Thursday, 19 April 2007

Learn to Implement the Stage Pattern in PHP 5

In the first article of a two-part series Alejandro Gervasio demonstrates another design pattern. This time in a two part series, he discusses about the Stage pattern. He introduces you to the key concepts and shows you how to implement it with code samples.

Alejandro says, in the huge area of pattern-based programming, there’s one pattern called ‘Stage’ that provides developers with a handy mechanism for building a class that’s capable of modifying its behavior in response to the changes introduced into its environment. He begins the tutorial under the following section:

• Creating the programmatic model of the stage pattern: in this section, he defines a ‘target’ class. This class is capable of modifying its behavior according to the variations introduced into its working environment.
• Changing the behavior of a target class: here he builds a brand new class to complete the model dictated by the stage pattern.
• Seeing the stage pattern in action: in this section, he sets up an example where the pair of classes that you learned earlier are put to work in tandem.