How can I call an HA service from a function node?

Third party integrations Node-RED
1

I have a function node that possibly needs to run between 0-5 service calls to HA based on the data it receives. What’s the easiest way to do that?

2

Use node.send and multiple outputs where each output maps to a particular call service node. Basically your code would look kinda like this:

if (msg.something === "option_1"){
  node.send([null, null, msg, null, null]);
}
else if (msg.something === "option_2"){
  node.send([null, msg, null, msg, null])
}
...

Obviously you’d also have to craft the msg object from the available data needed to make the service call before sending it.

2 Likes
3

Oh! That’s neat. I think all I need is a node.send for each, as all I need to do is asynchronously call the same service with different entities.

Thanks!

1 Like
4

Although this is an older post, I have been searching for a solution to make Node-RED work with various entities asynchronously, and I wanted to share my approach. I use a function node with the following logic:

const states = global.get('homeassistant.homeAssistant.states');

const lights = {
    bathroom: states['light.bathroom_lights_group'],
    bedroom: states['light.bedroom_lights_group'],
    kitchen: states['light.kitchen_lights_group'],
    livingRoom: states['light.living_room_lights_group'],
    office: states['light.office_lights_group'],
    stairs: states['light.stairs_lights_group'],
    workshop: states['light.workshop_lights_group'],
}

for (const lightId in lights)
{
    const light = lights[lightId]

    if(light && light.state && light.state === 'on')
    {
        node.send({
            payload: {
                "domain": "light",
                "target": { 
                    "entity_id": light.entity_id 
                    },
                "service": "turn_off"
                }
        });
    }
}

node.done();

  • runtime needs to know when the function node has completed its asynchronous work so node.done() is called

  • there should be no “return msg;” at the end in function node.

This is how flow in node red looks like in a nutshell:
Trigger Node > Function Node > Call Service Node

The Call Service node only needs to have the domain defined, which is “light” in my case. All other information will come from the “node.send()” method.

5

You can send that as well, you can leave a call service completely blank. You already have domain defined in the function. Also sending this message format to a defined call service, will override it’s settings.

Asynchronous is used to send a message while the node continues to do more work. For a simple statement like yours there is no reason to use asynchronous send.