The concept of Aspect-Oriented Programming (AOP) is fairly new to PHP. There's currently no official AOP support in PHP, but there are some extensions and libraries which implement this feature. In this lesson, we'll use the Go! PHP library to learn AOP in PHP, and review when it can be helpful.
They start with a brief history of AOP in general and a basic vocabulary of some of the common terms like "point-cut", "aspect" and "cross-concern." They briefly look at some of the other PHP tools for AOP, but then help you get Go! up and running. Sample code is included showing how to integrate it into your project and, more practically, create a logging system that can be used as an aspect.