RE: Reconciling hydra rest semantics for collections with typical RDF entity relationships

Hi Paul,

On Tuesday, February 04, 2014 8:43 PM, Paul Kuykendall wrote:
> 
> When we were trying to develop a container concept here, we went down
> both the RDF collection route as well as the way that Hydra is
> currently designed.  Both ways ended up being insufficient beyond the
> simplistic case for a workable application.  After discovering the
> Linked Data Platform specs, specifically the ldp:Container we finally
> had a solution for describing collections in a generic and usable way.
> I would recommend looking at http://www.w3.org/TR/ldp/ for more ideas.

I've been following LDP quite closely and am aware of most of the
discussions that happened around ldp:Container but I can't see how it
addresses the problem at hand. Please note that in Hydra the interaction is
*not* tied to Collection as it is the case for LDP's Container. Maybe I'm
also just missing something. Could you please go a bit more into the details
about what problems ldp:Container solves that you Hydra doesn't (I'm
deliberately not saying hydra:Collection here).

Thanks,
Markus



> /Paul Kuykendall
> 
> -----Original Message-----
> From: Gregg Kellogg [mailto:gregg@greggkellogg.net]
> Sent: Tuesday, February 04, 2014 1:27 PM
> To: Kingsley Idehen
> Cc: public-hydra@w3.org
> Subject: Re: Reconciling hydra rest semantics for collections with
> typical RDF entity relationships
> 
> On Feb 4, 2014, at 10:59 AM, Kingsley Idehen <kidehen@openlinksw.com>
> wrote:
> 
> > On 2/4/14 1:26 PM, Markus Lanthaler wrote:
> >> This is a general problem of RDF. AFAICT, there's no way general way
> >> to solve this issue for sets. If you would use a list, you could at
> >> least use the list's head node (which generally is a blank node).
> >> Remember our discussions in the JSON-LD group?
> >>
> >> Both Schema.org with its ItemList and Hydra with its Collection take
> >> a rather pragmatic approach. We could of course go ahead and define
> a
> >> Collection's semantics so that
> >
> > I assume you've looked at RDF Schema vocabulary which does describe
> RDF Collections [1] and Containers [2].
> 
> I believe Markus' was referring to RDF Collections when he said "list".
> Of course, a big problem with collections is the navigation cost in
> RDF, and you can't really chain lists together, presuming that they're
> conformant BNode-type lists. You also can't refer to such a list, as it
> also must start with a BNode (to be conformant, not from a vocabulary
> perspective).
> 
> Containers don't work well for a remote list of values, as they use a
> separate statement for each value, and you can't refer to an external
> container holding such values.
> 
> Another vocabulary to consider is the Ordered List Ontology [3].
> 
> Gregg
> 
> > [1] http://www.w3.org/TR/rdf-schema/#ch_collectionvocab
> > [2] http://www.w3.org/TR/rdf-schema/#ch_containervocab .
> [3] http://smiy.sourceforge.net/olo/spec/orderedlistontology.html
> > --
> >
> > Regards,
> >
> > Kingsley Idehen
> > Founder & CEO
> > OpenLink Software
> > Company Web: http://www.openlinksw.com Personal Weblog:
> > http://www.openlinksw.com/blog/~kidehen
> > Twitter Profile: https://twitter.com/kidehen
> > Google+ Profile: https://plus.google.com/+KingsleyIdehen/about
> > LinkedIn Profile: http://www.linkedin.com/in/kidehen
> >
> >
> >
> >
> >
> 
> 
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--
Markus Lanthaler
@markuslanthaler

Received on Wednesday, 5 February 2014 21:31:21 UTC