Three20: collection of iPhone UI classes
Three20 is an iPhone development library. It's the code that powers the Facebook iPhone app and many other apps in the app store.
Core
Think of core as your swiss-army knife of Objective-C development. You should take some time to familiarize yourself with its features.
With the Three20 Core you can
- generate md5 hashes from NSData objects,
- extend the logging and debug capabilities of Xcode,
- compare two version strings (is 3.0 older than 3.1?),
- create non-retaining NSArrays and NSDictionaries for delegate use,
- strip HTML tags from strings,
- safely add non-empty, non-nil strings to NSDictionaries,
- and format dates in relative time (5 hours ago).
You'll find all of these methods in the Three20 Xcode project in the
Global => Core and Global => Additions => Core groups.
Network
If you're building an app that uses a web-based API, Three20's Network component is going to make your job easier. Three20 supports disk and memory network caching. There is also a layer built upon requests that makes it easy to process the response data.
UI
A growing set of common views and controllers is available within the Three20 UI. The well-known Facebook photo browser/thumbnail viewer is one such controller.
