras can be provided by overriding getDefaultViewModelCreationExtras() in your ComponentActivity or Fragment, thus making them available to your custom ViewModelProvider.Factory as a built in form of assisted injection. These extras will automatically be made available to your custom Factory when used directly with ViewModelProvider or when using the by viewModels() and by activityViewModels() Kotlin property extensions. (I79f2b, b/207012584, b/207012585, b/207012490)

Bug Fixes

Fixed an issue where the default value provided to a SavedStateHandle would reappear after process death and recreation, even if it was specifically removed from the SavedStateHandle. As a consequence of this, SavedStateHandle will no longer merge default values and restored values together, instead only using the restored values as the source of truth. (I53a4b)

Version 2.4

Version 2.4.1

February 9, 2022

androidx.lifecycle:lifecycle-*:2.4.1 is released. Version 2.4.1 contains these commits.

Bug Fixes

Backported from Lifecycle 2.5.0-alpha01: Fixed an issue where the default value provided to a SavedStateHandle would re-appear after process death and recreation, even if it was specifically removed from the SavedStateHandle. As a consequence of this, SavedStateHandle will no longer merge default values and restored values together, instead only using the restored values as the source of truth. (I53a4b)
lifecycle-process now depends on Androidx Startup 1.1.1 which fixed a regression in where using ProcessLifecycleInitializer would cause an StartupException. (b/216490724)

Version 2.4.0

October 27, 2021

androidx.lifecycle:lifecycle-*:2.4.0 is released. Version 2.4.0 contains these commits.

Important changes since 2.3.0

@OnLifecycleEvent was deprecated. LifecycleEventObserver or DefaultLifecycleObserver should be used instead.
androidx.lifecycle:lifecycle-viewmodel-compose library was added. It provides viewModel() composable and LocalViewModelStoreOwner.
- Source-breaking change: ViewModelProvider has been rewritten in Kotlin. ViewModelProvider.Factory.create method no longer allows nullable generic.
New coroutines API were added to androidx.lifecycle:lifecycle-runtime-ktx:
Lifecycle.repeatOnLifecycle, API that executes a block of code in a coroutine when the Lifecycle is at least in a certain state. The block will cancel and re-launch as the lifecycle moves in and out of the target state;
Flow.flowWithLifecycle, API that emits values from the upstream Flow when the lifecycle is at least in a certain state.
DefaultLifecycleObserver was moved from lifecycle.lifecycle-common-java8 to lifecycle.lifecycle-common. lifecycle.lifecycle-common-java8doesn't provide anymore any additional functionality on top of lifecycle.lifecycle-common, so dependency on it can be replaced by lifecycle.lifecycle-common.
Non coroutines API from lifecycle-viewmodel-ktx have been moved to the lifecycle-viewmodel module.

lifecycle-process now uses androidx.startup to initialize the ProcessLifecycleOwner.

Previously, this was being done by androidx.lifecycle.ProcessLifecycleOwnerInitializer.

If you used tools:node="remove" the ContentProvider being used to initialize process lifecycle in the past, then you need to do the following instead.

 <provider
    android:name="androidx.startup.InitializationProvider"
    android:authorities=\"${applicationId}.androidx-startup"
    android:exported="false"
    tools:node=\"merge">
    <!-- If you are using androidx.startup to initialize other components -->
    <meta-data
        android:name="androidx.lifecycle.ProcessLifecycleInitializer"
        android:value="androidx.startup"
        tools:node="remove" />
 </provider>

(or)

 <!-- If you want to disable androidx.startup completely. -->
 <provider
    android:name="androidx.startup.InitializationProvider"
    android:authorities="${applicationId}.androidx-startup"
    tools:node="remove">
 </provider>

Version 2.4.0-rc01

September 29, 2021

androidx.lifecycle:lifecycle-*:2.4.0-rc01 is released with no changes from Lifecycle 2.4.0-beta01. Version 2.4.0-rc01 contains these commits.

Version 2.4.0-beta01

September 15, 2021

androidx.lifecycle:lifecycle-*:2.4.0-beta01 is released. Version 2.4.0-beta01 contains these commits.

API Changes

@OnLifecycleEvent was deprecated. LifecycleEventObserver or DefaultLifecycleObserver should be used instead. (I5a8fa)
DefaultLifecycleObserver was moved from androidx.lifecycle.lifecycle-common-java8 to androidx.lifecycle.lifecycle-common. androidx.lifecycle.lifecycle-common-java8 doesn't provide anymore any additional functionality on top of androidx.lifecycle.lifecycle-common, so dependency on it can be replaced by androidx.lifecycle.lifecycle-common. (I021aa)
Non coroutines API from lifecycle-viewmodel-ktx have been moved to the lifecycle-viewmodel module. (I6d5b2)

External Contribution

Thanks dmitrilc for fixing a type in the ViewModel documentation! (#221)

Version 2.4.0-alpha03

August 4, 2021

androidx.lifecycle:lifecycle-*:2.4.0-alpha03 is released. Version 2.4.0-alpha03 contains these commits.

API Changes

Source-breaking change: ViewModelProvider has been rewritten in Kotlin. ViewModelProvider.Factory.create method no longer allows nullable generic. (I9b9f6)

Behavior Changes

The Lifecycle.repeatOnLifecycle: block is now always invoked serially when repeating execution. (Ibab33)

External Contribution

Thanks chao2zhang for fixing the code snippets in the repeatOnLifecycle documentation. #205.

Version 2.4.0-alpha02

June 16, 2021

androidx.lifecycle:lifecycle-*:2.4.0-alpha02 is released. Version 2.4.0-alpha02 contains these commits.

New Features

Added a new RepeatOnLifecycleWrongUsage lint check to lifecycle-runtime-ktx that detects when repeateOnLifecycle is incorrectly used in onStart() or onResume(). (706078, b/187887400)

API Changes

The LifecycleOwner.addRepeatingJob API is removed in favor of Lifecycle.repeatOnLifecycle that respects structured concurrency and is easier to reason about. (I4a3a8)
Make ProcessLifecycleInitializer public so other androidx.startup.Initializers can use these as dependencies. (I94c31)

Bug Fixes

Fixed an issue with the NullSafeMutableLiveData lint check when the field has modifiers. (#147, b/183696616)
Fixed another issue with the NullSafeMutableLiveData lint check when using generics. (#161, b/184830263)

External Contribution

Thanks maxsav for improving the NullSafeMutableLiveData lint check. (#147, b/183696616)
Thanks kozaxinan for improving the NullSafeMutableLiveData lint check. (#161, b/184830263)

Version 2.4.0-alpha01

March 24, 2021

androidx.lifecycle:lifecycle-*:2.4.0-alpha01 is released. Version 2.4.0-alpha01 contains these commits.

Behavior Changes

lifecycle-process now uses androidx.startup to initialize the ProcessLifecycleOwner.

Previously, this was being done by androidx.lifecycle.ProcessLifecycleOwnerInitializer.

If you used tools:node="remove" the ContentProvider being used to initialize process lifecycle in the past, then you need to do the following instead.

 <provider
    android:name="androidx.startup.InitializationProvider"
    android:authorities=\"${applicationId}.androidx-startup"
    android:exported="false"
    tools:node=\"merge">
    <!-- If you are using androidx.startup to initialize other components -->
    <meta-data
        android:name="androidx.lifecycle.ProcessLifecycleInitializer"
        android:value="androidx.startup"
        tools:node="remove" />
 </provider>

(or)

 <!-- If you want to disable androidx.startup completely. -->
 <provider
    android:name="androidx.startup.InitializationProvider"
    android:authorities="${applicationId}.androidx-startup"
    tools:node="remove">
 </provider>

API Changes

Added a Flow.flowWithLifecycle API that emits values from the upstream Flow when the lifecycle is at least in a certain state using the Lifecycle.repeatOnLifecycle API. This is an alternative to the also new LifecycleOwner.addRepeatinJob API. (I0f4cd)

Bug Fixes

From Lifecycle 2.3.1: The NonNullableMutableLiveData lint rule can now properly differentiate between field variables with different nullability. (b/169249668)

Lifecycle Viewmodel Compose Version 1.0.0

Version 1.0.0-alpha07

June 16, 2021

androidx.lifecycle:lifecycle-viewmodel-compose:1.0.0-alpha07 is released. Version 1.0.0-alpha07 contains these commits.

Breaking API Changes

viewModel() now takes an optional ViewModelStoreOwner, making it easier to work with owners other than the LocalViewModelStoreOwner. For example, you can now use viewModel(navBackStackEntry) to retrieve a ViewModel associated with a particular navigation graph. (I2628d, b/188693123)

Version 1.0.0-alpha06

June 2, 2021

androidx.lifecycle:lifecycle-viewmodel-compose:1.0.0-alpha06 is released. Version 1.0.0-alpha06 contains these commits.

Updated to be compatible with Compose version 1.0.0-beta08.

Version 1.0.0-alpha05

May 18, 2021

androidx.lifecycle:lifecycle-viewmodel-compose:1.0.0-alpha05 is released. Version 1.0.0-alpha05 contains these commits.

New Features

Updated to be compatible with Compose version 1.0.0-beta07.

Bug Fixes

The AndroidManifest files from ui-test-manifest and ui-tooling-data are now compatible with Android 12 (I6f9de, b/184718994)

Version 1.0.0-alpha04

April 7, 2021

androidx.lifecycle:lifecycle-viewmodel-compose:1.0.0-alpha04 is released. Version 1.0.0-alpha04 contains these commits.

Dependency Changes

This version allows androidx.hilt:hilt-navigation-compose and androidx.navigation:navigation-compose to sync dependencies on androidx.compose.compiler:compiler:1.0.0-beta04 and androidx.compose.runtime:runtime:1.0.0-beta04. For 1.0.0, it is required that the compiler and runtime match.

Version 1.0.0-alpha03

March 10, 2021

androidx.lifecycle:lifecycle-viewmodel-compose:1.0.0-alpha03 is released. Version 1.0.0-alpha03 contains these commits.

API Changes

LocalViewModelStoreOwner.current now returns a nullable ViewModelStoreOwner to better determine whether a ViewModelStoreOwner is available in the current composition. APIs that require a ViewModelStoreOwner, such as viewModel() and NavHost, still throw an exception if a ViewModelStoreOwner is not set. (Idf39a)

Lifecycle-Viewmodel-Compose Version 1.0.0-alpha02

February 24, 2021

androidx.lifecycle:lifecycle-viewmodel-compose:1.0.0-alpha02 is released. Version 1.0.0-alpha02 contains these commits.

API Changes

LocalViewModelStoreOwner now has a provides functions that can be used with CompositionLocalProvider, replacing the asProvidableCompositionLocal() API. (I45d24)

Lifecycle-Viewmodel-Compose Version 1.0.0-alpha01

February 10, 2021

androidx.lifecycle:lifecycle-viewmodel-compose:1.0.0-alpha01 is released. Version 1.0.0-alpha01 contains these commits.

New Features

The viewModel() composable and LocalViewModelStoreOwner were moved from androidx.compose.ui.viewinterop to this artifact in the androidx.lifecycle.viewmodel.compose package. (I7a374)

Version 2.3.1

Lifecycle Version 2.3.1

March 24, 2021

androidx.lifecycle:lifecycle-*:2.3.1 is released. Version 2.3.1 contains these commits.

Bug Fixes

The NonNullableMutableLiveData lint rule can now properly differentiate between field variables with different nullability. (b/169249668)

Version 2.3.0

February 10, 2021

androidx.lifecycle:lifecycle-*:2.3.0 is released. Version 2.3.0 contains these commits.

Major changes since 2.2.0

SavedStateHandle support for non-parcelable classes: SavedStateHandle now supports lazy serialization by allowing you to call setSavedStateProvider() for a given key, providing a SavedStateProvider that will get a callback to saveState() when the SavedStateHandle is asked to save its state. See Saving non-parcelable classes.
Lifecycle Behavior Enforcement:
- LifecycleRegistry now enforces DESTROYED as a terminal state.
- LifecycleRegistry now verifies that its methods are called on main thread. It was always a requirement for lifecycles of activities, fragments etc. An addition of observers from non-main threads resulted in hard to catch crashes in runtime. For LifecycleRegistry objects that owned by your own components, you can explicitly opt out from checks by using LifecycleRegistry.createUnsafe(...), but then you have to ensure that a proper synchronization is in place when this LifecycleRegistry is accessed from different threads.
Lifecycle State and Event Helpers: Added static helper methods of downFrom(State), downTo(State), upFrom(State), upTo(State) to Lifecycle.Event for generating the Event given a State and transition direction. Added the getTargetState() method that provides the State that the Lifecycle will transition to directly following the Event.
withStateAtLeast: Added Lifecycle.withStateAtLeast APIs that await a lifecycle state and run a non-suspending block of code synchronously at the point of state change, then resume with the result. These APIs differ from the existing when* methods as they do not permit running suspending code and do not employ a custom dispatcher. (aosp/1326081)
ViewTree APIs: A new ViewTreeLifecycleOwner.get(View) and ViewTreeViewModelStoreOwner.get(View) API allows you to retrieve the containing LifecycleOwner and ViewModelStoreOwner, respectively, given a View instance. You must upgrade to Activity 1.2.0 and Fragment 1.3.0, and AppCompat 1.3.0-alpha01 or higher to populate this correctly. The findViewTreeLifecycleOwner and findViewTreeViewModelStoreOwner Kotlin extensions are available in lifecycle-runtime-ktx and lifecycle-viewmodel-ktx, respectively.
LiveData.observe() Kotlin extension deprecation: The LiveData.observe() Kotlin extension necessary to use lambda syntax is now deprecated as it is not necessary when using Kotlin 1.4.

Version 2.3.0-rc01

December 16, 2020

androidx.lifecycle:lifecycle-*:2.3.0-rc01 is released. Version 2.3.0-rc01 contains these commits.

Bug Fixes

The keys() method of SavedStateHandle is now consistent before and after the state is saved - it now includes keys previously used with setSavedStateProvider() in addition to the keys used with set() and getLiveData(). (aosp/1517919, b/174713653)

External Contribution

The APIs to suspend Lifecycle-aware coroutines now better handle calls to yield(). Thanks Nicklas Ansman Giertz! (aosp/1430830, b/168777346)

Version 2.3.0-beta01

October 1, 2020

androidx.lifecycle:lifecycle-*:2.3.0-beta01 is released. Version 2.3.0-beta01 contains these commits.

API Changes

The LiveData.observe() Kotlin extension necessary to use lambda syntax is now deprecated as it is not necessary when using Kotlin 1.4. (I40d3f)

Bug Fixes

Upgrade androidx to use Kotlin 1.4 (Id6471, b/165307851, b/165300826)

Documentation Changes

The liveData builder and asLiveData() docs have been updated to include details about changing the given timeout values. (aosp/1122324)

Version 2.3.0-alpha07

August 19, 2020

androidx.lifecycle:lifecycle-*:2.3.0-alpha07 is released. Version 2.3.0-alpha07 contains these commits.

Bug Fixes

Fixed a crash issue in the NullSafeMutableLiveData Lint check. (aosp/1395367)

Version 2.3.0-alpha06

July 22, 2020

androidx.lifecycle:lifecycle-*:2.3.0-alpha06 is released. Version 2.3.0-alpha06 contains these commits.

New Features

Added static helper methods of downFrom(State), downTo(State), upFrom(State), upTo(State) to Lifecycle.Event for generating the Event given a State and transition direction. Added the getTargetState() method that provides the State that the Lifecycle will transition to directly following the Event. (I00887)
Added Lifecycle.withStateAtLeast APIs that await a lifecycle state and run a non-suspending block of code synchronously at the point of state change, then resume with the result. These APIs differ from the existing when* methods as they do not permit running suspending code and do not employ a custom dispatcher. (aosp/1326081)

Behavior Changes

LifecycleRegistry now enforces DESTROYED as a terminal state. (I00887)
LifecycleRegistry now verifies that its methods are called on main thread. It was always a requirement for lifecycles of activities, fragments etc. An addition of observers from non-main threads resulted in hard to catch crashes in runtime. For LifecycleRegistry objects that owned by your own components, you can explicitly opt out from checks by using LifecycleRegistry.createUnsafe(...), but then you have to ensure that a proper synchronization is in place when this LifecycleRegistry is accessed from different threads (Ie7280, b/137392809)

Bug Fixes

Fixed a crash in NullSafeMutableLiveData. (b/159987480)
Fixed an ObsoleteLintCustomCheck for Lint checks bundled with lifecycle-livedata-core-ktx (and specifically NullSafeMutableLiveData). (b/158699265)

Version 2.3.0-alpha05

June 24, 2020

androidx.lifecycle:lifecycle-*:2.3.0-alpha05 is released. Version 2.3.0-alpha05 contains these commits.

Bug Fixes

LiveData now better handles reentrant cases, avoiding duplicate calls to onActive() or onInactive(). (b/157840298)
Fixed an issue where Lint checks would not run when using Android Studio 4.1 Canary 6 or higher. (aosp/1331903)

Version 2.3.0-alpha04

June 10, 2020

androidx.lifecycle:lifecycle-*:2.3.0-alpha04 is released. Version 2.3.0-alpha04 contains these commits.

Bug Fixes

Fixed a crash in the NonNullableMutableLiveData Lint check. (b/157294666)
The NonNullableMutableLiveData Lint check now covers significantly more cases where a null value was set on a MutableLiveData with a non-null type parameter. (b/156002218)

Version 2.3.0-alpha03

May 20, 2020

androidx.lifecycle:lifecycle-*:2.3.0-alpha03 are released. Version 2.3.0-alpha03 contains these commits.

New Features

SavedStateHandle now supports lazy serialization by allowing you to call setSavedStateProvider() for a given key, providing a SavedStateProvider that will get a callback to saveState() when the SavedStateHandle is asked to save its state. (b/155106862)
A new ViewTreeViewModelStoreOwner.get(View) API allows you to retrieve the containing ViewModelStoreOwner given a View instance. You must upgrade to Activity 1.2.0-alpha05, Fragment 1.3.0-alpha05, and AppCompat 1.3.0-alpha01 to populate this correctly. A findViewModelStoreOwner() Kotlin extension has been added to lifecycle-viewmodel-ktx. (aosp/1295522)

Bug Fixes

Fixed an issue that caused the MutableLiveData Lint checks released in Lifecycle 2.3.0-alpha01 from being published alongside the lifecycle-livedata-core-ktx artifact. (b/155323109)

Version 2.3.0-alpha02

April 29, 2020

androidx.lifecycle:lifecycle-*:2.3.0-alpha02 is released. Version 2.3.0-alpha02 contains these commits.

API Changes

SavedStateViewModelFactory now allows you to pass a null Application to its constructor to better support cases where one is not readily available and support for AndroidViewModel is not needed. (aosp/1285740)

Bug Fixes

Improved cold start performance by avoiding class verification failure on API 28 and lower devices. (aosp/1282118)

Version 2.3.0-alpha01

March 4, 2020

androidx.lifecycle:lifecycle-*:2.3.0-alpha01 is released. Version 2.3.0-alpha01 contains these commits.

New Features

A new ViewTreeLifecycleOwner.get(View) API allows you to retrieve the containing LifecycleOwner given a View instance. You must upgrade to Activity 1.2.0-alpha01 and Fragment 1.3.0-alpha01 to populate this correctly. A findViewTreeLifecycleOwner Kotlin extension is available in lifecycle-runtime-ktx. (aosp/1182361, aosp/1182956)
Added a new Lint check that warns you when setting a null value on a MutableLiveData that has been defined in Kotlin as non-null. This is available when using the livedata-core-ktx or livedata-ktx artifacts. (aosp/1154723, aosp/1159092)
A new lifecycle-runtime-testing artifact is available that provides a TestLifecycleOwner that implements LifecycleOwner and provides a thread safe mutable Lifecycle. (aosp/1242438)

Bug fixes

The lifecycle-runtime artifact now has a unique package name. (aosp/1187196)

Version 2.2.0

ViewModel-Savedstate Version 2.2.0

February 5, 2020

androidx.lifecycle:lifecycle-viewmodel-savedstate:2.2.0 is released. Version 2.2.0 contains these commits.

Lifecycle ViewModel SavedState now shares the same version as other Lifecycle artifacts. The behavior of 2.2.0 is identical to the behavior of 1.0.0.

Version 2.2.0

January 22, 2020

androidx.lifecycle:lifecycle-*:2.2.0 is released. Version 2.2.0 contains these commits.

Important changes since 2.1.0

Lifecycle Coroutine Integration: The new lifecycle-runtime-ktx artifact adds integration between Lifecycle and Kotlin coroutines. The lifecycle-livedata-ktx has also been expanded to take advantage of coroutines. See Use Kotlin coroutines with Architecture Components for more details.
ViewModelProviders.of() deprecation: ViewModelProviders.of() has been deprecated. You can pass a Fragment or FragmentActivity to the new ViewModelProvider(ViewModelStoreOwner) constructor to achieve the same functionality when using Fragment 1.2.0.
lifecycle-extensions Artifact Deprecation: With the above deprecation of ViewModelProviders.of(), this release marks the deprecation of the last API in lifecycle-extensions and this artifact should now be considered deprecated in its entirety. We strongly recommend depending on the specific Lifecycle artifacts you need (such as lifecycle-service if you’re using LifecycleService and lifecycle-process if you’re using ProcessLifecycleOwner) rather than lifecycle-extensions as there will not be a future 2.3.0 release of lifecycle-extensions.
Gradle Incremental Annotation Processor: Lifecycle's annotation processor is incremental by default. If your app is written in the Java 8 programming language you can use DefautLifecycleObserver instead; and if it's written in the Java 7 programming language you can use LifecycleEventObserver.

Version 2.2.0-rc03

December 4, 2019

androidx.lifecycle:lifecycle-*:2.2.0-rc03 is released. Version 2.2.0-rc03 contains these commits.

Bug fixes

Fixed a failure occurring when a mocked ViewModel was stored in ViewModelStore and queried later with default factory.
Fix a usage of Dispatchers.Main.immediate in launchWhenCreated and similar methods to be called synchronously during corresponding lifecycle event. (aosp/1156203)

External contributions

Thanks to Anders Järleberg for contributing the fix! (aosp/1156203)
Thanks to Vsevolod Tolstopyatov from Jetbrains for reviewing an implementation of inlined execution.

Dependency changes

Lifecycle Extensions now depends on Fragment 1.2.0-rc03.

Version 2.2.0-rc02

November 7, 2019

androidx.lifecycle:lifecycle-*:2.2.0-rc02 is released. Version 2.2.0-rc02 contains these commits.

Bug fixes

Fixed a bug in the proguard setup of the library that affected devices running API 28+ if the target API is below 29. (b/142778206)

Version 2.2.0-rc01

October 23, 2019

androidx.lifecycle:lifecycle-*:2.2.0-rc01 is released. Version 2.2.0-rc01 contains these commits.

Bug fixes

Fixed an issue where launchWhenCreated and related methods would run one frame later than the associated lifecycle method due to its use of Dispatchers.Main instead of Dispatchers.Main.immediate. (aosp/1145596)

External contributions

Thanks to Nicklas Ansman for contributing the fix! (aosp/1145596)

Version 2.2.0-beta01

October 9, 2019

androidx.lifecycle:lifecycle-*:2.2.0-beta01 is released. Version 2.2.0-beta01 contains these commits.

Bug fixes

Fixed a regression introduced in Lifecycle 2.2.0-alpha05 in the ordering of ProcessLifecycleOwner and the activity’s LifecycleOwner moving to started and resumed on Android 10 devices. (aosp/1128132)
Fixed a regression introduced in Lifecycle 2.2.0-alpha05 which would cause a NullPointerException when using version 2.0.0 or 2.1.0 of lifecycle-process. (b/141536990)

Version 2.2.0-alpha05

September 18, 2019

androidx.lifecycle:lifecycle-*:2.2.0-alpha05 is released. Version 2.2.0-alpha05 contains these commits.

Bug fixes

Fixed a race condition in coroutine livedata builder. b/140249349

Version 2.2.0-alpha04

September 5, 2019

androidx.lifecycle:lifecycle-*:2.2.0-alpha04 is released. The commits included in this version can be found here.

New features

lifecycleScope, whenCreated, whenStarted, whenResumed, viewModelScope, and the underlying implementation of liveData now use Dispatchers.Main.immediate instead of Dispatchers.Main. (b/139740492)

External contributions

Thanks to Nicklas Ansman for contributing the move to Dispatchers.Main.immediate! (aosp/1106073)

Version 2.2.0-alpha03

August 7, 2019

androidx.lifecycle:lifecycle-*:2.2.0-alpha03 is released. The commits included in this version can be found here.

New features

Implementations of ViewModelStoreOwner can now optionally implement HasDefaultViewModelProviderFactory to provide a default ViewModelProvider.Factory. This has been done for Activity 1.1.0-alpha02, Fragment 1.2.0-alpha02, and Navigation 2.2.0-alpha01. (aosp/1092370, b/135716331)

API changes

ViewModelProviders.of() has been deprecated. You can pass a Fragment or FragmentActivity to the new ViewModelProvider(ViewModelStoreOwner) constructor to achieve the same functionality. (aosp/1009889)

Version 2.2.0-alpha02

July 2, 2019

androidx.lifecycle:*:2.2.0-alpha02 is released. The commits included in this version can be found here.

API changes

Replaced LiveDataScope.initialValue with LiveDataScope.latestValue which will track the current emitted value of the liveData block.
Added a new overload to the liveData builder that receives timeout parameter as type Duration

Version 2.2.0-alpha01

May 7, 2019

androidx.lifecycle:*:2.2.0-alpha01 is released. The commits included in this version can be found here.

New features

This release adds new features that adds support for Kotlin coroutines for Lifecycle and LiveData. Detailed documentation on them can be found here.

ViewModel-SavedState Version 1.0.0

Version 1.0.0

January 22, 2020

androidx.lifecycle:lifecycle-viewmodel-savedstate:1.0.0 is released. Version 1.0.0 contains these commits.

Important features in 1.0.0

New SavedStateHandle class was added. It enables your ViewModel classes to access and to contribute to the saved state. This object can be received in constructor of ViewModel class and factories provided by default by Fragments and AppCompatActivity will inject SavedStateHandle automatically.
AbstractSavedStateViewModelFactory was added. It allows you to create custom factories for your ViewModel and provide them access to SavedStateHandle.

ViewModel-Savedstate Version 1.0.0-rc03

December 4, 2019

androidx.lifecycle:lifecycle-viewmodel-savedstate:1.0.0-rc03 is released. Version 1.0.0-rc03 contains these commits.

Dependency changes

Lifecycle ViewModel SavedState now depends on Lifecycle 2.2.0-rc03.

Viewmodel-Savedstate Version 1.0.0-rc02

November 7, 2019

androidx.lifecycle:lifecycle-viewmodel-savedstate:1.0.0-rc02 is released. Version 1.0.0-rc02 contains these commits.

Dependency changes

Now depends on lifecycle 2.2.0-rc02.

ViewModel-SavedState Version 1.0.0-rc01

October 23, 2019

androidx.lifecycle:lifecycle-viewmodel-savedstate:1.0.0-rc01 is released with no changes from 1.0.0-beta01. Version 1.0.0-rc01 contains these commits.

ViewModel-Savedstate Version 1.0.0-beta01

October 9, 2019

androidx.lifecycle:lifecycle-viewmodel-savedstate:1.0.0-beta01 is released. Version 1.0.0-beta01 contains these commits.

Bug fixes

Fixed an issue where accessing a SavedState ViewModel for the first time in Activity.onActivityResult() would result in an IllegalStateException. (b/139093676)
Fixed an IllegalStateException when using AbstractSavedStateViewModelFactory. (b/141225984)

ViewModel-SavedState Version 1.0.0-alpha05

September 18, 2019

androidx.lifecycle:lifecycle-viewmodel-savedstate:1.0.0-alpha05 is released. Version 1.0.0-alpha05 contains these commits.

API changes

SavedStateViewModelFactory no longer extends AbstractSavedStateViewModelFactory and SavedStateHandle is created only for ViewModels that requested have it (aosp/1113593)

ViewModel-SavedState Version 1.0.0-alpha03

August 7, 2019

androidx.lifecycle:lifecycle-viewmodel-savedstate:1.0.0-alpha03 is released. The commits included in this version can be found here.

Breaking Changes

lifecycle-viewmodel-savedstate no longer depends on fragment and the related SavedStateViewModelFactory(Fragment) and SavedStateViewModelFactory(FragmentActivity) constructors have been removed. Instead, SavedStateViewModelFactory is now the default factory for Activity 1.1.0-alpha02, Fragment 1.2.0-alpha02, and Navigation 2.2.0-alpha01. (b/135716331)

ViewModel-SavedState Version 1.0.0-alpha02

July 2, 2019

androidx.lifecycle:lifecycle-viewmodel-savedstate:1.0.0-alpha02 is released. The commits included in this version can be found here.

New features

Added SavedStateHandle.getLiveData() overload which accepts a default value.

API Changes

SavedStateVMFactory is renamed to SavedStateViewModelFactory.
AbstractSavedStateVMFactory is renamed to AbstractSavedStateViewModelFactory.

ViewModel-Savedstate Version 1.0.0-alpha01

March 13, 2019

androidx.lifecycle:lifecycle-viewmodel-savedstate:1.0.0-alpha01 is released. The full commit log for this initial release can be found here.

New features

Now ViewModels can contribute to savedstate. To do that you use newly introduced viewmodel’s factory SavedStateVMFactory and your ViewModel should have a constructor that receives SavedStateHandleobject as a parameter.

Version 2.1.0

Important changes since 2.0.0

Added LifecycleEventObserver for the cases when a stream of lifecycle events is needed. It is a public API instead of a hidden GenericLifecycleObserver class.
Added ktx extensions for LiveData.observe methods and Transformations.* methods.
Added Transformations.distinctUntilChanged, which creates a new LiveData object that does not emit a value until the source LiveData value has been changed.
Added coroutine support in ViewModels by adding the extension property ViewModel.viewModelScope.

Version 2.1.0

September 5, 2019

androidx.lifecycle:lifecycle-*:2.1.0 is released. The commits included in this version can be found here.

Version 2.1.0-rc01

July 2, 2019

androidx.lifecycle:*:2.1.0-rc01 is released with no changes from androidx.lifecycle:*:2.1.0-beta01. The commits included in this version can be found here.

Version 2.1.0-beta01

May 7, 2019

androidx.lifecycle:*:2.1.0-beta01 is released. The commits included in this version can be found here.

New features

Lifecycles are graduated to beta: api introduced in previous alphas such as liveData extension functions for transformations and observations, ViewModel initialisation with property delegation and others are stabilised and not going to change.

Version 2.1.0-alpha04

April 3, 2019

androidx.lifecycle:*:2.1.0-alpha04 is released. The commits included in this version can be found here.

API changes

Breaking change: the underlying API behind by viewModels() and by activityViewModels() has been changed to support a ViewModelStore directly, rather than only a ViewModelStoreOwner. (aosp/932932)

Version 2.1.0-alpha03

March 13, 2019

androidx.lifecycle:*:2.1.0-alpha03 is released. The full list of commits included in this version can be found here.

API changes

ViewModelProvider.KeyedFactory was removed. Second interface in addition to ViewModelProvider.Factory didn’t compose well with new features as property delegation in Kotlin by viewmodels {}. (aosp/914133)

Version 2.1.0-alpha02

January 30, 2019

androidx.lifecycle 2.1.0-alpha02 is released.

API changes

LifecycleRegistry now contains a setCurrentState() method that replaces the now deprecated setState() method. (aosp/880715)

Bug fixes

Fixed an issue where mock ViewModel instances would crash when the containing ViewModelStore was cleared. b/122273087

Version 2.1.0-alpha01

December 17, 2018

androidx.lifecycle 2.1.0-alpha01 is released.

New features

Added LifecycleEventObserver for the cases when a stream of lifecycle events is needed. It is a public api instead of a hidden GenericLifecycleObserver class.
Added ktx extensions for LiveData.observe methods and Transformations.* methods.
Method Transformations.distinctUntilChanged was added. It creates a new LiveData object that does not emit a value until the source LiveData value has been changed.
Coroutine support in ViewModels: extension property ViewModel.viewModelScope was added.
Added ViewModelProvider.KeyedFactory, a factory for ViewModels that receives key and Class in create method.

Version 2.0.0

September 21, 2018

Lifecycle 2.0.0 is released with one bugfix from 2.0.0-rc01 in ViewModel.

Bug Fixes

Fixed a ViewModel proguard rule that incorrectly removed constructors b/112230489

Version 2.0.0-beta01

July 2, 2018

Bug Fixes

Fixed LifecycleObserver proguard rule to keep only implementations, not subinterfaces b/71389427
Fixed ViewModel proguard rules to allow obfuscation and shrinking

Pre-AndroidX Versions

For the pre-AndroidX versions of Lifecycle that follow, include these dependencies:

dependencies {
    def lifecycle_version = "1.1.1"

    // ViewModel and LiveData
    implementation "android.arch.lifecycle:extensions:$lifecycle_version"
    // alternatively - just ViewModel
    implementation "android.arch.lifecycle:viewmodel:$lifecycle_version" // For Kotlin use viewmodel-ktx
    // alternatively - just LiveData
    implementation "android.arch.lifecycle:livedata:$lifecycle_version"
    // alternatively - Lifecycles only (no ViewModel or LiveData).
    //     Support library depends on this lightweight import
    implementation "android.arch.lifecycle:runtime:$lifecycle_version"

    annotationProcessor "android.arch.lifecycle:compiler:$lifecycle_version" // For Kotlin use kapt instead of annotationProcessor
    // alternately - if using Java8, use the following instead of compiler
    implementation "android.arch.lifecycle:common-java8:$lifecycle_version"

    // optional - ReactiveStreams support for LiveData
    implementation "android.arch.lifecycle:reactivestreams:$lifecycle_version"

    // optional - Test helpers for LiveData
    testImplementation "android.arch.core:core-testing:$lifecycle_version"
}

Version 1.1.1

March 21, 2018

Only one small change: android.arch.core.util.Function is moved from arch:runtime to arch:common. This allows it to be used without the runtime dependency, e.g. in paging:common below.

lifecycle:common is a dependency of lifecycle:runtime, so this change doesn’t affect lifecycle:runtime directly, only modules that depend directly on lifecycle:common, as Paging does.

Version 1.1.0

January 22, 2018

Packaging Changes

New, much smaller dependencies are now available:

android.arch.lifecycle:livedata:1.1.0
android.arch.lifecycle:viewmodel:1.1.0

API Changes

The deprecated LifecycleActivity and LifecycleFragment have now been removed - please use FragmentActivity, AppCompatActivity or support Fragment.
@NonNull annotations have been added to ViewModelProviders and ViewModelStores
ViewModelProviders constructor has been deprecated - please use its static methods directly
ViewModelProviders.DefaultFactory has been deprecated - please use ViewModelProvider.AndroidViewModelFactory
The static ViewModelProvider.AndroidViewModelFactory.getInstance(Application) method has been added to retrieve a static Factory suitable for creating ViewModel and AndroidViewModel instances.