Firebase console: How to specify click_action for notifications

Question

I implemented Firebase and testing the Firebase notifications. When the app is in the foreground I don't have problems, I implemented a service that extends FirebaseMessagingService and handle the message and data in onMessageReceived

I have problems when the app is in background, I would like to send a notification that opens a specific activity and does what I schedule to do, not just opening the App.

I did as described on the Firebase guide, but I'm not able to start the specific activity.

Here the manifest:

<activity android:name=".BasicNotificationActivity">
            <intent-filter>
                <action android:name="OPEN_ACTIVITY_1" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>

And here the Firebase Console. What do I have to write in those fields to open my "BasicNotificationActivity"?

Answer 1

This is a duplicate of this question: Firebase FCM notifications click_action payload

But the answer that was accepted by the author of this question just states that it is not possible with Firebase Console, but it is - with an easy workaround. This answer by diidu to the same question explains the workaround I would use.

UPDATE:
To elaborate on his answer:

Add a helper class (or implement startActivity() method somehow):

public class ClickActionHelper {
    public static void startActivity(String className, Bundle extras, Context context){
        Class cls;
        try {
            cls = Class.forName(className);
        }catch(ClassNotFoundException e){
            //means you made a wrong input in firebase console
        }
        Intent i = new Intent(context, cls);
        i.putExtras(extras);
        context.startActivity(i);
    }
}

In the launcher-activity of your app, call a mehtod to check any new intents in onCreate() and onNewIntent() (onNewIntent() is only called instead of onCreate() if Activity is launched with single-top flag):

@Override
protected void onCreate(Bundle bundle) {
    [...]
    checkIntent(getIntent());
 }

@Override
protected void onNewIntent(Intent intent) {
    super.onNewIntent(intent);
    [...]
    checkIntent(intent);
}

public void checkIntent(Intent intent) {
       if (intent.hasExtra("click_action")) {
        ClickActionHelper.startActivity(intent.getStringExtra("click_action"), intent.getExtras(), this);
       }
}

And in onMessageReceived():

 public void onMessageReceived(RemoteMessage remoteMessage) {
     Map<String, String> data = remoteMessage.getData();        
     if (data.containsKey("click_action")) {
         ClickActionHelper.startActivity(data.get("click_action"), null, this);
     }
 }

To send a notification with firebase console, put a key-value-pair as custom data like this:

Key: click_action
Value: <fully qualified classname of your activity>

Now when a notification is received and clicked on, it will open your activity. If your app is in foreground, it will also immediately change to the activity - it would probably be good to ask the user if he wants to go to this activity or not (by showing a dialog in onMessageReceived()).