Design Patterns by Moonlight: How I Do Interfaces

How do the building blocks come together to form a whole? Most resources on Design Patterns look at each pattern in isolation, allowing you to focus on the pattern and its uses without being distracted by side issues. What's missing, I have found, are examples of fitting those patterns into a working system. This month we'll look at a feature involving the validation of user input. We'll be using the PHP interface in quite a few different ways as we build out that feature.