A Flutter plugin for accessing the Android AlarmManager service, and running Dart code in the background when alarms fire.

• Flutter >=3.3.0
• Dart >=2.18.0 <4.0.0
• Android compileSDK 34
• Java 17
• Android Gradle Plugin >=8.3.0
• Gradle wrapper >=8.4

After importing this plugin to your project as usual, add the following to your AndroidManifest.xml within the <manifest></manifest> tags:

<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
<uses-permission android:name="android.permission.WAKE_LOCK"/>
<!-- For apps with targetSDK 31 (Android 12) and newer -->
<uses-permission android:name="android.permission.SCHEDULE_EXACT_ALARM"/>

Next, within the <application></application> tags, add:

<service
    android:name="dev.fluttercommunity.plus.androidalarmmanager.AlarmService"
    android:permission="android.permission.BIND_JOB_SERVICE"
    android:exported="false"/>
<receiver
    android:name="dev.fluttercommunity.plus.androidalarmmanager.AlarmBroadcastReceiver"
    android:exported="false"/>
<receiver
    android:name="dev.fluttercommunity.plus.androidalarmmanager.RebootBroadcastReceiver"
    android:enabled="false"
    android:exported="false">
    <intent-filter>
        <action android:name="android.intent.action.BOOT_COMPLETED" />
    </intent-filter>
</receiver>

Then in Dart code add:

import 'package:android_alarm_manager_plus/android_alarm_manager_plus.dart';

// Be sure to annotate your callback function to avoid issues in release mode on Flutter >= 3.3.0
@pragma('vm:entry-point')
static void printHello() {
  final DateTime now = DateTime.now();
  final int isolateId = Isolate.current.hashCode;
  print("[$now] Hello, world! isolate=${isolateId} function='$printHello'");
}

main() async {
  // Be sure to add this line if initialize() call happens before runApp()
  WidgetsFlutterBinding.ensureInitialized();

  await AndroidAlarmManager.initialize();
  runApp(...);
  final int helloAlarmID = 0;
  await AndroidAlarmManager.periodic(const Duration(minutes: 1), helloAlarmID, printHello);
}

printHello will then run (roughly) every minute, even if the main app ends. However, printHello will not run in the same isolate as the main application. Unlike threads, isolates do not share memory and communication between isolates must be done via message passing (see more documentation on isolates here).

If alarm callbacks will need access to other Flutter plugins, including the alarm manager plugin itself, it may be necessary to inform the background service how to initialize plugins depending on which Flutter Android embedding the application is using.

If your app is an alarm clock app and sets alarms using the alarmClock argument in oneShot or oneShotAt, you can receive intents when user interacts with system UI that shows the next alarm. An example is the alarm tile in Android quick-setting tiles. This functionality is to allow you to show users the relevant alarm, or allow them to edit it when they tap on such UIs.

This intent has the action android.intent.action.MAIN and includes the following extras:

• id: The alarm id that you passed when scheduling the alarm.
• params: The params argument that you passed when scheduling the alarm, if any.

Setting the alarm:

await AndroidAlarmManager.oneShotAt(
    time,
    id,
    callback,
    alarmClock: true,
    params: {
        'param1': 'Hello',
        'param2': 'World'
    }
    ...
)

To receive this intent in dart, you can use the receive_intent package:

import 'package:receive_intent/receive_intent.dart';
import 'dart:convert'; // for jsonDecode

final receivedIntent = await ReceiveIntent.getInitialIntent();
if (receivedIntent.action == "android.intent.action.MAIN"){
    final paramsExtra = receivedIntent.extra?["params"];
    if (paramsExtra != null){
      // The received params is a string, so we need to convert it into a json map
      final params = jsonDecode(params);
      // use params
      // params['param1']
      // params['param2']
    }
    final id = receivedIntent.extra?["id"];
    // navigate user to alarm with given id
}

For more information, check out the receive_intent getting started.

From the Android AlarmManager documentation:

Registered alarms are retained while the device is asleep (and can optionally wake the device up if they go off during that time), but will be cleared if it is turned off and rebooted.

https://developer.android.com/reference/android/app/AlarmManager

The Android OS will not fire alarms for apps that have been force stopped.

StackOverflow response: https://stackoverflow.com/questions/11241794/alarm-set-in-app-with-alarmmanager-got-removed-when-app-force-stop

Likely the device is running some battery optimization software that is preventing the alarm from firing. Check out https://dontkillmyapp.com/ to find out about more about optimizations done by different vendors.

Run normally with flutter test from the root of the project.

The Espresso test runs the same sample code provided in example/lib/main.dart but is run using the Flutter Espresso plugin.

Modifying the main.dart will cause this test to fail.

This test will call into the example/lib/main_espresso.dart file which will enable Flutter Driver and then calls into the main.dart.

See https://pub.dev/packages/espresso for more info on why.

To run the test, run from the example/android folder:

./gradlew app:connectedAndroidTest -Ptarget=`pwd`/../lib/main_espresso.dart

To run the Flutter Driver tests, cd into example and run:

flutter driver test_driver/android_alarm_manager_plus_e2e.dart

• API Documentation