Re: Comments on RDFa in XHTML Syntax draft

HI Laurens,

On 24/03/2008, Laurens Holst <lholst@students.cs.uu.nl> wrote:
> Mark Birbeck schreef:
>
> > If you let @src play the role of an object, then you'll see that you
>  > can only make one or other of these statements in a compact way, and
>  > then you have to repeat the URI for the image, in order to indicate
>  > the second statement. For example:
>
> I understand. Is there any particular reason then that @href isn't
>  treated in the same way? It seems to me it has the same benefits there.

The main difference with @href is that we're constrained by the fact
that we want to incrementally build upon HTML/XHTML, and @rel/@rev
with @href already has a meaning.

It's not something that is widely used, but @rel and @rev are
perfectly valid on the <a> tag. So the following is correct HTML,
regardless of RDFa:

  <a rel="next" href="next.html">chapter 2</a>

One of the main contributions of RDFa is not actually the syntax, but
that it looks at HTML and XHTML documents through the prism of RDF. So
the example just given could be interpreted as:

  <> xh:next <next.html> .

The same would go for @rel="stylesheet", @rel="first" and so on. (RDFa
adds some new values, like "license", too.)

RDFa enhances this already existing feature of HTML/XHTML, by allowing
a wider range of predicates to be set (by using CURIEs with prefixes)
and enabling the subject to be something other than the 'current
document' (by using @about). But these features are clearly building
on the metadata features already in HTML/XHTML.

Which is a long ways round way of saying that I'm afraid we can't
change @href in the way you suggest, because @href was already an
'object' in HTML, long before RDFa came along. :)

Regards,

Mark

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  Mark Birbeck

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Received on Monday, 24 March 2008 23:26:57 UTC