[Zope-CMF] DCWorkFlow Guard Expressions?

[Paul Winkler]

Hi,

i'm cooking up a workflow in which 
some states may be triggered by a combination of factors,
e.g. "if foo is true and bar is 
false we are in state A, but if foo and bar
are both true we are in state B."
foo and/or bar may be the state of something
outside the control of the user,
or even outside the entire CMF instance.

I suspect this is what Automatic transitions
are for, but how does an automatic transition
get triggered? That's what the guard expression
is, right?  But how do you write a guard expression?
I don't see any docs about it - 
the PDF at 
http://www.zope.org/Members/hathawsh/DCWorkflow_docs/
doesn't say, neither does anything in the wikis
that I can find.

Alternatively, anybody have examples of DCWorkFlow 
automatic transitions with Guard Expressions that 
I can look at? the CMFDefault example workflows 
don't have any, and I can't seem
to find anything in the PDF docs except basically
"you can have guard expressions". OK, but I don't
know what kind of expressions, or what triggers
a test of the expression, or anything.

-- 

Paul Winkler
http://www.slinkp.com
"Welcome to Muppet Labs, where the future is made - today!"