Implementing UIKit Sign in with Apple to be used in SwiftUI

In this recipe, you'll learn how to use Sign in with Apple in a SwiftUI app by wrapping the UIKit component.

In iOS 14, SwiftUI provides a native SignInWithApple button, but if you don't have support for it yet and are still using iOS 13, then don't worry – in this recipe, we are going to implement a wrapper around the UIKit class that works very well with SwiftUI.

Here, we are going to implement a simple app that permits us to log in using our Apple ID and presents our credentials when we are logged in.

Important Note

Sign in with Apple is still a bit flaky when it's run in a simulator, so it is safer to run this recipe on an iOS device.

The app that we'll be implementing in this recipe is simple, but it can be a good foundation to implement a proper app with Apple's authentication.

As you may recall, the AuthenticationServices framework only passes the user's...