Aspect-Oriented Programming in PHP with Go!

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, Patkos Csaba will use the Go! PHP library to teach you AOP in PHP, and review when it can be helpful.

At the heart of AOP is the aspect, but before we can define “aspect,” we must discuss two other terms: point-cut and advise. A point-cut represents a moment in our source code, specifying the right moment to run our code. The code that executes at a point-cut is called, advise, and the combination of one or more point-cuts and advises is the aspect.

Typically, each class has one core behavior or concern, but in many situations, a class may exhibit secondary behavior. For example, a class may need to call a logger or notify an observer. Because these functionalities are secondary, their behavior is mostly the same for all the classes that exhibit them. This scenario is called a cross-concern; these can be avoided by using AOP.