[esip-semanticweb] ESIP namespace definitions

[James Gallagher]

On Oct 26, 2009, at 8:48 AM, Christopher Lynnes wrote:

> We are now beginning to actually implement cross-ESIP applications  
> that have need of namespace declarations, specfically:
> o  Federated search
> o  Machine tagging of WMS capabilities documents
> I believe there are some semantic web applications that are not too  
> far behind...
>
> Given that permanence is a desirable feature of namespace  
> declarations, I would like to propose we settle on a definition  
> scheme that can be implemented soon, but which we expect to be stable.
>
> I would like to suggest we use a scheme like:
> http://esipfed.org/ns/foo/bar
>
> where
> o  http is the scheme
> o  esipfed.org is the authority
> o  ns indicates that it is a namespace
> o  foo/bar is a hierarchical path
>
> Examples of foo might be:
> o  fedsearch
> o  scast (for servicecasting)
> o  datatypes
>
> So for example, to uniquely identify a URI as refering to a URL to a  
> browse image (useful for typing in Federated Search) responses), we  
> might have:
>
> http://esipfed.org/ns/fedsearch/browseImage
>
> One minor downside to this scheme is that it is often useful, but  
> not required, to put an informational document, such as a schema  
> document, at the URI.  Brian, would this be feasible?  Again, I  
> don't believe it is required for a namespace URI.
>
> Any counter-proposals?

A suggestion: That you include in the scheme a version number and that  
you do it like this:

http://esipfed.org/ns/foo/bar/1.0#

For example, the DAP 3.3 schema has the following in the root element:

xmlns:dap3.3="http://xml.opendap.org/ns/DAP/3.3#" xmlns="http://xml.opendap.org/ns/DAP/3.3# 
"

I think the version number is obvious - even HTTP has more than one  
version. Benno and Nathan requested the trailing '#' and as far as I  
know it exists to simplify something when building RDF although I've  
forgotten what. Regardless, it follows the Specs and also the OASIS  
recommendations. Maybe someone on this list can remind me regarding  
the trailing hash...

Summary: Add a version number and I forget why we have the '#', but it  
might (will?) make working with RDF easier.

James

PS. Did you know that Hyrax now produces RDF? In the default  
configuration it's not enabled but you can see it in action at  
test.opendap.org (http://test.opendap.org/dap/data/hdf/contents.html  
and follow the 'rdf' links; e.g., http://test.opendap.org/dap/data/hdf/S2000415.HDF.rdf) 
. It's still in testing --> really big files break it in a nearly  
deterministic way ;-)

> --
> Christopher Lynnes             NASA/GSFC, Code 610.2          
> 301-614-5185
>
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> esip-semanticweb at lists.esipfed.org
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--
James Gallagher
jgallagher at opendap.org
406.723.8663