Vfrdtyky

I am investigating the use of androidx.work.WorkManager for background work within my current Android application.

The versions I am employing are :-

compileSdkVersion = 27

targetSdkVersion = 27

minSdkVersion = 21

buildToolsVersion = "27.0.3"

supportLibVersion = "27.1.1"



archLifecycleVersion = "1.1.1"

archWorkerRuntimeVersion = "1.0.0-alpha11"

My application consists of An activity with a Fragment, the Fragment has an associated android.arch.lifecycle.AndroidViewModel and the view model has a repository.

I control the WorkManager from within my repository class.

I set the fragment as the LifecycleOwner for the workManager Observer.

When I allow the workManager to complete its work without changing the orientation of my testing device it works as designed.

However when I start the workManager and then during its background processing I change the device orientation my observer is removed as the Fragment has been destroyed. The work manager still completes with success as I can see this in my application logs...

WorkerWrapper: Worker result SUCCESS for Work [ id=33058369-010d-4e07-ae94-fb04bcf4d805, tags={ com.sync.SyncWorker, SYNC-IN-PROGRESS-TAG } ]

I switched to using observeForever, however this approach gave worse results as my observer only received ENQUEUED and RUNNING, it never "saw" the SUCCEEDED state, even though I still saw the above WorkerWrapper log entry.

How can I observe WorkManager work before during and after a device configuration change?

My Code resembles this:-

private WorkManager mWorkManager;



/**

 * SINGLETON

 */

private MyRepository() {

    mWorkManager = WorkManager.getInstance();

}





private static final String WORK_IN_PROGRESS_TAG = "SYNC-IN-PROGRESS-TAG";

private static final String UNIQUE_WORK_NAME = "SYNC-UNIQUE_WORK_NAME";

private final Observer<WorkInfo> workerObserver = constructWorkStatusObserver();



private Observer<WorkInfo> constructWorkStatusObserver() {

    return workInfo -> {



        if (workInfo == null) {

            return;

        }



        if (workInfo.getState().equals(WorkInfo.State.SUCCEEDED)) {

            //DO SOMETHING 

        } else if (workInfo.getState().equals(WorkInfo.State.FAILED)) {

            Log.e(TAG, "SyncWorker FAILED:");

        }

    };

}





private Action manageSuccess(final LifecycleOwner lifecycleOwner) {

    return () -> {

        final LiveData<WorkInfo> workStatus = constructWorkRequest();

        workStatus.observe(lifecycleOwner, workerObserver);

    };

}



private LiveData<WorkInfo> constructWorkRequest() {

    final OneTimeWorkRequest refreshDatabaseWork = new OneTimeWorkRequest.Builder(SyncWorker.class).addTag(WORK_IN_PROGRESS_TAG).build();



    mWorkManager.beginUniqueWork(UNIQUE_WORK_NAME, ExistingWorkPolicy.KEEP, refreshDatabaseWork).enqueue();

    return mWorkManager.getWorkInfoByIdLiveData(refreshDatabaseWork.getId());

}