ngsi-ld

[gezever]

Hello,
I tried to transform the piece of ngsi-ld, presented in the workshop, to another type of rdf. I used jena riot, but there was an error.
tmp$ /opt/apache-jena-3.14.0/bin/riot --output=TURTLE test.json
15:00:47 ERROR riot :: [line: 2, col: 11] Expected BNode or IRI: Got: [STRING:urn:ngsi-ld:AirQualityObserved:RZ:Obsv4567]

My question is now: is this file realy rdf or is my software not compatible yet? (since we use apache jena in java for production backend code)

tmp$ cat test.json
{
"id": "urn:ngsi-ld:AirQualityObserved:RZ:Obsv4567",
"type": "AirQualityObserved",
"dateObserved": {
"type": "Property",
"value": {
"@type": "DateTime",
"@value": "2018-08-07T12:00:00Z"
}
},
"NO2": {
"type": "Property",
"value": 22,
"unitCode": "GP"
},
"refPointOfInterest": {
"type": "Relationship",
"object": "urn:ngsi-ld:PointOfInterest:RZ:MainSquare"
},
"@context": [
"https://schema.lab.fiware.org/ld/context",
"https://uri.etsi.org/ngsi-ld/v1/ngsi-ld-core-context.jsonld"
]
}

Kind regards

[bertvannuffelen]

It seems that "https://schema.lab.fiware.org/ld/context" has not enabled CORS.
When removing that the json-ld playground returns triples.

<urn:ngsi-ld:AirQualityObserved:RZ:Obsv4567> <https://uri.etsi.org/ngsi-ld/default-context/NO2> _:b0 .
<urn:ngsi-ld:AirQualityObserved:RZ:Obsv4567> <https://uri.etsi.org/ngsi-ld/default-context/dateObserved> _:b1 .
<urn:ngsi-ld:AirQualityObserved:RZ:Obsv4567> <https://uri.etsi.org/ngsi-ld/default-context/refPointOfInterest> _:b2 .
_:b0 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <https://uri.etsi.org/ngsi-ld/Property> .
_:b0 <https://uri.etsi.org/ngsi-ld/hasValue> "22"^^<http://www.w3.org/2001/XMLSchema#integer> .
_:b0 <https://uri.etsi.org/ngsi-ld/unitCode> "GP" .
_:b1 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <https://uri.etsi.org/ngsi-ld/Property> .
_:b1 <https://uri.etsi.org/ngsi-ld/hasValue> "2018-08-07T12:00:00Z"^^<https://uri.etsi.org/ngsi-ld/DateTime> .
_:b2 <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <https://uri.etsi.org/ngsi-ld/Relationship> .
_:b2 <https://uri.etsi.org/ngsi-ld/hasObject> <urn:ngsi-ld:PointOfInterest:RZ:MainSquare> .

So I think you hit a json-ld bug in riot. Or the Firware context contains additional transformations which are not spotted by this simple test.

[flopezag]

I suggest to use the context: https://smartdatamodels.org/context.jsonld

We made the migration of the previous context to this new one and we resolved some issues regarding JSON-LD format.