Updating FCM Token on Flutter App

Question

I have a Flutter app that creates a FCM Token on the first run, like this:

_firebaseMessaging.getToken().then((token) {
  //save my token here
});

However, I understand that this token can be refreshed once in awhile. In order to get this new refreshed token, I must call onTokenRefresh method:

Stream<String> fcmStream = _firebaseMessaging.onTokenRefresh;
fcmStream.listen((token) {
  saveToken(token);
});

The problem is that I don't know if this it is correct. The line saveToken(token) is always execute when the app runs, but it works when the app is not on foreground/background?

I mean, this onTokenRefresh will keep listening even if the user closes the app?

If not, how do I get the new token if the app doesn't get started for a long time?

Solution

Base on this firebase document fcm token will changed on below events:

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

If the app doesn't get started for a long time, and none of the above events has occurred, the app token will not changed.

Comments

[Notheros]

Thank you for your answer. If the documentation says that, then I have nothing to worry about.