How to receive push notifications from another server?

paphko

I would like to receive notifications from another server in my module. To be more precise, I have a running openhab server and I would like to display the state of lights and window contacts on my mirror. Up to now, I am using the first version of the mirror:

Currently, I use the openhab REST API to pull the states every 10 seconds, but this produces a lot of requests on the openhab server and an update delay of up to 10 seconds. Instead, I would like the openhab server to tell my mirror each state change. On the openhab side, I can easily add some arbitrary java code, for example to perform some http requests or to open and communicate via a socket connection to a specific IP.

But how to implement a listener in a MM module? I don’t have much experience with electron and the new MM application infrastructure yet. How can I configure my module to receive notifications from another server? Is there maybe some module that does something similar?

MichMich

The MagicMirror contains a SocketIO server. You could connect to that server and push notifications on the module specific channel. It’s an undocumented feature, so you might need to digg into the code.

paphko

Thanks for the really quick answer! :-)
Do you have any hint in which files I could start digging?

paphko

I did some experiments but no success yet. Maybe you could clarify some things:

What do you mean by ‘module specific channel’? How does that work?
I tried to emit an event via a java application, but I don’t know which parameters to use so that the event is passed to my module?
Where is the code that processes incoming socket events?

I tried socket.io-java-client, but nothing happens on the server (log remains empty, module does not return anything):

public static void main(String[] args) throws Exception {
	Socket socket = IO.socket("http://raspi:8080"); // I also tried: http://raspi:8080/socket-test-module
	socket.connect();
	socket.emit("notification", "ping");
	socket.close();
}

Any ideas how to get a simple external socket client running?

strawberry 3.141

@paphko said in How to receive push notifications from another server?:

On the openhab side, I can easily add some arbitrary java code, for example to perform some http requests or to open and communicate via a socket connection to a specific IP.

in a module i forked from paviro, there is a functionality where you can make http requests to the module https://github.com/fewieden/MMM-syslog/blob/master/node_helper.js#L16

paphko

@strawberry-3.141 Awesome, thank you! That’s exactly what I was looking for :-)