Observe intermediate worker progress

WorkManager has built-in support for setting and observing intermediate progress for workers. If the worker was running while the app was in the foreground, this information can also be shown to the user using APIs which return the LiveData of WorkInfo.

ListenableWorker now supports the setProgressAsync() API, which allows it to persist intermediate progress. These APIs allow developers to set intermediate progress that can be observed by the UI. Progress is represented by the Data type, which is a serializable container of properties (similar to input and output, and subject to the same restrictions).

Progress information can only be observed and updated while the ListenableWorker is running. Attempts to set progress on a ListenableWorker after it has completed its execution are ignored.

You can also observe progress information by using the one of the getWorkInfoBy…() or getWorkInfoBy…LiveData() methods. These methods return instances of WorkInfo, which has a new getProgress() method that returns Data.

Update progress

For Java developers using a ListenableWorker or a Worker, the setProgressAsync() API returns a ListenableFuture<Void>; updating progress is asynchronous, given that the update process involves storing progress information in a database. In Kotlin, you can use the CoroutineWorker object's setProgress() extension function to update progress information.

This example shows a ProgressWorker. The Worker sets its progress to 0 when it starts, and upon completion updates the progress value to 100.

Kotlin

import android.content.Context import androidx.work.CoroutineWorker import androidx.work.Data import androidx.work.WorkerParameters import kotlinx.coroutines.delay class ProgressWorker(context: Context, parameters: WorkerParameters) :  CoroutineWorker(context, parameters) {  companion object {  const val Progress = "Progress"  private const val delayDuration = 1L  }  override suspend fun doWork(): Result {  val firstUpdate = workDataOf(Progress to 0)  val lastUpdate = workDataOf(Progress to 100)  setProgress(firstUpdate)  delay(delayDuration)  setProgress(lastUpdate)  return Result.success()  } }

Java

import android.content.Context; import androidx.annotation.NonNull; import androidx.work.Data; import androidx.work.Worker; import androidx.work.WorkerParameters; public class ProgressWorker extends Worker {  private static final String PROGRESS = "PROGRESS";  private static final long DELAY = 1000L;  public ProgressWorker(  @NonNull Context context,  @NonNull WorkerParameters parameters) {  super(context, parameters);  // Set initial progress to 0  setProgressAsync(new Data.Builder().putInt(PROGRESS, 0).build());  }  @NonNull  @Override  public Result doWork() {  try {  // Doing work.  Thread.sleep(DELAY);  } catch (InterruptedException exception) {  // ... handle exception  }  // Set progress to 100 after you are done doing your work.  setProgressAsync(new Data.Builder().putInt(PROGRESS, 100).build());  return Result.success();  } }

Observe progress

To observe progress information, use the getWorkInfoById methods, and get a reference to WorkInfo.

Here is an example which uses getWorkInfoByIdFlow for Kotlin and getWorkInfoByIdLiveData for Java.

Kotlin

WorkManager.getInstance(applicationContext)  // requestId is the WorkRequest id  .getWorkInfoByIdFlow(requestId)  .collect { workInfo: WorkInfo? ->  if (workInfo != null) {  val progress = workInfo.progress  val value = progress.getInt("Progress", 0)  // Do something with progress information  }  }

Java

WorkManager.getInstance(getApplicationContext())  // requestId is the WorkRequest id  .getWorkInfoByIdLiveData(requestId)  .observe(lifecycleOwner, new Observer<WorkInfo>() {  @Override  public void onChanged(@Nullable WorkInfo workInfo) {  if (workInfo != null) {  Data progress = workInfo.getProgress();  int value = progress.getInt(PROGRESS, 0)  // Do something with progress  }  } });

Observe stop reason state

To debug why a Worker was stopped, you can log the stop reason by calling WorkInfo.getStopReason():

Kotlin

workManager.getWorkInfoByIdFlow(syncWorker.id)  .collect { workInfo ->  if (workInfo != null) {  val stopReason = workInfo.stopReason  logStopReason(syncWorker.id, stopReason)  }  }

Java

 workManager.getWorkInfoByIdLiveData(syncWorker.id)  .observe(getViewLifecycleOwner(), workInfo -> {  if (workInfo != null) {  int stopReason = workInfo.getStopReason();  logStopReason(syncWorker.id, workInfo.getStopReason());  }  });

For more documentation the lifecycle and states of Worker objects, read Work states.