Singleton and Factory Design Patterns in PHP

Alejandro Gervasio at Dev Shed gives a nice introduction to using the singleton and factory design patterns in PHP to build forms. This 5 part series takes the reader from an introduction to PHP classes and design patterns to creating a form using a form generator class and singleton and factory design patterns.

The five parts of the series:
1. Building object-oriented forms
2. Designing an object factory
3. A rendering-capable factory class
4. Working with Singletons
5. Building a form generator class