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Re: RDFa in HTML (was RDFa in HTML 5)

From: Sam Ruby <rubys@intertwingly.net>
Date: Tue, 19 May 2009 14:44:58 -0400
Message-ID: <4A12FE2A.8060105@intertwingly.net>
To: Philip Taylor <pjt47@cam.ac.uk>
CC: RDFa mailing list <public-rdf-in-xhtml-tf@w3.org>, HTML WG <public-html@w3.org>
Philip Taylor wrote:
> Seeing as people are implementing RDFa parsers for text/html, I guess it 
> would be good to have a specification that says how they should work.
> 
> http://www3.aptest.com/standards/rdfa-html/ doesn't answer the questions 
> I'd want answered (e.g. in 
> http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2009May/0102.html), 
> and HTML 4 seems to make it impossible to express an answer. Some 
> existing RDFa-in-text/html parsers are based on document models that 
> closely match the DOM-like model used by HTML 5 (e.g. browser-based JS 
> implementations, and some Python ones using an html5lib DOM, and maybe 
> others), and the model used by HTML 5 can be implemented in a variety of 
> other ways (e.g. unbuffered SAX) so it's not too restrictive, and so it 
> seems like the most useful way to define RDFa-in-text/html processing.

I'd suggest dropping the "5" from the document title, changing the 
Document conformance rules to allow various HTML4 and XHTML1 doctypes; 
furthermore, I'd suggest converting the statement that "any 
implementation is conforming as long as its output is identical to the 
specified algorithm" from "XXX" to spec text.

> I've not seen anyone else working on this, so I started writing a rough 
> draft at <http://philip.html5.org/docs/rdfa/>. Some of it is copied from 
> the RDFa-in-XHTML specification, and just tweaked to use some new 
> definitions and to share concepts (like base and lang) with HTML 5 and 
> to cope with text/html parsing (for xmlns:* attributes). The CURIE 
> definitions are new, since I didn't see any existing document that 
> defined them in an appropriate way.
> 
> There are several unresolved design issues (e.g. handling of 
> case-sensitivity, use of xmlns:* vs other mechanisms that cause fewer 
> problems, etc) - I haven't intended to make any decisions on such 
> issues, I've just attempted to define the behaviour with sufficient 
> detail that it should make those issues visible.
> 
> The current draft is far from complete or correct, but it shows roughly 
> the way I'd like to have things defined (and I hope it's roughly the way 
> that HTML5/WHATWG people would like it to be defined, in order to 
> support implementers and to be testable), and maybe it could end up 
> being useful for something, so I'm just throwing it out here for 
> discussion.

You added the text "running the (HTML5) XML fragment serialization 
algorithm", and the shortly thereafter noted that doing so makes it 
impossible to serialize such as XML.  Given that the this portion of the 
specification is dealing with XML literals, perhaps this addition should 
be rethought.

Also, http://www.w3.org/TR/rdf-concepts/#dfn-rdf-XMLLiteral might make a 
better target than the (unresolved) #s_xml_literals currently associated 
with the two occurrences of [XML literal] in this document.

- Sam Ruby
Received on Tuesday, 19 May 2009 18:45:38 UTC

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