Re: shapes-ISSUE-212 (Property constraints): Property constraints and focus node constraints [SHACL Spec]

I think this problem stems from merging  node constraints with shapes.
Before, focus node constraints were declared with sh:constraint and not
directly into the shape and  were disjoint with property constraints so
this problem could not occur.

The proposed solution fixes this problem, but adding exceptions to
definitions is not a good approach.
I would prefer to reconsider our resolution
https://www.w3.org/2016/07/28-shapes-minutes.html#resolution04

On Thu, Nov 24, 2016 at 6:17 AM, Holger Knublauch <holger@topquadrant.com>
wrote:

> The email thread quoted below went back and forth, because the original
> SHACL examples that Peter had given were syntactically incorrect. From what
> I can see, the last unanswered email on this topic was
>
> https://lists.w3.org/Archives/Public/public-rdf-shapes/2016Nov/0012.html
>
> In the last sentence there, Peter claims that
>
> sh:pc2 is also a property constraint so the
> constraint component is also checked with focus node ex:i1 and value node
> ex:i2, which produces a validation report.  Therefore se:s2 produces a
> validation report.
>
> However this case has been excluded through the addition of a sentence to
> the Validation Definition in section 3:
>
> Note that validation against a shape processes the shape as a focus node
> constraint <#m_5129570904457041819_dfn-focus-node-constraints> only, even
> if the shape may have rdf:type triples or an expected type
> <#m_5129570904457041819_dfn-expected-type> that would also make them property
> constraints <#m_5129570904457041819_dfn-property-constraints>.
>
> As a result of this, I believe we can close this issue as resolved.
>
> Holger
>
>
>
> On 23/11/2016 8:46, RDF Data Shapes Working Group Issue Tracker wrote:
>
> shapes-ISSUE-212 (Property constraints): Property constraints and focus node constraints [SHACL Spec]
> http://www.w3.org/2014/data-shapes/track/issues/212
>
> Raised by: Karen Coyle
> On product: SHACL Spec
>
> Peter's email: https://lists.w3.org/Archives/Public/public-rdf-shapes/2016Nov/0005.html
>
> Data Graph D:
>
> ex:i1 rdf:type ex:c ;
>  ex:p1 ex:i2 .
>
> 1/ property constraints and focus node constraints
>
> Shapes Graph S1:
>
> se:s1 rdf:type sh:Shape ;
>   sh:targetClass ex:c ;
>   sh:property [ sh:predicate ex:p2 ;
>                 sh:property se:s2 ] ;
>   sh:shape se:s2 .
> se:s2 sh:predicate ex:p1 ;
>   sh:class ex:c .
>
> Validating D against S1 produces the following validation report
>
> [ rdf:type sh:ValidationResult ;
>   sh:severity sh:Violation ;
>   sh:focusNode ex:i1 ;
>   sh:sourceConstraintComponent sh:ShapeConstraintComponent ;
>   sh:sourceShape se:s1 ] .
>
> It is actually a tiny bit unclear what makes a property constraint.  There
> is wording that values of sh:property have sh:PropertyConstraint as expected
> type, but there is no actual explicit connection between nodes with expected
> type sh:PropertyConstraint.  However, se:s2 is definitely a property
> constraint as it is the value of sh:property in a shape.
>
>
>
>
>
>


-- 
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