[Zope-dev] Defining permissions in inherited classes

[Brian Lloyd]

> I've been stuck with this problems for weeks... I posted an earlier 
> question bug got no replies, so I thought I'd try again.
> 
> I have a product that is used as a mix-in class in several other 
> products. This product adds a management interface screen and I want 
> to define permissions to control that screen in this class. So, I do:
> 
> class Publisher(RoleManager):
> 
>      __ac_permissions__ = (
>          ('Change publishing', ('manage_publish'))
>      )
> 
>      manage_publish = HTMLFile('publish', globals())
> 
> In the product that uses this class:
> 
> class Something(Folder, Publisher.Publisher):
> 
>      __ac_permissions__ = (
>          ('View management screens', ('manage_tabs', 
> 'manage_main', ....))
>         .....
>      )
> 
>      manage_options = (
>          {'label':'Edit', 'action':'manage_main'},
>          {'label':'Publish', 'action':'manage_publish'}
>      )
> 
> Now, I think this should work... that's how it's done in 
> AccessRole.Role.RoleManager - it defines __ac_permissions__ that get 
> added to the classes that inherit from it. But it doesn't work for 
> me... the permissions defined in Publisher don't appear anywhere. Any 
> idea why, or what I'm doing wrong?

There is a little bit of non-obvious initialization work that
needs to be done to gather the permission information from all
the subclasses of an object. This is done by calling the method
default__class_init__ (found in the Globals module), passing the
class that represents the creatable object. The default__class_init__
method does the correct permission initialization for you. *Note 
that you must do this for the class of each creatable object your
product defines. In your case, you would add to the bottom of your
module:

import Globals

# pass the class of the creatable object
# that we are defining so that permissions
# are gathered up automatically from the 
# base classes
Globals.default__class_init__(Something)


Hope this helps!

Brian Lloyd        brian@digicool.com
Software Engineer  540.371.6909              
Digital Creations  http://www.digicool.com