Xcode is Apple's integrated development environment (IDE) and is used for the development of iPhone applications. By providing all the tools you will need to design and write the code for your application, Xcode makes developing iPhone applications as easy as ever. During the process of creating your iPhone app, you can run it on your computer, iPhone or iPod touch. In this article, you will find some basic guidelines for developing your own applications which, when finished, you can submit to the AppStore so it can be shared with iPhone users from around the world.

iPhone Application Development Process

Developing an iPhone application can be broken down into a few essential phases. Of course, from the beginning you must have a project in mind. "What will your application do?" is the first question you should ask yourself. Once you have decided what you want to do, you're ready to get started and Xcode provides you with a number of templates to help you get started. Choose the type of application you want to make and start with the most appropriate template. The next stage in the application development project is designing the user interface. At this point, the interface builder application helps you to design the graphics of your user interface. These graphic designs are saved as resources files that will be loaded into your application at runtime.

The following step in developing your application involves writing the code. One of the major benefits of Xcode is that it can help you quickly write the code complete with class and data modeling, code completion, direct documentation access, and even refactoring. Building and running your application is obviously your next challenge. Your computer should have an iPhone Simulator application so that you can continue to build and run your application. Finally, you will want to measure and adjust your application. You want to be sure the application performs as you intended it and that it will provide users with an efficient and smooth experience.

Let's look at the finer details of developing an iPhone application.

Your iPhone Project

The iPhone SDK is a great tool as it gives developers a number of templates from which they can start building their application. There a number of types of iPhone applications and they correspond to these templates. Navigation-based templates are those that present data in an orderly fashion and use multiple screens. OpenGL ES templates are those that show images and animation in an OpenGL ES based view. Tab bar templates use a radio interface so that users have access to several screens. Utility templates employ a main view but allow users to view a flipside and perform customizations. View-based templates present only a single view to employ the user interface, and window based templates act as the foundation for any applications and include an application delegate and a window thus allowing for more creativity in the view hierarchy.

Code Edits

Xcode features a text editor and is the main mechanism by which you will be editing code. Xcode was cleverly designed to offer a range of features to make writing code easier and quicker than ever. Header-file lookups allow you to view the header file that declares the symbol while API reference lookup gives you control over the API reference that tells you how your symbol is used. Code completion is a nifty feature that predicts the code you're going to write: Xcode completes the text for the symbol it thinks you're entering. Plus, this feature is easily disabled so that it needed interfere with the development process. Finally, code folding allows you to focus on the code you are currently working on as you can collapse code that is not relevant to the current task.

Access to Documentation

Any seasoned developer knows that during the development process you might need to quickly access a certain symbol, advanced documentation concerning API usage, or even iPhone OS technology. Xcode was designed to give you easy access to these resources through the Research Assistant and Documentation windows. The research assistant is a window that gives you a compressed view of the API reference on a particular item. You needn't shift focus away from the editor and as such the research assistant provides an inconspicuous access point for API reference.

On the other hand, the documentation window gives you a more comprehensive reference point where you can browse and search developer documentation including API reference, guides, and articles and tools about different technologies. With the documentation window, you have more access to more details.

You're ready to Build and Run your Application

Building and running your application is best served using iPhone Simulator. By employing the iPhone OS API, iPhone Simulator closely recreates the environment provided by devices. You can run your application in Mac OS X and test the applications efficiency and functionality even if you don't have an iPhone or iPod Touch. Still, iPhone Simulator cannot fully recreate device performance so you should always test your application on a device. The iPhone Simulator cannot emulate the memory or processor limitations of various devices. Finally, you should carefully measure the performance of your application before submitting it to the AppStore so that you can be sure that end users are getting the best possible experience. Thorough testing gives you the opportunity to fine tune your application and improve the chances that your application will successfully run in the marketplace.