Problem with missing @ for @type about stellio-context-broker

[bobeal]

Hi @lucboj-htag,

Yes, this is the expected behavior. Better than my explanations, you can have a look at Annex C.6 (Date Representation) of the NGSI-LD API specification which explains this in details.

Btw, why don't you use the native temporal properties from NGSI-LD? For instance, you could define your entity in the following way:

{
    "id": "urn:ngsi:TestObserved:123",
    "type": "TestObserved",
    "temperature": {
        "type": "Property",
        "value": 20.5,
        "observedAt": "2024-02-19T12:32:52.98601Z"
    },
    "@context": [
        "https://smartdatamodels.org/context.jsonld"
    ]
}

That makes the temperature and the observation date more related and it allows you to use the NGSI-LD Temporal API on the temperature attribute (for instance, asking for the last values over a period of time, with aggregations,...)

PS: Fiware-ServicePath is an NGSIv2 concept (it will be ignored when calling an NGSI-LD context broker). If you want to use a similar concept in NGSI-LD, have a look at scopes (introduced in section 4.18 of the NGSI-LD API specification)

[lucboj-htag]

HI @bobeal,

thank you for your reply!

Annex C.6 explained it well and thank you for your tip on Fiware-ServicePath.

I am using "dateObserved" because I am migrating an existing NGSI V2 data model to NGSI-LD where "dateObserved" exist. Furthermore, many https://smartdatamodels.org require the field "dateObserved" to be used.

I do though add the "observedAt" field to fields where the NGSI-LD Temporal API is needed.

[bobeal]

I am using "dateObserved" because I am migrating an existing NGSI V2 data model to NGSI-LD where "dateObserved" exist. Furthermore, many https://smartdatamodels.org require the field "dateObserved" to be used.

Indeed, smart data models have a "constraint" to maintain compatibility with NGSIv2 and NGSI-LD. And it can sometimes add some fuzz in the data models :(

Closing this issue, don't hesitate to open a new one if you have other questions.