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

[Dieter Maurer]

Jeffrey Franks writes:
 > What is the determining factor that causes one to create
 > a ZClass instead of subclassing a default type?
ZClass' property sheet support is strong.
It can be done through the Web (TTW).

Subclassing requires more modification, especially in
not-TTW code.

 > 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?
I expect, you can do everything through sub-classing what
you can do with a ZClass.
It just can be more work. (There are people who do not like
ZClasses at all)

 > What is the determining factor that moves one to use one over
 > the other?
I use ZClasses for small not-to important projects (because
development is fast).
I use full fledged Python products when the project is more
essential and will probably need several rounds of enhancement
and upgrades.


Dieter