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Henri's RDFa statements in the XHTML2 FAQ

From: Manu Sporny <msporny@digitalbazaar.com>
Date: Tue, 07 Jul 2009 11:09:30 -0400
Message-ID: <4A53652A.8040804@digitalbazaar.com>
To: RDFa Developers <public-rdf-in-xhtml-tf@w3.org>
Just throwing this out there in case some of you haven't seen it yet:

http://hsivonen.iki.fi/xhtml2-html5-q-and-a/

In it, Henri makes the following assertions:

> What happens to RDFa?
>     RDFa (in XHTML but not in HTML!) is a W3C Recommendation and, as
> such, doesnít need any terminating action per the W3C Process. Itís
> unclear if another WG will develop further RDFa specs.

We will be developing further RDFa specs - whether it happens inside the
W3C or outside the W3C is still up in the air.

> Do semantics round-trip in an HTML5 to XHTML5 to HTML5 conversion?
>    Yes, provided that the first HTML5 input is valid and you donít
> ascribe semantics to characters that arenít allowed in XML (such as
> form feed or U+FFFF). Note that RDFa isnít valid in either HTML5 or
> XHTML5 as currently drafted.

We are certainly addressing all of the issues raised during the past
several months[1]. Henri failed to mention that this work continues and
that we are making progress.

> What about XHTML5 to HTML5 to XHTML5?
>    Not if namespace-based extensibility is used. However, in the
> common case, the conversion chain does round trip if the input is
> valid XHTML5 + SVG 1.1 + MathML 2.0 (this excludes RDFa), doesnít use
> namespaces from outside those specs (Itís debatable if the previous
> condition already covers this.), xml:space on HTML elements is not
> considered to affect semantics and relative URLs are rewritten so that
> xml:base attributes can be removed without breaking links. (Answer
> clarified/corrected 2009-07-07.)

My understanding is that XHTML5 and SVG 1.1 contain namespace support -
so why is RDFa excluded from those languages on the basis of using
namespaces and CURIEs in attributes (other than Henri's personal
preferences)?

> Are the semantics of HTML5 extensible?
>    Yes. With microdata.

It's difficult to believe that WHATWG doesn't have a bias (as Ian has
asserted repeatedly) when Microdata is being proposed as a solution.
Microdata clearly does not have a test suite, does not have a set of
implementations, and does not have much in the way of implementation
feedback. RDFa has all of those in spades, but gets absolutely no
mention as an alternative approach.

Henri's "FAQ" attempts to assert that RDFa is, and will continue to be,
an incompatible technology with HTML5 and XHTML5. This couldn't be
further from the truth. There will be an HTML+RDFa specification and
there will be implementations (and, yes, that includes HTML5 and
XHTML5). Whether WHATWG chooses to include it in their standard is what
Henri is asserting as not happening. On that point, only time will
tell... however, RDFa is out there in the wild now and it works. We'll
ensure that it works in HTML5/XHTML5 as well.

-- manu

[1]http://rdfa.info/wiki/rdfa-in-html-issues#RDFa_Task_Force_Discussion_Order

-- 
Manu Sporny
President/CEO - Digital Bazaar, Inc.
blog: Bitmunk 3.1 Released - Browser-based P2P Commerce
http://blog.digitalbazaar.com/2009/06/29/browser-based-p2p-commerce/
Received on Tuesday, 7 July 2009 15:10:08 GMT

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