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

[Martin Aspeli]

Sidnei da Silva wrote:
> Something that strikes me, by looking at this code is that we also
> want events that map to 'notifySuccess' and 'notifyException' too (ie,
> ITransitionSuccessEvent and ITransitionFailureEvent), not only
> 'before'/'after'. (see _invokeWithNotifications).
> 
> Those could be fired from the 'notifySuccess', etc. And the code that
> is currently in 'notifySuccess' would move to a subscriber.

I don't think I fully understand the use case or usage of 
notifySuccess() and notifyException(). They are called by 
portal_workflow, on the workflow definition. They don't seem to be used 
in the current code at least.

I think for code *outside* DCWorkflow/portal_workflow the most sensible 
things to subscribe to would be the IBeforeTransitionEvent and 
IAfterTransitionEvent events in my patch - you care that a transition is 
about to happen or has just happened, much like we have script_before 
and script_after.

It seems to me notifyBefore(), notifySuccess() and notifyException() are 
used internally by DCWorkflow to let the workflows set variables and 
mutate objects as needed. If that is correct, then I'd say it's a 
lower-priority refactoring (if it's inwardly focused rather than 
enabling other code to react to workflow events more easily, and thus 
outwardly-focused) and could be handled separately from this patch, to 
keep things simple.

> I guess that 'notifyCreated' could be replaced by a subscriber to
> 'IObjectCreatedEvent' or equivalent.

+1 to not inventing more events than we need to.

Martin