Created question in FIWARE Q/A platform on 09-01-2018 at 09:01
Please, ANSWER this question AT https://stackoverflow.com/questions/48163972/orion-cb-doesnt-update-lazy-attributes-on-iot-agent

Question:
Orion CB doesn't update lazy attributes on IoT Agent

Description:
I'm trying to use Orion CB as Contex Provider for an IoT Agent in which I have registred a device with lazy attributes only.

On the IoT Agent I need to handle updateContext requests so I did a handler for these requests like this:

iotAgentLib.setDataUpdateHandler(updateContextHandler);

And in the updateContextHandler function I have only one instruction:

console.log(attributes);

In order to see if all the values I want to update have been received correctly.

Now if I do an update on one of the attributes of the entity represented by the device:

curl -i -X POST \
-H "fiware-service:service1" \
-H "fiware-servicepath:/subservice1" \
-H "X-Auth-Token:wNRwDwqYlLoLD8U9sFkTAEE6PfYMbQ" \
-H "Content-Type:application/json" \
-d \
'{
"contextElements": [
{
"id": "ncc_estimate",
"attributes": [

]
}
],
"updateAction": "UPDATE"
} ' \
'http://

/v1/updateContext'

What I see on the IoT Agent output console is:

time=2018-01-09T08:14:59.539Z | lvl=DEBUG | corr=2f4fdb0c-f515-11e7-86b2-0242ac110003 | trans=6ac5c35d-d7bf-419c-8f64-bc843b991d47 | op=IoTAgentNGSI.GenericMiddlewares | srv=service1 | subsrv=/subservice1 | msg=Body:

{
"contextElements": [
{
"type": "nccestimate",
"isPattern": "false",
"id": "ncc_estimate",
"attributes": [

]
}
],
"updateAction": "UPDATE"
}

Where as you can see the value field is empty, as I can also see from the console.log() output in the UpdateHandler function that is:

[

]

It seems that Orion is deleting the value before sending it to the IoT Agent. What could be the problem? Am I wrong doing something?

edit:

Here is the response for the call to: /v1/registry/contextEntities/ncc_estimate

{"contextRegistrationResponses":[
{"contextRegistration":
{"entities":[

],
"attributes":[

,

],
"providingApplication":"http://192.168.199.151:4044"}
}
]}

edit2:

This is what Orion is sending to the iot agent when performing the updateContext operation described before:

POST //updateContext HTTP/1.1
User-Agent: orion/1.10.0-next libcurl/7.19.7
Host: 192.168.199.151:4044
fiware-service: service1
Fiware-ServicePath: /subservice1
X-Auth-Token: M62UkJc7yKX5aQwaHrsODfIrV4Ou85
Accept: application/json
Content-length: 169
Content-type: application/json; charset=utf-8
Fiware-Correlator: 42561e9a-f615-11e7-8610-0242ac110003

{"contextElements":[{"type":"nccestimate","isPattern":"false","id":"ncc_estimate","attributes":[

]}],"updateAction":"UPDATE"}

As you can see the "value" field for the attribute is empty.
I'm using Orion version 1.10.0 and iot agent node lib version 2.5.1.