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 10. Model-View-ViewModel in Swift

In the previous chapter, we detailed how the Model-View-Controller (MVC) pattern can be factored in an intuitive and scalable manner. While pervasive in all Cocoa environments, MVC is not the only valid architectural pattern that can be used in Swift. At Microsoft, while working on even driven programming for user interfaces, Ken Cooper and Ted Peters invented the Model-View-ViewModel (MVVM) pattern. In the MVVM pattern, views bind on ViewModels. Through this binding, ViewModel provides objects and methods from the Model layer to the View layer.

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

  • The basics of MVVM
  • How to refactor existing MVC code, in order to leverage MVVM
  • How to properly use MVVM in complex view controllers
  • The advantages and limitations of MVVM