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RE: Attributes and Namespaces.

From: Hart, Lewis <lhart@grci.com>
Date: Thu, 29 Mar 2001 08:17:06 -0500
Message-ID: <09A65DF294F8D311AAB000105A02DBAF026E5B17@thumper.va.grci.com>
To: Janne Saarela <janne.saarela@profium.com>, Aaron Swartz <aswartz@swartzfam.com>
Cc: RDF Interest <www-rdf-interest@w3.org>
Thanks. A direct statement in the specification about the common practice
implementation of what does "not directly apply" would certainly have saved
me some confusion.

BTW The RDF parser I am using creates triples with Publisher, Title and Date
having an empty string ("")  namespace, though it recognizes about as being
an RDF attribute! 

- Lewis

-----Original Message-----
From: Janne Saarela [mailto:janne.saarela@profium.com]
Sent: Thursday, March 29, 2001 2:09 AM
To: Aaron Swartz
Cc: Hart, Lewis; RDF Interest
Subject: Re: Attributes and Namespaces.


> > <rdf:Description about="http://www.w3.org">
> >        Publisher="World Wide Web Consortium"
> >        Title="W3C Home Page"
> >        Date="1998-10-03T02:27"/>
> 
> Yes, it does. In the second example, no triples should result.
> 
> > If not, why not?
> 
> I don't know the exact reasoning, but I've gathered that there were
> applications that required this to work this way. Perhaps someone with
more
> history than I can explain what those were.

Common practice appears to be to associate unqualified attributes
with the namespace of the element where they appear.

In the previous example, about, Publisher, Title, and Date
would all be associated with the RDF namespace.

RDF M&S spec says [1]:

"The formal namespace name for the properties and classes defined in
this
specification is http://www.w3.org/1999/02/22-rdf-syntax-ns#. When an
RDF processor encounters an XML element or attribute name that is
declared
to be from a namespace whose name begins with the string
"http://www.w3.org/TR/REC-rdf-syntax" and the processor does not
recognize
the semantics of that name then the processor is required to skip (i.e.,
generate no tuples for) the entire XML element, including its content,
whose name is unrecognized or that has an attribute whose name is
unrecognized."

Thus, Publisher, Title, and Date are skipped.

BTW1, this paragraph uses "http://www.w3.org/TR/REC-rdf-syntax" prefix
instead of "http://www.w3.org/1999/02/22-rdf-syntax-ns#". I believe this
is
an error and should be fixed.

BTW2, has someone picked up the data type URIs from the formal XML
Schema
specification [2]? I would love to use them as 'range' values in
RDF schemas and do data type validation for literal values in the
data model.

Regards,
Janne

[1] http://www.w3.org/TR/REC-rdf-syntax/#reservedURI
[2] http://www.w3.org/TR/xmlschema-formal/
--
Janne Saarela <janne.saarela@profium.com>
Profium (former Pro Solutions), Tekniikantie 12, FIN-02150 Espoo
Tel. +358 (0)9 25 172 172 Fax. +358 (0)9 25 172 200
Mob. +358 (0)40 508 4767
Internet: http://www.profium.com
Received on Thursday, 29 March 2001 08:17:45 GMT

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