- From: Norman Gray <norman@astro.gla.ac.uk>
- Date: Sat, 17 May 2008 13:38:23 +0100
- To: Harry Halpin <hhalpin@ibiblio.org>
- Cc: Jeremy Carroll <jjc@hpl.hp.com>, Bijan Parsia <bparsia@cs.man.ac.uk>, public-grddl-comments@w3.org, Alan Ruttenberg <alanruttenberg@gmail.com>
Greetings, On 2008 May 16, at 17:52, Harry Halpin wrote: > I think the central question is whether or not at this point the > GRDDL WG recommends that at least one GRDDL transform point to either: > > 1) A non-executable list of implementations > 2) An executable transform, likely an XSLT one. > > One could of course have *two* GRDDL transforms, one that points to > 1) and one that points to 2), but we are not sure how 1) would > behave with current GRDDL transforms. An apparently obvious solution here is to suggest that the transformation be retrieved using content-negotiation, so that dereferencing the GRDDL transform produces different documents depending on whether the request accept header included one or more of application/xslt+xml, application/x-javascript?, text/html, or even application/rdf+xml, with the last one potentially giving a machine- readable list of available transformers and their properties (of course, that machine-readable spec could be encoded within the text/ html version using GRDDL or RDFa, but this verges on the confusing...) That way, if there's no XSLT transform available for a document, then the origin server returns 406 Not Acceptable, and if there's more than one transformer implementation, in different languages, it could potentially return 300 Multiple Choices (that's not realistically supported in browsers, but could be in a GRDDL library). The example in the spec includes the XSLT transformation being retrieved with an accept:application/xml header, which is rather generic. This seems so obvious that I'm sure I'm missing something, but the only mention of content-negotiation in the GRDDL spec is in the context of namespace documents, and there's no mention of MIME types at all, except rather in passing in the example. Best wishes, Norman -- Norman Gray : http://nxg.me.uk Physics and Astronomy, University of Leicester
Received on Saturday, 17 May 2008 12:39:06 UTC