gistfile1.txt

In my iPhone app's home screen I need to check whether the user is logged in or not. In my `viewDidAppear()` I check like this:

    override func viewDidAppear(_ animated: Bool) {
       if let user = FIRAuth.auth()?.currentUser {
           // user is logged in
       } else {
           // user not logged in, send to home page
           self.performSegue(withIdentifier: "NotLoggedInSegue", sender: self)
       }
    }

In every example online I see people using `FIRAuth.auth()?.addStateDidChangeListener` in their code. If my app's only authentication is through gmail, do I need that or is the way I'm checking if the user is logged in fine?