resource identifiers

[Tony Linde]

I think we need to keep the <keyword>=<value> structure in case a resource
has more than one field. Likewise, the standard states that the <path> is
the unique identifier for the resource within the authority, so <path> =
ResourceKey and <query> is used for resource specific stuff.

I don't know where the standard for <keyword>=<value> comes from for the
structure of the query string, but it is pretty much ubiquitous in all the
web-based stuff I've come across. Eg just tried clicking stuff in the AG
forum and got: 
  http://forum.astrogrid.org/post.php?action=edit&PID=307

Or, indeed:
 
http://an.oa.org/OAI-script?verb=ListIdentifiers&from=1998-01-15&metadataPre
fix=oldArXiv&set=physics:hep

I'm not sure what to say about the OAI problem. 

I think that if we want to stick with the IETF standard we must have:
  ivo://<AuthorityID>/<ResourceKey>

If we mandate that we can only have ONE in-resource identifier (a bookmark,
say) then we might use the '#' fragment delimiter, so:
  ivo://<AuthorityID>/<ResourceKey>#<RecordKey>

But I am reluctant to limit the whole future scope of the registry ID in
that way. I think my earlier proposal of:

<ResourceID>
  <AuthorityID>ivo://www.ncsa.uiuc.edu/nvo/registry</AuthorityID>
  <ResourceKey>ADIL/SIA/targeted</ResourceKey>
  <Query>
    <p1>95.DR.01.01.fits</p1>
    <p2>wibble</p2>
  </Query>
</ResourceID>

where everything inside the Query tag is resource-specific and which
translates into:
 
ivo://www.ncsa.uiuc.edu/nvo/registry/ADIL/SIA/targeted?p1=95.DR.01.01.fits&p
2=wibble
is the more flexible approach.

Cheers,
Tony. 

> -----Original Message-----
> From: Roy Williams [mailto:roy at cacr.caltech.edu] 
> Sent: 23 May 2003 13:40
> To: ael at star.le.ac.uk; registry at ivoa.net
> Subject: Re: resource identifiers
> 
> 
> Tony
> 
> > This does not solve Roy's problem but the above is according to the
> standard
> > and to accepted use of that standard and I don't think we 
> should mess 
> > with
> it.
> >
> > If the OAI cannot cope with the above (eg by escaping the 
> problematic
> > characters) then we need to look elsewhere for a harvesting 
> standard.
> 
> If VO identifiers have = and &, it is not just an OAI 
> problem, it means that the identifier cannot be used in any 
> web service that has CGI GET implementation -- at least not 
> without character translation.
> 
> Another suggestion:
> 
> According to URI Generic Syntax (RFC-2396) the format is:  
> <scheme>://<authority>/<alias>/<path>?<conditions>#<fields>
> 
> Therefore we can have:
>     ivo://<AuthorityID>?ResourceKey#RecordKey
> 
> For example:
>     
> ivo://www.ncsa.uiuc.edu/nvo/registry?ADIL/SIA/targeted#95.DR.0
> 1.01.fits
> 
> Roy
>