Nsikak Thompson Abuja Background Task with WorkManager 

About Me Location ● I build for Android ● Co-organiser GDG Uyo ● ALC Program Assistant for South South Nigeria 

3 DevFest Uyo 

Scope ● What is WorkManager? ● Set up ● Creating a Worker ● Enqueuing WorkRequest ● Chain Work ● Observing your work ● Cancel Work 

What you may have used: ● AsynTask(Short duration task) ● Firebase JobSchedulars(long background task) ● AlarmManager(periodic task) 

JobSchedular AlarmManager WorkManager 

What is WorkManager WorkManager is part of Android Jetpack and an Architecture Component for background work that needs a combination of opportunistic and guaranteed execution. 

What is WorkManager WorkManager is a simple, but incredibly flexible library that has many additional benefits. These include: ● Support for both asynchronous one-off and periodic tasks ● Support for constraints such as network conditions, storage space, and charging status ● Chaining of complex work requests, including running work in parallel ● Output from one work request used as input for the next ● Handles API level compatibility back to API level 14(see note) 

What is WorkManager ● Works with or without Google Play services ● Follows system health best practices ● LiveData support to easily display work request state in UI(WorkInfo) 

..build.gradle file Dependencies{ //workmanager } 

11 Profile Photo Upload 

Classes you should know ● Worker: This is where you put the code for the actual work you want to perform in the background. You'll extend this class and override the doWork() method. ● WorkRequest: This represents a request to do some work. You'll pass in your Worker as part of creating your WorkRequest. When making the WorkRequest you can also specify things like Constraints on when the Worker should run. ● WorkManager: This class actually schedules your WorkRequest and makes it run. 

Ready to Cook 

Your worker class UploadImageWorker(var context:Context,var workerParams: WorkerParameters): Worker(context,workerParams){ override fun doWork(): Result { UploadImage() //your logic } 

Enqueuing WorkRequest ● OneTimeWorkRequest ● PeriodicWorkRequest var uploadImageRequest = OneTimeWorkRequest.Builder(UploadImageWorker::class.java) .setInputData(createInputDataForUri()) .addTag(“image Upload”) .setConstraints(//like when device is charging) .build() mWorkManager.enqueue(uploadImageRequest) 

Chain Work WorkerRequests that run in order or parallel. WR A Output WR B 

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Observing your work This section uses LiveData heavily. LiveData is an observable, lifecycle-aware data holder. getStatusByIdLiveData - Get work using request id getStatusesForUniqueWorkLiveData - Get work using unique chain name getStatusesByTagLiveData - Get work using request tag 

Observing your work Var status = mWorkManager.getWorkInfoByIdLiveData(uploadImageRequest.id): LiveData WorkInfo.State{ ENQUEUEING RUNNING SUCCEEDED FAILED BLOCKED CANCEL } 

Cancel work With WorkManager, you can cancel work using the id, by tag and by unique chain name. 

Cancel work /** * Cancel work using the work's unique name */ void cancelWork() { mWorkManager.cancelUniqueWork(IMAGE_MANIPULATION_WORK_NAME); } 

Recap Congratulations! ● Adding WorkManager to your Project ● Scheduling a OneOffWorkRequest ● Input and Output parameters ● Tagging WorkRequests ● Displaying WorkInfo in the UI ● Cancelling WorkRequests ● Adding constraints to a WorkRequest 

Abuja Thank you! Nsikak Thompson @thompson_nsikak 

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