[Zope-CMF] Extending portal types: Subclass default type or create a ZClass ?

[Jeffrey Franks]

Hi,

What is the determining factor that causes one to create
a ZClass instead of subclassing a default type?

I have a requirement whereby it looks like the default file
class could be subclassed, and just add several attributes
and provide edit and view of these. One of the attributes needs
to be a select one-of-a-list of fixed items. However, two
other new fields need to reference a table (or list?) of n,
where user adds items to the table.

Can I get away with just sub-classing the default file type
and adding these items for view and edit? Or, do I need to
create a ZClass?

What is the determining factor that moves one to use one over
the other?

-- 
Jeffrey L. Franks  (Web)  http://www.motiftools.org
                   (Mail) jfranks@quik.com