- From: Martynas Jusevičius <martynas@graphity.org>
- Date: Fri, 07 Aug 2015 16:55:14 +0000
- To: Arnaud Le Hors <lehors@us.ibm.com>, Holger Knublauch <holger@topquadrant.com>, Phil Archer <phila@w3.org>
- Cc: public-data-shapes-wg@w3.org, "public-rdf-shapes@w3.org" <public-rdf-shapes@w3.org>
- Message-ID: <CAE35VmwH65jAKu2kMvojomeeOdtC2=Hf9XJ2EsvBfJH3wn7ROg@mail.gmail.com>
Phil, why are you basing your design on the namespace URI? I think a more semantic way would be to allow all values of ?concept, where ?concept rdfs:isDefinedBy ?ontology, and ?ontology is the vocabulary you want to use. Martynas graphityhq.com On Fri 7 Aug 2015 at 18:48 Phil Archer <phila@w3.org> wrote: > Thanks for the replies everyone. > > Hmm... templates, special code, DIY... Meh. In short, the use case is > not covered out of the box. > > To be useful, I'd expect the validator to go and fetch the SKOS concept > scheme and check that the value of a property is valid. So I guess the > questions would be: > > 1. Does the URI given as the value of a property dereference? > 2. Does the type of that resource match what I expect (is it typed as a > SKOS Concept in this case). > > Of course, that's a heavy burden, I well understand that, and the burden > may be more than is needed in many cases, and too much in others, but > authoritative lists of allowed values are not uncommon. > > If this is out of scope for the work, OK, that's my answer. If the > answer is "you can bolt something on the side that does it" then, well, > I'd likely not bother with the bolt and just do it myself anyway - which > kind of defeats the object. > > Karen's Use Case 37 does indeed seem very similar and, yes, SHACL has > regEx matching, enumerated lists and so on, so a lot of what I'm asking > can be done - and that may be sufficient (or that may have to be > sufficient), but without fetching the authoritative list of allowed > values from an external source, the issue of synchronising will always > come up. > > I should indeed have some test data imminently, if it's wanted. > > Thanks > > Phil. > > PS. I'm very likely to join the f2f in Lille next month as I'll be > passing through on my way home from Brussels. Looking forward to > catching up with the wider work of the group. > > On 05/08/2015 01:01, Holger Knublauch wrote: > > This is correct and thanks for highlighting this. I wanted to be brief > > and could elaborate or even implement the template as an example. I was > > hoping that my statement "using a template" would have been sufficiently > > clear, but maybe it wasn't. Yes, there needs to be at least one person > > on the planet, knowledgeable of SPARQL and SHACL, who needed this > > feature to cast it into a template and publish it for everyone else to > use. > > > > (BTW I later noticed that the original requirement may have been about > > checking for the presence of URIs in a certain named graph. In that > > case, the SPARQL GRAPH keyword could be used, assuming the named graphs > > are present in the same dataset, or SERVICE for external graphs. There > > are all kinds of variations here, which is why my inclination is to > > leave this as an opportunity for third-party templates, not the core > > language.) > > > > Regards, > > Holger > > > > > > On 8/5/2015 9:29, Arnaud Le Hors wrote: > >> Holger, > >> > >> I think we ought to clarify that what you present here isn't all it > >> takes because it relies on having shx:allowedValueNamespaces defined > >> somewhere, presumably using the SPARQL extension. > >> > >> I know you wrote "an end-user syntax" and the implication is that some > >> advanced-user has defined such a template for the end-user but we need > >> to be careful not to set the wrong expectation. > >> > >> Regards. > >> -- > >> Arnaud Le Hors - Senior Technical Staff Member, Open Web Technologies > >> - IBM Software Group > >> > >> > >> Holger Knublauch <holger@topquadrant.com> wrote on 08/03/2015 03:29:13 > >> PM: > >> > >> > From: Holger Knublauch <holger@topquadrant.com> > >> > To: public-data-shapes-wg@w3.org, "public-rdf-shapes@w3.org" > >> > <public-rdf-shapes@w3.org> > >> > Date: 08/03/2015 03:30 PM > >> > Subject: Re: SKOS concept scheme URIs as values for constraints > >> > > >> > This could be represented in SHACL using a template, with an end-user > >> > syntax such as > >> > > >> > ex:MyShape > >> > a sh:Shape ; > >> > sh:property [ > >> > a shx:AllowedValueNamespacesConstraint ; > >> > sh:predicate ps:siteDesignation ; > >> > shx:allowedValueNamespaces ( > >> > "http://inspire.ec.europa.eu/codelist/DesignationValue/" ) ; > >> > sh:valueClass skos:Concept ; > >> > ] . > >> > > >> > In the above scenario I am assuming that the algorithm will check that > >> > all values of the given property must be URIs starting with one of the > >> > enumerated strings (using STRSTARTS in SPARQL). It would not go to the > >> > web to check whether there is actually a Graph at that namespace - > this > >> > would be outside of what SPARQL can do right now. > >> > > >> > I cannot comment on whether this particular pattern should become part > >> > of the Core vocabulary too, but the whole point of the extension > >> > mechanism is to allow anyone to represent and publish their own > >> favorite > >> > constraint design patterns, so that they don't rely on the choices > made > >> > by a particular working group in the year 2015. > >> > > >> > Holger > >> > > >> > > >> > > >> > On 8/4/2015 5:39, Karen Coyle wrote: > >> > > Phil, > >> > > > >> > > Thanks for bringing this up. I thought that I had covered this in > use > >> > > case #34 [1], and at one point I asked if all of these criteria were > >> > > met by the requirements and I was assured that they were. This is a > >> > > key use case for the cultural heritage community, so if there are > any > >> > > doubts that these requirements can be met we need to address this. > >> > > Perhaps the was to resolve this is to provide test cases. There seem > >> > > to be some functional versions of SHACL that could be used to test > >> > > this, if I'm not mistaken. Would you be able to provide some test > >> data? > >> > > > >> > > Thanks, > >> > > > >> > > kc > >> > > [1] > >> > > http://w3c.github.io/data-shapes/data-shapes-ucr/#uc37-defining- > >> > allowed-required-values > >> > > > >> > > On 8/3/15 9:48 AM, Phil Archer wrote: > >> > >> Hi, > >> > >> > >> > >> I've had an opportunity to take a look at the SHACL work today and > I > >> > >> notice one of the use cases looks set to be missed - although > >> only just. > >> > >> > >> > >> The UCR doc includes the one about self-describing Linked Data > >> [1] which > >> > >> talks about the value of a property being a skos:Concept. Are you > >> > >> considering making this a little tougher, i.e. that the value of > >> a given > >> > >> property is a concept defined in a specific scheme? > >> > >> > >> > >> I see that SHACL allows the enumeration of values [2], but I want > >> to be > >> > >> able to say "any value from the SKOS Concept scheme at <foo>". It > >> looks > >> > >> like SHACL won't support that? > >> > >> > >> > >> Use Case: INSPIRE > >> > >> > >> > >> INSPIRE [0] - the European Union's obligatory set of standards for > >> > >> environmental and geospatial data - has a handy registry of SKOS > >> concept > >> > >> schemes [3]. In one of my projects, I've been working on creating > >> RDF > >> > >> vocabularies that are compatible with the INSPIRE data model, > >> such as > >> > >> the one about protected sites [4]. That has a property > >> > >> ps:siteDesignation for which the range is defined as skos:Concept > >> but > >> > >> really what it should say is: > >> > >> > >> > >> the value of this property should be a skos:Concept in the scheme > at > >> > >> http://inspire.ec.europa.eu/codelist/DesignationValue/. > >> > >> > >> > >> It would be inappropriate to enumerate the concepts in that concept > >> > >> scheme (there are 6 of them) since it is under a different > >> > >> organisation's change control. > >> > >> > >> > >> I recognise that this leads to the possibility that a graph that is > >> > >> valid today may become invalid if the INSPIRE Registry were to be > >> > >> amended but that's a management task for the European Commission to > >> > >> worry about (i.e. the people responsible for the INSPIRE data > >> model) and > >> > >> they would need to be mindful of such situations which would occur > >> > >> whether we were talking about RDF graphs or dollops of GML, so I > >> don't > >> > >> think that's a show stopper here. > >> > >> > >> > >> WDYT? > >> > >> > >> > >> Phil. > >> > >> > >> > >> > >> > >> [0] http://inspire.ec.europa.eu/ > >> > >> > >> > >> [1] > >> > >> http://w3c.github.io/data-shapes/data-shapes-ucr/#uc28-self- > >> > describing-linked-data-resources > >> > >> > >> > >> > >> > >> > >> > >> [2] > >> > >> http://w3c.github.io/data-shapes/shacl/ > >> > #AbstractAllowedValuesPropertyConstraint > >> > >> > >> > >> > >> > >> > >> > >> [3] http://inspire.ec.europa.eu/registry/ > >> > >> > >> > >> [4] http://www.w3.org/2015/03/inspire/ps > >> > >> > >> > >> > >> > > > >> > > >> > > >> > > > > > > -- > > > Phil Archer > W3C Data Activity Lead > http://www.w3.org/2013/data/ > > http://philarcher.org > +44 (0)7887 767755 > @philarcher1 > >
Received on Friday, 7 August 2015 16:55:53 UTC