Sign in with Apple ID

Add Sign In With Apple to Your App

• Select the project under Project Navigator > select your project under Targets > select the Signing and Capabilities tab.
• After that, there is a button to add capabilities, click on that. You will be presented with a popup window. Type: Sign in with app and double-click on the option presented. Sign in with Apple capability will be added to your project.

Integration of Sign In With Apple

• After adding Sign in with Apple capability, now it’s time to code.

• Go to LoginViewController and import the framework for authentication. It provides the necessary libraries for integration.

    import AuthenticationServices
  

• Initialize the Sign in with Apple button:

    let button = ASAuthorizationAppleIDButton()
  

• Next, add a target on the button so that it can be used to call the sign-in functionality.

    button.addTarget(self, action: #selector(handleAppleIDAuthorization), for: .touchUpInside)
  

• You can add this button directly in the view or any other container view. In my project, I have added it inside UIStackView.

    loginStackView.addArrangedSubview(button)
  

Authentication

• As of now, you will see an error in your project because you have not created the method in the class that is mentioned while adding a target to the Sign in with Apple button. Let’s add it.

• Create the method handleAppleIDAuthorization() just after the end of the function in which the button is added.

• Keep in mind that this function should have the keyword @objc added at the beginning as it is a selector method which is Objective-C-library related. Add the below code to create the authorization request.

    let request = ASAuthorizationAppleIDProvider().createRequest()
    let controller = ASAuthorizationController(authorizationRequests: [request])
    controller.delegate = self
    controller.presentationContextProvider = self
    controller.performRequests()
  

• Let’s break it down one-by-one.

• First, initialize the Apple ID request. This is all it requires to create an account in the system.

• Initialize the controller to show the user authorization view.

• Next, assign delegates to provide the result of authorization.

• Lastly, trigger the request.

• Apart from this, optionally, if you require the user name or email, you can add the below line after initializing the request

    request.requestedScopes = [.fullName, .email]
  

Verification

• The final part is to get a response and verify the user. You need to extend the class to authentication delegates to get callbacks.

• The first is ASAuthorizationControllerPresentationContextProviding. When you extend the class with this, you will have to override the function:

    func presentationAnchor(for controller: ASAuthorizationController) -> ASPresentationAnchor
  

• It returns a view in which you want to show the authentication window. You need to return the current controller view window:

    return view.window!
  

• Now comes ASAuthorizationControllerDelegate. It has two required methods:

    func authorizationController(controller: ASAuthorizationController, didCompleteWithAuthorization authorization: ASAuthorization)
  

• This method is called when authorization is a success. You get an instance of ASAuthorization which has credentials for the user. You need to first check if the credentials are Apple ID credentials. If it affirms, you can retrieve the required details.

    func authorizationController(controller: ASAuthorizationController, didCompleteWithError error: Error)
  

• This function is called if authentication is canceled or an error occurred while authenticating. You can handle the error response as you like.

• The Apple authentication response provides the following information:

User ID

• A user identifier that is unique and belongs to a specific user only.

    let userId = credential.user
  

Verification data

• Identity token and authorization code. The identity token is a short-lived token that can be used to get refreshed tokens.

    let identityToken = credential.identityToken
    let code = credential.authorizationCode
  

Account information

• If you have requested a name and email address, then these details can be retrieved from the credentials object.

    let fullname = credential.fullName
    let email = credential.email
  

Real user indicator

• This indicates whether the user is real or not. You can use it to streamline the flow of your app.

• Now, you are all done. Run your app. You will see the Sign in with Apple button.

• When you click on it, you will be presented with a window where you can use FaceID or TouchID to authenticate and after that, you will get a success callback.

• Once you receive the response, you can use the details and create an account in your server/database as per your app flow. Apple provides a simple way for users to create their accounts instead of Facebook or Google.