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

The abstract factory pattern


You will probably find yourself needing to implement the abstract factory pattern when your program needs different concrete class implementations behind the same interface. Instead of writing the logic in terms of concrete classes, this will let you write programs based on exposed interfaces.

At runtime, the abstract factory will let you easily swap and choose concrete classes when they are instantiated at a single point, instead of writing lengthy and unmaintainable code.

To illustrate this, we'll use an example that you may relate to: registering push notifications and keeping up with changing APIs in a cross-platform environment.

Using the abstract factory pattern

With every Worldwide Developers Conference (WWDC), a new set of OSs is released. This often means tweaking our current projects to accommodate new APIs, provide backwards compatibility, and explore new and shiny features. All those changes can be tedious; even more so if you're maintaining multiple...