KODE SNIPPETS

Hi!
Today I am going to show to how to integrate Google Sign In to your app.

First of all create a project and install the following pod.

pod 'Google/SignIn'

Then go to this link:  Start Integrating Google Sign-In into your app.
Then click GET A CONFIGURATION FILE. Sign -in to your google account and it will redirect you to this page.

Click Enable Google Sign-In.

Next click Close then Generate configuration files. Then Download GoogleService-Info.plist.

Drag & drop that downloaded Info.plist to your project. Then click on your project -> Targets -> Info. Under your URL Types click +. Then select GoogleService-Info.plist and copy your REVERSED_CLIENT_ID and paste it in your URL Schemes.

Add a UIView, and two Buttons on your Storyboard. and set UIView class as GIDSignInButton and create @IBOutles for all buttons and @IBAction for custom sign-in and logout button.

Now in your AppDelegate do the following.

   
    func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
        GIDSignIn.sharedInstance().clientID = kClient
        var configureError:NSError?
        GGLContext.sharedInstance().configureWithError(&configureError)
        assert(configureError == nil, "Error configuring Google services: (configureError)")
        return true
    }
    func application(application: UIApplication,
                     openURL url: NSURL, options: [String: AnyObject]) -> Bool {
        return GIDSignIn.sharedInstance().handleURL(url,
                                                    sourceApplication: options[UIApplicationOpenURLOptionsSourceApplicationKey] as? String,
                                                    annotation: options[UIApplicationOpenURLOptionsAnnotationKey])
    }

Where kClient is CLIENT_ID from GoogleService-Info.plist.

Now in your UIViewController.Swift, Implement delegate GIDSignInDelegate and GIDSignInUIDelegate, and in your viewDidLoad().

 override func viewDidLoad() {
        super.viewDidLoad()
        GIDSignIn.sharedInstance().uiDelegate = self
        GIDSignIn.sharedInstance().delegate = self
    }

In didSignInForUser, you’ll get the logged In user object. Then do the following

 func signIn(signIn: GIDSignIn!, didSignInForUser user: GIDGoogleUser!,
                withError error: NSError!) {
        if (error == nil) {
            let userId = user.userID
            let idToken = user.authentication.idToken
            let fullName = user.profile.name
            let profilePicture = String(GIDSignIn.sharedInstance().currentUser.profile.imageURLWithDimension(400))
            let email = user.profile.email
            logout.hidden = false
            customButton.hidden = true
            defaultButton.hidden = true
            print("Auth:(idToken)nUserId:(userId)nFullname:(fullName)nEmail:(email)nProfile Picture:(profilePicture)")
            alert("Logged In", message: "Fullname:(fullName)nEmail:(email)nProfile Picture:(profilePicture)")
        } else {
            print("(error.localizedDescription)")
        }
    }

In your Custom Sign In button action. Just do this.

 GIDSignIn.sharedInstance().signIn()

In your Logout button.

 if GIDSignIn.sharedInstance().hasAuthInKeychain() == true {
        GIDSignIn.sharedInstance().signOut()
            logout.hidden = true
            customButton.hidden = false
            defaultButton.hidden = false
            alert("Logged Out", message: "")
        }

And at last for alert.

 func alert(title: String, message: String){
    let alert = UIAlertController(title: title, message: message, preferredStyle: .Alert)
    let okAction = UIAlertAction(title: "OK",style: .Default, handler: nil)
        alert.addAction(okAction)
        self.presentViewController(alert, animated: true, completion: nil)
    }

Build and Run your app and sign in with your Google account.

Source code on Github.
If you have any question, please leave a comment.

Happy Coding! 🙂