Sign in with Apple isn't hard, but it required some knowledge outside the Apple documentation to understand what they are trying to say.
Apple documentation introduced you with new terms and new things that you never heard of, stuff like JWT, JWK, weird public key format, creating a private key, and an ID for your web service. After finishing it, you might not even know where to start.
This book will prepare you with everything you need to know about Sign in with Apple. Then guide you step by step on what to do to implement it in your existing project.
Chapter 1 - Introducing
A brief introduction of what is Sign in with Apple and why should you care about it.
Chapter 2 - The Button
Start with the first element of every sign in service, a button. I will show you how to modify Sign in with Apple button to fit your needs. Cover how to do dark mode, localization, and appearances. I will also point out constraints, tips, and tricks that you might never know.
Chapter 3 - Foundations of Sign in with Apple
This chapter will give you an idea of what Apple has to offer. Learn every aspect of Sign in with Apple. How does it look likes? What privacy features that they are talking about? See everything that your users will see.
Chapter 4 - Private Email Relay Service
Learn what you need to do to support one of the privacy features of Sign in with Apple, a private email.
Chapter 5 - Basic backend with Firebase
Complete the whole authentication process by using Firebase as our backed. We will use everything from the last four chapters and put it into action. See how easy it is to create a user with Sign in with Apple.
Chapter 6 - Handle existing users
Sign in with Apple is not just about new users, existing users with username and password in your system can get the benefit of Sign in with Apple experience. Learn how to onboard users with credentials for your app in their iCloud Keychain.
Chapter 7 - Under the hood
Apple is good at explaining something without saying the underlying technology. Apple had a whole session of a new Combine framework without reference anything about React. In this chapter, we will learn about the underlying technology of Sign in with Apple. This is very crucial in understanding Sign in with Apple.
Chapter 8 - Web platform with a simple Rails backend
Use the knowledge from chapter 7 into use by integrating Sign in with Apple on a web platform. You will see every piece of the puzzle come together in this chapter. As an iOS developer, you might not need to understand everything in this sign in flow, but you are likely the one who prepares everything your colleague would ask, e.g., public/private key, client_id, a new app id, etc. This chapter will make sure you got everything you need.