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Re[2]: Summary: Section 2: What does a URI identify?

From: Brian McBride <bwm@hplb.hpl.hp.com>
Date: Tue, 19 Mar 2002 16:30:51 +0000
Message-Id: <5.1.0.14.0.20020319160256.03013300@0-mail-1.hpl.hp.com>
To: Chris Lilley <chris@w3.org>
Cc: Paul Grosso <pgrosso@arbortext.com>, "Jonathan Borden" <jonathan@openhealth.org>, <www-tag@w3.org>
At 16:36 19/03/2002 +0100, Chris Lilley wrote:
[...]

>BM> That looks like an eminently reasonable requirement for HTML.
>
>That seems like marginalization to me

Oh that was not my intent.  Please forgive my inept use of language.  I had 
just understood HTML's need for same document references being unaffected 
by the base and wanted to express recognition of that requirement.

I was also trying to explain RDF's need for a mechanism for creating 
absolute URI refs from fragid's which are affected by the base URI.

>  - the HTML WG is clearly working
>to make XHTML be generic XML, and the same methods should apply to
>XHTML, SVG, MathML, SMIL, fooML and barML when there is xml:base and a
>link with a URI that is just a fragment identifier.

Yup.  Consistency is good.  Note that there is some flexibility in RFC 2396 
in that, as pointed out earlier, an empty URI reference is interpreted in 
different ways in different contexts, i.e. if there is an implied retrieval 
action.

[...]

>BM>    <rdf:Resource rdf:ID="foo">
>
>BM> names a resource whose URI is <base-uri>#foo, i.e. it is relative to the
>BM> document containing the element.
>
>(Request for clarification - the rdf:ID attribute is of type ID in the
>DTD or Schema?)

No.  There is no DTD or XML schema for RDF.
[...]


>Its clear that any situation where something works online but a
>local(y accessed) copy suddenly breaks is a problem. The XML MIME type
>RFC, by introducing a precedence of headers over the XML encoding
>declaration, has a similar problem.

I should be clear.  It is possible to write RDF/XML such that it does not 
have this problem.  Instead of rdf:ID, one can write:

   <rdf:Description rdf:about="http://....">

where the contents of the attribute is the full URL.  One can also use 
entities to reduce the amount of typing.  The problem we have is:

   o some folks depricate the use of entities
   o typing out the full URI is pretty tedious and unfriendly
   o the rdf:ID idiom is common and used in other specs such as  daml+oil, 
PRISM and cc/pp.

Thus the use of the rdf:ID idiom is preferred.

[...]

>Lets not restrict this to "HTML vs RDF" but try to see a wider picture.

Absolutely.  Nor did I intend to imply HTML v RDF, but more HTML & RDF.  My 
goal is to try to find a way of reconciling the various requirements.

Brian
Received on Tuesday, 19 March 2002 11:32:47 GMT

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