NSBundle posts NSBundleDidLoadNotification to notify observers which classes and categories have been dynamically loaded.

NSBundle

classNamed:

principalClass

NSBundleDidLoadNotification

The notification object is the NSBundle instance that dynamically loads classes. The userInfo dictionary contains an NSLoadedClasses key.

In a typical use of this notification, an object might want to enumerate the userInfo array to check if each loaded class conformed to a certain protocol (say, an protocol for a plug-and-play tool set); if a class does conform, the object would create an instance of that class and add the instance to another NSArray object.

Available in Mac OS X v10.0 and later.