Re: [office-metadata] Question about the IRI of a RDF subject from an ODFdocument

[Elias Torres <eliast@us.ibm.com>]

Hello everyone,

I'm slowly starting to get back to work, after a long hiatus, but not only
because of my vacation but due to a death in the family and an additional
personal accident I had. I hope things have progressed while I was gone and
that there's still ways in which I can offer some help to the group. Let me
try for example to suggest some things on the subject of this email. Please
forgive me if I repeat some suggestion stated before and whether it was
already made clear that what I'm suggesting either doesn't apply or the
group decided it was not the right solution. I acknowledge I am not fully
up to date with all of the discussions that have been going on during my
absence.

-Elias

Svante.Schubert@Sun.COM wrote on 02/05/2007 03:10:55 PM:

> Bruce D'Arcus wrote:
> >
> > On Jan 30, 2007, at 1:51 PM, Bruce D'Arcus wrote:
> >
> >> This is a trick issue, BTW. Ideally you want a globally unique IRI

Definitely a tricky situation. But one that needs to be addressed. First, I
don't think that there is a simple solution (e.g. an almighty IRI that will
solve all of the problems). In my opinion, it's just a matter of providing
enough metadata to describe whatever it is that we are trying to
communicate/document.

> >> with which you can also locate the document. But that's not realistic
> >> in many desktop scenarios, so I think you're left with two choices:
> >>
> >> 1) the one above
> >> 2) using a URI-encoded UUID
> >
> > Well, and of course using the Flickr URI, which would be good for this
> > particular case.
> By this we have at least one case where the RDF subject IRI is not the
> reference to the local instance.
> As we use the flickr URL as the RDF subject IRI, we are in need of a way
> to reference to the image from our RDF syntax.
> Only by this, the RDF application would know, that we are talking about
> a picture in this document.
> BTW a similar reference would be needed for linking to other ODF
> elements, for instance if we would like to reference to a certain ODF
> table or the linked image, that is being used in the document.
>
> My question to you now, is it from the RDF point of view  sufficient to
> say, we have this picture somewhere in this document?
>
> In N3 something like:
> <> has <http://www.flickr.com/photos/images/holidayimage.png> .
>
> Or are we in need of a package URL to the described content?
>
> In N3 something like:
> @prefix odf: <http://www.oasis-open.org/package-rdf#>
> <http://www.flickr.com/photos/images/holidayimage.png> odf:pack-ref
> <odf:/images/holidayimage.png>
>
> (A package URL  as relative URI references are not allowed in RDF URI
> References [1] )

You can't use a relative URI in a triple at the model level, but you can
use a relative URI in the serialization of triples.

In a document located at /home/eliast/package.n3 you can have the
following:

<eliast.jpg> dc:title "Elias' mugshot" .

When the document is loaded eliast.jpg would be resolved to the URI:
"file:///home/eliast/eliast.jpg".

However, we need more than that, because our package doesn't have a stable
location. Hence, I would suggest we ground it on some URN, like LSID for
example or whatever.

urn:lsid:www.oasis-open.org:SOME_PACKAGE:SOME_UUID/eliast.jpg

Now if we use RDF/XML we can make use of
xml:base="urn:lsid:www.oasis-open.org:SOME_PACKAGE:SOME_UUID/".

<eliast.jpg> dc:title "Elias' mugshot" .

For the case that the same exact picture lived on Flickr, then we can use
owl:sameAs:

<eliast.jpg> owl:sameAs
<http://www.flickr.com/photos/images/holidayimage.png> .

N3 doesn't have an @base property like SPARQL or RDF/XML, but Turtle which
is updated by the SWIG, is in the process of adding such extension.

>
> > Might be nice if we could add the ability to have both a path and a
> > global IRI in the manifest entry for a file.
> >
>
>
> [1]  Note: Relative URI references are not allowed in RDF URI References:
> "RDF URI references are compatible with the anyURI
> <http://www.w3.org/TR/2001/REC-xmlschema-2-20010502/#anyURI> datatype as
> defined by XML schema datatypes [XML-SCHEMA2
> <http://www.w3.org/TR/rdf-concepts/#ref-xml-schema2>], constrained to be
> an absolute rather than a relative URI reference.", taken from
> http://www.w3.org/TR/rdf-concepts/#section-Graph-URIref
>