Hello Steven,
On 27/02/2009, at 9:06 PM, Steven Pemberton wrote:
On Fri, 27 Feb 2009 10:31:57 +0100, "Mark Nottingham"
<m...@mnot.net> said:
Creative Commons just released a new spec:
http://wiki.creativecommons.org/Ccplus
that has markup in this form:
<a xmlns:cc="http://creativecommons.org/ns#";
rel="cc:morePermissions" href="#agreement">below</a>
(in HTML4, one assumes, since they don't specify XHTML, and this is
what the vast majority of users will presume).
In the link you refer to they don't specify either, but I imagine
they mean XHTML,
I will wager any amount of money you care to name that more than 99%
of the document's readers (as it stands) will assume HTML4.
and I'm sure Ben Adida of CC can speak up here.
However, it appears that they adopted this practice from RDFa;
http://www.w3.org/TR/rdfa-syntax/#relValues
which, in turn, *does* rely upon XHTML. However, XHTML does *not*
specify the @rel value as a QName (or CURIE, as RDFa assumes);
http://www.w3.org/TR/2008/REC-xhtml-modularization-20081008/abstraction.html#dt_LinkTypes
"Note that in a future version of this specification, the Working
Group expects to evolve this type from a simple name to a Qualified
Name (QName)."
So, that's an expectation, not a current specification.
In fact it is a current specification. RDFa specifies a version of
XHTML that defines the meaning of CURIEs in rel and rev values. Note
that this is also not invalid HTML4 (which also allows such values
in a rel - they are CDATA - but doesn't specify what they mean).
http://www.w3.org/TR/rdfa-syntax/
refers to
http://www.w3.org/TR/2001/REC-xhtml11-20010531/
which contains
http://www.w3.org/TR/2001/REC-xhtml11-20010531/doctype.html
which refers to, for the Hypertext module (note 'latest version' URI):
http://www.w3.org/TR/xhtml-modularization/abstract_modules.html#s_hypertextmodule
which leads back to
http://www.w3.org/TR/xhtml-modularization/abstraction.html#dt_LinkTypes
i.e., the same, albeit most recent (instead of versioned) URI for
http://www.w3.org/TR/2008/REC-xhtml-modularization-20081008/abstraction.html#dt_LinkTypes
Even taking the other road and going with the contemporary version,
http://www.w3.org/TR/2001/REC-xhtml-modularization-20010410/abstraction.html#dt_LinkTypes
it's still just short names, with no reference to CURIEs or QNames at
all.
What am I missing?
The only place I see this defined is in the RDFa syntax document
itself -- do you mean that is the specification of authority? I note
that it specifies /html/@version="XHTML+RDFa 1.0", and it has its own
DTD, so in a way I suppose it's not really an extension to XHTML, but
a re-definition of it...
Of course, this conflicts with the Link draft;
http://tools.ietf.org/id/draft-nottingham-http-link-header-04.txt
which we've worked pretty hard to come to consensus on across a broad
selection of communities (Atom, POWDER, OAuth, HTTP, and
optimistically, HTML5).
A few observations and questions;
1) I'm more than happy to specify in the Link that in XHTML, a link
rel value is indeed a QName, if XHTML chooses to take that position
(although I believe a URI is a better fit than a QName here, as in
most other places). Can we get a current reading from the XHTML world
on this?
A CURIE is a URI not a QName, so you're OK.
I haven't paid a lot of attention to them to date, but as far as I can
see, a CURIE is most definitely not a URI; at most, it's a shorthand
for one.
CCing the XHTML2 WG and/or RDFa group would have helped in this case
if you wanted a response from them :-)
I wanted to get a feel from an architectural standpoint before talking
to WGs about potentially irrelevant problems, but point taken.
2) However, it seems like RDFa is jumping the gun by assuming @rel is
a CURIE right now.
See above. It is already a Rec.
[All the rest snipped since it was based on the assumption that XHTML
+RDFa isn't a Rec].
As I said before, the third point is IME the most concerning. Having
two subtly incompatible syntax for the same attribute in HTML and
XHTML isn't a great situation, but assuming that one is valid to use
in the other is far more troublesome.
Cheers,
--
Mark Nottingham http://www.mnot.net/
