Learning the iOS 4 SDK for JavaScript Programmers

Chapter 2. Welcome to the iOS SDK

Even in these days of powerful high-level web authoring tools, it’s still quite common for JavaScript programmers to compose or modify code with nothing more sophisticated than a text editor. Perhaps you use that text editor to work on .html, .css, and .js files that users access directly; or you use that text editor to write server code (in Python, Perl, Ruby on Rails, or one of several other languages), which in turn assembles HTML code served up to requesting browsers. With the browser operating as a code interpreter (even if it performs some fast precompiling behind the scenes), the write-test-debug cycle is pretty fast: make a code change and reload the browser to test the results. Egregious errors, such as JavaScript syntax errors, signal themselves while the page loads; more subtle errors, such as referencing an object that hasn’t yet been created, fill the error console when the code runs.

When you switch to native app development, this comfy authoring environment and cycle go out the window. Luckily, it’s replaced with an integrated and visually oriented environment that—once you learn its ways—reflects a lot of the best in modern programming environments. This is the native iOS app SDK, whose nucleus is Xcode. Among other things, Xcode helps you visualize and manage the potentially large number of files associated with each app in development.

Additionally, the tools delivered with Xcode are highly integrated. For example, you will write ...