Re: ISSUE-61 proposed resolution

On 10/14/2015 17:47, Dimitris Kontokostas wrote:
> I propose to resolve issue 61 by stating that
>
> Individual resources can be directly associated with a shape by 
> linking from the shape to the resource using the property sh:shapeNode 
> e.g.
> ex:myShape sh:shapeNode ex:myInstance
>
> when ever such a triple exists, ex:myInstance should comply with the 
> definition ex:myShape.
>
> This approach excludes validation data from direct resource's data in 
> cases of data merging and does not interfere with closed shapes where 
> the current sh:nodeShape property needs to be manually excluded.
>
> As an alternative for people who want the reverse relation (resource 
> to shape) is to use the existing sh:nodeShape property with the 
> property linking to an intermediate resource that has two properties, 
> a shape and a context e.g.
>
> ex:myInstance sh:nodeShape [
>   sh:shape ex:myShape
>   sh:context ex:MyGraph
> ]

I believe this reification takes it a bit too far (we could in theory 
apply this to every SHACL triple) and this info is already available via 
the quads of the named graphs.

My proposal is: Resolve ISSUE-61 by replacing sh:nodeShape with 
sh:scopeNode which points from a sh:Shape to a node. Like sh:scope and 
sh:scopeClass, the sh:scopeNode triples are expected to be in the shapes 
graph.

Note that the latter doesn't mean that these triples need to be saved 
together with the shapes - they could live in a separate graph, allowing 
shape reuse and different configurations in different contexts.

Also note that sh:scopeNode could be regarded as syntactic sugar for a 
more generic solution such as

ex:MyShape
     sh:scope [
         a sh:NodeScope ;
         sh:nodes ( ex:Instance1 ex:Instance2 ex:Instance3 )
     ] .

Holger


>
> The advantages of this approach compared to the existing one 
> (sh:nodeShape directly to a Shape) is the in cases of merging data 
> from different sources, the validation context is kept
>
> Dimitris
>
> -- 
> Dimitris Kontokostas
> Department of Computer Science, University of Leipzig & DBpedia 
> Association
> Events: http://wiki.dbpedia.org/meetings/California2015 (Nov 5th)
> Projects: http://dbpedia.org, http://rdfunit.aksw.org, 
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> Homepage:http://aksw.org/DimitrisKontokostas
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>