[Zope] How to create a new TAL statement?

[Garito]

Hi all!

As Aj and Chris advise my to forget the __getattr__ bussiness I try to 
solve the same question by other ways

Now I have a new question:

Can you point me to some help about how to create a new TAL statement?

I would like to create a tal:yanged (for example) statement to control 
how zope give to use some properties

Thanks!

-- 
Mis Cosas
http://blogs.sistes.net/Garito