Book Image

Hands-On Design Patterns with Swift

By : Florent Vilmart, Giordano Scalzo, Sergio De Simone
Book Image

Hands-On Design Patterns with Swift

By: Florent Vilmart, Giordano Scalzo, Sergio De Simone

Overview of this book

Swift keeps gaining traction not only amongst Apple developers but also as a server-side language. This book demonstrates how to apply design patterns and best practices in real-life situations, whether that's for new or already existing projects. You’ll begin with a quick refresher on Swift, the compiler, the standard library, and the foundation, followed by the Cocoa design patterns – the ones at the core of many cocoa libraries – to follow up with the creational, structural, and behavioral patterns as defined by the GoF. You'll get acquainted with application architecture, as well as the most popular architectural design patterns, such as MVC and MVVM, and learn to use them in the context of Swift. In addition, you’ll walk through dependency injection and functional reactive programming. Special emphasis will be given to techniques to handle concurrency, including callbacks, futures and promises, and reactive programming. These techniques will help you adopt a test-driven approach to your workflow in order to use Swift Package Manager and integrate the framework into the original code base, along with Unit and UI testing. By the end of the book, you'll be able to build applications that are scalable, faster, and easier to maintain.
Table of Contents (22 chapters)
Title Page
Copyright and Credits
About Packt
Contributors
Preface
Index

Chapter 4. Working with Objective-C in a Mixed Code Base

Swift builds upon the strong heritage of Objective-C. When Apple released the first version of Swift, they also reassured all developers that their Objective-C code bases would be able to integrate Swift progressively thanks to a strong interoperability layer. Even today, many applications haven't fully migrated to Swift, and interoperability is key to ensure that the Objective-C code isn't bringing instability and unsafe types into your shiny Swift modules.

In this chapter, we'll have a look at techniques to write safer Objective-C code:

  • How to import Swift code in Objective-C and vice versa
  • How to add nullability to Objective-C
  • How to expose renamed methods to Swift
  • How to leverage lightweight generics in Objective-C
  • How the Cocoa design patterns translate in Swift