[firebase_messaging]: Double Notifications in Firebase onMessage Listener

[nawafAlkhadidi]

Is there an existing issue for this?

• I have searched the existing issues.

Which plugins are affected?

Messaging

Which platforms are affected?

iOS

Description

I’m experiencing an issue where double notifications are being triggered in my Flutter app when using Firebase Cloud Messaging (FCM). This happens when handling the FirebaseMessaging.onMessage listener. Specifically, the issue occurs in the following scenario:

1 - Foreground: When the app is open, I’m manually displaying the notification using onMessage. However, the notification is being shown twice.

2 - Background: When the app is in the background, only one notification is shown, as expected.

my code :

final Set<String> hiddenChats = {};
class NotificationFCMUtils {
  Future init() async {
    try {
      await FirebaseMessaging.instance.requestPermission();
      await FirebaseMessaging.instance.subscribeToTopic("xx");
      await FirebaseMessaging.instance.subscribeToTopic("xx");
    } catch (e) {
      //   print(e);
    }
    FirebaseMessaging.onMessage.listen((RemoteMessage message) {
      final String? type = message.data['type'] ?? "";
      final String? id = message.data['id'] ?? "0";
      final RemoteNotification? notification = message.notification;
      if (notification != null) {
        locator.get<LocalNotificationsManager>().showNotification(
              title: message.notification?.title,
              body: message.notification?.body,
              payLoad: type ?? "no",
              id: int.parse(id!),
            );
      }
    });
  }
  Future onMessageOpenedApp() async {
    try {
      RemoteMessage? initialMessage = await FirebaseMessaging.instance.getInitialMessage();
      if (initialMessage != null) {
        final String? type = initialMessage.data['type'] ?? "";
        final String? id = initialMessage.data['id'] ?? "0";
        move(id: id, type: type);
      }
      FirebaseMessaging.onMessageOpenedApp.listen((RemoteMessage message) async {
        final String? type = message.data['type'] ?? "";
        final String? id = message.data['id'] ?? "0";
        move(id: id, type: type);
      });
    } catch (e) {
      throw Exception(e.toString());
    }
  }}

Reproducing the issue

1.	Implement FirebaseMessaging.onMessage.listen((RemoteMessage message) {...}).
2.	Send a notification while the app is in the foreground.
3.	Observe that the notification is displayed twice.

Firebase Core version

3.6.0

Flutter Version

3.24.1

Relevant Log Output

No response

Flutter dependencies

Expand Flutter dependencies snippet

Replace this line with the contents of your `flutter pub deps -- --style=compact`.

Additional context and comments

firebase_core: ^3.6.0
firebase_messaging: ^15.1.3

[moo-kesh]

I am experiencing the same issue on iOS 18.1 devices (not sure about 18.0), but it works fine on devices using iOS versions below 18.

[SelaseKay]

Duplicate of: 13366