Re: RDFa Lite and non-RDFa @rel values

Hi Alex,

On Tue, Apr 24, 2012 at 1:33 PM, Alex Milowski <alex@milowski.com> wrote:

> On Tue, Apr 24, 2012 at 9:55 AM, Ivan Herman <ivan@w3.org> wrote:
> > It is of course unfortunate that this discussion comes now. The
> practical problem is that a change of the processing rules as you are
> proposing means going back to last call and, as for now, would seriously
> jeopardize the publication of the spec in time. It would also seriously
> affect the acceptance of rdfa through a delay. I would really like to avoid
> that, unless there is a real bug somewhere.
>
> I understand the sentiment.  A substantive change would send the
> specification back through CR.
>
> That means, the real question comes down to what we expect from this
> kind of markup:
>
>   <a vocab="..." href="http://www.w3.org/" rel="nofollow"
> property="homepage">W3C's Home Page</a>
>
> Should it be:
>
>   <> <http://www.w3.org/1999/xhtml/vocab#nofollow> <http://www.w3.org/>
>   <> <...homepage> "W3C's Home Page"
>
> or
>
>   <> <http://www.w3.org/1999/xhtml/vocab#nofollow> <http://www.w3.org/>
>   <> <...homepage> <http://www.w3.org/>
>
> ?
>
> Note that you can't get the second set of triples from the same link
> (@href value) through some other structure without repeating the link
> element somehow.  As such, the second set isn't possible without
> changing the specification and that would lead to a new CR period.
>
> Via how Step 6 in section "7.5 Sequence" works, you can get a similar
> result by typing the link:
>
>   <a vocab="..." href="http://www.w3.org/" rel="nofollow"
> typeof="homepage">W3C's Home Page</a>
>
> which generates:
>
>   <> <http://www.w3.org/1999/xhtml/vocab#nofollow> <http://www.w3.org/>
>   <http://www.w3.org/> rdf:type <...homepage>
>
> and the neat thing about that is descendant facets are in relationship
> to the @href value as the new subject:
>
>   <a vocab="..." href="http://www.w3.org/" rel="nofollow"
> typeof="homepage">
>   <span property="dc:title">W3C's Home Page</span>
>   </a>
>
>   <> <http://www.w3.org/1999/xhtml/vocab#nofollow> <http://www.w3.org/>
>   <http://www.w3.org/> rdf:type <...homepage>
>   <http://www.w3.org/> dc:title "W3C's Home Page"
>
> Typing links like this has become my new favorite expression.  :)
>

I'm not sure what you're trying to achieve here. @resource behaves the same
way whether its element include a @typeof or not. the only difference is
that the new subject is typed. my point is that without @typeof you would
also get the same triple with the @href value a new subject:

  <http://www.w3.org/> dc:title "W3C's Home Page"

Expressing triples with the @href as new subject is not an issue with the
current processing steps, you just have to nest your markup inside the a
element.

But maybe I missed your point?

Steph.


>
> If this wasn't the CR period, I would suggestion changing how
> @property is handled in the presence of @rel/@rev.  That feels like
> the right thing to do so that authors aren't surprised by a "simple"
> change.
>
> I can live with how things are right now, even though it isn't ideal,
> given that I have a rational explanation: The resource identified by
> @href is "consumed" by the presence of the @rel, so @property is
> interpreted different.  Synopsis: you lose, change your markup if you
> want something different.
>
> But, if the right thing to do is to change Step 11, that option should
> strongly be considered.  We can't go back and change this after this
> becomes a Recommendation.  It would be a breaking change and so we'd
> have to live with it going forward.
>
> Maybe a different question is helpful?
>
> How common is it to want to associate the link target with a different
> predicate when @rel is present and already generating one predicate?
> That is, how common is it to have two predicates associated with one
> link target?
>
> --
> --Alex Milowski
> "The excellence of grammar as a guide is proportional to the paucity of the
> inflexions, i.e. to the degree of analysis effected by the language
> considered."
>
> Bertrand Russell in a footnote of Principles of Mathematics
>
>