Chapter 1

Setting Up an Xcode Swift Project

In This Chapter

Introducing Swift

Setting up your computer for Swift

Defining your development preferences

Creating and exploring your first project

Swift is Apple's new language for developers to use with iOS and OS X devices. As such, it is the successor to Apple's existing iOS/OS X development language, Objective-C, but Swift has been designed to cooperate with and work alongside Objective-C, so this should be a slow transition to power.

Some Swift beginners come to the language with proficiency in other languages, ranging from C and its offshoots such as C++ and Objective-C, to newer languages such as Ruby, Python, and Java, as well as scripting languages such as PHP and JavaScript.

Whether you're just starting out as an Apple developer or are an experienced developer who wants to add Swift to your skills, this chapter helps you get started. There's one very important point to remember: As of this writing, the iOS API (application programming interface) and SDK (software development kit) are less than ten years old. (They were launched in early 2008, six months after the launch of iPhone.) The early years of iOS development were an exciting period as the pieces of today's hardware and software environment fell into place. Only as thousands of developers and millions of users started actually using these devices and the languages that support them did some issues - bugs as well as great enhancements - begin to take shape.

Arguably, it took several years for the SDK to reach maturity. Many developers (including your humble author) believe that it was only with the release of iOS 4 in 2010 that the platform more or less stabilized as the operating system we recognize today. This was the first version to be called "iOS" rather than "iPhone OS," and, with the release of iOS 4.2.1 in the fall of 2010, it was the first to support both iPhone and iPad. The first version of multitasking was present, and preparations were made for iCloud that was first released in iOS 5.

If you haven't looked at iOS since that time, a lot has changed. The release of Swift and iOS 8 is a good opportunity to look around and get up to date with iOS (and, for that matter, OS X). This chapter helps you do that.

In this book, you'll occasionally find warnings like this one about serious issues you should avoid. The warnings are used sparingly, so pay attention to them when they appear. The focus in this book is on getting you up and running as a Swift developer. That involves giving you the information you need as well as helping you along the way with encouragement and, from time to time, reminding you that you're not the first person to learn Swift. Others have been there before, and, in most cases, others (most definitely including the author) have encountered the problems you may be facing. There are a multitude of warnings in this chapter. This isn't intended to scare you off: Rather, it's designed to help you over that first hump of becoming a Swift developer. After you have your first clean compile and have finished a build of a project (in the section, "Planning Your Environment," later in this chapter), you'll be on your way.

Looking Ahead to the End

As you make progress in Swift, this book helps you build an app - a real, live app - based on one of the built-in Xcode templates. Sure, you're probably thinking, that's just what I need - another "Hello World" app.

Actually, no. There's no "Hello World" here. Instead, the app you'll be building, called Locatapp, is a full-fledged Swift app created using the Master-Detail Application template that's built into Xcode, and it uses Cocoa Touch and a number of its frameworks to do its work. Locatapp uses location services on Cocoa Touch and the iOS mobile devices to find your location, as you see in Figure 1-1.

Figure 1-1: Locatapp finds your location.

If you prefer, you can download Locatapp from this book's companion website, as described in the Introduction, but be warned - some of the details of registering as a developer described later in this chapter are needed to get Locatapp to run on your own device.

The pulsing blue dot shows your current location. Locatapp lets you store other locations you've visited. The latitude and longitude values of locations that have been visited are shown in the list at the left of Figure 1-1. Tap one of them, and you'll see a map with your current location and with the tapped location indicated by a red pin.

You can zoom in on the map (see Figure 1-2). This zoom-in functionality is all built into MapKit and the device so you don't have to write any code. As you zoom in, you can see that the two locations shown in Figure 1-1 are actually over 100 miles apart. The annotation for Current Location is also part of the framework.

Figure 1-2: Zooming the map.

In addition to the built-in annotation for Current Location, you can write your own annotations in Locatapp. Figure 1-3 shows a custom annotation that you'll write in the course of this book.

Figure 1-3: Writing your own annotations.

That action button at the right of the bar in the interface (the box with the arrow poking out of the top) is an interface element you can drag from the Xcode library into your user interface (called a storyboard). What happens when you tap that action button depends on a method you'll build in this book. This method uses the built-in actions such as Messages, Mail, Twitter, Facebook, and so forth, as shown in Figure 1-4. (Yes, you'll write this code, but Cocoa Touch writes the supporting code to interact with Messages, Mail, Twitter, Facebook, and more.)

Figure 1-4: Implementing an action button.

Figure 1-5 shows a tweet you can construct in your app. Users can modify it (note that there are 57 characters left), but you write the code for the message and to insert the map coordinates. Note, too, that the image of a web page is part of the tweet. You'll see how to automatically put that into the tweet. Although you can tap the image of the web page all you want in this book, in Locatapp, tapping that image will take you to the web page in Safari.

Figure 1-5: Constructing social media messages from your code.

I'm sure you'll like Locatapp and enjoy thinking of ways you can build on it.

As I like to say, "Goodbye, 'Hello World.'"

Working with Swift

Apple has two annual calendars of events. Each is highlighted by one or more major announcements with periodic updates throughout the year. For consumers and end users, the annual calendar focuses on the releases of new and updated devices. As is true throughout the world of electronics, a large portion of annual sales occur during the summer and fall ("back-to-school") and during the year-end holiday season.

On the software side, there is a related peak period. It's no accident that Apple, Google, and Microsoft all hold conferences for their developers in May and June. Typically, they unveil the new features in their operating systems at that time, allowing developers a few months to work with those features before the peak period of hardware sales.

In June of 2014, one of the highlights of Apple's Worldwide Developers Conference (WWDC) was the announcement - a surprise to many attendees - of a new development language for iOS and OS X devices. Called Swift, it was presented as the language of the future for Apple's developers, but it was made very clear that it would co-operate with the existing basic development language - Objective-C.

This book gets you started developing with Swift. You'll quickly see how to create projects in Swift from the built-in templates that are part of the Xcode development tool. From there, you'll delve into features of the languages ranging from the basics to the advanced features that are unique to Swift as well as some features of Swift that may be familiar to you from other modern programming languages.

Swift and Objective-C are the languages most often used in building apps for iOS and OS X. Combined with the Cocoa (OS X) and Cocoa Touch (iOS) frameworks and Xcode, these languages allow you to develop just about anything you can dream of. It is hard to find an app that can't be written with these tools: OS X and iOS apps as well as other Apple products such as Pages, Keynote, and Numbers are developed using Xcode and the Cocoa frameworks. Most of the language work for these products is in Objective-C or Swift, although some sections are still in C++. Apps developed with these technologies are native apps.

If you don't want to go the native route, you can consider using other (non-Apple) frameworks. Three widely used frameworks are Titanium Appcelerator, PhoneGap, and HTML5, which is frequently used as a development tool without being a framework. In the world of Titanium Appcelerator, you typically write in JavaScript, whereas in PhoneGap you use Javascript, HTML, and CSS. HTML5, of course,...