Define a SHACL shape to control "compliance" with MOD or certain MOD-based profile

[jonquet]

From @ckindermann in issue #114

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It seems to me that you want to do some kind of data validation. If I understand correctly, then you want to constrain the values of say mod:knownUsage to strings (with or without a language tag). I would use SHACL to specify and check such data constraints.

Something like this:

@prefix sh: <http://www.w3.org/ns/shacl#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
@prefix mod: <http://example.org/mod#> .

mod:UsageShape a sh:NodeShape ;
    sh:targetSubjectsOf mod:knownUsage ;
    sh:property [
        sh:path mod:knownUsage ;
        sh:or (
            [ sh:datatype xsd:string ]
            [ sh:datatype rdf:langString ]
        ) ;
    ] .

Here's an example of how this would look like:

Input:

@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix mod: <http://example.org/mod#> .

mod:Example1 mod:knownUsage "Used in AgroPortal."^^xsd:string .
mod:Example2 mod:knownUsage "Used in BioPortal." .
mod:Example3 mod:knownUsage "Utilisé dans AgroPortal."@fr .
mod:Example4 mod:knownUsage "42"^^xsd:integer .

Running a SHACL validator on the input with the shape above returns a report of the form

[
	a sh:ValidationResult ;
	sh:resultSeverity sh:Violation ;
	sh:sourceConstraintComponent sh:OrConstraintComponent ;
	sh:sourceShape _:n125 ;
	sh:focusNode mod:Example4 ;
	sh:value 42 ;
	sh:resultPath mod:knownUsage ;
] .

FYI:

The triple

mod:Example2 mod:knownUsage "Used in BioPortal." .

is syntactic sugar in RDF for

mod:Example2 mod:knownUsage "Used in BioPortal."^^xsd:string .

See here:

Please note that concrete syntaxes MAY support simple literals consisting of only a lexical form without any datatype IRI or language tag. Simple literals are syntactic sugar for abstract syntax literals with the datatype IRI http://www.w3.org/2001/XMLSchema#string. Similarly, most concrete syntaxes represent language-tagged strings without the datatype IRI because it always equals http://www.w3.org/1999/02/22-rdf-syntax-ns#langString.