Sending a specific entity to FIWARE QuantumLeap

Question

In my application I have a very specific entity format, where one of the attributes' values is a json array of values.

    {
        "id": "Proximity3",
        "type": "SensorAgent",
        "measurementType": {
            "type": "string",
            "value": "boolean",
            "metadata": {}
        },
        "modifiedTime": {
            "type": "string",
            "value": "2020-06-08T12:30:11.091506Z",
            "metadata": {}
        },
        "readings": {
            "type": "array",
            "value": [
                {
                    "type": "SensorReading",
                    "value": {
                        "reading": {
                            "type": "boolean",
                            "value": false
                        }
                    }
                }
            ],
            "metadata": {}
        },
        "sanID": {
            "type": "string",
            "value": "SAN_3",
            "metadata": {}
        },
        "sensorID": {
            "type": "string",
            "value": "Proximity3",
            "metadata": {}
        },
        "sensorManufacturer": {
            "type": "string",
            "value": "Unknown",
            "metadata": {}
        },
        "sensorType": {
            "type": "string",
            "value": "ON_OFF_SENSOR",
            "metadata": {}
        }
    }
] 

As you can see, readings attribute has an array of values stored in it (in this example only one.

Whenever I try to subscribe QuantumLeap to Orion Context Broker, subscription is successful, but there is no data received by QuantumLeap (even querying http://localhost:8668/v2/attrs gives me 'No records were found for such query.'). Tried using attrFormat on subscription, but unsuccessful.

At the same time, this https://quantumleap.readthedocs.io/en/latest/user/ suggests that the QuantumLeap expects a specific entity. My question is, is there anything possible to do in order to get this entity to QuantumLeap, or I would need to change the entity?

Answer 1

It is clear from the QuantumLeap Data Insertion documentation that QuantumLeap expects the notification it receives to contain attributes passed as Native JSON types (like Number )

"temperature": {
    "value": 24.2,
    "type": "Number",
    "metadata": {}
}

If your context broker holds attributes in a different way, direct notification will always fail, but there is nothing stopping you from proxying the notification and reformatting it in the manner that QuantumLeap prefers.

Create a simple subscription listener to read the current subscription data, reformat the bits you need and forward to Quantum Leap and return the received HTTP success/failure back to the context broker.

const request = require('request');

function receiver(req, res) {
  let data = [];

  // Manipulate the data
  req.body.data.readings.value.forEach((reading) => {
        data.push[reading.value]
  });
  // Copy the rest of data from the original subscription
  // Then Forward to QuantumLeap - replace with real values
  const options = {
      url: '/subscription/to/quantum/leap',
      method: 'POST',
      json: data,
      headers: 
    };

  // Respond back to context broker with response from QL
  request(options, (error, response, body) => {
      return error ? res.send(error) :  res.status(204).send();
  });

}