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

Mastering concurrency with Dispatch


Grand Central Dispatch (GCD) is a technology that provides a high-level API for safely dealing with concurrency and leveraging multicore architectures. With Dispatch, you don't need to deal with threads and thread pools anymore; instead, you'll work with operations and queues.

Using GCD, you'll be able to write efficient, multitasking code that scales from few to many CPU cores. Let's begin with the basic concepts of queues and tasks; then we'll cover the different techniques for synchronizing tasks. 

Tasks and queues

Queues are objects that abstract series of operations to execute. The system creates many queues for you, but the most important one is probably the main queue. Queues come in two major flavors, as follows:

  • Serial: A serial queue guarantees that no two operations will be executed at the same time. This is a particularly interesting feature if you need to write thread-safe code.
  • Concurrent: A concurrent queue will let different operations run in...