[Zope3-dev] EventService, references, and subscription semantics

[Steve Alexander]

Casey Duncan wrote:
> 
> 
>>Then, we still have the issue of what to use for references.
>>We can use object references provided we're happy to only allow
>>persistent objects to be passed to subscribe().
>>
> 
> This is the problem I tried to work on in my ExplicitObjectReferences 
> proposal. The problem with using regular object references is that the 
> subscriber looses its original context and the reference makes the object 
> persist even if it is deleted from its original location.
> 
> So unless these two things aren't an issue, I don't think object references 
> will work for this. I will definitely not mind being wrong, however.

I thinnk you're wrong :-)

The object references are only used in the EventService to keep a 
collection of subscribers.

A separate issue is of ObjectEvents, which are passed around by a 
traversable location.

The ObjectEvents get converted into RuidObjectEvents in the ObjectHub.
The ObjectHub keeps track of an ruid<->location mapping. So, if you have 
an ruid, you can ask the ObjectHub to resolve it into a location (which 
lets you get an object with appropriate context).

--
Steve Alexander