Firebase - iOS Swift: FIRAuth.auth().signOut() not signing out current user

Question

I\'m building an app using Firebase with an initial SignInViewController that loads a sign in page for users to authenticate with email which triggers the follo

Answer 1

GIDSignIn.sharedInstance().signOut()

Answer 2

Some answers are using a force unwrap when the firebase signing out method can throw an error. DO NOT DO THIS!

Instead the call should be done in a do - catch - block as shown below

   do {
        try Auth.auth().signOut()
    } catch let error {
        // handle error here
        print("Error trying to sign out of Firebase: \(error.localizedDescription)")
    }

You can then listen to the state change using Auth.auth().addStateDidChangeListener and handle accordingly.

Answer 3

I actually had this issue as well. I was also logging out the user (as you are) with the method's provided by Firebase but when I printed to the console it said that I still had a optional user.

I had to change the logic of setting the current user so that it is always configured by the authentication handler provided by Firebase:

var currentUser: User? = Auth.auth().currentUser
var handle: AuthStateDidChangeListenerHandle!

init() {

    handle = Auth.auth().addStateDidChangeListener { (auth, user) in
        self.currentUser = user

        if user == nil {
             UserDefaults.standard.setValue(false, forKey: UserDefaults.loggedIn)
        } else {  
             UserDefaults.standard.setValue(true, forKey: UserDefaults.loggedIn)
        }

    }

}

As long as you are referencing the current user from this handle, it will update the current user no matter the authentication state.

Answer 4

Use exclamation points not question marks.

  try! FIRAuth.auth()!.signOut()

Answer 5

You can add a listener in your viewDidAppear method of your view controller like so:

FIRAuth.auth()?.addStateDidChangeListener { auth, user in
    if let user = user {
        print("User is signed in.")
    } else {
        print("User is signed out.")
    }
}

This allows you to execute code when the user's authentication state has changed. It allows you to listen for the event since the signOut method from Firebase does not have a completion handler.

Answer 6

I just had what I think is the same problem - Firebase + Swift 3 wouldn't trigger stateDidChangeListeners on logout, which left my app thinking the user was still logged in.

What ended up working for me was to save and reuse a single reference to the FIRAuth.auth() instance rather than calling FIRAuth.auth() each time.

Calling FIRAuth.auth()?.signOut() would not trigger stateDidChangeListeners that I had previously attached. But when I saved the variable and reused it in both methods, it worked as expected.