[python-win32] returning COM objects from a COM server

[Sébastien de Menten]

Hi,

I have several classes that I would like to map to COM objects to make them 
accessible from Excel via COM.

I have looked at the COM server interp.py supplied as example in the 
win32all package and I can access it easily from Excel.

Now, if I add a new class Foo
class Foo:
   def test(self):
      return 4
and a new funcion in this Interpreter class like
   def return_foo(self):
       return Foo()
when I call from Excel the function return_foo() on the object 
Python.Interpreter, I get in the "Python trace collector" an exception:

in _Invoke_ with 1002 1033 3 (4,)
pythoncom error: Python error invoking COM method.
exceptions.TypeError: Objects for SAFEARRAYS must be sequences (of 
sequences), or a buffer object.

Evidently, Foo is not a COM Object. So how do I make it a COM Object ?

I can register a new COM server "Python.Foo" and use
   def return_foo(self):
       return win32com.client.Dispatch("Python.Foo")
but then:
   a) anybody could create it while I only want Python.Interpreter to do 
that
   b) it is not very elegant :-)

So, is it possible to create new COM objects that map Python classes 
automatically ? Do they need to register ?

Any example to advise ?

BTW, why is not there a COMServer class in win32all that could enjoy 
metaclass facilities and inheritance to ease the work (I agree it is already 
quite easy but ...) ? Is it for historical reasons or is there a deep 
explanation ?

tx

Seb

ps: could you reply to my address as I am not subscribed to the mailing list 
?