NGSI attribute

This custom node is a simple node that allows to read, update or delete an attribute in NGSIv2 entity.

Read an attribute

It allows to read an attribute in NGSIv2 entity.

Properties

name: A name for a node instance
Context Broker: An endpoint of a context broker
ServicePath: FIWARE Service Path
Action type: read
Entity id: Id of an entity containing an attribute to be read
Entity type: Type of an entity containing an attribute to be read
Attribute name: Attribute name of an attribute to be read
Metadata: List of metadata names
Skip forwarding: If true, Context Broker skips forwarding to Context Providers

Example

Input

Payload JSON Object

A msg.payload should contain information related to the attribute to read.

{}

{
  "attrName": "relativeHumidity"
}

{
  "id": "E",
  "type": "T",
  "attrName": "relativeHumidity"
}

Output

Payload JSON Object

A msg.payload contains an object representing the attribute.

{
  "type":"Number",
  "value":45,
  "metadata":{}
}

Update an attribute

It allows to update an attribute in NGSIv2 entity.

Properties

name: A name for a node instance
Context Broker: An endpoint of a context broker
ServicePath: FIWARE Service Path
Action type: update
Entity id: Id of an entity containing an attribute to be updated
Entity type: Type of an entity containing an attribute to be updated
Attribute name: Attribute name of an attribute to be updated
Override metadata: If true, it replaces the existing metadata
Forced update: If true, it triggers matching subscriptions
Flow control: If true, it enables flow control mechanism

Example

Input

Payload JSON Object

A msg.payload should contain an object representing the attribute to update.

{
  "type": "Number",
  "value": 1234.5
}

Output

Payload Number or null

A msg.payload contains a status code.

null

Delete an attribute

It allows to delete an attribute in NGSIv2 entity.

Properties

name: A name for a node instance
Context Broker: An endpoint of a context broker
ServicePath: FIWARE Service Path
Action type: delete
Entity id: Id of an entity containing an attribute to be deleted
Entity type: Type of an entity containing an attribute to be delete
Attribute name: Attribute name of an attribute to be deleted

Example

Input

Payload JSON Object

A msg.payload should contain information related to the attribute to delete.

{}

{
  "attrName": "relativeHumidity"
}

{
  "id": "E",
  "type": "T",
  "attrName": "relativeHumidity"
}

Output

Payload Number or null

A msg.payload contains a status code.

null

Use value of actionType in payload

It allows to read, update or delete an attribute in NGSIv2 entity.

Properties

name: A name for a node instance
Context Broker: An endpoint of a context broker
ServicePath: FIWARE Service Path
Action type: value of actionType in payload
Entity id: Id of an entity containing an attribute to be read, updated or delete
Entity type: Type of an entity containing an attribute to be read, updated or delete
Attribute name: Attribute name of an attribute to be read, updated or delete
Metadata: List of metadata names
Skip forwarding: If true, Context Broker skips forwarding to Context Providers
Override metadata: If true, it replaces the existing metadata
Forced update: If true, it triggers matching subscriptions
Flow control: If true, it enables flow control mechanism

Examples

When reading an attribute, a msg.payload should contain a JSON Object with actionType and related information the attribute to be read.

Input 1

Payload JSON Object

{
  "actionType": "read",
  "attrName": "relativeHumidity"
}

Output 1

Payload JSON Object

A msg.payload contains an object representing the attribute.

{
  "type":"Number",
  "value":45,
  "metadata":{}
}

When updating an attribute, a msg.payload should contain a JSON Object with actionType and attribute with related information the attribute to be updated.

Input 2

Payload JSON Object

{
  "actionType": "update",
  "attribute": {
    "type": "Number",
    "value": 1234.5
  }
}

Output 2

Payload Number or null

A msg.payload contains a status code.

null

When deleting an attribute, a msg.payload should contain a JSON Object with actionType and related information the attribute to be deleted.

Input 3

Payload JSON Object

{
  "actionType": "delete",
  "attrName": "relativeHumidity"
}

Output 3

Payload JSON Object

Payload Number or null

A msg.payload contains a status code.

null