Migrating Push notification from firebase_messaging 6 to firebase_messaging 10+

Question

I am coming from an old Firebase_messaging plugin 6 + to the newer Firebase_messenger plugin 10 +, I am able to do most of the thing but can't get the message data, I want to convert this code from the older plugin to a newer one and use methods like configure launch and onResume.I can receive the push notifications, foreground and background information about the message but can't read it.

class _ChatScreenState extends State<ChatScreen> {
  @override
  void initState() {
    super.initState();
    final fbm = FirebaseMessaging();
    fbm.requestNotificationPermissions();
    fbm.configure(onMessage: (msg) {
      print(msg);
      return;
    }, onLaunch: (msg) {
      print(msg);
      return;
    }, onResume: (msg) {
      print(msg);
      return;
    });
   
  }

What I have done so far Under AndroidManifest.xml added

<meta-data android:name="com.google.firebase.messaging.default_notification_channel_id" 
      android:value="high_importance_channel" />

On main.dart

Future<void> _firebaseMessagingBackgroundHandler(RemoteMessage message) async {
  await Firebase.initializeApp();
  print('Handling a background message ${message.messageId}');
}

Future <void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  FirebaseMessaging.onBackgroundMessage(_firebaseMessagingBackgroundHandler);
   runApp(MyApp());
}

Here is where I want to get the data from the server

class _ChatScreenState extends State<ChatScreen> {
  @override
  void initState() {
    FirebaseMessaging.instance
        .getInitialMessage()
        .then((RemoteMessage message) {
      if (message != null) {
        print(message);
      }

      FirebaseMessaging.onMessage.listen((RemoteMessage message) {
        print('Got a message whilst in the foreground!');
        print('Message data: ${message.data}');

        if (message.notification != null) {
          print(
              'Message also contained a notification: ${message.notification}');
        }
      });
    });

    super.initState();
  }

On Debug while the App is in the foreground

D/FLTFireMsgReceiver(15437): broadcast received for message
I/flutter (15437): Got a message whilst in the foreground!
I/flutter (15437): Message data: {}
I/flutter (15437): Message also contained a notification: Instance of 'RemoteNotification'

On Background

D/FLTFireMsgReceiver(15437): broadcast received for message
W/FirebaseMessaging(15437): Missing Default Notification Channel metadata in AndroidManifest. Default value will be used.
I/flutter (15437): Handling a background message 0:1624718321445677%ba7e1d8bba7e1d8b

Although the Notification Text and body is fine in the notification window but can't get the same info in the debug screen, it returns empty. Also is my implementation correct?

Solution

With a little bit of searching I believe the missing piece was flutter_local_notifications: ^5.0.0+4 The changes I have made in main.dart

Future<void> _firebaseMessagingBackgroundHandler(RemoteMessage message) async {
  // If you're going to use other Firebase services in the background, such as Firestore,
  // make sure you call `initializeApp` before using other Firebase services.
  await Firebase.initializeApp();
  print('Handling a background message ${message.messageId}');
}

const AndroidNotificationChannel channel = const AndroidNotificationChannel(
  //for notificaiton initialization
  'high_importance_channel', // id
  'High Importance Notifications', // title
  'This channel is used for important notifications.', // description
  importance: Importance.high,
  playSound: true,
);

//initialize plugin
final FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin =
    FlutterLocalNotificationsPlugin();

Future<void> main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
//for background messaging  
FirebaseMessaging.onBackgroundMessage(_firebaseMessagingBackgroundHandler);
  //Local Notification implementation
  await flutterLocalNotificationsPlugin
      .resolvePlatformSpecificImplementation<
          AndroidFlutterLocalNotificationsPlugin>()
      ?.createNotificationChannel(channel);
  //for firebase  plugin and messaging required

  await FirebaseMessaging.instance.setForegroundNotificationPresentationOptions(
      alert: true, badge: true, sound: true);

  runApp(MyApp());
}

In the class where I want the notification

class _ChatScreenState extends State<ChatScreen> {
  @override
  void initState() {
    //foreground messaging

    FirebaseMessaging.onMessage.listen((RemoteMessage message) {
      RemoteNotification notification = message
          .notification; //assign two variables for remotenotification and android notification
      AndroidNotification android = message.notification?.android;
      if (notification != null && android != null) {
        print(message);
        flutterLocalNotificationsPlugin.show(
          notification.hashCode,
          notification.title,
          notification.body,
          NotificationDetails(
            android: AndroidNotificationDetails(
                channel.id, channel.name, channel.description,
                color: Colors.blue,
                playSound: true,
                icon: '@mipmap/ic_launcher'),
          ),
        );
        print(notification.title);
        print(notification.body);
      }
    });
    //Do when the user taps the notification
    FirebaseMessaging.onMessageOpenedApp.listen((RemoteMessage message) {
      //same as above
    });
    super.initState();
  }

Would be nice if some one update this process for IOS as I don't have a developer Id to test it.