Re: RDFa reliance on namespace declaration

Anne,

On 15/06/06, Anne van Kesteren <annevk@opera.com> wrote:
>
> On Wed, 14 Jun 2006 20:38:23 +0200, Ian Davis <iand@internetalchemy.org>
> wrote:
> >> [snip]
> > eRDF uses a convention that I first saw described in a W3C workshop
> > report from 1996 [1]. This was later adopted for the Dublin Core[2].
> >
> > Basically a schema prefix is declared in the head of the document like
> > this:
> >
> > <link rel="schema.dc" href="http://purl.org/dc/elements/1.1/" />
>
> That's interesting. It also seems a better solution than RDFa as it
> integrates with text/html documents rather nicely.

Not really.

First, it overloads the @rel attribute (although it does so following
a precedent dubiously set by Dublin Core...painful!), since to work
out the mapping you need to parse the @rel value, but @rel/@rev are
essentially predicates, so it's really dodgy to start cracking their
string values open to create further stuff.

I think the Dublin Core usage actually goes *against* the principles
of HTML, although unfortunately there is a definite trend towards
bending the attributes in HTML to conform to 'whatever works for some
processor'. The problem with doing that is that we lose the generic
aspects of HTML.

Secondly, the rest of the world is using this rather interesting new
approach to mark-up languages, called XML. It got off to a little bit
of a bumpy start since it forgot to include namespaces, but this has
since been rectified. I suggest we make use of it. :)

To put that a little more seriously, Misha's problem is fairly
specific and is something that we can easily solve, either in NewsML
itself, or in CURIEs, or whatever. However, that particular problem
does not mean we should not be using namespaces in XHTML's use of
RDFa--we are after all, using XML, and in the same way that most other
XML specifications from the W3C use XML namespaces, so should we.

In addition, as I've said already, Ian's issues are all to do with how
you use XSLT, and are the same if you are creating stylesheets that
produce WSDL files, XML schemas, other XSLT files, and so on.
(Basically, any time you use a non-schema aware processor, you are
going to be unaware of the 'type' of an attribute.) But these issues
are all well known, are actually easily solved in the way you
construct your stylesheets, and are certainly not a reason for
dropping namespaces in XML attributes in *any* XML langauge, never
mind XHTML+RDFa.

Regards,

Mark

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Received on Thursday, 15 June 2006 14:19:39 UTC