Firebase onMessageReceived not called when app in background

Question

I'm working with Firebase and testing sending notifications to my app from my server while the app is in the background. The notification is sent successfully, it even appears on the notification centre of the device, but when the notification appears or even if I click on it, the onMessageReceived method inside my FCMessagingService is never called.

When I tested this while my app was in the foreground, the onMessageReceived method was called and everything worked fine. The problem occurs when the app is running in the background.

Is this intended behaviour, or is there a way I can fix this?

Here is my FBMessagingService:

import android.util.Log;

import com.google.firebase.messaging.FirebaseMessagingService;
import com.google.firebase.messaging.RemoteMessage;

public class FBMessagingService extends FirebaseMessagingService {

    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        Log.i("PVL", "MESSAGE RECEIVED!!");
        if (remoteMessage.getNotification().getBody() != null) {
            Log.i("PVL", "RECEIVED MESSAGE: " + remoteMessage.getNotification().getBody());
        } else {
            Log.i("PVL", "RECEIVED MESSAGE: " + remoteMessage.getData().get("message"));
        }
    }
}

Answer 1

This is working as intended, notification messages are delivered to your onMessageReceived callback only when your app is in the foreground. If your app is in the background or closed then a notification message is shown in the notification center, and any data from that message is passed to the intent that is launched as a result of the user tapping on the notification.

You can specify a click_action to indicate the intent that should be launched when the notification is tapped by the user. The main activity is used if no click_action is specified.

When the intent is launched you can use the

getIntent().getExtras();

to retrieve a Set that would include any data sent along with the notification message.

For more on notification message see docs.