[Zope] dtml syntax help

[Chris Withers]

Sean Kelley wrote:
> Hi
> I need help with dtml syntax...

...learn ZPT ;-)

> I have the following line before a dtml-in on a catalog:
> <dtml-call "REQUEST.set('Verified','on')">
> I want to be able to list only items where Verified is not set to 'on'  
> The default value of verified is no value at all.  If I say:
> <dtml-call "REQUEST.set('Verified','')">
> (empty value)  I get everything. 
> How does one say Verified = to NOT 'on' in dtml?

This has nothing to do with DTML, it is a catalog question.
If 'Verified' can either be '' or 'on', then your search can be achieved with:

your_catalog(Verified=('',))
...or:
REQUEST.set('Verified',('',))
...but I don't like seeing that. Doing that polutes the REQUEST and is rarely 
necessary or a good idea.

cheers,

Chris