Matt Neuburg - Programming iOS 14

by Matt Neuburg

Copyright 2021 Matt Neuburg. All rights reserved.

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978-1-492-09217-9

[MBP]

Aut lego vel scribo; doceo scrutorve sophian.

Sedulius Scottus

This chapter has been revised for Early Release. It reflects iOS 14, Xcode 12, and Swift 5.3. But screenshots have not been retaken; they still show the Xcode 11 / iOS 13 interface.

Ten years ago, in July of 2010, Chris Lattner created a folder on his computer called Shiny, and a new computer language was born. Four years later, in 2014, that language, renamed Swift, was introduced to the public. Since then, the Swift language has attained a high degree of maturity. Among other things, it has achieved ABI stability, which means that the Swift language has become part of the system. Swift apps are smaller and faster than ever. It is fair to assume that, for the vast majority of iOS programmers, Swift is the language of choice.

Swift, therefore, is the programming language used throughout this book. Still, some awareness of Objective-C (including C) can be useful. The Foundation and Cocoa APIs are still written in Objective-C and C. So when youre programming Cocoa, a major part of Swifts job is to interact with those languages. In order to do that, you might need to know something about what those languages would expect. So I do refer to Objective-C and C from time to time, even though the book contains no actual Objective-C code.

In 2019, Apple released the first public version of SwiftUI. This is an exciting opportunity to program iOS without reference to the Cocoa UIKit framework. In SwiftUI, there are no UIViews and no UIViewControllers. Data flow helps to ensure that the interface coherently reflects the state of the app. And the same code, for the most part, works on multiple platforms, not just the iPhone and iPad, but also the Apple Watch and the Mac desktop. Nevertheless, in the real world, UIKit is by no means superseded; Cocoa UIKit remains the primary subject of this book.