[Zope3-dev] Re: Contained events interface inheritance order

[Florent Guillaume]

I'm surprised no-one has commented on this. Jim, you did the last work 
on this, could you tell me what you think?

Florent

Florent Guillaume wrote:
> Today the contained events interfaces are:
>   class IObjectMovedEvent(IObjectEvent)
>   class IObjectAddedEvent(IObjectMovedEvent)
>   class IObjectRemovedEvent(IObjectMovedEvent)
> 
>  From the archives I can find this was decided after:
> http://www.zope.org/Wikis/DevSite/Projects/ComponentArchitecture/ 
> SimplifyObjectLifecycleAndLocationEvents
> but without motivation for this part. I'm still looking for the  
> motivation...
> 
> Before that proposal, the hierarchy was:
>   class IObjectAddedEvent(IObjectEvent)
>   class IObjectRemovedEvent(IObjectEvent)
>   class IObjectMovedEvent(IObjectAddedEvent, IObjectRemovedEvent)
> 
> I contend that this second hierarchy is much more useful to deal  with. 
> The arguments I have are in the use cases explained in:
> http://blogs.nuxeo.com/sections/blogs/florent_guillaume/ 
> 2005_11_08_events-in-zope-2-9
> where you can see the hoops one has to go through to react to objects  
> being created, deleted or moved with the current event hierarchy.
> 
> I'd like to know what non-framework use cases people have today with  
> the current event interfaces hierarchy, and if they really find it  more 
> useful than the old one.
> 
> If not, or if the use cases are borderline, I'd like to propose that  
> the hierarchy be moved back to the second form. This would have to go  
> through a deprecation phase, I'm not sure exactly how, but if there's  
> consensus we can find a way.
> 
> Myself I consider the current hierarchy to be a design bug.
> 
> Florent
> 


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