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Re: [RDFa] ISSUE-3 @class and @role for rdf:type

From: Shane McCarron <shane@aptest.com>
Date: Thu, 05 Jul 2007 12:04:49 -0500
Message-ID: <468D24B1.6030409@aptest.com>
To: Steven Pemberton <steven.pemberton@cwi.nl>
CC: Ben Adida <ben@adida.net>, public-rdf-in-xhtml-tf@w3.org

I have kept quite on this issue, but have been ruminating on it for weeks.

Steven Pemberton wrote:
> Let me try and summarise the positions as I see them
> For class:
>     Used by microformats in a similar way
>     HTML Spec allows it
>     Already there, no new attribute
>     Implementations already using it
> Against class:
>     Special rule for namespaced/non-namespaced values
>     Confusion/objection by/upset for current class users
>     Used by microformats in a similar way
The class attribute does not take QNAMEs as values, it takes CDATA. 
Moreover, CSS2 does not know how to deal with namespace-qualified class 
names at all, so if we introduce this concept we run afoul of the 
community that has, by all accounts, the best claim to the @class space. 
While the similarity with microformats (how I *hate* that term) is both 
good and bad, I do not think that we should attempt to steal the march 
from microformats by co-opting the space they are ad-hoc operating in.  
We would be much better off working in a separate space and 
demonstrating how much more powerful that other space is.
> For role:
>     Clean start, no legacy
>     No special namespace-prefix rules; can use default namespace rules.
XHTML is designed to permit the introduction of new attributes.  The 
XHTML working group has already introduced this attribute into the XHTML 
namespace, so it is available for use in this way.
> Against role:
>     Potential conflict with WAI use of role needs to be resolved
I think there is no conflict, but that's from an XHTML / WAI 
perspective.  From an RDF perspective there may be. 

The more I think about this, the more I believe that using @class in an 
XHTML 1.1+RDFa context is just wrong.  Even using it in an HTML4 context 
is wrong.  Having special rules for prefixed vs. non-prefixed values is 
inconsistent with everything else we have done.  @role is a clean 
solution that dovetails nicely with the original intent of the 
attribute.  How it is transformed into RDF (rdf:type vs xh:role) I don't 
understand or care, really. 

Shane P. McCarron                          Phone: +1 763 786-8160 x120
Managing Director                            Fax: +1 763 786-8180
ApTest Minnesota                            Inet: shane@aptest.com
Received on Thursday, 5 July 2007 17:05:17 UTC

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