[Zope3-Users] (Ab)using utilities

[Stephan Richter]

On Tuesday 29 November 2005 18:16, Thomas Lotze wrote:
> Our current solution is to register utilities that handle type two and
> three items, and turn them into folders actually containing the items
> while we're at it. This does provide uniqueness of the type two and three
> item containers, as well as well-defined access by an interface name.
> However, I'm not at all sure that containing application data is what
> utilities are meant for. Is it?
>
> I get a feeling that we might want folders as attributes of the top-level
> container, for all the uniqueness and well-defined access that provides.
> But would that be Zope-3-ish?

There are several approaches:

(1) Use the catalog. I bet you can find a way to create an index by class name 
or by the content type interface.

(2) Write a special folder that keeps track of all ids of type A, B, C... This 
is the cheap way of getting a catalog-like feature.

(3) a derivation of (2) would be to write adapters that store the ids of type 
A, B, C in annotations. Use event subscribers to update the annotations.

Overall, I agree with you that utilities are not meant to solve this type of 
problem for the reasons you listed yourself.

Regards,
Stephan
-- 
Stephan Richter
CBU Physics & Chemistry (B.S.) / Tufts Physics (Ph.D. student)
Web2k - Web Software Design, Development and Training