How to Sign Out of Google After Being Authenticated

Question

So my app has the option to sign in with Google. Upon clicking the button that Google provides, a web view opens and has the user input their credentials. After allowing the app

Answer 1

  public func logOut(on:UIViewController){

    let firebaseAuth = Auth.auth()
    do {
        try  firebaseAuth.signOut()
            GIDSignIn.sharedInstance().signOut()
            GIDSignIn.sharedInstance().disconnect()

        if let url = NSURL(string:  "https://www.google.com/accounts/Logout?continue=https://appengine.google.com/_ah/logout?continue=https://google.com"){
            UIApplication.shared.open(url as URL, options: [:]) { (true) in
                let appDel:AppDelegate = UIApplication.shared.delegate as! AppDelegate
                appDel.window?.rootViewController = LoginViewController()
            }
        }
    } catch let signOutError as NSError {
        Help.shared.Snack(messageString: "Error signing out: \(signOutError)" 
)
        print ("Error signing out: %@", signOutError)
    }
}