Introduction

iOS App Development For Dummies is a beginner’s guide to developing iOS apps. And not only do you not need any iOS development experience to get started, but you also don’t need any Mac development experience, either. I’ve written this book as though you are coming to iPhone and iPad app development as a blank slate, ready to be filled with useful information and new ways to do things. Well, almost a blank slate, anyway; see the upcoming “Foolish Assumptions” section for details on what you do need to know before using this book.

Because of the nature of the iPhone and iPad, you can create small, bite-sized apps that can be quite powerful. Also, because you can start small and create real applications that do something important for a user, it’s relatively easy to transform yourself from an “I know nothing” person into a developer who, though not (yet) a superstar, can still crank out quite a respectable app.

But the iPhone and iPad can be home to some pretty fancy software as well — so I’ll take you on a journey through building an industrial-strength app and show you the ropes for developing one on your own.

A Bit of History

It’s 6:00 a.m. PST on January 9, 2007. A distressingly long line of nerds wrapped all the way around San Francisco’s Moscone Center. Why? To hear Steve Jobs give his MacWorld Expo keynote address. It was nuts to get up so early on a cold morning, but Steve Jobs was rumored to be introducing an Apple phone.

No one knew whether an Apple phone would be any good, but perhaps Steve would show us magic — something that would revolutionize an industry. Perhaps it would be as cool and important as the iPod! A few hours later, Steve told the crowd that “Apple is going to reinvent the phone.” Steve was never modest, but he was certainly correct — Apple completely blew away the phone industry that day. The damage was not yet visible to the current phone vendors (Palm, Motorola, Nokia, Sony, Ericsson, RIM, and Microsoft), but they were suddenly left back in the 20th century. The future had arrived.

The iPhone stands alone

The first iPhone shipped in late June 2007. It came with a bunch of Apple’s native apps such as Contacts, Maps, Stocks, Safari, and so on. The problem was that only Apple could develop these native apps. The Apple developer “evangelists” told developers that we should be happy writing web apps. This did not make us happy — we wanted to write native Objective-C apps.

Steve Jobs and Apple eventually saw the light (in fact, some people believe that there was always the possibility of releasing tools to let developers write native apps, but getting the iPhone itself launched took a higher priority). Apple released a beta version of the iPhone Software Development Kit (SDK) in the spring of 2008, and it opened the App Store for business in July 2008. At this point, you could develop native apps — but only for the iPhone, because the iPad did not yet exist.

Enter the App Store

The App Store in July 2008 was a far cry from today’s App Store. The numbers of apps and the numbers of downloads today are staggering. Search for “App Store” on Wikipedia to get the latest numbers. The billions of dollars that developers have earned directly from the App Store are fantastic.

But beyond these large numbers, there’s something about the App Store that I didn’t truly appreciate until my first app went on sale. On the first day, more than 20 copies were sold. (My initial advertising was a mass e-mail to friends.) This was very much a niche-of-a-niche product, but it continued to sell a few copies each week. I added a link to the app to my e-mail signature, and, when I saw a few copies had been sold in Great Britain, I assumed that some of my English cousins had pitched in (bless their hearts, as they say in the South).

But I don’t have any relatives in Argentina. I’m pretty certain I don’t know anyone in Malaysia. Okay, the first couple of sales in Canada might be explained by the fact that I live 20 miles south of the border. But why would someone in China be buying the app? I certainly hope the people in South Africa who have bought the app are using it productively.

Almost all of those people found the app by searching on the App Store. Apple provides a great deal of help and advice for you to put your app’s best face forward on the App Store, and they provide tips and continually refine their search algorithms so that if you use good keywords, people can discover your apps. Apple wants to sell hardware, and they want users of their devices to discover apps that enhance their experiences with the devices.

The numbers of iOS devices are so vast that, with good keywords and a good app description, a niche-of-a-niche-of-a-niche app can find a home on the App Store. You may write the next blockbuster app, but you also may write an app that gets modest results. The highly automated App Store provides the infrastructure to make it all possible.

You can count me among the people who think that the App Store itself may turn out to be a more significant achievement for Apple than the iPhone itself.

The iPad joins the party

Apple released the first iPad in April 2010. In some ways, the iPad was an even more remarkable achievement than the iPhone. The mobile phone existed before iPhone. iPad was the first time that a high-powered computing and communicating device that was truly mobile caught on.

Initially, the iPad ran the iPhone OS. That was a little hard for some people to understand, and before long, the operating system was renamed iOS. We’re now at version 7 of iOS. In addition to the renaming, there has been some restructuring of the developer tools and environment so that things fit together very well.

When I look at developer features such as universal apps (they can run on both iPhone and iPad with minimal code changes), support for in-app purchases, and iBeacon integration, I see a full-featured environment that matches and even surpasses some of the most sophisticated development environments I’ve worked with.

Even though there are many more features today than there were back in 2008, iOS development today is easier than it was a few years ago. The developer tools have matured, and the frameworks themselves have been tweaked with tools such as auto layout that make the placement of interface elements on a screen automatic as devices are rotated and as new screen sizes appear on the devices.

The Plan for This Book

You will build this book’s RoadTrip app using the following steps:

1. Create the initial storyboards for both the iPad and iPhone versions, starting with Xcode’s Master-Detail project template.

   The template’s iPad storyboard is based on using UIKit’s UISplitView
Controller, which uses the same custom MasterViewController and custom DetailViewController used in the iPhone version. The Master View controller will appear on the left when the iPad is held in landscape orientation, whereas the Detail View controller appears on the right.

2. Build and test the iPad version in the iPad simulator. You should see a Table view embedded in a Navigation controller in the Master view.

   The template’s initial iPhone storyboard design begins with a custom MasterViewController (a Table view) embedded in a Navigation view. Selecting an item in the Table view displays data managed by a custom DetailViewController.

3. Build and test the iPhone version in the iPhone simulator. It should also work perfectly because you haven’t had a chance to make any mistakes yet.
4. Add a TestDriveController to the iPhone storyboard. Build and test. Add it to the iPad storyboard. Build and test.
5. Add animation and sound to the Test Drive controller. Build and test both the iPhone and iPad versions.
6. Add additional features to each version until done.

iOS and Xcode Game Changers

With iOS 7 and — more importantly — with Xcode 5 (and later versions), the nuts and bolts of iOS app development have changed dramatically. Xcode 5 has added much more functionality to the integrated development environment (IDE) you use to develop iOS applications, especially when it comes to writing syntactically correct (and bug-free) code that’s better able to manage memory. The latest versions bring much simpler integration with the App Store as well as newly designed performance-monitoring tools. Of course, the rub is getting the hang of Xcode 5. That’s where this book comes in. I carefully take you through Xcode 5, pointing out its features and describing how to best use them. When you set this book aside, you’ll have a great understanding of how to take advantage of all those features that will make your life easier.

You find out how to develop a single app that includes features that readers and students of earlier editions have been asking for — including more animation and sound — as well as an infrastructure that people can use to develop more robust applications. The resulting example is an app called RoadTrip, which can send you on your way...