<http://schema.org/description>
"I&amp;#x27;ve always wondered why the Foundation and Cocoa frameworks in Objective-C are so biased towards the delegate pattern. Don&amp;#x27;t get me wrong, I don&amp;#x27;t have anything against it. But there are some cases where using the observer pattern would make..."^^<http://www.w3.org/2001/XMLSchema#string>
<http://a-coding.com/observer-pattern-in-objective-c/>