Integrating Google Sign-In into your iOS or macOS app

Swift

func application(
  _ app: UIApplication,
  open url: URL, options: [UIApplication.OpenURLOptionsKey : Any] = [:]
) -> Bool {
  var handled: Bool

  handled = GIDSignIn.sharedInstance.handle(url)
  if handled {
    return true
  }

  // Handle other custom URL types.

  // If not handled by this app, return false.
  return false
}

Objective-C

- (BOOL)application:(UIApplication *)app
            openURL:(NSURL *)url
            options:(NSDictionary<UIApplicationOpenURLOptionsKey,id> *)options {
  BOOL handled;

  handled = [GIDSignIn.sharedInstance handleURL:url];
  if (handled) {
    return YES;
  }

  // Handle other custom URL types.

  // If not handled by this app, return NO.
  return NO;
}

Swift

@main
struct MyApp: App {

  var body: some Scene {
    WindowGroup {
      ContentView()
        // ...
        .onOpenURL { url in
          GIDSignIn.sharedInstance.handle(url)
        }
    }
  }
}

Swift

func application(
  _ application: UIApplication,
  didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
) -> Bool {
  GIDSignIn.sharedInstance.restorePreviousSignIn { user, error in
    if error != nil || user == nil {
      // Show the app's signed-out state.
    } else {
      // Show the app's signed-in state.
    }
  }
  return true
}

Objective-C

- (BOOL)application:(UIApplication *)application
    didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
  [GIDSignIn.sharedInstance restorePreviousSignInWithCompletion:^(GIDGoogleUser * _Nullable user,
                                                                  NSError * _Nullable error) {
    if (error) {
      // Show the app's signed-out state.
    } else {
      // Show the app's signed-in state.
    }
  }];
  return YES;
}

Swift

@main
struct MyApp: App {
  var body: some Scene {
    WindowGroup {
      ContentView()
        // ...
        .onAppear {
          GIDSignIn.sharedInstance.restorePreviousSignIn { user, error in
            // Check if `user` exists; otherwise, do something with `error`
          }
        }
    }
  }
}

Using SwiftUI

1. Make sure that you have added the dependency for the SwiftUI "Sign in with Google" button to your project.

2. In the file where you want to add the SwiftUI button, add the required import to the top of the file:

   import GoogleSignInSwift
   

3. Add a "Sign in with Google" button to your View and specify the action that will be called when the button is pressed:

   GoogleSignInButton(action: handleSignInButton)
   

4. Trigger the sign in process when the button is pressed by adding a call to GIDSignIn's signIn(presentingViewController:completion:) method in your action:

   func handleSignInButton() {
     GIDSignIn.sharedInstance.signIn(
       withPresenting: rootViewController) { signInResult, error in
         guard let result = signInResult else {
           // Inspect error
           return
         }
         // If sign in succeeded, display the app's main content View.
       }
     )
   }
   

This uses the default view model that provides standard styling information for the button. To control the button's appearance, you need to create a custom GoogleSignInButtonViewModel and set it as the viewModel in the button's initializer using GoogleSignInButton(viewModel: yourViewModel, action: yourAction). See the GoogleSignInButtonViewModel source code for more information.

Using UIKit

1. Add a "Sign in with Google" button to your sign-in View. You can use the GIDSignInButton class to automatically generate a button with Google branding (recommended) or create your own button with custom styling.

   To add a GIDSignInButton to a storyboard or XIB file, add a View and set its custom class to GIDSignInButton. Note that when you add a GIDSignInButton View to your storyboard, the sign-in button doesn't render in the interface builder. Run the app to see the sign-in button.

   You can customize the appearance of a GIDSignInButton by setting its colorScheme and style properties:

   GIDSignInButton style properties
   colorScheme	kGIDSignInButtonColorSchemeLight kGIDSignInButtonColorSchemeDark
   style	kGIDSignInButtonStyleStandard kGIDSignInButtonStyleWide kGIDSignInButtonStyleIconOnly

2. Connect the button to a method in your ViewController that calls signIn:. For example, use an IBAction:

   Swift

   @IBAction func signIn(sender: Any) {
     GIDSignIn.sharedInstance.signIn(withPresenting: self) { signInResult, error in
       guard error == nil else { return }
   
       // If sign in succeeded, display the app's main content View.
     }
   }
   

   Objective-C

   - (IBAction)signIn:(id)sender {
     [GIDSignIn.sharedInstance
         signInWithPresentingViewController:self
                                 completion:^(GIDSignInResult * _Nullable signInResult,
                                              NSError * _Nullable error) {
       if (error) {
         return;
       }
   
       // If sign in succeeded, display the app's main content View.
     }];
   }