[Zope3-Users] classProvides and inheritance

Iain Duncan iainduncan at telus.net
Sat Aug 15 17:06:49 EDT 2009

On Sat, 2009-08-15 at 16:57 -0400, Jim Fulton wrote:
> On Sat, Aug 15, 2009 at 4:49 PM, Iain Duncan<iainduncan at telus.net> wrote:
> > Hi, I'm new here so please tell me if this is the wrong list.
> >
> > I have a case where I want a class, ( the class object itself, not an
> > instantiated class ) to provide an interface so that a utility look up
> > can get me the class itself. This is working ok with:
> >
> > class IPet(PersistentResource):
> >  implements(Pet)
> >  classProvides(IResourceClass)
> >
> > but, all classes that inherit from PersistentResource should provide
> > this too,
> That's a matter of opinion.

Sorry, my sentence came across wrong! I definitely did not mean that the
ZCA should make it so by default, I meant that in my particular
application I would like it to be that way without necessarily having to
add a classProvides statement to each derived class. My fault for not
being more clear.

> > and this does not get inherited just by using classProvides in
> > the definitiation of PersistentResource.
> >
> > Before I go making metaclasses and stuff, thought I should check if I am
> > missing something simple!
> No.  Class provides isn't inherited by design.

I understood that, I just phrased my question poorly. So given the
clarification, is there a straightforward way for me to make it so, or
will I need to make a metaclass that enforces my desired behaviour?


More information about the Zope3-users mailing list