Interface BackgroundFetchConfig

const status = await BackgroundFetch.configure({
  minimumFetchInterval: 15,
  stopOnTerminate: false,  // <-- required
  enableHeadless: true     // <-- required
}, async (taskId) => {
  console.log('[BackgroundFetch] EVENT', taskId);
  BackgroundFetch.finish(taskId);
}, async (taskId) => {
  console.log('[BackgroundFetch] TIMEOUT', taskId);
  BackgroundFetch.finish(taskId);
})

Android Headless Setup

• With your app open in Android Studio, browse the app folder to find the MainActivity class. Right-click the containing folder and click New > Java Class.

• You MUST name the file BackgroundFetchHeadlessTask.

• Add the following Java code to BackgroundFetchHeadlessTask, taking care to preserve the top line:

package com.your.package.name:

package com.your.package.name  // <-- DO NOT REPLACE THIS LINE!!!!!!!!!!!!

/// ---------------- Paste everything BELOW THIS LINE: -----------------------
import android.content.Context;
import android.util.Log;

import com.transistorsoft.tsbackgroundfetch.BackgroundFetch;
import com.transistorsoft.tsbackgroundfetch.BGTask;

public class BackgroundFetchHeadlessTask{
    public void onFetch(Context context,  BGTask task) {
        // Get a reference to the BackgroundFetch Android API.
        BackgroundFetch backgroundFetch = BackgroundFetch.getInstance(context);
        // Get the taskId.
        String taskId = task.getTaskId();
        // Log a message to adb logcat.
        Log.d("MyHeadlessTask", "BackgroundFetchHeadlessTask onFetch -- CUSTOM IMPLEMENTATION: " + taskId);

        boolean isTimeout = task.getTimedOut();
        // Is this a timeout?
        if (isTimeout) {
          backgroundFetch.finish(taskId);
          return;
        }
        // Do your work here...
        //
        //
        // Signal finish just like the Javascript API.
        backgroundFetch.finish(taskId);
    }
}

Testing Your Headless-task:

After terminating your app with Javascript configuration above, simulate a fetch-event while observing $ adb logcat

In the following command, replace com.your.app.package.name with your app's actual package-name:

adb shell cmd jobscheduler run -f com.your.app.package.name 999

 

$ adb logcat

TSBackgroundFetch: - Background Fetch event received: capacitor-background-fetch
MyHeadlessTask: BackgroundFetchHeadlessTask onFetch -- CUSTOM IMPLEMENTATION: capacitor-background-fetch
TSBackgroundFetch: - finish: capacitor-background-fetch
TSBackgroundFetch: - jobFinished

By default, the BackgroundFetch Android SDK will use JobScheduler to schedule tasks, which are subject to throttling. For more accurate scheduling of tasks (at the expense of higher battery-usage), you can tell BackgroundFetch to use Android's AlarmManager.

Note: All "criteria" options will no longer apply, since these are available only with JobScheduler.

• requiredNetworkType
• requiresBatteryNotLow
• requiresStorageNotLow
• requiresCharging
• requiresDeviceIdle

If your job doesn't need a network connection, you don't need to use this option, as the default is BackgroundFetch.NETWORK_TYPE_NONE.

Calling this method defines network as a strict requirement for your job. If the network requested is not available your job will never run.

This defaults to false. If true, the job will only run when the battery level is not low, which is generally the point where the user is given a "low battery" warning.

The default state is false: that is, the for the job to be runnable even when someone is interacting with the device.

This state is a loose definition provided by the system. In general, it means that the device is not currently being used interactively, and has not been in use for some time. As such, it is a good time to perform resource heavy jobs. Bear in mind that battery usage will still be attributed to your application, and surfaced to the user in battery stats.

This defaults to false. If true, the job will only run when the device is not in a low storage state, which is generally the point where the user is given a "low storage" warning.