[Zope-CMF] opaque items, events

[Florent Guillaume]

Hi Kapil,

On 6 Dec 2004, at 22:21, Kapil Thangavelu wrote:
> On Mon, 2004-12-06 at 18:16 +0100, Florent Guillaume wrote:
>> We really need to add events to Zope 2 or CMF. Zope 3 couldn't live
>> without them, CPS couldn't live without them. Many many ugliness, such
>> as this explicit manage_after* and business, goes away when they are
>> available.
>>
>> Currently CPS monkey-patches Zope and CMF to publish events on object
>> creation/destruction/clone. Could we add these simple hooks before the
>> rest of the framework is in place ?
>
> so there are two thingies needed. an event framework an integration of
> the event framework within objectmanager core and cmf tools.
>
> for event framework, tres suggested the interfaces and default
> implementation of the Event product in zc cvs. does that sound okay?

I think so, I haven't yet looked at them in detail but I trust Tres on  
a sound framework.

> for the framework integration.. what sort of hooks do you need? do you
> have a url to cps monkeypatches ?

CPS's monkeypatches are in
http://cvs.nuxeo.org/cgi-bin/viewcvs.cgi/CPS3/CPSCore/ 
EventServicePatches.py?rev=HEAD&content-type=text/vnd.viewcvs-markup

The methods that need to send events are:
   manage_afterAdd
   manage_beforeDelete (both in various classes)
   move_object_to_position (would be moveObjectsByDelta for straight  
Zope)
   manage_renameObject
   manage_pasteObjects
   manage_clone

We'll need to standardize the different kinds events that are sent,  
that's actually the most subtle part of all this. You want an event  
when a "zope" object is set in its container, but you also want an  
event when it is fully CMFized.

Actually you want to refactor everything in terms of events once you  
have them. manage_afterAdd & co should be called by a global event  
listener. CMF cataloging, workflow insertion, etc, can all be  
event-driven. Workflow transitions (scripts, security settings) too...

Florent

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