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

Template pattern with protocol-oriented programming


The template design pattern is a popular behavioral design pattern usually implemented with abstract classes. It helps design algorithms at a high level while letting subclasses or implementers modify or provide parts of it.

Protocol-oriented programming is particularly suited to implementing this pattern, as protocol extensions let you provide default implementations. Default implementations are perfect places to design and implement generic algorithms, as those algorithms can later be applied to a slew of concrete types.

To illustrate this design pattern, we'll build a simple recommendation engine that is tailored to the user's need.

A recommendation engine

A recommendation engine can be thought of as a software system that gives you the most relevant answer based on a list of objects:

protocol RecommendationEngine {
    associatedtype Model
var models: [Model] { get }
func filter(elements: [Model]) -> [Model]
func sort(elements: [Model...