[Zope3-dev] Missing ObjectContentModifiedEvent

[Florent Guillaume]

Jim Fulton  <jim at zope.com> wrote:
> Based on the discussion so far, I'm convinced that something like this
> would be useful, at least as an optional feature, as you suggest.
> 
> I suggest we generalize this a bit.  I suggest that the ObjectModified
> event could accept one or more modification descriptions (hints?).
> Some examples:
> 
>    ObjectModifiedEvent(obj, IObjectFile)
> 
> This says that we modified the objects file data.  Note that
> an interface is an acceptable description.  In fact, we
> might allow pretty muich anything as a description.
> 
>    ObjectModifiedEvent(obj, IObjectFile,
>                        Attributes(IZopeDublinCore, 'title', 'description'),
>                        )
> 
> This says we modified the file data and the DC title and description.

That looks good to me. Especially because, using interfaces, we could
theoretically express more than just a set of attributes that have
changed on an object. I'm thinking of:

- having the interface itself add semantics to what a subscriber could
  want to do about the change (i.e., it could recognize IZopeDublinCore and
  decide to delay its work),

- having the interface express more complex object structure than just a
  set of attributes (I'm thinking about XML Schema-derived / XForms
  interfaces, where you can represent deep structures).

That's all science-fiction of course.

Florent

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