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Re: question about attributes on the main document element

From: Dave Beckett <dave.beckett@bristol.ac.uk>
Date: Mon, 05 May 2003 22:23:11 +0100
To: "Peter F. Patel-Schneider" <pfps@research.bell-labs.com>
cc: www-rdf-comments@w3.org
Message-ID: <13799.1052169791@hoth.ilrt.bris.ac.uk>

>>>"Peter F. Patel-Schneider" said:
> 
> Is the following legal RDF/XML?  If so, is it a good idea to allow
> arbitrary attributes in the top-level element?

Hmm.  It isn't legal XML :)


> <?xml version="1.0"?>
> 
> <http://www.w3.org/1999/02/22-rdf-syntax-ns#RDF foo="bar">
> 
> <http://www.w3.org/1999/02/22-rdf-syntax-ns#Description
>  http://www.w3.org/1999/02/22-rdf-syntax-ns#about="http://foo.ex#baa">
>   <http://foo.ex#bar>
>     <http://www.w3.org/1999/02/22-rdf-syntax-ns#Description
> 	 http://www.w3.org/1999/02/22-rdf-syntax-ns#about="http://foo.ex#baz" /
    >
>   </http://foo.ex#bar>
> </http://www.w3.org/1999/02/22-rdf-syntax-ns#Description>
> 
> </http://www.w3.org/1999/02/22-rdf-syntax-ns#RDF>


As to whether (simplifying)

<?xml version="1.0"?>
<rdf:RDF foo="bar" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
  <rdf:Description rdf:about="http://example.org/" rdf:value="blah" />
</rdf:RDF>

is legal: no.

In RDF/XML, rdf:RDF can have no attributes apart from the xml ones
(xml* which include xmlns, xml:lang and xml:base)

The grammar for this bit of syntax is:
   [[ start-element(URI == rdf:RDF, attributes == set())
        nodeElementList
      end-element()
   ]] -- http://www.w3.org/TR/rdf-syntax-grammar/#RDF

(the xml* attributes are removed in the syntax data model stage)
 
I note the W3C's RDF validator gives a warning on this point but I
feel it should be an error.  Since no attributes are allowed and will
not be interoperable, warning is probably acceptable.

As I recall it, RDFCore has not seriously considered allowing adding
anything to rdf:RDF.  I think we would need a good reason to make
such an addition, plus we would need a very good reason to allow
adding arbitrary attributes.  This syntax doesn't need more, period :)

Dave
Received on Monday, 5 May 2003 17:29:34 GMT

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