Re: [xri] Link Processing Rules [was: Agenda: XRI TC Telecon 2-3PM PT Thursday 2009-07-09]

[Joseph A Holsten <joseph@josephholsten.com>]

On Jul 9, 2009, at 12:48 PM, Eran Hammer-Lahav wrote:
> I will not be able to attend. Here is my feedback for the meeting.
>> 2) XRD 1.0 - LINK PROCESSING RULES
>> We need to complete the decision about the "link priority order  
>> model" vs. the "flat model". See this thread:
>>   http://lists.oasis-open.org/archives/xri/200907/msg00063.html
> ...
> What I suggest we do is define a new relation type that means 'XRD  
> include' and then we can remove any ambiguity about the semantic  
> meaning of such links. But the order in which such links are  
> processed should still be as I described above.
I think the POWDER working group came to the same conclusion in their  
section on "Associating Resources and DRs"[1]. This is where they  
originally define the semantics of the describedby relationship and  
wdrs:describedby property in "Linking a Resource to a POWDER Document:  
Relationship and Media types"[2]. Like XRD, they think it's worthwhile  
to link to other POWDER documents, and that's why they defined the  
wdr:more XML element[3]. But when their processor outputs the  
properties of an URI, it doesn't link to those other POWDER docs with  
wdrs:describedby or some custom link property. Instead, they use the  
standard rdfs:seeAlso RDF property as formal defined in the RDF  
Schema[4]. rdfs:seeAlso is designed for linking RDF documents, it  
basically means that the resource at the other side of the link also  
shares the same relationship with the subject. That's why RDF specs,  
like FOAF, don't need to define some way to include other RDF files,  
they just use rdfs:seeAlso.

With that precedent, I think that a "seealso" relationship, with the  
same semantics as rdfs:seeAlso, is the best solution.

> In other words, my proposal is:
> 1. Look for a link matching your requirements, if found, end.
> 2. If no link sufficiently matches your requirements, look for "XRD  
> includes". Process them in priority order from step 1.

+1

Joseph Holsten

[1]: http://www.w3.org/TR/powder-dr/#assoc
[2]: http://www.w3.org/TR/powder-dr/#assoc-linking
[3]: http://www.w3.org/TR/powder-dr/#linkingDRdocs
[4]: http://www.w3.org/TR/rdf-schema/#ch_seealso