Checking Firebase current signed-in user via Listener in iOS

Question

I\'ve implement Firebase Authorization to login on my iOS app via Facebook and Google. I\'m coding Swift. When the app starts up I need to check whether a user is already si

Answer 1

If you're setting up the StateDidChangeListener in application:didFinishLaunchingWithOptions, you'll notice that it fires once when the listener is attached (to set the initial state, which is nil when initialising) and then again once it's finished initialising (potentially not nil). This is intended behaviour, but really impractical if you're setting it up early.

An alternative to using the listener is using NotificationCenter. This will fire once initialisation has finished:

NotificationCenter.default.addObserver(forName: NSNotification.Name.AuthStateDidChange, object: Auth.auth(), queue: nil) { _ in
    let user = Auth.auth().currentUser
}