RE: hydra:manages

Hi François-Paul,

Sorry for the delay. I have been busy and unfortunately no one else jumped
in answering your question.

On 24 Feb 2015 at 15:20, François-Paul Servant wrote:
> if I understand correctly, the first goal of the "manages" bloc is to tell
clients what a
> collection represents. As it is, it allows to define a simple triple
pattern, eg.
> </alice> foaf:knows ?x

Yes, kind of. It works around the issue you would have with vocabularies
that use RDFS range. Assume you would have a triple

    </alice> foaf:knows </my-collection>

In principle, that would make it very clear to the client what can be
expected to be found in that collection. The issue, though, is that the
semantics of foaf:knows are defined in such a way that </my-collection> is
interpreted to be a person. So we need to indirectly reference the
collection but nevertheless tell the client enough to be able to find the
right one (there could be multiple)

    </alice> hydra:collection </my-collection>

    </my-collection> hydra:manages [
        hydra:subject </alice>
        hydra:property foaf:knows
    ]


> In many cases however, a collection could be much more complex than that.

Certainly. But if that's the case, I wouldn't generally use the manages
block but introduce a special property pointing to it (something replacing
foaf:knows in the first example).


> For instance, it could be the list of people who share an interest with
Alice (a server
> may well want to publicize its capability to return such interesting
information about persons).
> What could we do for such collections? One solution of course would be to
define an ad-
> hoc property. We can think of other ways, including some ways based on
well established
> standards. For instance, we could think of using SPARQL to define the
collection, or
> OWL. Shouldn't hydra tries to open such possibilities ?

Yeah. We can certainly look at them as well. But I'd say first we need to
get the basics right. We still haven't consensus on paging for instance.
That being said, if you have concrete proposals, don't hesitate to share
them. I'm more than happy to discuss them. I would just like to avoid
getting sidetracked with too abstract discussions for advanced use cases.


--
Markus Lanthaler
@markuslanthaler

Received on Wednesday, 4 March 2015 21:14:17 UTC