node-red-contrib-fusion

A Node-RED node to fusion incoming messages by category.

This node will save all incoming messages in memory and publish dictionaries of messages whenever a message is updated.

Dictionaries must be configured by sending a message with the topic fusion-configuration. Its payload is a configuration object. The key outputTopic configures the topic of the published dictionary (fusion by default). The key inputTopics is a list of topics to fusion (empty list by default). When allowUndefined is true, dictionaries containing undefined values will be published as well (false by default). A additionalData object could be set to include in the fused messages. When onlyPayloads is true (false by default), only the payloads are merged.

Dictionaries may be deleted by sending a message with the topic fusion-deletion and the outputTopic as payload.

All other messages with topics different to fusion-configuration or fusion-deletion will simply be saved for usage in dictionaries. In the current implementation, the messages are saved forever, or until the next NodeRed deployment.

Example

Configuration

{
  "topic": "fusion-configuration",
  "payload": {
    "outputTopic": "a-and-b-merged",
    "inputTopics": [
      "topicA",
      "topicB"
    ],
    "allowUndefined": false,
    "onlyPayloads": false,
    "additionalData": {
      "fromage": false
    }
  }
}

Input messages

{
  "topic": "topicA",
  "payload": 123
}

{
  "topic": "topicB",
  "payload": 456,
  "otherfield": "abc"
}

Output message

{
  "topic": "a-and-b-merged",
  "payload": {
    "topicA": {
      "topic": "topicA",
      "payload": 123
    },
    "topicB": {
      "topic": "topicB",
      "payload": 456,
      "otherfield": "abc"
    }
  },
  "additionalData": {
    "fromage": false
  }
}