RDFA - ugly, unnecessary and offtopic (was Re: [uf-discuss] RDFa)

[Tantek Ç elik]

Short answer - seen it, rejected (see microformat principles), off-topic for
microformats. (see bad topic #2 in /wiki/mailing-lists )


Longer answer inline.

On 5/19/06 5:31 PM, "Ben Ward" <lists at ben-ward.co.uk> wrote:

> A W3C Working Draft published on May 16th:
> http://www.w3.org/TR/2006/WD-xhtml-rdfa-primer-20060516/
> 
> For Embedding RDF in XHTML.

XHTML 2.0 to be specific.

Which is not "XHTML" by any common use of the term on the Web.

Typical use of XHTML implies XHTML 1.0, nothing more.


> Gives iCal and vCard examples. In
> practice, there's a bit mark-up involved than with µF (namespace
> declarations for a start) but seems to acheive much the same thing in
> the end.

Uglier and achieves nothing more.


> One interesting thing to note is the use of the META element for
> embedding computer-readible data, e.g.
> 
> <meta property="cal:dtstart" content="20060508T1000-0500">May 8th at
> 10am</meta>

Interesting is one way to put it.  It's also:

* Invalid in today's XHTML.
* Not CSS friendly (hint: classes are much easier to use with style rules)
* Makes the same mistake as XML ('property' attribute can only take one
value, unlike 'class' which is a multivalued set.  They will encounter this
problem with their examples as soon as they try to markup a vCard for
someone with a middlename for example.
* Misleading/unnecessary use of <meta> - there is nothing "meta" about the
datetime of an event, that is information core to the event.


> Has this ever been considered for Microformats?

Yes, I've been familiar with and tracking RDF/A ever since it was first
proposed.

You might even say that the insanity of the ugliness of RDF/A was one of
inspirations for a lot of simplicity and human-centric aspects of
microformats.


> It seems especially
> relevant given the recent uncertainty regarding ABBR/@TITLE and
> accessibility tools.

No uncertainty there, that's a resolved issue, see URL in previous message
on the subject.  Anything else is just FUD.


> I have to admit, I've never seen META used
> outside the HEAD and never even considered it as valid.

That's because it's not valid, neither in HTML4.x nor in XHTML1.x.


> Could it be a  
> viable alternative (if it's considered that an alternative is ever
> needed).

I don't think it is viable no.  I put RDF/A in the bucket of interesting
science projects doomed to failure in the real world, and certainly not even
worth the time to discuss on this list.

Thanks,

Tantek

P.S. For extra nitpickers:
* The use of QNames is *NOT* a use of "standard XML namespaces", not by a
long shot. QNames don't work with CSS Selectors, thus being impractical for
presentation, thus failing to satisfy the primary use of semantic markup.
* The fact that this draft had to invent a new form of URI (CURIE) should be
a strong indicator that there is something wrong.  Whenever you find
yourself inventing new piece of technology for an orthogonal part of the
stack, it usually means you're doing something wrong in your layer.