Eidhof C. Thinking in SwiftUI (Updated for iOS 17) 2023

Textbook in PDF format

SwiftUI is radically different from UIKit. In this short book, we will help you build a mental model of how SwiftUI works. We explain the most important concepts in detail and help you build a solid foundation for understanding SwiftUI.
Since SwiftUI is a large framework, the book focuses on the concepts behind the framework that we believe are essential to understand. It is not a reference for SwiftUI’s platform-specific APIs, but rather a guide to honing your intuition about how SwiftUI works.
Thinking in SwiftUI is geared toward developers who have both prior experience with Apple’s platforms and a good understanding of the Swift language