Problems with FCM Data Message in Background

[thselukas]

Hello, I am writing an app that notifies volunteer firefighers when an operation is ongoing. It allows them to press a button, if they will be available or not. I have had no issues until now, but this is quite severe. When I send a Data Message with High priority, when the app is just minimized. there is no problem and the notification shows without problem. When swiping it away in the app drawer however, the notification shown with flutter_local_notifications is just not showing. I have tried disabling battery optimisation (on samsung a12), but no success. I hope you can help me in any way.

Relevant part of the main.dart file:

@pragma('vm:entry-point')
Future<void> _handleFirebaseMessage(RemoteMessage remoteMessage) async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();

  const androidInitalisationSettings =
      AndroidInitializationSettings('@mipmap/ic_launcher');
  const iosInitialisationSettings = DarwinInitializationSettings();

  const initSettings = InitializationSettings(
      android: androidInitalisationSettings, iOS: iosInitialisationSettings);

  var _flutterLocalNotificationPlugin = FlutterLocalNotificationsPlugin();
  await _flutterLocalNotificationPlugin.initialize(initSettings);

  const androidNotificationDetail = AndroidNotificationDetails(
    '1',
    'general',
    sound: RawResourceAndroidNotificationSound("ton8"),
    priority: Priority.high,
    importance: Importance.max,
    visibility: NotificationVisibility.public,
    audioAttributesUsage: AudioAttributesUsage.alarm,
  );
  const iosNotificationDetail =
      DarwinNotificationDetails(interruptionLevel: InterruptionLevel.critical);

  const notificationDetails = NotificationDetails(
      android: androidNotificationDetail, iOS: iosNotificationDetail);

  _flutterLocalNotificationPlugin.show(
      (1), "Background", "Notification", notificationDetails);
}

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  if (Platform.isAndroid) {
    OptimizeBattery.isIgnoringBatteryOptimizations().then((e) async {
      if (!e) {
        await OptimizeBattery.stopOptimizingBatteryUsage();
        ToastSerivce.showSuccessToast(
            "Akku Optimierung für diese App ausgeschaltet!");
      }
    });
  }

  await Firebase.initializeApp(options: DefaultFirebaseOptions.currentPlatform);

  await FirebaseMessaging.instance.setAutoInitEnabled(true);

  FirebaseMessaging.instance.onTokenRefresh.listen((newFcmToken) {
    // TODO: Send new token to backend for refresh
    print(newFcmToken.toString());
  });

  RemoteMessage? initalMessage =
      await FirebaseMessaging.instance.getInitialMessage();

  if (initalMessage != null) {
    _handleSwitchingToOperationsView(initalMessage);
  }

  FirebaseMessaging.onMessageOpenedApp.listen((message) {
    if (!message.data.isEmpty && message.data["notification_type"] != null) {
      if (message.data["notification_type"] == "operation") {
        _handleSwitchingToOperationsView(message);
      }
    }
  });

  FirebaseMessaging firebaseMessaging = FirebaseMessaging.instance;
  NotificationSettings ns = await firebaseMessaging.requestPermission(
    alert: true,
    announcement: false,
    badge: true,
    carPlay: false,
    criticalAlert: true,
    provisional: false,
    sound: true,
  );

  FirebaseMessaging.onBackgroundMessage(_handleFirebaseMessage);

  FirebaseMessaging.onMessage.listen((message) {
    if (!message.data.isEmpty && message.data["notification_type"] != null) {
      if (message.data["notification_type"] == "operation") {
        _handleSwitchingToOperationsView(message);
      }
    }
  });

.... (rest of main file)

[thselukas]

I forgot to mention, that i also tried extracting the setup and notification part of flutter_local_notifications as I thought this was the problem. (you can probably see that)

[thselukas]

I am a dumbass, I forgot to disable battery optimisation and add the POST_NOTIFICATIONS permission to my manifest. I am sorry if i wasted anyones time.