[Zope-CMF] Re: Zope 3 events from workflow

[Martin Aspeli]

Hi Tres,

> Looks farily good overall.  I think one useful extension would be useful
> to provide access to the same information currently exposed via
> Products.DCWorkflow.Expression.StaTeChangeInfo (these are what the
> guard expressions use):
> 
>   - The workflow object itself.
> 
>   - The transition object itself
> 
>   - The history of the object
> 
>   - Any keywords passed to the transition-trigger ('doActionFor')
> 
> Naming those attributes with the same names used in the expression
> context might make porting some scripts / guard expressions to event
> handlers simpler.

Right. I just passed the names in to keep things simple, but we could
just as easily pass in the tdef, old_sdef, new_sdef.

For the kwargs, we could pass those along from the function (def
_executeTransition(self, ob, tdef=None, kwargs=None)).

When you say history, do you mean former_status in that function
(former_status = self._getStatusOf(ob))? They would of course be easy to
move over.

> For full generality, we also need to allow the "before" handlers to veto
> the transition, e.g. by raising WorkflowException.  Looking at the code,
> it doesn't appear that the definition or the tool make any effort to
> catch exceptions raised by transition scripts, so we should just emulate
> how it handles them.

Meaning, we don't need to do anything more?

Let me try to refactor as you say and post a new patch.

Martin