There is some discussion in the symfony which is the better ORM layer. Propel or Doctrine.

To be honest, I prefer Propel right now. It is simple, you can easily override functionality (even when its ugly by copy pasting just to force a certain PK to be set). But the best thing is the availability of behavior plugins from the community.

The Plugin-Wiki hosts currently 17 propel plugins. And those are growing from day to day. You might say, oh well why do i need to add a plugin to be able to rate one of my domain objects?
The answer is: You don’t need. you can code it yourself. But why would you, if you get a maintained flexible and readymade plugin for it? Actually I switched from a home grown rating solution to that plugin and contributed my ideas. It is more powerful, more robust and more structured than the solution I came up.

Here my top 3 of the propel plugins:

  1. sfPropelActAsNestedSetBehaviorPlugin : Have you ever tried to build a tree from an RDB? It is a hell of work and this plugin solves this like a charm. There are many improvments discussed on the mailinglist and constantly integrated. This plugin saves you A LOT of work.
  2. sfPropelActAsRatableBehaviorPlugin : As described above. This helps you rating your domain objects. It includes a module for displaying a star rater plugin.
  3. sfPropelActAsCommentableBehaviorPlugin : Pretty new plugin, but similar to ratable. But only for comments. As ratings and comments are two main features of modern web 2.0 apps this is a must too. Again: Not complicated to do yourself, but a solution that is maintained enhanced and gets features you would have liked but not thought of yet, is much better than reinventing the wheel.

And of course I take the chance to point you at sfPokaYokePlugin which brings you degrading javascript validation using exactly the same validation files than your regular symfony serverside validation is using. No extra effort! Why am I referencing that plugin? Because I contributed to that as well :)

Have a look at symfony plugins today. Don’t reinvent the wheel, but contribute to make existing wheels even rounder!

Update:

I just checked how you would do these behaviours in propel. pookey pointed me to something Doctrine calles templates:
http://www.phpdoctrine.org/documentation/manual/trunk?one-page#class-templates

this should be pretty much similar to behaviours. Although there are no readymade symfony plugins for common use cases existing yet. Hope that helps you Doctrine users. I am not (yet) one :-)