By the end of this series, hopefully you'll have a clear idea of how to force object types inside of your PHP application, in this way avoiding further problems related to the so-called code contamination.
When you are writing an object-based web application in PHP, you want to prevent your classes from being convoluted with input objects of the incorrect type. These input objects can cause the application to throw a fatal error. In this article, you will learn how to enforce object types in PHP 4.
They start off with the creation of an (X)HTML widgets class to render certain page elements. Then, they show you the creation of a class to render the page and display them in a full document. There are examples of what happens when type checking isn't done and how to enforce the types inside of your class.
