- From: Holger Knublauch <holger@topquadrant.com>
- Date: Thu, 13 Apr 2017 10:30:44 +1000
- To: Dimitris Kontokostas <kontokostas@informatik.uni-leipzig.de>, Sandro Hawke <sandro@w3.org>
- Cc: public-data-shapes-wg <public-data-shapes-wg@w3.org>
- Message-ID: <46195953-f1c3-1bdc-9fcb-d6b7e76776be@topquadrant.com>
As decided yesterday, I have added a new property
sh:suggestedShapesGraph to the TTL file (adding it to the main spec
would cause unnecessary formal changes such as new syntax rules, so it
will be our first "extension"). It has no "meaning" whatsoever at this
stage. No need for any changes to implementations. It is merely a "hint".
https://github.com/w3c/data-shapes/commit/8ad2fcdb851663885af7022c73a11be6d2a0cd10
@Sandro, not sure whether you want to copy this over to the official
namespace URL?
Regards,
Holger
On 12/04/2017 18:54, Dimitris Kontokostas wrote:
> Hi, this issue was originally raised by me and we had a few
> alternatives available, including something like
> sh:suggestedShapesGraph iirc.
> In the end we decided to keep sh:shapesGraph to reduce the terms we
> produce.
>
> I am not sure if I can make it to the call today but.
> I think having a link from a vocabulary to the "suggested" shapes
> graph is a good practice and we should keep and use this feature on
> shacl.ttl as well
> We can revisit our decision to overload the sh:shapesGraph with this
> semantics if this brings (or could bring) problems
>
> Best,
> Dimitris
>
> On Mon, Apr 10, 2017 at 1:39 PM, Sandro Hawke <sandro@w3.org
> <mailto:sandro@w3.org>> wrote:
>
>
>
> On April 10, 2017 12:22:58 AM EDT, Holger Knublauch
> <holger@topquadrant.com <mailto:holger@topquadrant.com>> wrote:
> >I do agree that for many data models there will be one very strong
> >"default" shapes graph. However, there was quite some resistance
> >against
> >that idea within the WG leading to the point where even
> sh:targetClass
> >statements were frowned upon by some, because they may tie
> classes too
> >much to shapes.
> >
> >In the case of shacl.ttl the shacl-shacl.ttl is one candidate default
> >shapes graph (albeit only for SHACL Core). But I expect that many
> >shapes
> >graphs/ontologies will owl:import the shacl.ttl file.
> >
> >As soon as any file has a transitive owl:imports relation to that
> file,
> >
> >it would mean that any locally defined sh:shapesGraph triples
> would be
> >augmented by that automatic sh:shapesGraph triple. We should be
> >prepared
> >for a future in which some people will mix shape, class and data
> >definitions all in the same owl:imports closure. So assuming someone
> >has
> >a data graph "mypersons" which owl:imports "personontology" and this
> >has
> >a sh:shapesGraph link, then these shapes would apply to all data
> graphs
> >
> >that use that ontology. Even worse, there might be a lot of
> unnecessary
> >
> >churn with the same shapes being validated over and over again.
> >
> >While I have no experience with using sh:shapesGraph "in the
> wild" yet,
> >
> >I think I would prefer to reserve sh:shapesGraph for the cases in
> which
> >
> >a data graph ("instances") points at a shapes graph. The
> SHACL.ttl file
> >
> >contains classes, so it does not really fall into that category. So
> >yes,
> >I believe there may be cases that need further discussion and it
> might
> >be more prudent to select another property for this particular case.
> >
> >How urgent is this decision? I would suggest we put it on the agenda
> >for
> >Wednesday.
> >
>
> It's not urgent. This link doesn't have to be normative in SHACL.
>
> I agree with your argument. Maybe the link is
> suggestedShapesGraph, and it's legit to have have multiple ones as
> alternatives, instead of all applying.
>
> - Sandro
>
> >Holger
> >
> >
> >On 10/04/2017 13:44, Sandro Hawke wrote:
> >> Tim was explicit that rdfs:seeAlso wouldn't be good enough,
> since he
> >> wants machines to able to do the importing.
> >>
> >> He may not have thought through all the implications, though. What
> >> kinds of unpredictable things might happen, do you think? I
> suppose
> >> it make make some systems validate all their shapes, when that
> isn't
> >> needed.
> >>
> >> -- Sandro
> >>
> >>
> >> On 04/09/2017 10:56 PM, Holger Knublauch wrote:
> >>> I think sh:shapesGraph would be an option here:
> >>>
> >>> https://www.w3.org/TR/shacl/#sh-shapes-graph
> <https://www.w3.org/TR/shacl/#sh-shapes-graph>
> >>>
> >>> However, given that the shacl namespace may be imported into a
> wide
> >>> variety of use cases and thus the potential wide implications of
> >>> adding such a triple are unpredictable right now, what about just
> >>> rdfs:seeAlso?
> >>>
> >>> Holger
> >>>
> >>>
> >>> On 10/04/2017 12:21, Sandro Hawke wrote:
> >>>> TimBL asked us to put a machine readable link from the SHACL
> >>>> namespace document (https://www.w3.org/ns/shacl) to the SHACL
> >>>> document which can be used to validate documents written
> using that
> >
> >>>> namespace (https://www.w3.org/ns/shacl-shacl
> <https://www.w3.org/ns/shacl-shacl>). This seems like
> >the
> >>>> kind of link that would be generally useful, even if only as a
> >rough
> >>>> default. Obviously in many cases, one namespace would be
> >>>> appropriately used in lots of different shapes. But in some
> cases
> >>>> (eg SHACL) where there's a sensible default, it'd be nice for the
> >>>> machines to be able to find it. So, has anyone made such a
> >>>> predicate? If not, is there a reason not to make it up
> now, as a
> >
> >>>> non-rec-track extension?
> >>>>
> >>>> -- Sandro
> >>>>
> >>>>
> >>>
> >>>
> >>
> >>
>
>
>
>
>
> --
> Dimitris Kontokostas
> Department of Computer Science, University of Leipzig & DBpedia
> Association
> Projects: http://dbpedia.org, http://rdfunit.aksw.org,
> http://aligned-project.eu
> Homepage: http://aksw.org/DimitrisKontokostas
> Research Group: AKSW/KILT http://aksw.org/Groups/KILT
Received on Thursday, 13 April 2017 00:31:28 UTC