JSON-LD serialization of rightOperand values

[simonstey]

Preliminaries:
Values of property odrl:rightOperand can be literals or IRIs:

one rightOperand property value of type:

• literal, or IRI [rfc3987], or RightOperand; or
• for set-based operators; list of literals, or list of IRIs [rfc3987], or list of RightOperands;

http://www.w3.org/ns/odrl.jsonld :

"rightOperand": "odrl:rightOperand",

---

Problem:
By default, all JSON-LD values are interpreted as strings (cf. schemaorg/schemaorg#51) ->

{
    "@context": "http://www.w3.org/ns/odrl.jsonld",
    "@type": "Offer",
    "uid": "http://example.com/policy:88",
    "profile": "http://example.com/odrl:profile:09",
    "permission": [{
        "assigner": "http://example.com/assigner:sony",
        "target": "http://example.com/music/1999.mp3",
        "action": "play",
        "duty": [{
           "action": [{
              "rdf:value": { "@id": "odrl:compensate" },
              "refinement": [{
                 "leftOperand": "payAmount",
                 "operator": "eq",
                 "rightOperand": "5.00",
                 "unit": "http://dbpedia.org/resource/Euro"
              }]
            }],
            "constraint": [{
                "leftOperand": "event",
                "operator": "lt",
                "rightOperand": "policyUsage"
            }]
        }]
    }]
}  

-->

<http://example.com/policy:88> a odrl:Offer ;
    odrl:permission [ odrl:action odrl:play ;
            odrl:assigner <http://example.com/assigner:sony> ;
            odrl:duty [ odrl:action [ rdf:value odrl:compensate ;
                            odrl:refinement [ odrl:leftOperand odrl:payAmount ;
                                    odrl:operator odrl:eq ;
                                    odrl:rightOperand "5.00" ;
                                    odrl:unit "http://dbpedia.org/resource/Euro" ] ] ;
                    odrl:constraint [ odrl:leftOperand odrl:event ;
                            odrl:operator odrl:lt ;
                            odrl:rightOperand "policyUsage" ] ] ;
            odrl:target <http://example.com/music/1999.mp3> ] ;
    odrl:profile <http://example.com/odrl:profile:09> .

---

Solution:

From schemaorg/schemaorg#51 (comment):

I think in this situation, it seems safest to always stay explicit and always use

• { "@id": "https://foo.example/" }
• { "@value": "bar" }

and don't rely on schema.org JSON-LD context having or not having "@type": "@id"

{
	"@context": "http://www.w3.org/ns/odrl.jsonld",
	"@type": "Offer",
	"uid": "http://example.com/policy:88",
	"profile": "http://example.com/odrl:profile:09",
	"permission": [{
		"assigner": "http://example.com/assigner:sony",
		"target": "http://example.com/music/1999.mp3",
		"action": "play",
		"duty": [{
			"action": [{
				"rdf:value": {
					"@id": "odrl:compensate"
				},
				"refinement": [{
					"leftOperand": "payAmount",
					"operator": "eq",
					"rightOperand": {
						"@value": "5.00",
						"@type": "xsd:decimal"
					},
					"unit": "http://dbpedia.org/resource/Euro"
				}]
			}],
			"constraint": [{
				"leftOperand": "event",
				"operator": "lt",
				"rightOperand": {
					"@id": "odrl:policyUsage"
				}
			}]
		}]
	}]
}

-->

<http://example.com/policy:88> a odrl:Offer ;
    odrl:permission [ odrl:action odrl:play ;
            odrl:assigner <http://example.com/assigner:sony> ;
            odrl:duty [ odrl:action [ rdf:value odrl:compensate ;
                            odrl:refinement [ odrl:leftOperand odrl:payAmount ;
                                    odrl:operator odrl:eq ;
                                    odrl:rightOperand 5.00 ;
                                    odrl:unit "http://dbpedia.org/resource/Euro" ] ] ;
                    odrl:constraint [ odrl:leftOperand odrl:event ;
                            odrl:operator odrl:lt ;
                            odrl:rightOperand odrl:policyUsage ] ] ;
            odrl:target <http://example.com/music/1999.mp3> ] ;
    odrl:profile <http://example.com/odrl:profile:09> .

[vroddon]

Which specific change has to be done where?

[simonstey]

instead of writing :

• (IRIs): "rightOperand": "policyUsage" -> "rightOperand": { "@id": "odrl:policyUsage" }
• (Literals): "rightOperand": "5.00" -> "rightOperand": { "@value": "5.00", "@type": "xsd:decimal" }

[iherman]

@simonstey, can you please prepare a Pull Request with the proposed changes in vocab/ODRL22.jsonld ? The version on the W3C space is merely a copy of the file in the repo, and I am uneasy "just" changing it directly.

[simonstey]

we wouldn't change anything in the context file, but would fix the examples of the IM

[iherman]

Oh, I am sorry, I misunderstood.

[riannella]

Fixed