[Zope] Customizing or Hooking Access Control

[rossp@ppc.ucsc.edu]

I have a bunch of classes and objects that have a boolean 'active'
attribute that gets set on and off variously throughout my code.  I
also have a 'View Inactive' permission that I use in some of my own
object listing methods.

But what I really want is to be able to control the AccessControl
validation.  I would like to be able to say that if an object is
active (its 'active' attribute is on) that someone who has the 'View'
permission can visit it.  If the object is inactive, however, I would
like to be able to say that someone who doesn't have the 'View
Inactive' permission can't visit it.

It would seem that this could be fairly easily accomplished with
something like manage_beforeDelete, manage_beforeValidate for example,
where I can reject the validation before the rest of the checks are
made.  Niether the docs, nor googling, nor reading the source, nor
pestering #zope has yielded anything so far so here I am pestering the
list.

Any ideas?  Thanks.

Ross Patterson
Programmer/Analyst
831-459-2792
rossp@ucsc.edu
1156 High St, Barn G, PP&C
Santa Cruz, CA 95064