[Zope3-Users] Re: Referencing objects in auto-generated forms

[Philipp von Weitershausen]

Gary Poster wrote:
>>> Frank, I thought vocabularies were being de-emphasized though, in
>>> favor of the newer 'sources' component?
>>> Vocabularies were good for short lists of choices, but because it
>>> read them all into memory at once not so good
>>> at lazy evaluation.  Sources supposedly uses an iterator and is good
>>> for both short and long lists, as I roughly
>>> understand it.
> 
> No, actually, both can be used for infinite choices or finite choices. 
> The primary difference to me is purity: sources break apart the token
> functionality--an aspect of display that widgets need--from the data
> definition.
> 
> Up until fairly recently (i.e., post-3.2, I believe) you couldn't even
> express a finite source.
> 
> There are still more vocabulary widgets than source widgets in
> zope.app.form.
> 
> Sources are slated to replace vocabularies, but the uptake has been
> slow: I don't know of a hard date.

We can understand vocabularies as a special type of source that's
perhaps not as pure in its concept. It works though :).

I will continue to document and work with vocabularies for the lack of
better alternatives, especially regarding forms. That self-set policy
would change if someone actually took it up to deprecate vocabularies.

Philipp