Re: On GRDDL and XML Documents

On Fri, 25 Aug 2006, Dan Connolly wrote:

> As to why not use it: because I don't want to implement attribute
> parsing above the XML parser layer. It's bad enough that XSLT
> doesn't have a standard library function for making an absolute
> URI out of a base and a relative URI and that I had to code that
> by hand.
>  http://www.w3.org/2000/07/uri43/uri.xsl

This is Off topic, but I wonder if this is the motivation for having the 
base URI passed as a parameter (which I don't think is a good mechanism for XSLT) - if it isn't 
then disregard.

I can see the general value of needing such a function (4Suite 
XSLT had to have one implemented explicitely since not even EXSLT provides 
this functionality) but I would think the 'native' resolving mechanism 
(http://www.w3.org/TR/xslt#base-uri) should be driven by the base provided 
in the source document (explicitely with xml:base) rather than overiding 
it with an XSLT function / macro.

> Also, I consider the <?xml-stylesheet ?> link to relate a document
> to a transformation of that document for display for a human.
> I guess the spec doesn't say that.
>
> If I had a purchase order or something, I'd expect to be able
> to use the <?xml-stylesheet ?> PI to tell user agents how
> to display it for people, and a grddl:transformation link to
> tell data agents how to get data out of it.

I see.  I think it would help to express this distinction in the 
specification itself.

>>
>> - Respond to grddl:transformation attribute on root document, resolving transform by HTTP URL
>> - Respond to <?xml-stylesheet type='..' href='..' appropriately to resolve transformation (fail if not one of the *expected* transformation types)
>> - Resolve RDF from namespace URI and respond to namespaceTransformation assertions (in RDF)
>> - Resolve a (master/default) RDF document from a URI (which would this be?) for a set of 'default' namespaceTransformation assertions
>
> I don't understand the last one at all. Maybe you could
> elaborate by way of an example?

I.e., (perhaps) the GRDDL namespace URL returns a document a GRDDL client 
can use to extract a default set of namespaceTransformations (for major 
vocabularies).

1) GRDDL namespace -> GRDDL profile XHTML
2) GRDDL transform -> RDF statements which include (amongst other things) 
default namespaceTransformations

> Otherwise, I could live with that. But I won't actively support
> the <?xml-stylesheet?> PI; I'll expect other people to provide
> the relevant test cases and trial implementation experience.

I think explicitely distinguishing between <?xml-stylesheet?> and the 
GRDDL-specific mechanism gives implementors enough guidance to make a 
determination of how to accomodate both (possibly).

Chimezie Ogbuji
Lead Systems Analyst
Thoracic and Cardiovascular Surgery
Cleveland Clinic Foundation
9500 Euclid Avenue/ W26
Cleveland, Ohio 44195
Office: (216)444-8593
ogbujic@ccf.org

Received on Friday, 25 August 2006 20:02:27 UTC