mdv mdv - 7 months ago 111
Node.js Question emit on Express Route

I want to emit some data to the client when some API route gets called.
I have to following code on server.js

var app = express();
var http = require('http').Server(app);

var io = require('')(http);

io.on('connection', function(socket){
console.log('a user connected');

socket.emit('tx', 'msg');

socket.on('disconnect', function(){
console.log('user disconnected');

Now I have this route /test:

var bsg = require('./routes/test');

And that file:

var express = require('express');
var passport = require('passport');
var router = express.Router();

router.get('/test', function(req, res) {
//work here

module.exports = router;

On client side:

<script type="text/javascript">
var socket = io();

socket.on('tx', function(data) {

Whats the best solution for this?


Express 4 / 1.4.5


Attach the io instance to your app. = io;

Then you can access it via the request.

router.get('/test',  function(req, res) {'tx', {key:"value"});

If you are expecting to emit data to a single client you would need keep some kind of session mapping to link a standalone http request back to a socket. That's not a one to one mapping though as you can have many sockets open for one session id. You are better of doing the request/response with callbacks.