Level 14

Deferrable Background Work (WorkManager)

WorkManager for Guaranteed Work

For work that must run even if the app closes (syncing, uploads), use `WorkManager`. It survives process death and reboots, respects constraints (network, charging), and retries with backoff.

📚 Explanation

`WorkManager` is the standard API for deferrable, guaranteed background work. Extending `CoroutineWorker` lets `doWork()` be a `suspend` function. `Constraints` gate execution (e.g. only on Wi-Fi/charging); `Result.retry()` plus a backoff policy handles transient failures. `enqueueUniquePeriodicWork` with `KEEP` prevents scheduling duplicate jobs across app launches.

Note: Code execution is not available for Android/Kotlin in the browser. Use Android Studio to run and test the app.

kotlin

import android.content.Context
import androidx.work.*
import java.util.concurrent.TimeUnit

// 1. Define the unit of work
class SyncWorker(
    context: Context,
    params: WorkerParameters
) : CoroutineWorker(context, params) {

    override suspend fun doWork(): Result {
        return try {
            // suspend work runs on a background dispatcher
            uploadPendingData()
            Result.success()
        } catch (e: Exception) {
            // Ask WorkManager to retry later with backoff
            Result.retry()
        }
    }
}

// 2. Schedule it with constraints
fun scheduleSync(context: Context) {
    val constraints = Constraints.Builder()
        .setRequiredNetworkType(NetworkType.CONNECTED)
        .build()

    val request = PeriodicWorkRequestBuilder<SyncWorker>(6, TimeUnit.HOURS)
        .setConstraints(constraints)
        .setBackoffCriteria(BackoffPolicy.EXPONENTIAL, 30, TimeUnit.SECONDS)
        .build()

    WorkManager.getInstance(context).enqueueUniquePeriodicWork(
        "data-sync",
        ExistingPeriodicWorkPolicy.KEEP, // don't duplicate an existing job
        request
    )
}

Back to Android Levels Back to Developer Hub

Deferrable Background Work (WorkManager)

WorkManager for Guaranteed Work

For work that must run even if the app closes (syncing, uploads), use `WorkManager`. It survives process death and reboots, respects constraints (network, charging), and retries with backoff.

📚 Explanation

Note: Code execution is not available for Android/Kotlin in the browser. Use Android Studio to run and test the app.

import android.content.Context

import androidx.work.*

import java.util.concurrent.TimeUnit

// 1. Define the unit of work

class SyncWorker(

context: Context,

params: WorkerParameters

) : CoroutineWorker(context, params) {

override suspend fun doWork(): Result {

return try {

// suspend work runs on a background dispatcher

uploadPendingData()

Result.success()

} catch (e: Exception) {

// Ask WorkManager to retry later with backoff

Result.retry()

}

// 2. Schedule it with constraints

fun scheduleSync(context: Context) {

val constraints = Constraints.Builder()

.setRequiredNetworkType(NetworkType.CONNECTED)

.build()

val request = PeriodicWorkRequestBuilder<SyncWorker>(6, TimeUnit.HOURS)

.setConstraints(constraints)

.setBackoffCriteria(BackoffPolicy.EXPONENTIAL, 30, TimeUnit.SECONDS)

.build()

WorkManager.getInstance(context).enqueueUniquePeriodicWork(

"data-sync",

ExistingPeriodicWorkPolicy.KEEP, // don't duplicate an existing job

request

)

}