KVO+Blocks

Just found out this little NSObject category. It’s awesome. A must #include in your project.

“To get observation notices, you have to override a lengthy selector (observeValueForKeyPath:ofObject:change:context:), provide a static context pointer, and essentially implement a big switch statement on the key path.

That’s unwieldy, but I think it also makes for unmaintainable code: the callbacks end up thrown in the same method, and they’re separated from the observer registration.”

~ KVO+Blocks: Block Callbacks for Cocoa Observers

Since iOS 4 support blocks, it’s possible to use this for iPhone projects too.