Book Image

Mastering iOS 12 Programming - Third Edition

By : Donny Wals
Book Image

Mastering iOS 12 Programming - Third Edition

By: Donny Wals

Overview of this book

The iOS development environment has significantly matured, and with Apple users spending more money in the App Store, there are plenty of development opportunities for professional iOS developers. However, the journey to mastering iOS development and the new features of iOS 12 is not straightforward. This book will help you make that transition smoothly and easily. With the help of Swift 4.2, you’ll not only learn how to program for iOS 12, but also how to write efficient, readable, and maintainable Swift code that maintains industry best practices. Mastering iOS 12 Programming will help you build real-world applications and reflect the real-world development flow. You will also find a mix of thorough background information and practical examples, teaching you how to start implementing your newly gained knowledge. By the end of this book, you will have got to grips with building iOS applications that harness advanced techniques and make best use of the latest and greatest features available in iOS 12.
Table of Contents (35 chapters)
Title Page
Copyright and Credits
Dedication
Packt Upsell
Contributors
Preface
Index

Defining your own protocols


Swift and UIKit have protocols at the core of their design. You might have noticed this when you were implementing custom UIViewController transitions, or when you worked on a table view or collection view. When you implement these features, you create objects that function as delegates for the transitions, table views, and collection views, and conform them to specific protocols. When you worked on view controller transitions in Chapter 4, Immersing Your Users with Animation, you also implemented an NSObject subclass that conformed to UIViewControllerAnimatedTransitioning.

It's possible for you to define and use your own protocols. Protocols are not confined to delegate behavior only. Defining a protocol is very similar to defining a class, struct, or enum. The main difference is that a protocol does not implement or store any values on its own. It acts as a contract between whoever calls an object that conforms to a protocol and the object that claims to conform...