13.3.06. ZCML Needs To Do Less

A few months ago I defended ZCML pretty staunchly. These days, it's becoming feature #1 that makes me NOT want to use Zope.

For the uninitiated, ZCML is an XML configuration language to load up Zope components. I think that having registration separate from implementation, even in another 'language', is a good thing. But ZCML has also taken on heaps of automation capabilities. And those suck. Instead of respecting the Python programmer, it holds your hand and provides a lot of automatic features. Sometimes that's nice. A lot of times, that's wrong. You can't subclass, you can't override, you can't provide slightly different behavior. And don't even think that you can read the code behind the ZCML directives. Most of the code is full of internal handshakes in the configuration loading system. And if all you're trying to do is figure out whether you can provide javascript to a ZCML 'menuItem' directive: good luck trying to figure that one out.

So I stand firmly behind this: ZCML Needs To Do Less (although I don't agree with all of the examples shown).