resource identifiers

[Tony Linde]

Aaarrrgghhh - need to go home!

> keyword=value pairs after the '/' separated by '&' if there 

That should read: keyword=value pairs after the '?' separated by '&'

Cheers,
Tony. 

> -----Original Message-----
> From: Tony Linde [mailto:ael at star.le.ac.uk] 
> Sent: 23 May 2003 19:11
> To: 'Ray Plante'
> Cc: registry at ivoa.net
> Subject: RE: resource identifiers
> 
> 
> Ray,
> 
> You're right about being able to recover the xml structure. 
> I'd go for the option of not having '/' characters in the 
> authority, so just the www.ncsa.uiuc.edu bit as the 
> authority, nvo/registry as the path (resource id), with 
> keyword=value pairs after the '/' separated by '&' if there 
> are more than two.
> 
> >  <ResourceID>
> >    <AuthorityID>ivo://www.ncsa.uiuc.edu/nvo/registry</AuthorityID>
> >    <ResourceKey>ADIL/SIA/targeted</ResourceKey>
> >    <RecordKey>95.DR.01.01.fits</RecordKey>
> >    <RecordKey>wibble</RecordKey>
> >  </ResourceID>
> 
> I really think we should delimit the 'query' part, or 
> whatever you want to call it (at least Query relates back to 
> the URI standard and it can be seen as a 'query' for a 
> specific item within the resource). We should have unique 
> names for the keywords as well, not all called RecordKey.
> 
> >   *  It is not possible (I believe) to allow either an
> > element (Query) to 
> >        have either a simple type content (string) or a complex type 
> >        (<p1>...), apart from specifying the free-wheeling 
> > "any" type.  
> 
> I don't know about this - is there a problem with 'any'? As 
> long as the resource knows what to do with it, does it matter 
> what goes in the <Query> structure?
> 
> >   *  It is not possible to define elements like <p#> where # can be 
> >        unbounded.
> 
> I wasn't proposing p1, p2, etc should be mandated, it was 
> just easier than making up keywords :)
> 
> So, I'd stick to my original amendment but with the '/' 
> disallowed in the authority.
> 
> Cheers,
> Tony. 
> 
> 
> 
> > -----Original Message-----
> > From: Ray Plante [mailto:rplante at poplar.ncsa.uiuc.edu]
> > Sent: 23 May 2003 18:48
> > To: Tony Linde
> > Cc: registry at ivoa.net
> > Subject: RE: resource identifiers
> > 
> > 
> > Hi Guys,
> > 
> > Just so we on the same page, the URI standard we are referencing is
> > Berners-Lee et al. 1998, "Uniform Resource Identifiers 
> (URI): Generic 
> > Syntax", IETF RFC 2396, http://www.ietf.org/rfc/rfc2396.txt
> > 
> > Please also note that the OAI specification simply says that
> > identifiers 
> > must be URIs, full stop.  In practice, ?, =, and & do not 
> need to be 
> > encoded over the wire as URLs (spaces are usually the 
> problem).  The 
> > trouble Roy sees is when the URI is encoded as such within an XML 
> > document; the & must be encoded as &.
> > 
> > (Roy - I don't see encoding & as & as a problem.  The XSL
> > stylesheet 
> > we use to convert our VO-XMLized identifier into a URI form 
> > can take care 
> > of this easily.)
> > 
> > I like Tony's proposal.  I was beginning to dislike the
> > resourceKey= bit 
> > because it suggested that the order of the two arguments was not 
> > important.  If this were true, it would be harder to match URIs.  
> > 
> > Combining the AuthorityID and the ResourceKey with a slash is
> > closer to 
> > what I had in mind originally; however, we do lose one 
> capability: we 
> > cannot convert it back to XML because, in general, we don't 
> > know where the 
> > authorityID part ends.  
> > 
> > Note that in rfc2396, section 3 where it describes the pattern,
> > 
> >    <scheme>://<authority><path>?<query>
> > 
> > the authority is described has being a simple name without
> > slashes (sect. 
> > 3.2).  With this pattern, it is possible to parse the 
> > authority separate 
> > from the path.  
> > 
> > Nevertheless, if we want the AuthorityID portion to allow
> > slashes, I think the ? and & are sufficient for delimiting 
> > the components.  We would say that the first argument after 
> > the ? (i.e. before the first &) is the ResourceKey.  Any 
> > following arguments (after the first & and delimited by
> > &'s) are components of the RecordKey (the Query Tony refers to).
> > 
> >   Question: How should we delimit the AuthorityID from the
> > ResourceKey?
> >     A.  Conform to the above pattern: disallow slashes from the 
> >           AuthorityID
> >     B.  Use ? as the delimiter.  
> >     C.  Use some other delimiter (e.g. :)
> > 
> > I like breaking up the RecordKey into components.  My only
> > concerns (which 
> > I consider minor) relate to how they are rendered in XML.  They are:
> >   *  Query is a bit of a loaded term; I would prefer RecordKey or 
> >        RecordKeys
> >   *  It is not possible (I believe) to allow either an 
> > element (Query) to 
> >        have either a simple type content (string) or a complex type 
> >        (<p1>...), apart from specifying the free-wheeling 
> > "any" type.  
> >   *  It is not possible to define elements like <p#> where # can be 
> >        unbounded.
> > 
> > Instead, I would recommend some variation on the following:
> > 
> >  <ResourceID>
> >    <AuthorityID>ivo://www.ncsa.uiuc.edu/nvo/registry</AuthorityID>
> >    <ResourceKey>ADIL/SIA/targeted</ResourceKey>
> >    <RecordKey>95.DR.01.01.fits</RecordKey>
> >    <RecordKey>wibble</RecordKey>
> >  </ResourceID>
> >   
> > cheers,
> > Ray
> > 
> > 
>