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 2. Understanding ARC and Memory Management

Swift has a very particular and almost unique memory management strategy: Automatic Reference Counting (ARC). When using ARC, the compiler will inject memory management code for us, but it's very easy to write poor, leaky code, either on purpose or by accident. In this chapter, we'll cover all of the basics for good memory management in Swift. From its origins in Objective-C, to the pre-ARC era, to today, we'll look at how to properly manage our memory and object life cycles. We'll also explore the powerful tools available with Xcode to track memory usage, leaks, cycles, and other defects, through the inspector and the leaks instrument.

In this chapter, we'll cover the following topics:

  • A brief history of reference counting
  • What is ARC?
  • Debugging memory
  • Leaks, cycles, and dangling references