rdfs:subClassOf property inheritance

[verweijs]

I am messing around in the shacl playground and added a subclass to the Person class in the example: Child

@prefix dash: <http://datashapes.org/dash#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix schema: <http://schema.org/> .
@prefix sh: <http://www.w3.org/ns/shacl#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix owl:   <http://www.w3.org/2002/07/owl#>  .

schema:Person
    a sh:NodeShape , owl:Class ;
    sh:property [
        sh:path schema:givenName ;
        sh:datatype xsd:string ;
        sh:name "given name" ;
    ] ;
    sh:property [
        sh:path schema:birthDate ;
        sh:lessThan schema:deathDate ;
        sh:maxCount 1 ;
    ] ;
    sh:property [
        sh:path schema:gender ;
        sh:in ( "female" "male" ) ;
    ] ;
    sh:property [
        sh:path schema:address ;
        sh:node schema:Address ;
    ] .

schema:Child
    a sh:NodeShape , owl:Class ;
    rdfs:subClassOf schema:Person ;
    .

Now my understanding of subclasses is that the properties of the parent class are inherited. However, when I change the schema:Person into schema:Child in the data graph it does not seem like the properties are inherited correctly (it seems to ignore the sh:lessThan constraint that is violated:

@prefix ex: <http://example.org/ns#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix schema: <http://schema.org/> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

ex:Bob
    a schema:Child ;
    schema:givenName "Robert" ;
    schema:familyName "Junior" ;
    schema:birthDate "1971-07-07"^^xsd:date ;
    schema:deathDate "1970-09-10"^^xsd:date ;
    schema:address ex:BobsAddress .

Why are the properties of Person not inherited to child in this case?

[HolgerKnublauch]

You have only added the subClassOf statement into the shapes graph. This is good but not sufficient, because the statements also need to be available to the data graph. In a typical scenario, the data graph would import the shapes graph and thus also include the subClassOf triples. But the Playground doesn't do that. Adding schema:Child rdfs:subClassOf schema:Person into the data graph should solve it for this toy example.

Formal background is in the spec: https://www.w3.org/TR/shacl/#implicit-targetClass note the use of the term "data graph" in the textual definition.

[verweijs]

In a typical scenario, the data graph would import the shapes graph and thus also include the subClassOf triples. But the Playground doesn't do that.

I see, but then how does the standard data graph example in the playground 'read' that a person should have another shape: address? Or is this just how SHACL is implemented in JavaScript?

Thanks again for your patience, it is much appreciated!

[HolgerKnublauch]

The address is validated because there is a sh:node constraint in

sh:property [ sh:path schema:address ; sh:node schema:AddressShape ; ]

which causes the engine to walk from the Person into the Address shape.

If this answers your questions, feel free to close the ticket. Thanks.