CODEWITHSUNDEEP
javascriptnode.js
Oz Bar-Shalom
Oz Bar-Shalom

Reputation: 1855

NodeJS emit event is not firing

I have this NodeJS code, and I have no idea why the emit function is not firing, It only fires when I put it inside a callback function like setTimeout

 const url = require('url');
const WebSocket = require('ws');
const events = require('events');

WebSocketServer = new events.EventEmitter();

WebSocketServer.start =  (server) => {
    const wss = new WebSocket.Server({server});
    console.log('websocket started');
    WebSocketServer.emit('started');
};

module.exports = WebSocketServer;

Here I test if emitted:

const ExpressServer = require('./server/api/expressServer');
const WebsocketServer = require('./server/websocket/websocketServer');

WebsocketServer.start(ExpressServer.server);

WebsocketServer.on('started', () => {
    console.log('web socket emitted');
    ExpressServer.start();
});

Upvotes: 0

Views: 2058

Answers (2)

Oz Bar-Shalom
Oz Bar-Shalom

Reputation: 1855

Ok, the problem was the order, first listen to events and then fire fuctions:

const ExpressServer = require('./server/api/expressServer');
const WebsocketServer = require('./server/websocket/websocketServer');

WebsocketServer.on('started', () => {
    console.log('web socket emitted');
    ExpressServer.start();
});

WebsocketServer.start(ExpressServer.server);

Upvotes: 1

Julien Klepatch
Julien Klepatch

Reputation: 348

It seems like you are not using EventEmitter and Websocket the right away. Below is a working example of both combined:

const EventEmitter = require('events').EventEmitter(); //You didnt call EventEmitter() in your code
const WebSocket = require('ws');

const ws = new WebSocket(//Your path here);

ws.on('open', function open() {
  console.log('websocket started');
  EventEmitter.emit('started');
});

Upvotes: 1

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