Android JetPack - Scheduling Tasks with WorkManager

-

Introduction:

WorkManager is one of the Android JetPack component. It is specifically designed for scheduling and managing background tasks. If the app is running, task will be executed in a new thread. Otherwise, WorkManager automatically chooses an appropriate way to do so. It can be AlarmManager, JobScheduler or Firebase JobDispatcher, depends on device's API level and its dependencies.

WorkManager Basics:

  • Worker
  • WorkRequest
  • WorkManager
  • WorkInfo

(i) Worker:

It specifies what task need to be performed.


class SampleWorker(context: Context, workerParams: WorkerParameters) : Worker(context, workerParams) {

    override fun doWork(): ListenableWorker.Result {
        //do the work here
        return ListenableWorker.Result.SUCCESS
    }
}

(ii) WorkRequest:

It represents which Worker should perform the task. Also we can specify any constraints/circumstances, based on which the task should be performed. Constraints can be of NetworkType, charging status, battery status, etc.

Two kinds of WorkRequest are there:

    (a) OneTimeWorkRequest - Non-repeating work request. 


val requestBuilder = OneTimeWorkRequest.Builder(SampleWorker::class.java).build()

    (b) PeriodicWorkRequest - WorkRequest that repeats periodically.


val requestBuilder = PeriodicWorkRequest.Builder(SampleWorker::class.java, 24, TimeUnit.HOURS)

(iii) WorkManager:

It enqueues and manages the work requests. 


WorkManager.getInstance().enqueue(requestBuilder)

We can also enqueue WorkRequest as unique, so that the same WorkRequest will not be assigned again and again. 

val workTag = "workTag"
WorkManager.getInstance().beginUniqueWork(workTag, ExistingWorkPolicy.REPLACE, requestBuilder).enqueue()

(iv) WorkInfo:

It contains information about a particular task. We can get the WorkInfo of every WorkRequest, by observing LiveData.


 WorkManager.getInstance().getStatusByIdLiveData(requestBuilder.id).observe(this@DataActivity, android.arch.lifecycle.Observer { workerStatus ->
                if (workerStatus != null && workerStatus.state.isFinished) {
                    Toast.makeText(this@DataActivity, workerStatus.outputData.getString(Constants.EXTRA_OUTPUT_MESSAGE), Toast.LENGTH_SHORT).show()
                }

            })

You can find the Project on Github.

Implementation:

Let's first add WorkManager in our app-level gradle.

 implementation "android.arch.work:work-runtime-ktx:1.0.0-alpha10"

build.gradle

apply plugin: 'com.android.application'

apply plugin: 'kotlin-android'

apply plugin: 'kotlin-android-extensions'

apply plugin: 'kotlin-kapt'


android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.yamikrish.app.workmanagerdemo"
        minSdkVersion 15
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
// Temporary fix until alpha10
    packagingOptions {
        exclude 'META-INF/proguard/androidx-annotations.pro'
    }

}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation"org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    implementation 'com.android.support:appcompat-v7:28.0.0'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    implementation "android.arch.work:work-runtime-ktx:1.0.0-alpha10"
    implementation "androidx.lifecycle:lifecycle-livedata:2.0.0"
    kapt "androidx.lifecycle:lifecycle-compiler:2.0.0"
 

    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
}
Let's see about WorkManager in detail with example. So first, let's create an activity, where we can have no. of options to check each kind.

BaseActivity.kt

It have 4 buttons for showing SingleTask, PeriodicTask, ChainedTask and Constraints & Data Task.

import android.content.Intent
import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import android.view.View
import com.yamikrish.app.workmanagerdemo.R
import com.yamikrish.app.workmanagerdemo.activity.ChainTaskActivity
import com.yamikrish.app.workmanagerdemo.activity.ConstraintsDataActivity
import com.yamikrish.app.workmanagerdemo.activity.PeriodicTaskActivity
import com.yamikrish.app.workmanagerdemo.activity.SingleTaskActivity
import kotlinx.android.synthetic.main.activity_main.*

class BaseActivity : AppCompatActivity(), View.OnClickListener {
    override fun onClick(v: View?) {
        when (v?.id) {
            R.id.btn_periodic_task -> startActivity(Intent(this@BaseActivity, PeriodicTaskActivity::class.java))

            R.id.btn_single_task -> startActivity(Intent(this@BaseActivity, SingleTaskActivity::class.java))

            R.id.btn_recurring_task -> startActivity(Intent(this@BaseActivity, ChainTaskActivity::class.java))

            R.id.btn_constraints_data -> startActivity(Intent(this@BaseActivity, ConstraintsDataActivity::class.java))


        }
    }


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        btn_periodic_task.setOnClickListener(this)
        btn_single_task.setOnClickListener(this)
        btn_recurring_task.setOnClickListener(this)
        btn_constraints_data.setOnClickListener(this)
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <Button
        android:id="@+id/btn_single_task"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/single_task"
        app:layout_constraintBottom_toTopOf="@+id/btn_periodic_task"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/btn_periodic_task"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/periodic_task"
        app:layout_constraintBottom_toTopOf="@+id/btn_recurring_task"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/btn_single_task" />


    <Button
        android:id="@+id/btn_recurring_task"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/chain_task"
        app:layout_constraintBottom_toTopOf="@+id/btn_constraints_data"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/btn_periodic_task" />


    <Button
        android:id="@+id/btn_constraints_data"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/constraints"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/btn_recurring_task" />


</android.support.constraint.ConstraintLayout>



(i) Simple Work:

Lets begin with simple one ;) We can create a Worker, which will send a push-notification after starts. So, create an activity with one button to start the Worker. Once the button is clicked, we can enqueue the WorkRequest (sending pushnotification worker) to WorkManager.

We can also delay the start of the task with the help of setInitialDelay() method.

setInitialDelay(10, TimeUnit.MINUTES)

SingleTaskActivity.kt

import android.os.Bundle
import android.support.annotation.Nullable
import android.support.v7.app.AppCompatActivity
import androidx.work.OneTimeWorkRequest
import androidx.work.WorkManager
import com.yamikrish.app.workmanagerdemo.worker.SingleWorker
import com.yamikrish.app.workmanagerdemo.R
import kotlinx.android.synthetic.main.activity_start_task.*


class SingleTaskActivity : AppCompatActivity() {

    private lateinit var workManager: WorkManager

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        setContentView(R.layout.activity_start_task)

        supportActionBar?.apply {
            setHomeButtonEnabled(true)
            setDisplayHomeAsUpEnabled(true)
            title = getString(R.string.single_task)
        }

        workManager = WorkManager.getInstance()

        start_single_task.setOnClickListener {
            val requestBuilder = OneTimeWorkRequest.Builder(SingleWorker::class.java).build()
            workManager.enqueue(requestBuilder)
        }
    }

    override fun onSupportNavigateUp(): Boolean {
        finish()
        return super.onSupportNavigateUp()
    }

    override fun onBackPressed() {
        finish()
        super.onBackPressed()
    }
}

SingleWorker.kt

This Worker class is to create and send notifications in the app.

import android.R
import android.app.NotificationChannel
import android.app.NotificationManager
import android.content.Context
import android.support.v4.app.NotificationCompat
import androidx.work.ListenableWorker
import androidx.work.Worker
import androidx.work.WorkerParameters

class SingleWorker(context: Context, workerParams: WorkerParameters) : Worker(context, workerParams) {
    val mContext = context
    override fun doWork(): ListenableWorker.Result {
        sendNotification()
        return ListenableWorker.Result.SUCCESS
    }

    fun sendNotification() {
        val notificationManager = mContext.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
        val channelId = "WorkManager_00"
        //If on Oreo then notification required a notification channel.
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            val channel = NotificationChannel(channelId, "WorkManager", NotificationManager.IMPORTANCE_DEFAULT)
            notificationManager.createNotificationChannel(channel)
        }

        val notification = NotificationCompat.Builder(mContext, channelId)
                .setContentTitle("Single Worker")
                .setContentText("This notification is from Single Worker!!")
                .setSmallIcon(R.drawable.ic_lock_idle_alarm)

        notificationManager.notify(1, notification.build())
    }
}

activity_start_task.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto">

    <Button
        android:id="@+id/start_single_task"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/start"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"/>

</android.support.constraint.ConstraintLayout>


 


(ii) Periodic Tasks:

PeriodicTaskActivity.kt

Next, we will see about PeriodicWorker. PeriodicWorker can schedule a task to be performed, for every specified time. It can be of MINUTES, HOURS or DAY. Time should be minimum of 15 minutes.

Let's create a Worker to send notification every 15 mins.

import android.content.Context
import android.content.SharedPreferences
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import androidx.work.*
import com.yamikrish.app.workmanagerdemo.worker.periodicWorker.NotifyWorker
import kotlinx.android.synthetic.main.activity_periodic_notifier.*
import java.util.concurrent.TimeUnit
import com.yamikrish.app.workmanagerdemo.R
import com.yamikrish.app.workmanagerdemo.worker.periodicWorker.NotifyInitialWorker

class PeriodicTaskActivity : AppCompatActivity() {

    private lateinit var workManager: WorkManager
    private val workTag = "starterNotifiWork"

    private lateinit var prefs: SharedPreferences
    private lateinit var editor: SharedPreferences.Editor
    private val NOTIFICATION_STATUS = "notification_status"
    private lateinit var requestBuilder: OneTimeWorkRequest

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_periodic_notifier)

        supportActionBar?.apply {
            setHomeButtonEnabled(true)
            setDisplayHomeAsUpEnabled(true)
            title = getString(R.string.single_task)
        }

        prefs = getPreferences(Context.MODE_PRIVATE)
        editor = prefs.edit()

        workManager = WorkManager.getInstance()


        remindSwitch.isChecked = prefs.getBoolean(NOTIFICATION_STATUS, false)

        remindSwitch.setOnClickListener {
            if (remindSwitch.isChecked) {
                val requestBuilder = PeriodicWorkRequest.Builder(NotifyWorker::class.java, 15, TimeUnit.MINUTES)
                workManager.enqueueUniquePeriodicWork(workTag, ExistingPeriodicWorkPolicy.REPLACE, requestBuilder.build())
            } else {
                workManager.cancelUniqueWork(workTag)
            }
            editor.putBoolean(NOTIFICATION_STATUS, remindSwitch.isChecked)
            editor.apply()
        }     

    override fun onSupportNavigateUp(): Boolean {
        finish()
        return super.onSupportNavigateUp()
    }

    override fun onBackPressed() {
        finish()
        super.onBackPressed()
    }
}


NotifyWorker.kt


import android.util.Log
import androidx.work.Worker
import android.support.v4.app.NotificationCompat
import android.app.NotificationManager
import android.app.NotificationChannel
import android.content.Context
import android.content.Context.NOTIFICATION_SERVICE
import android.R;
import androidx.work.ListenableWorker
import androidx.work.WorkerParameters
import android.support.annotation.NonNull


class NotifyWorker(context: Context, workerParams: WorkerParameters) : Worker(context, workerParams) {

    val mContext = context

    override fun doWork(): ListenableWorker.Result {
        sendNotification()
        return ListenableWorker.Result.SUCCESS
    }

    fun sendNotification() {
        val notificationManager = mContext.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
        val channelId = "WorkManager_01"

        //If on Oreo then notification required a notification channel.
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            val channel = NotificationChannel(channelId, "WorkManager", NotificationManager.IMPORTANCE_DEFAULT)
            notificationManager.createNotificationChannel(channel)
        }

        val notification = NotificationCompat.Builder(mContext, channelId)
                .setContentTitle("Timer Reminder")
                .setContentText("It's been 15 minutes!!!")
                .setSmallIcon(R.drawable.ic_lock_idle_alarm)

        notificationManager.notify(2, notification.build())
    }
}

The above works fine at scheduling notification every 15 mins, even when the app is not in foreground or background state, also after device restart.

But one issue I encountered is, we can't set initial delay for PeriodicRequest, so that the task is sending notification while starting itself. It's not the correct way of doing it, know? (What to do??!!!) 

Let's use some magic.. Nah..! Logic!!.

First we can create a OneTimeRequest with intialDelay of 15 minutes, then in that worker's doWork(), we can schedule the periodic tasks to show notification. Problem solved!!

 PeriodicTaskActivity.kt

import android.content.Context
import android.content.SharedPreferences
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import androidx.work.*
import com.yamikrish.app.workmanagerdemo.worker.periodicWorker.NotifyWorker
import kotlinx.android.synthetic.main.activity_periodic_notifier.*
import java.util.concurrent.TimeUnit
import com.yamikrish.app.workmanagerdemo.R
import com.yamikrish.app.workmanagerdemo.worker.periodicWorker.NotifyInitialWorker

class PeriodicTaskActivity : AppCompatActivity() {

    private lateinit var workManager: WorkManager
    private val workTag = "starterNotifiWork"

    private lateinit var prefs: SharedPreferences
    private lateinit var editor: SharedPreferences.Editor
    private val NOTIFICATION_STATUS = "notification_status"
    private lateinit var requestBuilder: OneTimeWorkRequest

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_periodic_notifier)

        supportActionBar?.apply {
            setHomeButtonEnabled(true)
            setDisplayHomeAsUpEnabled(true)
            title = getString(R.string.single_task)
        }

        prefs = getPreferences(Context.MODE_PRIVATE)
        editor = prefs.edit()

        workManager = WorkManager.getInstance()


        remindSwitch.isChecked = prefs.getBoolean(NOTIFICATION_STATUS, false)

        remindSwitch.setOnClickListener {
            if (remindSwitch.isChecked) {
                requestBuilder = OneTimeWorkRequest.Builder(NotifyInitialWorker::class.java)
                        .setInitialDelay(1, TimeUnit.MINUTES)
                        .build()
                workManager.getStatusByIdLiveData(requestBuilder.id).observe(this@PeriodicTaskActivity, android.arch.lifecycle.Observer { workerStatus ->
                    if (workerStatus != null && workerStatus.state.isFinished) {
                        startNotifyWorker()
                    }

                })
                workManager.beginUniqueWork(workTag, ExistingWorkPolicy.REPLACE, requestBuilder).enqueue()
            } else {
                workManager.cancelAllWork()
            }
            editor.putBoolean(NOTIFICATION_STATUS, remindSwitch.isChecked)
            editor.apply()
        }

    }

    /** Schedule PeriodicWorkRequest
    private fun startNotifyWorker() {
        val requestBuilder = PeriodicWorkRequest.Builder(NotifyWorker::class.java, 15, TimeUnit.MINUTES)
        WorkManager.getInstance().enqueueUniquePeriodicWork(workTag, ExistingPeriodicWorkPolicy.REPLACE, requestBuilder.build())
    }

    override fun onSupportNavigateUp(): Boolean {
        finish()
        return super.onSupportNavigateUp()
    }

    override fun onBackPressed() {
        finish()
        super.onBackPressed()
    }
}


NotifyInitialWorker.kt


import android.content.Context
import androidx.work.*

class NotifyInitialWorker(context: Context, workerParams: WorkerParameters) : Worker(context, workerParams) {

    override fun doWork(): ListenableWorker.Result {
        return ListenableWorker.Result.SUCCESS
    }

}

activity_periodic_notifier.xml

 
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".activity.PeriodicTaskActivity">

    <TextView
        android:id="@+id/infoText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Remind me every 15 minutes"
        android:padding="10dp"
        android:textAppearance="@android:style/TextAppearance.Medium"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Switch
        android:id="@+id/remindSwitch"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text=""
        android:layout_margin="10dp"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

 

(iii) Chained Tasks

WorkManager can also schedule series of task to be executed in serial or parallel. Lets create three workers to send notifications.

To enqueue it serially, 

WorkManager.getInstance().beginWith(request1).then(request2).then(request3).enqueue()
To enqueue it parallelly, 

WorkManager.getInstance().beginWith(request1).then(request2, request3).enqueue()
Here, we can setInitialDelay to workers to exactly find out how it works.

ChainTaskActivity.kt

import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import androidx.work.OneTimeWorkRequest
import androidx.work.WorkManager
import com.yamikrish.app.workmanagerdemo.worker.chainWorker.FirstWorker
import com.yamikrish.app.workmanagerdemo.worker.chainWorker.SecondWorker
import com.yamikrish.app.workmanagerdemo.worker.chainWorker.ThirdWorker
import kotlinx.android.synthetic.main.activity_start_task.*
import com.yamikrish.app.workmanagerdemo.R
import java.util.concurrent.TimeUnit


class ChainTaskActivity : AppCompatActivity() {

    private lateinit var workManager: WorkManager

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        setContentView(R.layout.activity_start_task)

        supportActionBar?.apply {
            setHomeButtonEnabled(true)
            setDisplayHomeAsUpEnabled(true)
            title = getString(R.string.single_task)
        }

        workManager = WorkManager.getInstance()


        start_single_task.setOnClickListener {
            val request1 = OneTimeWorkRequest.Builder(FirstWorker::class.java).build()
            val request2 = OneTimeWorkRequest.Builder(SecondWorker::class.java).setInitialDelay(30, TimeUnit.SECONDS).build()
            val request3 = OneTimeWorkRequest.Builder(ThirdWorker::class.java).setInitialDelay(30, TimeUnit.SECONDS).build()
  
       workManager.beginWith(request1).then(request2).then(request3).enqueue() 

        }
    }

    override fun onSupportNavigateUp(): Boolean {
        finish()
        return super.onSupportNavigateUp()
    }

    override fun onBackPressed() {
        finish()
        super.onBackPressed()
    }
}

We can also make requests run parrallelly, by queuing like below:
workManager.beginWith(request1).then(request2, request3).enqueue()

 FirstWorker.kt

 
import android.R
import android.app.NotificationChannel
import android.app.NotificationManager
import android.content.Context
import android.support.v4.app.NotificationCompat
import androidx.work.ListenableWorker
import androidx.work.Worker
import androidx.work.WorkerParameters

class FirstWorker(context: Context, workerParams: WorkerParameters) : Worker(context, workerParams) {

    val mContext = context

    override fun doWork(): ListenableWorker.Result {
        sendNotification()
        return ListenableWorker.Result.SUCCESS
    }

    fun sendNotification() {
        val notificationManager = mContext.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
        val channelId = "WorkManager_02"

        //If on Oreo then notification required a notification channel.
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            val channel = NotificationChannel(channelId, "WorkManager", NotificationManager.IMPORTANCE_DEFAULT)
            notificationManager.createNotificationChannel(channel)
        }

        val notification = NotificationCompat.Builder(mContext, channelId)
                .setContentTitle("WorkManager")
                .setContentText("Message from First Worker!!")
                .setSmallIcon(R.drawable.ic_lock_idle_alarm)

        notificationManager.notify(3, notification.build())
    }

}

SecondWorker.kt

import android.R
import android.app.NotificationChannel
import android.app.NotificationManager
import android.content.Context
import android.support.v4.app.NotificationCompat
import androidx.work.ListenableWorker
import androidx.work.Worker
import androidx.work.WorkerParameters

class SecondWorker(context: Context, workerParams: WorkerParameters) : Worker(context, workerParams) {

    val mContext = context

    override fun doWork(): ListenableWorker.Result {
        sendNotification()
        return ListenableWorker.Result.SUCCESS
    }

    fun sendNotification() {
        val notificationManager = mContext.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
        val channelId = "WorkManager_03"

        //If on Oreo then notification required a notification channel.
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            val channel = NotificationChannel(channelId, "WorkManager", NotificationManager.IMPORTANCE_DEFAULT)
            notificationManager.createNotificationChannel(channel)
        }

        val notification = NotificationCompat.Builder(mContext, channelId)
                .setContentTitle("WorkManager")
                .setContentText("Message from Second Worker!!")
                .setSmallIcon(R.drawable.ic_lock_idle_alarm)

        notificationManager.notify(4, notification.build())
    }

}

ThirdWorker.kt

import android.R
import android.app.NotificationChannel
import android.app.NotificationManager
import android.content.Context
import android.support.v4.app.NotificationCompat
import androidx.work.ListenableWorker
import androidx.work.Worker
import androidx.work.WorkerParameters


class ThirdWorker(context: Context, workerParams: WorkerParameters) : Worker(context, workerParams) {

    val mContext = context

    override fun doWork(): ListenableWorker.Result {
        sendNotification()
        return ListenableWorker.Result.SUCCESS
    }

    fun sendNotification() {
        val notificationManager = mContext.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
        val channelId = "WorkManager_04"

        //If on Oreo then notification required a notification channel.
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            val channel = NotificationChannel(channelId, "WorkManager", NotificationManager.IMPORTANCE_DEFAULT)
            notificationManager.createNotificationChannel(channel)
        }

        val notification = NotificationCompat.Builder(mContext, channelId)
                .setContentTitle("WorkManager")
                .setContentText("Message from Third Worker!!")
                .setSmallIcon(R.drawable.ic_lock_idle_alarm)

        notificationManager.notify(5, notification.build())
    }

}

 

(iv) Constraints & Data

Now, let's see how to set constraints and how to send and receive data to/from Worker. We can easily set constraints to the Worker, by using, 

val constraints = Constraints.Builder().setRequiresCharging(true).build()

We can send data to Worker and also can receive data from Worker.
To send data: 

val data = Data.Builder()
                .putString(Constants.EXTRA_TITLE, "Title")
                .putString(Constants.EXTRA_MESSAGE, "Message sent!!")
                .build()



 val requestBuilder = OneTimeWorkRequest.Builder(MyWorker::class.java)
                    .setInputData(data)
                    .build()

To receive data: 

title = inputData.getString(Constants.EXTRA_TITLE)
message = inputData.getString(Constants.EXTRA_MESSAGE)

We can send OutputData from Worker to Activity/Fragment as well. We have to set OutputData before success return, ListenableWorker.Result.SUCCESS.

val output = Data.Builder()
                .putString(EXTRA_OUTPUT_MESSAGE, "Message from Worker!")
                .build()
outputData = output

ConstraintDataActivity.kt


In this class, let's send Data from Activity to Worker and send notification with that data. Once done, send OutputData back to the called Activity. To receive that output data, that Activity can listen by using LiveData.

import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import android.widget.Toast
import androidx.work.Constraints
import androidx.work.Data
import androidx.work.OneTimeWorkRequest
import androidx.work.WorkManager
import com.yamikrish.app.workmanagerdemo.utils.Constants
import com.yamikrish.app.workmanagerdemo.worker.constraintDataWorker.ConstraintWorker
import kotlinx.android.synthetic.main.activity_start_task.*
import com.yamikrish.app.workmanagerdemo.R


class ConstraintsDataActivity : AppCompatActivity() {


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_start_task)

        supportActionBar?.apply {
            setHomeButtonEnabled(true)
            setDisplayHomeAsUpEnabled(true)
            title = getString(R.string.single_task)
        }

        val constraints = Constraints.Builder().setRequiresCharging(true).build()

        val data = Data.Builder()
                .putString(Constants.EXTRA_TITLE, "Message!!")
                .putString(Constants.EXTRA_MESSAGE, "Message sent from Activity")
                .build()

        start_single_task.setOnClickListener {
            val requestBuilder = OneTimeWorkRequest.Builder(ConstraintWorker::class.java)
                    .setConstraints(constraints)
                    .setInputData(data)
                    .build()
            WorkManager.getInstance().enqueue(requestBuilder)

            WorkManager.getInstance().getStatusByIdLiveData(requestBuilder.id).observe(this@ConstraintsDataActivity, android.arch.lifecycle.Observer { workerStatus ->
                if (workerStatus != null && workerStatus.state.isFinished) {
                    Toast.makeText(this@ConstraintsDataActivity, workerStatus.outputData.getString(Constants.EXTRA_OUTPUT_MESSAGE), Toast.LENGTH_SHORT).show()
                }

            })
        }
    }

    override fun onSupportNavigateUp(): Boolean {
        finish()
        return super.onSupportNavigateUp()
    }

    override fun onBackPressed() {
        finish()
        super.onBackPressed()
    }

}

ConstraintWorker.kt 


import android.R
import android.app.NotificationChannel
import android.app.NotificationManager
import android.content.Context
import android.support.v4.app.NotificationCompat
import androidx.work.Data
import androidx.work.ListenableWorker
import androidx.work.Worker
import androidx.work.WorkerParameters
import com.yamikrish.app.workmanagerdemo.utils.Constants
import com.yamikrish.app.workmanagerdemo.utils.Constants.Companion.EXTRA_OUTPUT_MESSAGE

class ConstraintWorker(context: Context, workerParams: WorkerParameters) : Worker(context, workerParams) {

    val mContext = context
    var title: String? = ""
    var message: String? = ""

    override fun doWork(): ListenableWorker.Result {
        title = inputData.getString(Constants.EXTRA_TITLE)
        message = inputData.getString(Constants.EXTRA_MESSAGE)

        sendNotification()

        val output = Data.Builder()
                .putString(EXTRA_OUTPUT_MESSAGE, "Message from ConstraintWorker!")
                .build()

        outputData = output
        return ListenableWorker.Result.SUCCESS
    }

    fun sendNotification() {
        val notificationManager = mContext.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
        val channelId = "WorkManager_05"

        //If on Oreo then notification required a notification channel.
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            val channel = NotificationChannel(channelId, "WorkManager", NotificationManager.IMPORTANCE_DEFAULT)
            notificationManager.createNotificationChannel(channel)
        }

        val notification = NotificationCompat.Builder(mContext, channelId)
                .setContentTitle(title)
                .setContentText(message)
                .setSmallIcon(R.drawable.ic_lock_idle_alarm)

        notificationManager.notify(6, notification.build())
    }

}

DataWorker.kt 


import android.R
import android.app.NotificationChannel
import android.app.NotificationManager
import android.content.Context
import android.support.v4.app.NotificationCompat
import androidx.work.ListenableWorker
import androidx.work.Worker
import androidx.work.WorkerParameters

class DataWorker(context: Context, workerParams: WorkerParameters) : Worker(context, workerParams) {

    val mContext = context

    override fun doWork(): ListenableWorker.Result {
        sendNotification()
        return ListenableWorker.Result.SUCCESS
    }

    fun sendNotification() {
        val notificationManager = mContext.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
        val channelId = "WorkManager_06"

        //In Oreo, notification required a notification channel.
        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {
            val channel = NotificationChannel(channelId, "WorkManager", NotificationManager.IMPORTANCE_DEFAULT)
            notificationManager.createNotificationChannel(channel)
        }

        val notification = NotificationCompat.Builder(mContext, channelId)
                .setContentTitle("WorkManager")
                .setContentText("Message from Data Worker!!")
                .setSmallIcon(R.drawable.ic_lock_idle_alarm)

        notificationManager.notify(7, notification.build())
    }

}

Constants.kt 


class Constants {
    companion object {
        val EXTRA_TITLE = "TITLE_TEXT"
        val EXTRA_MESSAGE = "MESSAGE_TEXT"
        val EXTRA_OUTPUT_MESSAGE = "OUTPUT_TEXT"
    }
}

















 









That's it for WorkManager. Bubyeeee!!!
























































Comments











Post a Comment








































Popular posts from this blog









SOAP Client using ksoap2 in Android - Kotlin






-














Image







            Introduction:     SOAP stands for Simple Object Access Protocol. It is XML-based protocol that allows programs that run on different operating systems (like Windows, Linux, etc) to communicate using HTTP and XML.   Pros:    Security - SOAP provides its own security known as WS Security .  Platform Independent - SOAP web services can be written in any programming language and executed in any platform    Cons:     Slow - It uses XML format that must be parsed, to be read. It defines many standards to be followed while developing. So its slow and consumes more bandwidth and resource.  WSDL dependent - It uses WSDL mechanism and doesn't have any other mechanism to discover the service.    Things to know:    The following are the things we have to know before we proceed further:                         URL  - It is the URL of WSDL file.                         NAMESPACE  - It is ta...








Read more










Retrofit Integration in Android - Kotlin






-














Image







            Retrofit is a Networking library, which is faster to use and easier to develop.   Let’s see how to integrate Retrofit in Android with Kotlin.   If you'd like to integrate RxJava  as well, you can check here .   1. Configure:     Include the following in app-level build.gradle.     build.gradle     compile "com.squareup.retrofit2:retrofit:2.3.0"   compile "com.squareup.retrofit2:converter-gson:2.3.0"      Include internet permission in Manifest file.       AndroidManifest.xml      <uses-permission android:name="android.permission.INTERNET" />   2. Preparing Helper classes:   ApiInterface.kt     interface ApiInterface {       @POST("get_users_detail") // Your url       fun getUser(@Body requestBody: RequestBody): Call<UserResponse>   }   Model classes:                         Response from Retrofit will be stored in POJO classes dir...








Read more










Using Camera in Android - Kotlin






-














Image







         Nowadays, most of our Android app require access to Camera to capture picture or Video. We can do that in two ways.                                  (i) Using built-in Camera,                                  (ii) Using custom Camera.   Using Built-in Camera  In this post, Let's see how to use the built-in camera to capture images and save it.     Its a simple way to capture pics. We can use the mobile's built-in camera app using Intent.      val REQUEST_IMAGE_CAPTURE =  1    private fun takePictureIntent() {       val takePictureIntent =  Intent(MediaStore . ACTION_IMAGE_CAPTURE)       if  (takePictureIntent . resolveActivity(packageManager) !=  null) {            startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE)       }  }           After the picture has been captured, the result will received on on...








Read more










Room with LiveData, ViewModel - Android Architecture Components - Kotlin






-














Image







              Introduction:     We have already learnt about Room in last post,  Room-Kotlin . In this post, lets learn about how to use ViewModel and LiveData with Room to improve usablity. Using LiveData with Room, allows views to be notified about data changes automatically.   LiveData:    LiveData is nothing but observable data holder class. It allows us to observer changes in data across multiple components of app. It is also aware of and respects lifecycle of Activities/Fragments. It also ensures that LiveData only updates app component observers that are in an active lifecycle state.     The following image depicts the Lifecycle and States:     Here, CREATED, STARTED, RESUMED - Active States            INTIALIZED, DESTROYED - InActive States   So, LiveData will remove the updates automatically while in InActive States, i.e., INTIALIZED and DESTROYED.   ViewModel:    ViewModel is an entity that is free of Activity/Fragment's lifecycle. So it allows us...








Read more










Map, Location update and AutoComplete Places - Kotlin






-














Image







         Let's see how to show current location in Maps and also show the location which is chosen from AutoComplete in Maps with the updated Google play services. That is, for location listening we gonna use   FusedLocationProviderClient and for autocomplete places, we gonna use, GeoDataClient with AutoCompletePrediction, i.e., no need to call places url from our end, Google Playservices will do that work for you. Okiee, Let's start now.   You can find the project in Github .   PreRequisite:  Navigate to  https://developers.google.com/maps/documentation/android-api/signup  and do as per the instructions to start.   Manifest:   Include your API key, which you got from previous step in AndroidManifest.xml              <meta-data             android:name= "com.google.android.geo.API_KEY"              android:value= "AIzXXXXXXXXXX_XXXXXXXXXXXXXX"  />     Gradle:  Include the following in app-level build 's dependencies.         implementation 'com...








Read more










RecyclerView  with different number of columns using SpanSizeLookup






-














Image







         We already know how to design RecyclerView. But how to create RecyclerView with different columns depending on its row? Like below image?       Yeah, we can do that, by using two different layouts with different viewType on Adapter. Another way is do some logic to do so. But, it's cumbersome. Luckily, we have another simple way to do that using SpanSizeLookUp . Let's see how to implement that in this post.   Implementation:   build.gradle   Include the following in app-level gradle file.       implementation  'com.android.support:recyclerview-v7:27.0.2'    implementation  'com.android.support.constraint:constraint-layout:1.1.0-beta5'     recycler.xml    <?xml version= "1.0"  encoding= "utf-8" ?> <android.support.constraint.ConstraintLayout xmlns:android= "http://schemas.android.com/apk/res/android"      android:layout_width= "match_parent"      android:layout_height= "match_parent"      xmlns:ap...








Read more










Bottom Navigation using design Library in Android - Kotlin






-














Image







           Introduction:   Let's implement BottomNavigationView in our layout using Design Support Library. First, we have to go through the factors like, when  and how to use that.   When to use?   As per Material Design specs, the following criteria is there:     (a) Tabs  (TabLayout) - Should be used when there are two navigations.     (b) Bottom Navigation  - Should be used when there are 3 to 5 navigations.     (c) Navigation Drawer  - Should be used when there are 6 or more navigations.   Also to remember that, Viewpager shouldn't be used with BottomNavigationView. You can read the complete design specs, here .   How to use?   BottomNavigationView have to be added  at the bottom of the screen. Also, the following are some of the important attributes:     app:itemBackground  - to apply background color    app:itemTextColor  - to apply the color for the text of BottomNavigation item.   app:itemIconTint  - to apply the color for the icon of BottomNavigation item.   app...








Read more










Exploring Android Navigation Architecture Component - MVVM - Kotlin






-














Image







            Navigation Architecture Component is released as a part of JetPack and androidx package. Its aim is to simplify the implementation of Navigation in our Android App. It defines a set of principles to build an in-app navigation with consistent and predictable user experience. Its main concept is to use single-activity architecture. It also has support for both Activity and Fragment.   Principle of Navigation:   The following are the principles of Navigation.    App should have fixed starting destination  A stack is used to represent the navigation state of app  The 'Up' button never exits the app  Up and Back are equivalent within your app's task  Deep linking to a destination or navigating to the same destination should yield the same stack    You can find the detailed explanation, here .   Components of Navigation:     (i) Navigation Graph - It's nothing but a map/blueprint of our in-app navigation. It has a list of all fragments and activities. We can also ...








Read more










Exploring Android Slices - JetPack






-














Image







  Introduction:   Slices are a new way of embedding our app's content in other surfaces, like Google Search and later in other places like Google Assistant. Slices are UI templates, which gives look and feel at home in whatever surface, they get hosts in. Also they are rich, interactive and dynamically updatable.    Before jumping into that, first migrate your project to AndroidX, (Android Studio 3.2 & above), by navigating as,                                           Refactor --> Migrate  to AndroidX         Setup:   build.gradle        implementation 'androidx.slice:slice-core:1.0.0'     implementation 'androidx.slice:slice-builders-ktx:1.0.0-alpha6'     implementation 'androidx.slice:slice-builders:1.0.0'      Creating Slice Provider:   Slice Provider is a component that let us display the slices we are creating, on outside our application. We can create the Slice Pro...








Read more










FCM Integration in Android - Kotlin






-














Image







                                                                Firebase Cloud Messaging inherits GCM’s core infrastructure but simplifies the client development. It works for all platforms (Android, IOS and Web). Let's see how to integrate FCM in Android with Kotlin.    FCM Messages:             Two types of FCM messages are there.          Notification messages,  which are handled by the FCM SDK automatically.        Data messages, which are handled by the client app. It can have custom fields, which have to be sent by our server.        1. Configure FCM in Firebase Console     (a) Go to https://console.firebase.google.com/             (b) Then click Add Project , a...








Read more