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Re: GRDDL

From: Julian Reschke <julian.reschke@gmx.de>
Date: Wed, 06 Aug 2008 09:21:44 +0200
Message-ID: <48995108.4010209@gmx.de>
To: Henri Sivonen <hsivonen@iki.fi>
CC: Toby A Inkster <tai@g5n.co.uk>, Justin James <j_james@mindspring.com>, public-html@w3.org

Henri Sivonen wrote:
> GRDDL it is a very different from CSS in a way that is crucial 
> considering the question of "CSS for semantics" particularly full 
> accessibility:
> 
> CSS doesn't throw away the original DOM. Instead, it annotates the 
> document tree with properties that are updated when the DOM is updated.
> 
> GRDDL, on the other hand, transforms the original document tree into RDF 
> discarding the relationship between the RDF triples and the original 
> tree nodes once the transformation has completed. Also, if you want the 
> RDF triples to be updated when the document tree changes, you need to 
> rerun the whole transformation. Therefore, GRDDL is not suitable for 
> annotating an in-browser DOM with accessibility semantics.
> 
> (ARIA annotates the DOM without a layer of indirection: the ARIA 
> properties are attached directly to DOM element nodes as attributes.)

Yes.

GRDDL allows extracting RDF out of other vocabularies. The vocabularies 
aren't changed (well, except for the hook pointing to the transform, if 
you want to count that).

If you're looking for a technology that keeps the RDF information in 
place, look for RDFa.

> I'm not sure if abusing HTML is the right characterization, but the 
> GRDDL setup violates the The Rule of Least Power TAG Finding.
> http://www.w3.org/2001/tag/doc/leastPower

I'm not sure how using XSLT 1.0 violates that finding (please 
elaborate); but it's interested to see TAG findings quoted here.

> Instead of serving non-scripted HTML with well-known semantics 
> (<title>foo</title>) at URI u or serving some RDF triples 
> (http://purl.org/dc/elements/1.1/title of u is "foo"), GRDDL is about 
> serving a program and a black box of data and telling the consumer to 
> run the program with the data as the input in order to obtain RDF 
> triples as the output of the program.

Yes. But it's not meant to replace those other techniques.

> Would it be an abuse of SVG if an SVG image wasn't served directly, but 
> instead a script that fetched the SVG file using XHR and rendered it to 
> <canvas> was served?

Yes, that would be bad.

Not sure what your point is, though.

GRDDL is a solution for languages that do not allow direct embedding of 
RDF. Extend the languages to allow it, then you don't need GRDDL.

BR, Julian
Received on Wednesday, 6 August 2008 07:22:28 GMT

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