https://github.com/njh/node-red-contrib-collector

https://github.com/njh/node-red-contrib-collector

Last synced: about 2 months ago
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• Host: GitHub
• URL: https://github.com/njh/node-red-contrib-collector
• Owner: njh
• License: apache-2.0
• Created: 2014-10-26T23:16:31.000Z (almost 10 years ago)
• Default Branch: main
• Last Pushed: 2021-07-30T10:41:27.000Z (about 3 years ago)
• Last Synced: 2024-07-21T03:10:35.134Z (2 months ago)
• Language: HTML
• Size: 33.2 KB
• Stars: 6
• Watchers: 3
• Forks: 2
• Open Issues: 3
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
node-red-contrib-collector

==========================

A [Node-RED] node that collects topic/payload pairs and outputs all values as an object,

for every message received. This can be useful if you want to perform a condition or calculation on more than one message value at once.

It can also be used to only pass a message through if the value has changed since last time the message was received.

Install

-------

Run the following command in the root directory of your Node-RED install

    npm install node-red-contrib-collector

Usage

-----

The node collects message payloads and stores them against topic names. Upon recieving a message it will output all previously received **msg.topic**/**msg.payload** pairs as an object.

If "**Only return message if value changed?**" is set, then a message will only be output, if the payload has changed since the last message with the same topic was received.

If if a message is received with a **msg.topic** but no **msg.payload**, then that topic will be deleted from the collector.

Example

-------

Illustrating what this node does may be easier with this example flow:

![screenshot](https://github.com/njh/node-red-contrib-collector/raw/master/screenshot.png)

After pressing the *a*, *b* and *c* inject buttons, the following XML is output in the debug tab:

```xml

  Value A

  Value B

  Value C

```

Pressing the *no b* button causes the ```Value B``` element to be removed again.

The flow can be downloaded from the Node-Red Flow Library here:

http://flows.nodered.org/flow/bce112d484f93a8c282a

[Node-RED]:  http://nodered.org/