[Zope3-dev] Re: Container interface issues

[Garrett Smith]

Jim Fulton wrote:

> Anthony Baxter wrote:
> 
>>>>> Jim Fulton wrote
>>>
>>>
>>> I proposed that application code, rather than containers, be
>>> responsible for generating events and calling necessary hooks when
>>> adding or removing objects.  
>>
>>
>>
>> I understand the rationale for it (indeed, I can't see a better way) but
>> this makes me uneasy. In the process of hooking up the catalog I found a
>> number of existing places that were not Doing The Right Thing with event
>> generation - making more places to do this Would Be Bad. Tracking down
>> missing event generation stuff also sucks - things are just wacky, and
>> it takes some time to find the problem.
> 
> 
> I suspect that this would be almost as likely of Doing The Right Thing
> was the container's responsibility.
> 
> I think we can arrange for making Doing The Right Thing easier.  For 
> example,
> instead of:
> 
>   container.setObject(name, object)
> 
> people will use:
> 
>   zapi.add(container, name, object)
> 
> I think that these are of comparable difficulty.

I would expect to see an adapter used here:

   container = zapi.getAdapter(container, IStandardNotifyContainer)
   container[name] = object

This way, notification policies could be encapsulated in specific 
adapters. There would be little impact on existing code since containers 
are usually 'adapted' to IZopeContainer. It also provides a simple 
pattern for implementing alternative notification schemes.

I personally would not be comfortable with zapi.add because of its opacity.

  -- Garrett