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@nuxeo.com