Firebase(FCM) notifications not coming when android app removed from recent tray

Question

I'm sending Firebase notifications through my own webservice with PHP like below.

$url = 'https://fcm.googleapis.com/fcm/send';
        $fields = array(
             'registration_ids' => $tokens,
             'data' => $message
            );
        $headers = array(
            'Authorization:key = SERVER_KEY ',
            'Content-Type: application/json'
            );

1.Notifications are coming when App is in Foreground and Background without any issues , But if I removed app from recent tray then notifications not coming , I must have to handle this any solution for this ? (like Whatsup notifications are showing all scenarios even I force stopped this app from settings)

2.Once I received notification , from "onMessageReceived" how to pass these message,body content to my Activity /Fragments?

3.In some cases I want to send notification to all , Instead of adding all tokens to array . any other way to handle like "send to ALL" something like that ?

public class MyFirebaseMessagingService extends FirebaseMessagingService {
    private static final String TAG = "MsgService";
    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        Log.d(TAG, "From: " + remoteMessage.getFrom());
        Log.d(TAG, "Data Payload : " + remoteMessage.getData());
        sendNotification(remoteMessage.getData().get("message"));
    }
    private void sendNotification(String messageBody) {
        Intent intent = new Intent(this, MainActivity.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent,
                PendingIntent.FLAG_ONE_SHOT);
        Uri defaultSoundUri= RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this)
                .setSmallIcon(R.mipmap.ic_launcher)
                .setContentTitle("Firebase Push Notification")
                .setContentText(messageBody)
                .setAutoCancel(true)
                .setSound(defaultSoundUri)
                .setContentIntent(pendingIntent);
        NotificationManager notificationManager =
                (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        notificationManager.notify(0, notificationBuilder.build());
    }
} 

Failed devices: (Notifications are not coming after removed from Recent Tray)

• MI Redmi Note 2 (5.0.2 Lollipop)
• Huawei honor 5c (5.1.1 Lollipop)

Succeed devices: (Notifications are coming after removed from Recent Tray)

• HTC One X (4.2 Jelly Bean)
• Samsung galaxy grand prime (4.4 Kitkat)

Answer 1

1.Notifications are coming when App is in Foreground and Background without any issues , But if I removed app from recent tray then notifications not coming , I must have to handle this any solution for this ? (like Whatsup notifications are showing all scenarios even I force stopped this app from settings)

As per your code you must be getting a null pointer exception on remoteMessage.getNotification().getBody() as you are not sending notification, instead you are sending data payload from your curl request. As per my personal experience, the issue you just mentioned is seen especially in Android Kitkat or below devices. On Lollipop or above Firebase push seems to work fine.

2.Once I received notification , from "onMessageReceived" how to pass these message,body content to my Activity /Fragments?

You can issue a Broadcast from onMessageReceived() and register a Braodcast Receiver in your Activity and send the data in your broadcast intent. Example code:

Activity

private BroadcastReceiver receiver;

@Overrride
public void onCreate(Bundle savedInstanceState){

  // your oncreate code

  IntentFilter filter = new IntentFilter();
  filter.addAction("SOME_ACTION");

  receiver = new BroadcastReceiver() {
    @Override
    public void onReceive(Context context, Intent intent) {
      String message = intent.getStringExtra("message");
    }
  };
     registerReceiver(receiver, filter);
}

 @Override
 protected void onDestroy() {
  if (receiver != null) {
   unregisterReceiver(receiver);
   receiver = null
  }
  super.onDestroy();
 }

FirebaseMessagingService

public class MyFirebaseMessagingService extends FirebaseMessagingService {
    private static final String TAG = "MsgService";
    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        Log.d(TAG, "From: " + remoteMessage.getFrom());
        Log.d(TAG, "Notification Message Body: " + remoteMessage.getData());

        Intent intent=new Intent();
        intent.setAction("SOME_ACTION");
        intent.putExtra("message", remoteMessage.getNotification().getBody());
        sendBroadcast(intent);
    }
} 

3.In some cases I want to send notification to all , Instead of adding all tokens to array . any other way to handle like "send to ALL" something like that ?

There is nothing like "Send to ALL" in Firebase API, the only way to do this is using Firebase Console which have its own issues to handle like white icon issue, and ripping the custom params of your notification.

Answer 2

I was having problem with FCM on exactly Mi Phone and Huawei phone as well! Turns out that it was not a problem with FCM or your app, but on their device level.

They have device level app settings that disable notifications or even wake lock, so onMessageReceived() is not fired when the message arrives. After I changed the settings (mainly allow notifications & disable battery optimisation for my app), everything works just fine!

Refer to Firebase cloud messaging not received when app in background.