Professional Swift E-Book

Michael Dippery

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 427

Veröffentlichungsjahr: 2015

Beschreibung

Transition from Objective-C to the cleaner, more functional Swift quickly and easily Professional Swift shows you how to create Mac and iPhone applications using Apple's new programming language. This code-intensive, practical guide walks you through Swift best practices as you learn the language, build an application, and refine it using advanced concepts and techniques. Organized for easy navigation, this book can be read end-to-end for a self-paced tutorial, or used as an on-demand desk reference as unfamiliar situations arise. The first section of the book guides you through the basics of Swift programming, with clear instruction on everything from writing code to storing data, and Section II adds advanced data types, advanced debugging, extending classes, and more. You'll learn everything you need to know to make the transition from Objective-C to Swift smooth and painless, so you can begin building faster, more secure apps than ever before. * Get acquainted with the Swift language and syntax * Write, deploy, and debug Swift programs * Store data and interface with web services * Master advanced usage, and bridge Swift and Objective-C Professional Swift is your guide to the future of OS X and iOS development.

Leseprobe

INTRODUCTION

THE POPULARITY OF IOS has drawn many programmers to Apple’s platforms. Software on both OS X and iOS has long been written in Objective-C, a language first developed in the 1980s that is best described as an amalgamation of C and Smalltalk. Objective-C lacks many features that modern programmers expect to find in a programming language. Over the last ten years, Apple has adapted and improved Objective-C, but many programmers still find it to be an alien language.

Enter Swift. Swift is a modern programming language, built with knowledge gained in the last 30 years of programming language research. Developed by the same researchers who developed clang, the modern compiler toolchain used by Apple to build OS X and iOS software, Swift incorporates many features that are expected of a modern programming language. It sports a strong type system to prevent many of the mistakes prevalent in both C and Objective-C programming. It has a refined class system complete with static and computable properties. It supports closures and treats functions as first-class objects, allowing them to easily be saved as variables or passed to functions and methods as parameters. As you read this book, you’ll find many more advanced features that are present in Swift as well.

Swift has been designed from the ground up to be a modern programming language suitable for both systems and application development on Apple’s platforms. Apple has already thrown a lot of support behind Swift, and the language is constantly being improved. Swift represents the future of software development on iOS and OS X, and programmers working on that platform should expect Swift to occupy an increasingly dominant position on those systems.

WHO THIS BOOK IS FOR

This book is aimed at software developers with experience writing Objective-C applications on OS X or iOS. Some knowledge and experience with Swift are recommended but are by no means necessary to understand the material presented in this book. The book introduces the key concepts of Swift that may be new even to advanced iOS and OS X programmers. Over the course of the book, several small projects are used to illustrate the concepts as they are introduced. The text also makes extensive use of playgrounds, a new feature of Xcode that allows you to write and interact with Swift code without the overhead of an entire Xcode project.

The first chapter is an overview of Swift’s syntax and semantics but does not cover any advanced features of the language. The second chapter covers the use of Xcode, including playgrounds. If you already have some familiarity with Swift and Xcode, you may want to skip the first and second chapters and get started immediately with Chapter 3.

WHAT THIS BOOK COVERS

This book first offers a primer to the Swift programming language, released by Apple in June 2014. It quickly moves on to more advanced Swift programming topics, including the new playgrounds feature in Xcode; classes, structs, and enums; concurrent programming; and advanced features of Swift’s type system. It also covers practical topics that you will deal with on a regular basis as a Swift programmer, including interfacing with web services using JSON, Core Data, and using C and Objective-C code in your Swift project. It shows some of the advanced features of Xcode, including the use of the debugger built in to Xcode, and discusses the lower-level details of the Swift and Objective-C runtimes. And because it is impossible to completely avoid C when writing software on OS X and iOS, an index provides a quick overview of the C programming language.

Swift has been constantly evolving since its release in June 2014. This book covers version 1.1.

Because Swift is still changing, you may find some minor differences between the version discussed in this book and the latest released version. However, the vast majority of material presented in this book will still be valid for future versions of Swift.

HOW THIS BOOK IS STRUCTURED

This book is divided into two sections. The first section provides an introduction to the Swift programming language and covers many of the more practical topics you will encounter as a Swift programmer. The second section is a “deep dive” into the intricacies of Swift.

➤   

Chapter 1:

Reviews the syntax and semantics of the Swift programming language. It is useful for those programmers who are new to the language or want a quick refresher.

➤   

Chapter 2:

Covers the Swift-related changes to Xcode. It introduces Xcode’s new feature, playgrounds, which provide a way to interactively work with Swift code.

➤   

Chapter 3:

Covers Swift’s classes, structs, and enums in greater detail than Chapter 1, providing a solid foundation for object-oriented programming in Swift.

➤   

Chapter 4:

Discusses concurrent programming in the context of Swift and the Foundation framework on iOS and OS X.

➤   

Chapter 5:

Shows you how to communicate with remote web services using JSON.

➤   

Chapter 6:

Discusses how to use Core Data to store and search for information used by your program.

➤   

Chapter 7:

Shows you how to extend classes using protocols and class extensions.

➤   

Chapter 8:

Covers Swift’s type system in fine detail and shows you how to take advantage of Swift’s strong type system to write less error-prone code.

➤   

Chapter 9:

Shows you how you can mix C and Objective-C code in your Swift programs.

➤   

Chapter 10:

Introduces the debugger and shows you how you can track down and fix problems in your code.

➤   

Chapter 11:

Discusses the runtime architecture of both Swift and Objective-C and demonstrates how programs are loaded and executed on iOS and OS X.

➤   

Appendix:

Covers the features and concepts that the C programming language introduces.

If you are already familiar with Swift and Xcode, you may want to skip Chapters 1 and 2 and start right in on Chapter 3.

WHAT YOU NEED TO USE THIS BOOK

To run the samples in the book, you will need the following:

➤    A Mac running OS X 10.9 or later

➤    Xcode 6

➤    An iPhone, iPod Touch, or iPad if you want to run the examples on an actual device instead of the iOS simulator that ships with Xcode

The source code for the samples is available for download from the Wrox website at: www.wrox.com/go/proswift.

CONVENTIONS

To help you get the most from the text and keep track of what’s happening, this book uses a number of conventions.

WARNING   Warnings hold important, not-to-be-forgotten information that is directly relevant to the surrounding text.

NOTE   Notes indicate notes, tips, hints, tricks, or asides to the current discussion.

As for styles in the text:

➤    We

highlight

new terms and important words when we introduce them.

➤    We show keyboard strokes like this: Ctrl+A.

➤    We show file names, URLs, and code within the text like so:

persistence.properties

.

We present code in two different ways:

We use a monofont type with no highlighting for most code examples.

We use bold to emphasize code that is particularly important in the present context or to show changes from a previous code snippet.

SOURCE CODE

As you work through the examples in this book, you may choose either to type in all the code manually or to use the source code files that accompany the book. All the source code used in this book is available for download at www.wrox.com. Specifically for this book, the code download is on the Download Code tab at www.wrox.com/go/proswift.

You can also search for the book at www.wrox.com by ISBN (the ISBN for this book is 978-1-119-01677-9) to find the code. And a complete list of code downloads for all current Wrox books is available at www.wrox.com/dynamic/books/download.aspx.

At the beginning of each chapter, we’ve provided a list of the major code files for the chapter. Throughout each chapter, you’ll also find references to the names of code files as needed in listing titles and text.

Most of the code on www.wrox.com is compressed in a .ZIP, .RAR, or similar archive format appropriate to the platform. Once you download the code, just decompress it with an appropriate compression tool.

NOTE   Because many books have similar titles, you may find it easiest to search by ISBN; this book’s ISBN is 978-1-119-01677-9.

Once you download the code, just decompress it with your favorite compression tool. Alternately, you can go to the main Wrox code download page at www.wrox.com/dynamic/books/download .aspx to see the code available for this book and all other Wrox books.

ERRATA

We make every effort to ensure that there are no errors in the text or in the code. However, no one is perfect, and mistakes do occur. If you find an error in one of our books, such as a spelling mistake or faulty piece of code, we would be very grateful for your feedback. By sending in errata, you may save another reader hours of frustration, and at the same time, you will be helping us provide even higher quality information.

To find the errata page for this book, go to www.wrox.com/go/proswift, and click the Errata link. On this page you can view all errata that has been submitted for this book and posted by Wrox editors.

If you don’t spot “your” error on the Book Errata page, go to www.wrox.com/contact/techsupport.shtml and complete the form there to send us the error you have found. We’ll check the information and, if appropriate, post a message to the book’s errata page and fix the problem in subsequent editions of the book.

P2P.WROX.COM

For author and peer discussion, join the P2P forums at http://p2p.wrox.com. The forums are a Web-based system to which you can post messages relating to Wrox books and related technologies and where you can interact with other readers and technology users. The forums offer a subscription feature to e-mail you topics of interest of your choosing when new posts are made to the forums. Wrox authors, editors, other industry experts, and your fellow readers are present on these forums.

At http://p2p.wrox.com, you will find a number of different forums that will help you, not only as you read this book, but also as you develop your own applications. To join the forums, just follow these steps:

Go to

http://p2p.wrox.com

and click the Register link.

Read the terms of use and click Agree.

Complete the required information to join, as well as any optional information you wish to provide, and click Submit.

You will receive an e-mail with information describing how to verify your account and complete the joining process.

NOTE   You can read messages in the forums without joining P2P, but in order to post your own messages, you must join.

Once you join, you can post new messages and respond to messages other users post. You can read messages at any time on the Web. If you would like to have new messages from a particular forum e-mailed to you, click the Subscribe to this Forum icon by the forum name in the forum listing.

For more information about how to use the Wrox P2P, be sure to read the P2P FAQs for answers to questions about how the forum software works, as well as many common questions specific to P2P and Wrox books. To read the FAQs, click the FAQ link on any P2P page.

Contents

Introduction

WHO THIS BOOK IS FOR

WHAT THIS BOOK COVERS

HOW THIS BOOK IS STRUCTURED

WHAT YOU NEED TO USE THIS BOOK

CONVENTIONS

SOURCE CODE

ERRATA

P2P.WROX.COM

Part I: Building Applications with Swift

1: A Swift Primer

WHAT IS SWIFT?

WHY LEARN SWIFT?

WORKING WITH CONSTANTS AND VARIABLES

WORKING WITH OPERATORS

MAKING DECISIONS WITH CONTROL FLOW

GROUPING TYPES WITH ENUMERATIONS

WORKING WITH FUNCTIONS

SUMMARY

2: Writing a Swift Program

SETTING UP XCODE

EXPERIMENTING WITH PLAYGROUNDS

WRITING SWIFT IN XCODE

DEBUGGING SWIFT APPLICATIONS

SUMMARY

3: Classes, Structs, and Enums

WORKING WITH CLASSES AND STRUCTS

WORKING WITH PROPERTIES

UNDERSTANDING METHODS

UNDERSTANDING THE DIFFERENCE BETWEEN CLASSES AND STRUCTS

WORKING WITH ENUMERATIONS

SUMMARY

4: Concurrency in Swift

WHAT IS CONCURRENCY?

CONCURRENCY IN iOS AND OS X

SUMMARY

5: Interfacing with Web Services

UNDERSTANDING WEB SERVICES

IMPLEMENTING A WEB SERVICES CLIENT

SUMMARY

6: Storing Data with Core Data

WHAT IS CORE DATA?

USING CORE DATA WITH SWIFT

SUMMARY

Part II: Advanced Swift Concepts

7: Extending Classes

WORKING WITH CLASS EXTENSIONS

SPECIFYING BEHAVIOR WITH PROTOCOLS

WORKING WITH GENERICS

SUMMARY

8: Advanced Data Types

WORKING WITH ENUMS AND ALGEBRAIC DATA TYPES

WORKING WITH OPTIONAL TYPES

UNDERSTANDING TYPE CASTING

GROUPING VALUES WITH TUPLES

CUSTOM OPERATORS

USING FUNCTIONS AND CLOSURES

SUMMARY

9: Bridging Swift and Objective-C

THE SUCCESSOR TO OBJECTIVE-C

INTRODUCING NAMESPACES AND MODULES

HOW SWIFT AND OBJECTIVE-C INTERACT

USING C AND C++ CODE WITH SWIFT

SUMMARY

10: Debugging Swift Applications

THE ART OF DEBUGGING

CREATING CIRCLEVIEW

PRINTING VALUES

WORKING WITH DEBUGGERS

EXAMINING ERRORS WITH LLDB, THE LLVM DEBUGGER

SUMMARY

11: The Swift Runtime

WHAT IS A RUNTIME?

UNDERSTANDING THE OBJECTIVE-C RUNTIME

EXPLORING THE SWIFT RUNTIME

SUMMARY

Appendix: An Overview of C

COMPARING PROCEDURAL AND OBJECT-ORIENTED PROGRAMMING STYLES

UNDERSTANDING THE IMPORTANCE OF C LANGUAGE SYNTAX

Title Page

Copyright

Dedication

About the Author

Credits

Acknowledgments

Advert

EULA

List of Tables

Chapter 8

Table 8.1

Chapter 9

Table 9.1

Table 9.2

List of Illustrations

Chapter 2

Figure 2.1

Figure 2.2

Figure 2.3

Figure 2.4

Figure 2.5

Figure 2.6

Figure 2.7

Figure 2.8

Figure 2.9

Figure 2.10

Figure 2.11

Figure 2.12

Figure 2.13

Figure 2.14

Figure 2.15

Figure 2.16

Figure 2.17

Figure 2.18

Figure 2.19

Figure 2.20

Figure 2.21

Figure 2.22

Figure 2.23

Figure 2.24

Chapter 5

Figure 5.1

Figure 5.2

Figure 5.3

Figure 5.4

Figure 5.5

Figure 5.6

Figure 5.7

Figure 5.8

Figure 5.9

Figure 5.10

Figure 5.11

Figure 5.12

Figure 5.13

Figure 5.14

Chapter 6

Figure 6.1

Figure 6.2

Figure 6.3

Figure 6.4

Figure 6.5

Figure 6.6

Figure 6.7

Figure 6.8

Figure 6.9

Figure 6.10

Chapter 9

Figure 9.1

Figure 9.2

Figure 9.3

Figure 9.4

Chapter 10

Figure 10.1

Figure 10.2

Figure 10.3

Figure 10.4

Figure 10.5

Figure 10.6

Figure 10.7

Figure 10.8

Figure 10.9

Figure 10.10

Figure 10.11

Figure 10.12

Figure 10.13

Figure 10.14

Figure 10.15

Guide

Cover

Table of Contents

Part I

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PART IBuilding Applications with Swift

▶

Chapter 1:

A Swift Primer

▶

Chapter 2:

Writing a Swift Program

▶

Chapter 3:

Classes, Structs, and Enums

▶

Chapter 4:

Concurrency in Swift

▶

Chapter 5:

Interfacing with Web Services

▶

Chapter 6:

Storing Data with Core Data

1A Swift Primer

WHAT’S IN THIS CHAPTER?

➤    Understanding Swift

➤    Declaring constants and variables and working with Swift’s data types

➤    Transforming values with operators

➤    Controlling code execution with conditional statements and loops

➤    Defining and using Swift’s enumerated data types

➤    Understanding, declaring, and using functions, anonymous functions, and closures

This chapter introduces the key concepts featured in the Swift programming language and covers the language’s new syntax and data types. It is not intended as an introductory guide to Swift, but rather, as a way for programmers who have already worked with Swift to refresh their knowledge of the language. Prior knowledge of C and Objective-C programming on iOS and OS X is also assumed, although the information presented in this chapter should still make sense to those with no experience in C and Objective-C.

If you are already familiar with the foundations of the Swift programming language, you may want to dive right in with Chapter 2. Chapter 2 also shows you how to use Xcode’s new playgrounds feature, which allows you to experiment with the effects of Swift code as you write it. The examples in this chapter can be entered directly into a playground so you can see the results of your code immediately, without having to create an Xcode project and compile the code.