[Zope] ZCallable

[Dieter Maurer]

Stefan H. Holek writes:
 > I have this ZCallable product (from the PTK, I think). I do however not
 > manage to derive a ZClass from ZCallable. The error is something like "Too
 > many datafull base classes".
 > 
 > Is ZCallable not intended to work like that (the source hints to
 > some ExtensionClass business) or am I missing something?
The ExtensionClass docu tells that among all classes involved
in a class, at most one extension class may define data extensions.

Apparently, ZCallable is such an extension class that defines
a data extension (or inherits from a class that does).
And obviously, your class derives from another such class.

If you are lucky, ZCallable is a superset of
the other class and you can drop the other.

Unfortunately, I do not know with ExtensionClass'es define
extensions.


Dieter