ios App Development for Everyone

Transcription

1 ios App Development for Everyone Kevin McNeish Getting Started Plugging into the Mother Ship Welcome! This is the part of the book where you learn how to get yourself and your computer set for App development and discover how to get the code samples that come with this book. To be clear, when we use the term ios in this book, we are referring to Apple devices that run the ios operating system such as ipod Touch, iphone, and ipad. The Cost of Becoming an ios App Developer These days cost is a real consideration in any new venture. Fortunately, getting into ios App development isn t going to break the bank, but there are definitely some costs involved. First of all, you need to have a computer on which you can create ios Apps (see the next section for details). If you already have the right computer, you have bypassed the greatest expense. Even if you don t, you can buy a brand new Mac Mini for just $ if you purchase from Amazon. Becoming a registered Apple Developer is free, but if you want to test your Apps on an actual device (you do) and submit them to the App Store, you need to pay an annual developer fee starting at $99. But you can wait to pay this fee until you have climbed the ios App development learning curve. The phrase it takes money to make money is very true in this case. There is a great potential for getting a return on your investment as you sell Apps in the App Store, or even write Apps for others. This initial investment is well worth it. Getting the Right Computer for ios App Development Your first step in creating ios Apps is to get a computer on which you can run Apple s Xcode development tool for creating ios Apps in the Objective-C programming language that run on the iphone/ipad Simulator.

2 To run the OSX Lion version of Xcode, you need an Intel-based Mac running Mac OS X Lion or later. If you are still running Snow Leopard, you can install the Snow Leopard version of Xcode. If you want the least expensive Mac available, definitely check out the Mac Mini. The Mac Mini isn t a laptop computer, but it s a very small (7.7 x 1.4 x 7.7 inches) and lightweight (2.7 pounds) device to which you can connect your existing PC or Mac keyboard and external monitor. You can get a Mac Mini for just $568.95, with no tax (depending on where you live) from Amazon. Make sure you get the newest 2.3 GHz Mac Mini model MC815LL/A. This model comes with 2GB of memory and a 500GB hard drive. The processor speed (2.3 GHz) and the amount of memory (2GB) dictate how fast your Mac Mini runs. Higher processor speeds and larger memory increase your speed. The size of the hard drive (500 GB) indicates how much information you can store on your Mac Mini. How much memory do you need on your Mac? The bare minimum is 2GB, but you should really get as much as you can afford. 4 GB of memory is much better, but if you plan to do a lot of App development, definitely invest in 8GB. With 8GB you won t spend time sitting on your hands waiting for Xcode to do something! Running Mac OSX on a PC Although it s not officially recognized by Apple, you can run Mac OSX and in turn Xcode on a PC. In every ios class I have taught there is at least one student running Xcode on a PC. Although I can t advocate this approach because I haven t tried running OSX on a PC myself, there are a variety of tutorials on the web that show you how to do this. Just Google Hackintosh and you re in. Know in advance that this is not a simple process and it may be well worth your time and energy to get a Mac Mini instead. Registering as an Apple Developer (free) It s not until you register as an Apple Developer (free of charge) that you get access to all the goodness that is Apple s full ios developer tools, documentation, and support forums. You can download and install Xcode to create ios apps in the Objective-C programming language that run on the iphone and ipad Simulator as well as real ios devices. Here s where you get started: When you navigate to this page you see a list of what you get as a registered Apple developer as shown in Figure 1.

3 Figure 1: All the goodness that comes from registering (free of charge) as an Apple Developer As you can see, you get access to Xcode, as well as the IOS SDK (Software Development Kit) that includes a full suite of development tools. The ios videos and documentation are also good resources for learning about ios development, although most of them assume you already have a background in programming on the Apple platform. If you click the Get Started button, you are taken to the web page shown in Figure 2. If you already have an Apple ID (you do if you have an itunes account), you can use that same ID to register as an Apple Developer. Otherwise, you can choose to Create an Apple ID.

4 Figure 2: You need an Apple ID to register as an Apple Developer After creating an Apple ID or using your existing ID, you are taken through a series of web pages where you first enter your personal profile (name, company, address, phone, ). Next, you are asked to complete a professional profile where you specify the Apple platforms you develop with (you should select ios on this page) and your primary market (business, education, entertainment, and so on), the type of ios Apps you plan to develop, and your development experience (if any). The next web page displays a Registered Apple Developer Agreement that you can read and sign. This includes verification that you are of legal age in the country in which you live. After signing the agreement, a web page displays letting you know a verification code was sent to your address. You need to enter this verification code you received via and click Continue as shown in Figure 3.

5 Figure 3: To complete your registration, enter the verification code you received via After you enter the code and press Continue, you are greeted with the happy welcome message shown in Figure 4! Figure 4: It s official nothing quite like being officially in the program! When you click Continue on this page, you are taken to the Apple Developer Member Center shown in Figure 5.

6 Figure 5: Once you are a Registered Apple Developer you can join one of Apple s Developer Programs Here you will see an option to Enroll in one of the Apple Developer Programs. You re already a registered Apple Developer so what s this about? Joining the ios Developer Program If you click the Join Today link in Figure 5, you will be taken to a web page that talks about individual or company/organization developer programs. To get full access to the complete ios developer experience, including he ability to take the training wheels off your Apps, run them on a real ios device, and distribute them to the App Store, you need to pay your fee (starting at $99) to become part of the ios Developer Program. For this book, you only need to be registered (for free) as an Apple Developer. Since there is an annual developer fee, you can choose to join an Apple Developer Program at a later date once you re past the initial ios learning curve. Downloading and Installing Xcode To get to the ios Dev Center where you can download Xcode, click the ios link under Dev Centers as shown in the web page in Figure 5. Ultimately, you will be redirected to download to the Mac App Store to download Xcode, but it s free of charge to registered Apple developers. The installation file for Xcode is huge (although it can vary between versions, it will be at least over 1.4 GB). Depending on the speed of your Internet connection, plan for a relatively long download time. Once you have downloaded the installation file, it takes only 5-10 minutes to perform the actual installation.

7 Note that there are different Xcode downloads for the Snow Leopard and the Lion operating systems, so make sure you grab the correct download! Warning: Before installing Xcode make sure you have plenty of disk space available (at least a few gigabytes). If you don t have enough disk space available, the Xcode installer doesn t always warn you and simply displays a vague error message! When you go to the Mac App Store, you will see a button in the upper left corner with the word Free as shown in Figure 6. Figure 6: Click the Free button to select Xcode to be downloaded Click this button and the color changes to green and the text changes to Install App as shown in Figure 7. Figure 7: Click the Install App button to begin the Xcode download Click this button and you are prompted for your Apple ID (Figure 8).

8 Figure 8: Enter your Apple ID and Password to verify your identity After entering your Apple ID and Password, click Sign In and the button in the App Store window changes to say Installing (Figure 9). Figure 9: The button indicates Xcode is being installed While Xcode is installing, you can do other tasks on your Mac. If you want to check the installation progress, click the Purchases icon at the top of the App Store window and you can check the amount of megabytes and time remaining (Figure 10). Figure 10: Checking Xcode s installation progress After installation is complete, if you are still on the main App Store panel, the text in the button changes to Installed as shown in Figure 11.

9 Figure 11: Xcode is finished installing If you are on the App Store s Purchases tab, the Xcode item also shows it is installed (Figure 12). Figure 12: Xcode shows Installed on the App Store s Purchases tab If Xcode doesn t open automatically after installation, click the Applications folder in your Mac OSX Dock (the folder with the large letter A on it) as shown in Figure 13. Figure 13: Select the Applications folder in the Mac OSX Dock Next, click the Xcode.app icon from the popup list of applications shown in Figure 14 (you may need to scroll down to see it).

10 Figure 14: Select the Install Xcode.app icon to complete the installation The first time you launch Xcode you may see an Xcode Component Installation dialog that tells you to install the Mobile Device Framework (Figure 15). If you see this dialog, click Install, and enter the id and password for your computer. It takes just a few minutes to install these files. Figure 15: Installing the Mobile Device Framework When the Mobile Device Framework installation is complete, the Installation Complete message appears (Figure 16). Click Start Using Xcode to continue.

11 Figure 16: Installation is complete! You should now see the Welcome to Xcode screen shown in Figure 17. Figure 17: Xcode is installed and ready for you! Now your computer is completely set up to begin creating ios Apps!

12 Designing with Humans in Mind I know you re itching to put fingers to keyboard and get on with the fun of creating your App, but you should absolutely read Apple s ios Human Interface Guidelines document first. One of the biggest problems in software development is forgetting about end users. If you lose sight of the people who will be using your App, you may create an App that is difficult to comprehend and use. There is a reason why Apple has taken over the world with ios devices in contrast with products like Microsoft s Zune that are now acting as expensive paperweights. It s because Apple has designed the devices and Apps with humans in mind. And not just any humans they are designed for what Apple likes to call the 80 percent, or the majority of your users. Sometimes it s hard to ignore the very vocal 20 percent of users, but if you fold on this point and add complex features to please a smaller percentage of users, your App will not be easily used by the other 80 percent. I highly recommend you read this document thoroughly and keep it close in mind through the entire adventure of building your App.