[Zope3-dev] ItemTypePrecondition and __setitem__

[Stephan Richter]

On Monday 27 September 2004 21:15, Peter Mayne wrote:
> Why does the IMessageContainer/IBugContainer form of precondition work
> for Message/Bug, but not for my type? 

Can you send more of your code? You have to provide the interfaces in a  
particular order, so that the inheritance works correctly.

> Why does the IMessageBoard interface do this directly, rather than letting 
> MessageBoard implement an IMessageContainer style interface?

This is a really good question, which got me thinking at first too. But you 
must not have read the explanation carefully. IMessageContainer does *not* 
describe containers that can contain messages, but requires the message *to 
be* a container. Note that the message board only allows IMessage 
implementations, while the IMessageContainer allows both, IMessage and IFile 
objects. IFile's are attachments to a message.

Regards,
Stephan
-- 
Stephan Richter
CBU Physics & Chemistry (B.S.) / Tufts Physics (Ph.D. student)
Web2k - Web Software Design, Development and Training