Facebook deep linking on Android

Question

I\'m trying to implement Facebook\'s Deep Linking feature on my app and encountered the following scenario:

I have an activity called MainActivity which is declared like

Answer 1

Facebook is starting your app from their own app by explicitly start your "MainActivity" (the one your provided them in the developer page).

by that - Android's default behavior is: if the application already runs, then calling again to startActivity() won't start new task from scratch, but only restore to foreground the already running task.

but the good news are that you can change this default behavior by adding to your MainActivity the android:launchMode="singleTask". it definition is:

the system creates a new task and instantiates the activity at the root of the new task. However, if an instance of the activity already exists in a separate task, the system routes the intent to the existing instance through a call to its onNewIntent() method, rather than creating a new instance. Only one instance of the activity can exist at a time.

from this point you could always respond to the starting intent, and from that point you can always navigate back to the task that already was in background(if exists) by restarting activity with both flags Intent.FLAG_ACTIVITY_SINGLE_TOP && Intent.FLAG_ACTIVITY_CLEAR_TOP combination