Firebase Google SignIn asks every time for permissions

Question

I have implemented a Google SignIn with Firebase in my iOS app, following the Firebase guide. The problem is that every time I test the login, it always asks for permissions.

Here is the code of AppDelegate involved in Google SignIn:

class AppDelegate: UIResponder, UIApplicationDelegate, GIDSignInDelegate {

    var window: UIWindow?


    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey : Any]? = nil) -> Bool {
        // Override point for customization after application launch.
        FIRApp.configure()

        GIDSignIn.sharedInstance().clientID = FIRApp.defaultApp()?.options.clientID
        GIDSignIn.sharedInstance().delegate = self


        return true
    }

    func application(_ app: UIApplication, open url: URL, options: [UIApplicationOpenURLOptionsKey : Any] = [:]) -> Bool {
        return GIDSignIn.sharedInstance().handle(url, sourceApplication: options[UIApplicationOpenURLOptionsKey.sourceApplication] as? String, annotation: options[UIApplicationOpenURLOptionsKey.annotation])
    }

    func sign(_ signIn: GIDSignIn!, didSignInFor user: GIDGoogleUser!, withError error: Error!) {

        if let error = error {
            print(error.localizedDescription)
            return
        }


        print("Logged in with Google successfull")


        // ... Firebase authentication ...

    }
}

And here the code of View Controller with GIDSignInButton:

import UIKit

class IntroViewController: UIViewController, GIDSignInUIDelegate {


    @IBOutlet weak var signInButton: GIDSignInButton!


    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.

        GIDSignIn.sharedInstance().uiDelegate = self
        signInButton.style = .wide
    }


}

I've searched a lot on the web but found nothing... So, how can I prevent to ask for permission every time?

Answer 1

I believe this is working as intended. The issue is that you're signing out the user when you're testing your app, and the Google Sign-in library makes the assumption that if a user has explicitly signed out of your app, it should ask that user for permission again before signing that user in.

If you don't explicitly sign out the user, both signIn() calls and signInSilently() calls should succeed without displaying any kind of sign-in screen.