Re: http-link-header in GRDDL

    As the chair of the W3C GRDDL WG, the GRDDL WG has achieved
consensus on the use of "Link" headers and are so supportive of Mark
Nottingham's draft[1] " HTTP Header Linking" that proposes
re-introducing "Link" headers and also "Profile" headers to HTTP 1.1.
GRDDL is a W3C Recommendation stack standard to help convert
HTML/XML/microformats to RDF, and thus very important for the W3C's
future efforts [2], and has received considerable interest from the
wider Web community, being voted the best discussion at the 2006 W3C
Tech Plenary.

       In order for us to include this dependency of HTTP's "Link" and
"Profile" header in GRDDL, we will include these headers as "Features at
Risk." However, if Mark Nottingham's draft does not achieve consensus
and approval we are going to have to drop the feature. So as the W3C
GRDDL WG Chair, I would like to lend my support to Mark Nottingham's draft.


Danny Ayers wrote:
> re.
> GRDDL is a set of mechanisms for automatically providing an RDF view
> of XML documents. The W3C grddl-wg [1] is aiming to request the
> specification, primer and use case documents (drafts linked from [1])
> go forward to Last Call on, or soon after the 15th Feb.
> A proposal has just been accepted by the GRDDL WG to provisionally
> include a mechanism [2] (pasted below) involving the Link: and
> Profile: HTTP headers.
> Inclusion is contingent on:
> * IETF registration of Profile header
> * successful test experience
> The grddl-wg's charter has the 1st quarter 2007 as the target for
> taking the spec to CR, so if anything can be done to expedite the
> progress of the link-header draft to RFC it would be most welcome.
> (Actions have been accepted to try the mechanism in two different
> GRDDL implementations, results of which should be available in the
> next few days).
> Comments are invited on the GRDDL spec and associated docs through the
> public-grddl-comments mailing list, see [1].
> Proposed text:
> ----
> Using GRDDL With HTTP Headers
> To accommodate XML dialects that do not have the necessary extension
> mechanisms in either their schemas or instances we can use HTTP headers
> to specify the necessary profile and transformation.
> To associate an instance document with a GRDDL transformation include a
> Link and a Profile header in the HTTP message. The Link header contains
> the URI of the transformation and a "rel" parameter having a value of
> "transformation". The Profile header contains the URI of the GRDDL
> profile
> An example HTTP Message
> This HTTP message is the response to a request for the document at
> HTTP/1.1 200 OK
> Date: Tue, 06 Feb 2007 08:34:16 GMT
> Content-Length: 35537
> Content-Type: application/xml; charset=utf-8
> Last-Modified: Fri, 03 Feb 2007 15:00:10 GMT
> ETag: "45c3a65a;42380ddc"
> Link: <>;
> rel="transformation"
> Profile: <>
> <?xml version="1.0" encoding="utf-8"?>
> <doc>
> ...
> </doc>
> ----
> Cheers,
> Danny.
> [1]
> [2]


Harry Halpin,  University of Edinburgh 6B522426

Received on Sunday, 11 February 2007 03:54:14 UTC