Book review: “The iPhone Developer’s Cookbook”

You’ll find two kinds of software on Apple’s iPhone App Store: that which should be given away regardless of its price tag, and commercial-grade applications worth paying for. Any developer that aims to produce the latter should consider Erica Sadun’s The iPhone Developer’s Cookbook, Building Applications with the iPhone SDK (Addison-Wesley) required reading.

The book’s prerequisites are few, but none can be ignored. You must bring knowledge of Objective-C, which is easily acquired, paid membership in the iPhone Developer Program, and an iPhone device. Only paid members can use upload code and debug on a physical iPhone or iPod Touch. As Sadun’s readers learn, there is a great deal that the iPhone emulator, bundled with the free edition of the iPhone SDK, cannot do.

After a short ramp-up, this book puts you to work, hard work. It opens with a welcome tutorial on using Xcode to provision a device for development, and there is a little bit of walk-through of Interface Builder, an IDE component that might not be familiar to coders coming to iPhone from other platforms. Then it’s down to Sadun’s rapid-fire recipes, where the real work and skill-building begin. I have a survival tip: Read the succinct description of the each concept illustrated by the recipe, type in (not download — you learn slowly from downloaded code) the samples, and compile and debug them on a real iPhone. Most of the recipes are self-contained, and several are complete applications. It is left to you to combine and expand on the recipes, which is where your real learning is done. This book is presented an IDE-friendly style, reinforcing the point that The iPhone Developer’s Cookbook is to be read with Xcode and a tethered iPhone awaiting your orders.

Don’t take my description of the serious, hard-working nature of the book to indicate that you won’t have any fun. Each of the samples delivers a real sense of satisfaction when you make it work; you’re constantly rewarded for your effort. Sadun is also a fan of style, and much of the book is devoted to GUI presentation of the sort that separates casual apps from commercial ones. The spectrum from drawing pixels directly to the display to using Core Animation and nested views is covered. Sadun takes the mystery out of multi-touch so that your app can be among the few that use gestures for more than just scrolling. The author also illustrates fascinating undocumented (and, the author warns, subject to change without notice) APIs such as the page curl effect used in Google Maps. Sadun also ventures into outside-the-SDK territory such as reverse geocoding as an aid to developers who would rather do things themselves than hand off control to one of Apple’s canned apps.

GUI presentation dominates the book, but the last few chapters cram a lot of system services into a few briskly presented yet ambitious recipes. If you want to plant a rudimentary Web or FTP server on your iPhone, Sadun shows that it’s child’s play. Triggering one iPhone application from another, passing data between them, is an effective and well-illustrated workaround for iPhone’s one-app-at-a-time rule. Raw recording and playback of audio aren’t so easy, but if you want to do it inside your app instead of calling out to Media Player, this book has the recipes. Sadun’s not shy about showing better ways than Apple’s, particularly when she keeps readers mindful of the fact that whatever one needs that Apple doesn’t provide can be cobbled together from open source.

Apple’s iPhone SDK documentation lays out a far gentler, if scattered, path to expertise. Erica Sadun’s book doesn’t supplant the SDK docs, but it will leave you able to create software that doesn’t end up lost in the morass that is the App Store. The iPhone Developer’s Cookbook can take a serious, creative developer to the five-star user ratings that grab attention, get the App Store money moving, or if you’re coding for your employer, lead to tight, gorgeous apps that spell job security. In short, I can’t imagine any commercial iPhone application of value being written without The iPhone Developer’s Cookbook on its creator’s desk.