epdoc-node-red-utils

epdoc-node-red-utils

General purpose utilities for use with Node-RED and Home Assistant.

• Service wrapper, to generate payloads for use with the Call Service node.
• HA wrapper, to retrieve state from home assistant

Utilities for my personal use of Node-RED with Home Assistant. Included are:

• A setFan function that is specific to my RF control of fans using both a Bond Bridge to control speed (0 to 6), and wall switches to decouple the fans from power when they are off. I do this to prevent mains noise from blowing the susceptible controllers on my Minka fans.
• LocationHistory and LocationMoving classes that I use to monitor movement from our house, for gate automation purposes. These are at a pre-release level of quality.

Developer Notes

This module was originally written in ES6 and transpiled using Babel to generate a module that could be loaded using require or import. Soon thereafter it was migrated to TypeScript (developer hint: this resulted in catching quite a few bugs). It was also migrated to Bun for build and unit testing. Bun generates a different type of module that can only be loaded in Node-RED using a dynamic import, as you will see in the next section.

git clone epdoc-node-red-utils
cd epdoc-node-red-utils
bun install
bun test
bun run build

Installation and Use

Perhaps the most predictable way to install this package with Home Assistant is to add this dependency to the Node-RED package.json file and restart Node-RED. Node-RED is restarted from Settings > Add-ons > Node-Red. The restart should cause the module to be installed and available. For module updates you can edit the version number in package.json, delete node_modules/epdoc-node-red-utils, then restart Node-RED.

For convenience you can add the module to globals, so that you don't need to specify the module in each Function Node where it is used. Here are the required changes to /config/Node-RED/settings.json for this to work:

// Don't set module.exports yet
let settings = {
  
  // No need to touch any of the settings 

};

// Must use dynamic import because of the nature of how bun generates this module
async function loadModules() {
  const utils = await import('epdoc-node-red-utils');
  settings.functionGlobalContext['epdoc-node-red-utils'] = utils;
}

loadModules();

module.exports = settings;

Then, to use the following code in a Function Node, it's simply a matter of accessing the global context to get the module. In this example, the Function Node has two outputs, with the 2nd output wired to a Call Service node.

const u = global.get("epdoc-node-red-utils");
const payload = u.newLightService('master_bedroom').on().payload();
node.send([null,{payload:payload}]);
node.send([msg,null]);
node.done();

Unfortunately there is no code completion in Node-RED's Function Node editor.

You can find a more exhaustive discussion of various ways to use your own libraries in Node-RED here.

Service Class

The Service object is used to build a payload that can be passed to the Call Service node. Provided too are a number of subclasses for specific types of entities, including SwitchService, LightService, AlarmService, CoverService, FanService and, finally FanSpeed6Service, which is a 6-speed fan that uses a Bond Bridge to set the fan speed and a smart switch to turn the fans on and off.

There is the possibility for many more subclasses to be written, or you can build your service payload directly using the base Service class, or one of the other subclasses.

The following shows the code for a function node that uses three equivalent implementations to tell a Cover to stop.

let payload = newService('cover.garage').service('stop_cover').payload();

payload = new CoverService('garage').stop().payload();

let payloadBuilder = newCoverService('garage');
payload = payloadBuilder.stop().payload();
msg.payload = payload;
return msg;

The following function node code creates a payload that can be used to set a light's brightness to 50%.

msg.payload = new LightService('bedroom').percentage(50).payload();
return msg;

The following function node code shows several ways to create a payload that turns a light on.

// In this example we directly use the LightService, 
// which will set the domain to `light` for us. 
// The LightService is a subclass of SwitchService.
msg.payload = new LightService('bedroom').on().payload();

// In this example we use the SwitchService, but change it's default
// domain from `switch` to `light` by specifying the full `entity_id`.
msg.payload = new SwitchService('light.bedroom').on().payload();

// Override the default domain using the `domain` method.
msg.payload = new SwitchService('bedroom').domain('light').on().payload();
return msg;

HA Class

The HA class is again meant for use in Function Nodes. It provides a wrapper for a Home Assistant instance, and has methods to access the state of Home Assitant entities.

Example retrieves the state of a light.

const gHA = global.get('homeassistant');

const ha = new HA(gHA);
const lightEntity = ha.entity('light.bedroom');
const isOn = lightEntity.isOn();
node.warn(`The ${lightEntity.id} is ${isOn?'on':'off'}`)

HA retrieveSensorsData method

This method takes a dictionary containing an id field and optional type field and retrieves sensor data for the listed sensors. This is a shortcut that you might use when you have multiple sensors that you efficiently want to get data for, and you need to access that data more than once.

const gHA = global.get('homeassistant');
const ha = new HA(gHA);

const sensorDict = {
  sensor1: { id: 'input_boolean.evening', type: 'boolean' },
  sensor2: { id: 'sensor.outdoor_temperature', type: 'number' }
};

ha.retrieveSensorsData(sensorDict);
if( sensorDict.sensor1.on ) {
  console.log('It is the evening');
}
if( sensorDict.sensor2.val > 30 ) {
  console.log('It is hot today');
}

The above code is equivalent to the following:

const gHA = global.get('homeassistant');
const ha = new HA(gHA);

if( ha.entity('input_boolean.evening').isOn() ) {
  console.log('It is the evening');
}
if( ha.entity('sensor.outdoor_temperature').asNumber() > 30 ) {
  console.log('It is hot today');
}