The conversation split between just the Hydra mailing list, and the wider
mailing list including Web Schemas and LOD.
In my opinion, we have a way forward: For a generic Hydra interface use a
rdfs:seeAlso predicate to reference a void:Linkset annotated with the predicate
it relates to (based on Niklas' suggestion). For example, the example we've
been using might be described as follows:
</markus> a foaf:Person;
rdfs:seeAlso [
a void:Linkset;
void:subjectsTarget </markus>;
void:objectsTarget </markus/friends>;
void:linkPredicate foaf:knows
] .
The resource at </markus/friends> is a hydra:Collection, but also contains
triples that assert the individual foaf:knows relations:
</markus/friends> a hydra:Collection; hydra:member </gregg>, ...
</markus> foaf:knows </gregg> .
In a schema.org variety, this might simply be done with a more direct
relationship:
</markus> a schema:Person; rdfs:seeAlso </markus/friends> .
</markus/friends> schema:about schema:knows .
Then in the </markus/friends> resource:
</markus/friends> a schema:ItemList; schema:itemListMember </gregg>, ...
</markus> schema:knows </gregg> .
In the first (pure) example, the void:Linkset specifically relates subects in
</markus> with objects in </markus/friends> using the foaf:knows predicate. An
API client would know to dereference the </markus/friends> if it is interested
in following foaf:knows relationships.
In the second example, a client knows which of possibly several rdfs:seeAlso
relationships are follow because each object is described as being "about"
whatever the predicate used within the ItemList uses. It's less accurate than
the void:Linkset, but seems more in keeping with the simplicity of schema.org.
A schema:seeAlso predicate might also be useful.
Gregg Kellogg
gr...@greggkellogg.net
On Mar 25, 2014, at 11:55 AM, Vuk Milicic <vuk.mili...@eurecom.fr> wrote:
> Markus,
>
>> OK.. this is quite similar to what we discussed in the Hydra CG (and what
>> LDP does):
>>
>> </markus> a schema:Person ;
>>
>> </markus/friends/>:manages [
>> :subject </markus> ;
>> :property schema:knows
>> ] ;
>>
>> The thing I don't really like with these approaches is that you have to peek
>> into the container to find out whether it contains/manages the information
>> you are interested in.
>
> Conceptually, </marcus/friends> is not a container, but a class -- my point
> from the beginning.
> That RDF is basically equivalent to what I wrote in [1] using OWL, why
> reinventing the wheel?
>
> [1] http://lists.w3.org/Archives/Public/public-lod/2014Mar/0111.html
>
> -
> Vuk MIilcic
> @faviki
