[Zope-dev] Events in the core

[Florent Guillaume]

I'd like to revive this discussion about having events in the core.

Sidnei even mentionned getting them in Zope directly,
http://dev.zope.org/Wikis/DevSite/Proposals/IncludeEventsInCore

I'm all for it, and would really help many people.

It would be awesome if a minimal implementation could be compatible with
Zope 2.7.4, maybe as an addon product. But there needs to be a few hooks
in the core (object create/move/clone/delete).

Could we try to move together on this ?

For the record, CPS has to monkey-patch many things to have its events
work, and now that many others want events (Plone for starters), it
would be nice to have a common framework, a Zope3-ish framework if
possible.

Florent


Tres wrote:
> Sidnei da Silva wrote:
> 
> > Is there any concrete plan for adding Events to CMF? It would be
> > really nice if we could somehow use Five for that, but given all the
> > constraints, what options we have?
> 
> Events are the major new feature planned ATM for CMF 1.6.  My intent for 
> them was to use the "thrown-over-the-wall" Zope 2 event products as a basis:
> 
>   - http://cvs.zope.org/Products/Event
> 
>   - http://cvs.zope.org/Products/EventListenerTool
> 
> as the basis for a CMFEvent product.  Those tools are used in production 
> in very large sites, and have been pounded pretty hard.  Note that the 
> listener tool allows you to define interface-based subscriptions, which 
> invoke arbitrary scripts:  that is a pretty powerful combination.
> 
> We would then modify the current content classes to pubish events 
> (following the Zope3 pattern as closely as possible) rather than 
> directly notifying the workflow, or cataloguing themselves, and make the 
> appropriate tools subscribers via the listener tool.
> 
> > I've implemented a very simple event registry, highly based on Zope3
> > events, which I think would be more than enough for most of the use
> > cases. Would anyone be interested in adding this into CMF while we
> > wait for the day some Zope3 stuff gets merged into Zope2?
> > 
> > Doctest attached. The implementation is about the same number of lines
> > as the doctest *wink*.
> 
> The tools above are "placeful" ("local" in the Zope3 sense), which seems 
> to be more Zope2 / CMF like than the global one (they allow 
> subscriptions to persist across restarts, for one thing).


-- 
Florent Guillaume, Nuxeo (Paris, France)   CTO, Director of R&D
+33 1 40 33 71 59   http://nuxeo.com   fg at nuxeo.com