DevShed starts off a new two-part series today with this first look at building proxy classes with PHP 5.
In short, in the proxy pattern, one object is created by another only when the functionality of the first one is required. In this two-part series, I'm going to walk you through the key points of how to use this pattern with PHP 5, as well as how to apply it in different real-world situations.
They start with the creation of an expandable XML processor class that can be enhanced when additional functionality is needed. They use this class as a proxy for the requests and create a separate class (a normal XMLProcessor class) to perform the actual requests for the information - grabbing information from the loaded XML document.