Thanks again, I now added def undoable_transactions(self, first_transaction=None, last_transaction=None, PrincipiaUndoBatchSize=None): return () to my class. This seems to work. Is this advisable or are there caveat to be avare of? Robert Am Sonntag, 26. Oktober 2003 21:49 schrieb Andreas Jung:

By removing the Undo tab or by removing Un doSupport from the baseclasses of your objects?

-aj

--On Sonntag, 26. Oktober 2003 20:38 Uhr +0100 robert <robert@redcor.ch>

wrote:

...

Hi there, I have objects that are linked to an external database. When they are deleted, also the data in the external database is deleted. Now an undo is bad, because I then get an object with ab link to non existing data. I must therefore prevent undo. How can I do that?

Thanks, Robert

-- mit freundlichen Grüssen Robert Rottermann www.redCOR.ch