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Understanding RDF as extensible vs. embeddable

From: Jon Garfunkel <jgarfunk@coopdata.net>
Date: Sat, 29 Sep 2001 19:21:46 -0400
Message-ID: <000301c1493d$8e680920$0400a8c0@coopdata.net>
To: <www-rdf-comments@w3.org>
Hello RDF developers, I would appreciate your help on understanding a basic
aspect of RDF which I've been trouble finding an explanation on. I have a
fair amount of experience with XML/XSLT, and am now having a look at RDF. I
explain more about the usage below. I'll call the schema/top-level element
I'm working with "E". I am wondering how to mix it with RDF. Two possible
ways:

By "extensible" I am thinking of object inheritance (E "extends" RDF)
and by "embeddable" I am thinking of a variable (E "has variable" RDF)

In the HTML examples for RDF, the model is necessarily embeddable: we deal
only with HTML documents, so the RDF information appears in embedded META
tags.

In all the XML examples I see, the XML documents appear to have their E
information embedded within an RDF structure. I understand that this is
*functionally* extensible, and thus a good strategy. And it of course is a
helpful high-level interface.

Still, I am looking to embed the RDF metadata in my E documents. Does this
have any present or future (I use several different schemas) I can give a
few reasons:

1. Conceptually, I like to think of my E's as the specific things they are
(like "entity", "presentation", "agenda"), instead of as a "RDF Resource
which contains an 'entity'". But I'm open to conversion.
2. I need to rewrite some DOM, XSLT, XML code to reflect this. Again, this
is a one-off effort.
3. I'm very satisfied with my XML editor, XMLSpy 3.5. But neither it nor
version 4.0 seem to enable the creation of RDF-based XML schemas out of the
box (unless I'm mistaken). So instead it seems easier to embed my own pidgin
metadata.
4. I don't even know how to create a schema for E which embeds/extends RDF
(or visa-versa). I've been pleased with using the XML Schema Primer for
reference, but I haven't found any examples for creating E extending RDF.
Further complicating this is that I get the sense that RDF schemas are
orthogonal to XML schemas.


The overall purpose is a web-basd collaboration system. It has similar
functions to the Annotea project (I've been following their updates on the
www-annotation list) among other capabilities. I'm focusing on a
server-based solution, so I have a module which reads all of the XHTML, XML
documents on a designated area of the filesystem. Thus I am looking for a
solution to get the metadata from XML documents.

Thanks,

Jon
Received on Saturday, 29 September 2001 19:18:03 GMT

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