Im trying to implement the whatsapp like functionality of message being delivered when the receiver's app is in background state and the wifi is on.

I want to call the function to update the message document status from 'sent' to 'delivered'. But cant find where to call it from. I tried calling it inside FirebaseMessaging.onMessage.listen but it is still not working on background.

static setDeliveredStatus(
          {required String senderId,
          required String receiverId,
          required String receiverName}) async {
        print('setting = ${receiverName   receiverId}');
        print('${currentUser!.displayName!}   ${senderId}');
        QuerySnapshot query = await _firestore
            .collection(CollectionKeys.messages)
            .doc(receiverName   receiverId)
            .collection(currentUser!.displayName!   senderId)
            .where('status', isEqualTo: describeEnum(MessageStatus.sent))
            .get();
        query.docs.forEach((doc) async {
          await doc.reference
              .update({'status': describeEnum(MessageStatus.delivered)});
        });
      }

This above function is currently being called inside initState of my home.dart screen in a onMessage Listener:

FirebaseMessaging.onMessage.listen((message) {
      if (message.notification != null) {
        LocalNotificationService.createAndDisplayNotificationChannel(message);
        FirebaseServices.setDeliveredStatus(
            senderId: message.data['senderId'],
            receiverId: message.data['receiverId'],
            receiverName: message.data['receiverName']);
      }
    });

CodePudding user response：

The FCM SDK has an onBackgroundMessage function where you can configure a callback function when receiving messages while the app is in the background.

FirebaseMessaging.onBackgroundMessage(_onBackgroundHandler);

See this document for reference. In the call back method you could put the logic to update the document.