As described in the Overview of Google Play services article, SDKs powered by Google Play services are backed by on-device services on Google-certified Android devices. To conserve storage and memory across the entire fleet of devices, some services are installed on-demand when it is clear that a specific device requires the relevant functionality. For example, ML Kit provides this option when using models in Google Play services.
The most common case is for a service (or “module”) to be downloaded and
installed in parallel to an app that requires it, based on a dependency in the
AndroidManifest.xml
of the SDK. For more control, the module install APIs
provide the ability to explicitly check for module availability, request module
installation, monitor request state, and handle errors.
Follow the steps below to ensure API availability with ModuleInstallClient
.
Note that the code snippets below use the
TensorFlow Lite SDK
(play-services-tflite-java
) as an example library, but these steps are
applicable for any library that's integrated with OptionalModuleApi
. This
guide will be updated with additional information as more SDKs add support.
Before you begin
To prepare your app, complete the steps in the following sections.
App prerequisites
Make sure that your app's build file uses the following values:
- A
minSdkVersion
of19
or higher
Configure your app
In your top-level
settings.gradle
file, include Google's Maven repository and the Maven central repository within thedependencyResolutionManagement
block:dependencyResolutionManagement { repositories { google() mavenCentral() } }
In your module's Gradle build file (usually
app/build.gradle
), add the Google Play services dependencies forplay-services-base
andplay-services-tflite-java
:dependencies { implementation 'com.google.android.gms:play-services-base:18.5.0' implementation 'com.google.android.gms:play-services-tflite-java:16.2.0-beta02' }
Check module availability
Get an instance of
ModuleInstallClient
:Kotlin
val moduleInstallClient = ModuleInstall.getClient(context)
Java
ModuleInstallClient moduleInstallClient = ModuleInstall.getClient(context);
Check the availability of an optional module using its
OptionalModuleApi
:Kotlin
val optionalModuleApi = TfLite.getClient(context) moduleInstallClient .areModulesAvailable(optionalModuleApi) .addOnSuccessListener { if (it.areModulesAvailable()) { // Modules are present on the device... } else { // Modules are not present on the device... } } .addOnFailureListener { // Handle failure... }
Java
OptionalModuleApi optionalModuleApi = TfLite.getClient(context); moduleInstallClient .areModulesAvailable(optionalModuleApi) .addOnSuccessListener( response -> { if (response.areModulesAvailable()) { // Modules are present on the device... } else { // Modules are not present on the device... } }) .addOnFailureListener( e -> { // Handle failure… });
Send a deferred install request
Get an instance of
ModuleInstallClient
:Kotlin
val moduleInstallClient = ModuleInstall.getClient(context)
Java
ModuleInstallClient moduleInstallClient = ModuleInstall.getClient(context);
Send the deferred request:
Kotlin
val optionalModuleApi = TfLite.getClient(context) moduleInstallClient.deferredInstall(optionalModuleApi)
Java
OptionalModuleApi optionalModuleApi = TfLite.getClient(context); moduleInstallClient.deferredInstall(optionalModuleApi);
Send an urgent module install request
Get an instance of
ModuleInstallClient
:Kotlin
val moduleInstallClient = ModuleInstall.getClient(context)
Java
ModuleInstallClient moduleInstallClient = ModuleInstall.getClient(context);
(Optional) Create an
InstallStatusListener
to handle the install status updates.If you want to monitor the download progress in a customized UI (for example, a progress bar), you can create a
InstallStatusListener
to receive the install status updates.Kotlin
inner class ModuleInstallProgressListener : InstallStatusListener { override fun onInstallStatusUpdated(update: ModuleInstallStatusUpdate) { // Progress info is only set when modules are in the progress of downloading. update.progressInfo?.let { val progress = (it.bytesDownloaded * 100 / it.totalBytesToDownload).toInt() // Set the progress for the progress bar. progressBar.setProgress(progress) } if (isTerminateState(update.installState)) { moduleInstallClient.unregisterListener(this) } } fun isTerminateState(@InstallState state: Int): Boolean { return state == STATE_CANCELED || state == STATE_COMPLETED || state == STATE_FAILED } } val listener = ModuleInstallProgressListener()
Java
static final class ModuleInstallProgressListener implements InstallStatusListener { @Override public void onInstallStatusUpdated(ModuleInstallStatusUpdate update) { ProgressInfo progressInfo = update.getProgressInfo(); // Progress info is only set when modules are in the progress of downloading. if (progressInfo != null) { int progress = (int) (progressInfo.getBytesDownloaded() * 100 / progressInfo.getTotalBytesToDownload()); // Set the progress for the progress bar. progressBar.setProgress(progress); } // Handle failure status maybe… // Unregister listener when there are no more install status updates. if (isTerminateState(update.getInstallState())) { moduleInstallClient.unregisterListener(this); } } public boolean isTerminateState(@InstallState int state) { return state == STATE_CANCELED || state == STATE_COMPLETED || state == STATE_FAILED; } } InstallStatusListener listener = new ModuleInstallProgressListener();
Configure the
ModuleInstallRequest
and add theOptionalModuleApi
to the request:Kotlin
val optionalModuleApi = TfLite.getClient(context) val moduleInstallRequest = ModuleInstallRequest.newBuilder() .addApi(optionalModuleApi) // Add more APIs if you would like to request multiple optional modules. // .addApi(...) // Set the listener if you need to monitor the download progress. // .setListener(listener) .build()
Java
OptionalModuleApi optionalModuleApi = TfLite.getClient(context); ModuleInstallRequest moduleInstallRequest = ModuleInstallRequest.newBuilder() .addApi(optionalModuleApi) // Add more API if you would like to request multiple optional modules //.addApi(...) // Set the listener if you need to monitor the download progress //.setListener(listener) .build();
Send the install request:
Kotlin
moduleInstallClient .installModules(moduleInstallRequest) .addOnSuccessListener { if (it.areModulesAlreadyInstalled()) { // Modules are already installed when the request is sent. } } .addOnFailureListener { // Handle failure… }
Java
moduleInstallClient.installModules(moduleInstallRequest) .addOnSuccessListener( response -> { if (response.areModulesAlreadyInstalled()) { // Modules are already installed when the request is sent. } }) .addOnFailureListener( e -> { // Handle failure... });
Local testing with FakeModuleInstallClient
Google Play services SDKs provide the FakeModuleInstallClient
to allow you to
simulate the results of the module install APIs in tests using dependency
injection.
App prerequisites
Configure your app to use Hilt dependency injection framework.
Replace ModuleInstallClient
with FakeModuleInstallClient
in test
Add dependency:
In your module's Gradle build file (usually
app/build.gradle
), add the Google Play services dependencies forplay-services-base-testing
in your test.dependencies { // other dependencies... testImplementation 'com.google.android.gms:play-services-base-testing:16.1.0' }
Create a Hilt module to provide
ModuleInstallClient
:Kotlin
@Module @InstallIn(ActivityComponent::class) object ModuleInstallModule { @Provides fun provideModuleInstallClient( @ActivityContext context: Context ): ModuleInstallClient = ModuleInstall.getClient(context) }
Java
@Module @InstallIn(ActivityComponent.class) public class ModuleInstallModule { @Provides public static ModuleInstallClient provideModuleInstallClient( @ActivityContext Context context) { return ModuleInstall.getClient(context); } }
Inject the
ModuleInstallClient
in the activity:Kotlin
@AndroidEntryPoint class MyActivity: AppCompatActivity() { @Inject lateinit var moduleInstallClient: ModuleInstallClient ... }
Java
@AndroidEntryPoint public class MyActivity extends AppCompatActivity { @Inject ModuleInstallClient moduleInstallClient; ... }
Replace the binding in test:
Kotlin
@UninstallModules(ModuleInstallModule::class) @HiltAndroidTest class MyActivityTest { ... private val context:Context = ApplicationProvider.getApplicationContext() private val fakeModuleInstallClient = FakeModuleInstallClient(context) @BindValue @JvmField val moduleInstallClient: ModuleInstallClient = fakeModuleInstallClient ... }
Java
@UninstallModules(ModuleInstallModule.class) @HiltAndroidTest class MyActivityTest { ... private static final Context context = ApplicationProvider.getApplicationContext(); private final FakeModuleInstallClient fakeModuleInstallClient = new FakeModuleInstallClient(context); @BindValue ModuleInstallClient moduleInstallClient = fakeModuleInstallClient; ... }
Simulate module availability
Kotlin
@Test fun checkAvailability_available() { // Reset any previously installed modules. fakeModuleInstallClient.reset() val availableModule = TfLite.getClient(context) fakeModuleInstallClient.setInstalledModules(api) // Verify the case where modules are already available... } @Test fun checkAvailability_unavailable() { // Reset any previously installed modules. fakeModuleInstallClient.reset() // Do not set any installed modules in the test. // Verify the case where modules unavailable on device... } @Test fun checkAvailability_failed() { // Reset any previously installed modules. fakeModuleInstallClient.reset() fakeModuleInstallClient.setModulesAvailabilityTask(Tasks.forException(RuntimeException())) // Verify the case where an RuntimeException happened when trying to get module's availability... }
Java
@Test public void checkAvailability_available() { // Reset any previously installed modules. fakeModuleInstallClient.reset(); OptionalModuleApi optionalModuleApi = TfLite.getClient(context); fakeModuleInstallClient.setInstalledModules(api); // Verify the case where modules are already available... } @Test public void checkAvailability_unavailable() { // Reset any previously installed modules. fakeModuleInstallClient.reset(); // Do not set any installed modules in the test. // Verify the case where modules unavailable on device... } @Test public void checkAvailability_failed() { fakeModuleInstallClient.setModulesAvailabilityTask(Tasks.forException(new RuntimeException())); // Verify the case where an RuntimeException happened when trying to get module's availability... }
Simulate result for a deferred install request
Kotlin
@Test fun deferredInstall_success() { fakeModuleInstallClient.setDeferredInstallTask(Tasks.forResult(null)) // Verify the case where the deferred install request has been sent successfully... } @Test fun deferredInstall_failed() { fakeModuleInstallClient.setDeferredInstallTask(Tasks.forException(RuntimeException())) // Verify the case where an RuntimeException happened when trying to send the deferred install request... }
Java
@Test public void deferredInstall_success() { fakeModuleInstallClient.setDeferredInstallTask(Tasks.forResult(null)); // Verify the case where the deferred install request has been sent successfully... } @Test public void deferredInstall_failed() { fakeModuleInstallClient.setDeferredInstallTask(Tasks.forException(new RuntimeException())); // Verify the case where an RuntimeException happened when trying to send the deferred install request... }
Simulate result for an urgent install request
Kotlin
@Test fun installModules_alreadyExist() { // Reset any previously installed modules. fakeModuleInstallClient.reset(); OptionalModuleApi optionalModuleApi = TfLite.getClient(context); fakeModuleInstallClient.setInstalledModules(api); // Verify the case where the modules already exist when sending the install request... } @Test fun installModules_withoutListener() { // Reset any previously installed modules. fakeModuleInstallClient.reset(); // Verify the case where the urgent install request has been sent successfully... } @Test fun installModules_withListener() { // Reset any previously installed modules. fakeModuleInstallClient.reset(); // Generates a ModuleInstallResponse and set it as the result for installModules(). val moduleInstallResponse = FakeModuleInstallUtil.generateModuleInstallResponse() fakeModuleInstallClient.setInstallModulesTask(Tasks.forResult(moduleInstallResponse)) // Verify the case where the urgent install request has been sent successfully... // Generates some fake ModuleInstallStatusUpdate and send it to listener. val update = FakeModuleInstallUtil.createModuleInstallStatusUpdate( moduleInstallResponse.sessionId, STATE_COMPLETED) fakeModuleInstallClient.sendInstallUpdates(listOf(update)) // Verify the corresponding updates are handled correctly... } @Test fun installModules_failed() { fakeModuleInstallClient.setInstallModulesTask(Tasks.forException(RuntimeException())) // Verify the case where an RuntimeException happened when trying to send the urgent install request... }
Java
@Test public void installModules_alreadyExist() { // Reset any previously installed modules. fakeModuleInstallClient.reset(); OptionalModuleApi optionalModuleApi = TfLite.getClient(context); fakeModuleInstallClient.setInstalledModules(api); // Verify the case where the modules already exist when sending the install request... } @Test public void installModules_withoutListener() { // Reset any previously installed modules. fakeModuleInstallClient.reset(); // Verify the case where the urgent install request has been sent successfully... } @Test public void installModules_withListener() { // Reset any previously installed modules. fakeModuleInstallClient.reset(); // Generates a ModuleInstallResponse and set it as the result for installModules(). ModuleInstallResponse moduleInstallResponse = FakeModuleInstallUtil.generateModuleInstallResponse(); fakeModuleInstallClient.setInstallModulesTask(Tasks.forResult(moduleInstallResponse)); // Verify the case where the urgent install request has been sent successfully... // Generates some fake ModuleInstallStatusUpdate and send it to listener. ModuleInstallStatusUpdate update = FakeModuleInstallUtil.createModuleInstallStatusUpdate( moduleInstallResponse.getSessionId(), STATE_COMPLETED); fakeModuleInstallClient.sendInstallUpdates(ImmutableList.of(update)); // Verify the corresponding updates are handled correctly... } @Test public void installModules_failed() { fakeModuleInstallClient.setInstallModulesTask(Tasks.forException(new RuntimeException())); // Verify the case where an RuntimeException happened when trying to send the urgent install request... }