In a recent post Marcelo Gornstein takes a look at using dependency injection with Doctrine2 using his Ding container.

This article will show how we can develop software in php with a nifty design and architecture, and very much like other languages like java, using an ORM and an AOP, DI, Events container. I will assume you've read (or at least took a quick look) at this article that explains the tree layout used throughout the code, and that you have some basic knowledge of Doctrine2 and used it before on your own.

He starts with the result - an easy to use, self-contained (and decoupled) system for accessing the Doctrine2 instance. It's event-driven and uses Aspect-oriented programming to mange interactions between components (or as he calls them "beans"). Code is included for the entire process for a logger, the User entity, entity manager, user repository and transactional aspect. You can find the complete source for his example on his github account.

Matthew Weier O'Phinney has a new in-depth post to his blog that looks at a few features of Aspect Oriented Programming and what technologies are out there that help support it right now. He mainly focuses on the features of the Lithium framework because of its filtering techniques.

Last month, during PHP Advent, gwoo wrote an interesting post on Aspect-Oriented Design, or Aspect Oriented Programming (AOP) as it is more commonly known. The article got me to thinking, and revisiting what I know about AOP, Intercepting Filters, and Signal Slots -- in particular, what use cases I see for them, what the state of current PHP offerings are, and where the future may lie.

He gives a base class to help make things a bit clearer for the rest of the post - a simple Foo instance that uses a Listener interface to "doSomething". Matthew also talks about intercepting filters (extracting things like logging/debugging out of the code and put on its own) and signal slots. For both, he gives examples of how Lithium handles them and some of his opinions on the methods. He points out a few concerns that he has for the current state of AOP in PHP (frameworks) and suggests that, if you haven't looked at these ideas, you do so sooner rather than later.

On of the frameworks rising up through the ranks is Lithium (created by some of the original CakePHP developers). In his latest post Chris Hartjes looks at the framework and a particularly useful feature it includes - filters.

As far as I can tell, Lithium is trying it's hardest to be fast, lightweight, and use all the features that PHP 5.3 has to offer. [...] I want to talk about something that I feel is a very underrated part of Lithium, the ability to define filters. This is a concept that you find in Aspect-oriented programming, and one that I imagine most programmers have never considered. Here's why I think it's a big deal.

The filters in Lithium allow you to use code from other classes without having to actually extend them. As Nate Abele says in one of the comments on the post:

While not having to extend classes or dig inside core functionality is certainly pretty central, the way I've been explaining it is that it's important because classes no longer need to know anything about each other in order to be integrated.

You can find out more about the Lithium project (and RAD-Dev) on the project's wiki.

If you've been looking for more information on the phpAspect project but have been sad to note it having fallen by the wayside, you'll be happy to know that Willliam Candillon is alive and well and so is the project!

The first news concerns the windows developers, the windows build of PHP_Parse_Tree is finally available (click here to download)! [...] The second news is that my proposal "phpAspect eclipse plugin" for the Google Summer of Code 2007 under the mentoring of Gilles Vanwormhoudt has been accepted!

Be sure to keep an eye on the project's website and their Summer of Code page to keep up with the latest.

Willliam Candillon has a (very) quick note for all of the phpAspect fans out there:

I will be performing a talk about phpAspect at Solution Linux 2007, the 31th january 2007 and a lightning talk at FOSDEM next month. I'm looking forward to collect your feedbacks, questions and suggestions about phpAspect!

The Solution Linux 2007 conference is happening in Paris from the 30th of January to the 1st of February. FOSDEM will be in Brussels, Belgium and is happening the 24th and 25th of February.