[Zope3-dev] Re: best practices for registry-like functionality

[Garrett Smith]

Jim Fulton wrote:

> Garrett Smith wrote:
> 
>> I need to manage a set of vocabulary-like objects for a site. These 
>> vocab objects will be used by widgets.
>>
>> These objects are not content, so I want to store and manage them in a 
>> site management folder. Specifically, I need to be able to:
>>
>> - Add new vocab objects
>> - Edit existing vocab objects
>> - Delete vocab objects
>> - Lookup a vocabulary by name
>> - Get a list of all registered vocab objects
>>
>> In the past, I would have written a service for this, which would 
>> maintain its own contained set of vocab objects. But I suspect I 
>> really want a utility,
> 
> 
> In particular, you want to treat each vocabulary as a utility.

Okay, that makes sense.

As for:

 >> - Get a list of all registered vocab objects

Is there a way to enumerate registered utilities that provide a 
particular interface?

I suppose I could use a convention and store the utilities in a site 
management folder, and use the folder's container API. But this feels a 
bit to implicit to me.

Btw, if this is a use case for utilities, 'singleton' would be a 
misleading term. The term 'utility' is a bit of a stretch for that 
matter. We're talking about 'named objects, registered for a site, that 
provide a particular interface'. A good term doesn't come to mind, but 
it seems to me worth some more consideration.

  -- Garrett