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

Composition and child view controllers


As you saw previously, you should always pay attention to the view life cycle and never rush it. Another thing that we need to pay attention to is the size of our view controller. Smaller view controllers are beneficial for the following:

  • Reusability: Smaller view controllers are reusable, as they tend to be very specialized.
  • Testability: A small view controller has a smaller footprint and a smaller API. Having a smaller API makes it easier to test.
  • Maintainability: Isolating features and components always helps with the separation of concerns.

All of these features come for free when you compose your view controllers accordingly.

Composing view controllers implies using a custom container view controller. The container view controller will be responsible for maintaining the hierarchy of controllers, as well as the views provided by those child view controllers.

Adding child view controllers

Adding a child view controller is possible with the func addChild...