android - Is FCM token refreshed on app update?

Question

I am using FCM in my android app for push notifications. I have the below class to get the fcm token.

public class MyFirebaseInstanceIdService extends FirebaseInstanceIdService {
    @Override
    public void onTokenRefresh() {
        String refreshedToken = FirebaseInstanceId.getInstance().getToken();
    }
}

This is called correctly when my app is installed and I am able to get the token. However I am not sure if my app is updated(from play store) then this method will be called or not. The documentation just says that the method will be called whenever the token changes. But updating the app might not change the token.

Answer 1

As pointed out in the post by @Dharmitabhatt in the comments section, a registration token is not refereshed when an app is updated.

Whenever a token is refreshed in Android, it should call the onTokenRefresh() method:

Called when the system determines that the tokens need to be refreshed. The application should call getToken() and send the tokens to all application servers.

This will not be called very frequently, it is needed for key rotation and to handle Instance ID changes due to:

• App deletes Instance ID
• App is restored on a new device
• User uninstalls/reinstall the app
• User clears app data

The system will throttle the refresh event across all devices to avoid overloading application servers with token updates.

So you are right to say that updating the app doesn't necessarily refresh the token.