Subject: Question about WebDAV and Dublin Core ...

From: Carmen Pancerella <[email-masked]>
Date: Wed, 08 May 2002 10:38:55 -0400

Hello.

I posted this question to the Dublin Core mailing list and didn't
get any responses, so I'm trying this resource as well.

I'm putting together a collection of datasets in WebDAV,
and I want to use WebDAV properties to contain Dublin
Core metadata.  I searched the web archives and found a
1999 document about WebDAV and Dublin Core.  Has anything
else been done since this time?  Has anybody done this?
Any advice?

In particular, I'm interested in how others have used qualified
Dublin Core and have included encoding schemes in the WebDAV
properties, and have searched for metadata in WebDAV
repositories.  (This isn't covered by the 1999 document.)

Also, have people used XML or RDF or plain text to give
the DC element values in the WebDAV properties?

Any experiences are of interest to me.

Thanks.
Carmen

[email-masked]

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Carmen Pancerella, PhD                           [email-masked]
Distributed Systems Research & Development
Sandia National Laboratories                    Phone: (617) 630-0316
P.O. Box 969, Mailstop 9012                 Voicemail: (925) 294-3538
Livermore, CA 94551-0969                          Fax: (508) 300-8815
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From: "Jim Whitehead" <[email-masked]>
Date: Thu, 9 May 2002 10:54:48 -0700

Hi Carmen,

There has not been any significant work on "Use of Dublin Core Metadata in
WebDAV" since the 1999 document, draft-ietf-webdav-dublin-core-01,
http://www-old.ics.uci.edu/pub/ietf/webdav/dc/draft-ietf-webdav-dublin-core-
01.txt

In part, we have been waiting for the Dublin Core group to develop a
normative specification of how to represent Dublin Core elements in XML/RDF,
an effort that has been stalled for many years. Looking at the Dublin Core
website, it appears they may release some documents this month.

However, I no longer think it makes sense to tie the WebDAV property
expression of Dublin Core elements exactly to a Dublin Core standard. The DC
documents assume that you'll have all of the DC elements in one chunk of
XML. With WebDAV, it makes sense to put each DC elements into a separate
properties. Hence, the XML representation of DC elements in DAV will be
somewhat different from the DC/XML and DC/RDF drafts I have seen:

http://dublincore.org/documents/2001/11/28/dcmes-xml/
http://www.ukoln.ac.uk/metadata/dcmi/dc-xml-guidelines/

Also, I don't think it makes sense to use RDF for DC elements. It just adds
extra bytes on the wire, without gaining much. It would be trivial to write
a routine on top of an existing DAV client library to extract the DC
properties, then return them in the DC-approved RDF format. Hence, an
RDF-aware application could easily get DC elements stored as DAV properties,
in RDF format. No need to send all the RDF data over the wire.

> else been done since this time?  Has anybody done this?

My recommendations are:

* one property per DC element
  - use standard DC namespace, and element names
* use a standard convention for multiple items per property (such as
multiple authors for a resource). Using <ul><li>{auth 1)<li>(auth 2)...</ul>
makes some sense to me (similar to the existing draft).
* use xml:lang as appropriate to represent elements in multiple languages

> repositories.  (This isn't covered by the 1999 document.)

I don't know of any efforts that use DC elements in WebDAV properties, but
definitely encourage the development of same.

- Jim