Subscribe to changes in Domoticz switches, Possible?

[rgroothuis]

I'm polling the Domoticz system via API calls (http...../json.htm......) to get the latest status of the switches. Polling is not efficient, status only updated according the polling speed, extra data traffic, etc. Is there a way to subscribe to Domoticz and be informed if the status of a Switch changes?
In other words, my app is being informed by Domoticz if there is a status change in one or more switches.

Looking forward to your feedback and suggestions.

[Lokonli]

You can open a websocket. Changes in devices are pushed by Domoticz via the websocket to clients.

This mechanism is used by the Domoticz web client and by Dashticz.

Or use mqtt

[heggink]

Mqtt should work. Domoticz will post all changes to domoticz/out topic...

[PierreT]

What's wrong with on/off action script entry?

[waltervl]

You can also use the push HTTPlink option if your application supports it. https://www.domoticz.com/wiki/HttpLink

[rgroothuis]

What's wrong with on/off action script entry?

I've thought about that as well indeed. I'm playing with a mobile app. I don't know the IP address of the mobile device and also I don't know within Domoticz if the App is running on the mobile or not. Apart from that I don't want to make much config changes within Domoticz as that makes the installation process for a wider audience more complex. Hence my idea/question if it is possible when the App is running to subscribe to switch changes in Domoticz and that Domoticz then sends message to the mobile App.

[grecof973]

You can open a websocket. Changes in devices are pushed by Domoticz via the websocket to clients.

This mechanism is used by the Domoticz web client and by Dashticz.

Or use mqtt

Greetings!! Can you give me some more info on using the websocket???
Or some links about it

[Lokonli]

You can open a websocket. Changes in devices are pushed by Domoticz via the websocket to clients.

This mechanism is used by the Domoticz web client and by Dashticz.

Or use mqtt

Greetings!! Can you give me some more info on using the websocket???
Or some links about it

I can give a link to the js code:
https://github.com/Dashticz/dashticz/bl ... i.js#LL182

The code is a bit messy...

[rgroothuis]

The websocket sounds really interesting. The only thing left is to find out how this is working. Any more info available apart from the source code which is difficult to read how it works?

[rgroothuis]

Somebody a suggestion on how to make a websocket connection to Domoticz? I'm playing around with this for a couple of hours but without success.

React native example I tried (not a complete list):

var ws = new WebSocket('ws://192.168.0.100/')
var ws = new WebSocket('wss://192.168.0.100/')
var ws = new WebSocket('ws://192.168.0.100/json')
var ws = new WebSocket('wss://192.168.0.100/json')
var ws = new WebSocket('ws://192.168.0.100/json'/)
var ws = new WebSocket('wss://192.168.0.100/json'/)
var ws = new WebSocket('wss://xxxxxx:[email protected]/json')
and many more variations but I cannot get a successful connection.

When using the socket.io module within the Postman application I also cannot get a connection.

Is there a specific configuration required in Domoticz? I'm running the latest version so websockets should be support.

Also I don't know how otherwise to debug this! All support is more then welcome.

[Lokonli]

You have to define the protocol. Add ['domoticz'] as second WebSocket parameter.

[rgroothuis]

You have to define the protocol. Add ['domoticz'] as second WebSocket parameter.

Excellent, thanks. That was the trick.

This is not working for me:

var ws = new WebSocket('https://192.168.0.100/json/', ["domoticz"])

ws.onopen = () => {
// connection opened
ws.send('something'); // send a message
};
ws.onmessage = (e) => {
// a message was received
console.log(e.data);
};
ws.onerror = (e) => {
// an error occurred
console.log(e.message);
};

[Lokonli]

You have to define the protocol. Add ['domoticz'] as second WebSocket parameter.

Excellent, thanks. That was the trick.

This is not working for me:

var ws = new WebSocket('https://192.168.0.100/json/', ["domoticz"])

ws.onopen = () => {
// connection opened
ws.send('something'); // send a message
};
ws.onmessage = (e) => {
// a message was received
console.log(e.data);
};
ws.onerror = (e) => {
// an error occurred
console.log(e.message);
};

Is the connection opening? (is the onopen function called?)

You have to remove the ending slash of the url (/json, not /json/)

In the onopen callback you can send your first message. Something like:

Code: Select all

          var msg = {
            event: 'request',
            requestid: requestid,
            query: myquery,
          };
          requestid = (requestid + 1) % 1000;
          try {
            socket.send(JSON.stringify(msg));
          } catch (ev) {
          	...
          }
 

Example for myquery:

Code: Select all

myquery='type=devices&filter=all&used=true&order=Name'

You will receive a reply via the onmessage callback.

Only after sending a first query via the websocket to Domoticz, Domoticz will send device updates via the websocket to the client.
These device updates will have a requestid -1

[Lokonli]

In Chrome DevTools (F12), Network tab, you should see the websocket connection, and the messages that are sent and received.

[rgroothuis]

Sorry. Typo in my text above. Should have been: it is NOW working!! The onopgemerkt is called and without sending data to Domoticz I already get data delivered from Domoticz. This is looking promising. Next is to under the message coming in, how to parse them.

[PierreT]

I've thought about that as well indeed. I'm playing with a mobile app. I don't know the IP address of the mobile device and also I don't know within Domoticz if the App is running on the mobile or not. Apart from that I don't want to make much config changes within Domoticz as that makes the installation process for a wider audience more complex. Hence my idea/question if it is possible when the App is running to subscribe to switch changes in Domoticz and that Domoticz then sends message to the mobile App.

Okay, seems I misunderstood the objective.