On the Zend Developer Zone today, there's this new tutorial that looks at making the move from PHP4's object-oriented programming up to the "more complete obejct model of PHP5" - specifically with the Decorator design pattern.
While working on a project I realized one particular solution was a pretty good way to demonstrate the decorator design pattern together with some of PHP5's features, including abstract classes, interfaces, type hinting, the final keyword and the visibility of properties and methods. This article is intended for those of you who, like myself, are moving from object-oriented programming, including some use of design patterns, in PHP4, to the more complete object model of PHP5.
He sets up a scenario about the development of an online pizza ordering system to show how to "decorate" a pizza with each of the toppings on a list (instead of having to list out every pizza in every possible topping combination). Of course, all of the code is included and explained so you understand exactly what's happening. Finally, there's a demonstration of its usage - a simple call that grabs the stock level/name/cost of each of the items in stock (pizza combinations).