Christopher Warner "So, it's not like the code is my brain; keep it"

Zope/Plone have changed my life

I can't stress enough how pleased I am with Zope/Plone in regards to a CMS system. If you are doing content management and are using Python then I strongly suggest you look at Zope/Plone. Python being  such a strong and usable language that makes the impossible; possible and the architecture of Zope and the CMF Framework which Plone is built from makes it a CMS killer. Period. Which brings me to the reason for this entry.

Here at New York Magazine we have a fashion section. It's a mismash of Krang and other random Dreamweaver run around all over the place HTML. This is obviously no way to manage the content in this, the year, 2007. So I have begun to take on the process of breaking it down into Plone and came across the subscriber/event model system available in Zope3. It's great and here's a quick tutorial on how to use it.

A user is working with a Model Biography and the Fashion editor want's an IM when each Model Biography is created.

First we setup an interface (marker interface) for our Model Biography:
from zope.interface import Interface

class IModelBio(Interface):
""" Model Biography """

Think of the interface as documentation for the class, describing what it can and can't do. As this class doesn't have any methods there is just a comment describing that it's a Model Biography.

We then have the actual ModelBio class which implements our interface.

class ModelBio(BaseContent):

"""A Model Object """
implements(IModelBio)

From here we can now modify our configure.zcml (this configures Zope the way we want it), where we add our subscriber. Here is a good description of ZCML and why it gives our code more structure.

note: Do to the way Wordpress filters html tag/close tag should be replaced with the appropriate markup. Seems I need to either upgrade or find some new blog software.

tag subscriber
for=".interfaces.IModelBio
Products.Archetypes.interfaces.IObjectInitializedEvent"
handler=".events.model_created"close tag

What this says is that for ModelBio we want to know when a ModelBio object is created. When we know that, events.model_created, will be handling said situation. So, all that's left to do is add a method called model_created in events.py

def model_created(model, event):
""" blah blah """
print model.title + " has been created"

That is pretty much it! Again, if you are doing CMS anything you may as well investigate Zope/Plone. I also highly recommend picking up a copy of Martin Aspeli's book; "Professional Plone Development", available here. It will definitely help, even if you are a beginner to Plone. Here's a recent review of the book on Slashdot. As usual the commentary on Slashdot is to be used as toilet paper. Needless to say I don't make a dime off of any of this the book is just that good.