php - autoload and multiple directories

Question

I've just been looking at php's autoload() function. Seems a nice idea, but I'm not sure how it handles multiple directories. My current development basically has a library directory structure grouping classes into subdirectories by operation. I'm wondering I have to declare a include() for each directory ... which I really hope I don't have to do.

Can you advise - thanks

Answer 1

You might want to take a look at the PEAR Convention for class names, which is really great for autoloading.

Basically, it states that :

The PEAR class hierarchy is also reflected in the class name, each level of the hierarchy separated with a single underscore.

Which means finding the file to include for a classe name HTML_Upload_Error is just a matter of replacing '_' by '/' ; giving you HTML/Upload/Error.php

For more explanations, and a couple of examples, you can take a look at the articles :

• Autoloading PHP Classes to Reduce CPU Usage
• Autoload Magic

BTW : this convention is used by many big Frameworks / libraries ;-)
For instance, Zend Framework uses this convention -- and it's really helpful !