CODEWITHSUNDEEP
javascriptnode.jssocketswebsocketsocket.io
Martin Davidov
Martin Davidov

Reputation: 43

Cannot read property 'on' of undefined? -> ERROR

So I'm creating a web app and while building the server part I got stuck because of an error in the CMD that says:

     TypeError: Cannot read property 'on' of undefined

I tried to make the connection between the server.js and client.js but it seems not to work even though I've included all the needed modules.

var fs = require('fs'); // required for file serving
var http = require('http');
var express = require('express');
var app = express();
var socket = require('socket.io');
var io = require('socket.io');

// loading all HTMl files

// loading CSS, JS, Pictues

//  for the HTML index 

// server.listen

//  !!! HERE IS THE PROBLEM !!!
 io.sockets.on('connection', newConnection);
 function newConnection(socket){
    console.log('new connection');
    console.log(socket);
 }

I want my server.js to contact with the client.js (there's nothing written in it) and run as a normal server!

Every advice is much appreciated! :)

Upvotes: 0

Views: 564

Answers (3)

Mukesh Fulwariya
Mukesh Fulwariya

Reputation: 46

Only One require statement is required.Remove one of them.

like

const io=require("socket.io");

io.on("conn",function(){
        console.log("New Connection");
})

Upvotes: 0

Nayeemul Islam Swad
Nayeemul Islam Swad

Reputation: 157

You need to pass your server object to the io initializer. The following code might help:

var fs = require('fs'); // required for file serving
var express = require('express');
var app = express();
var server = require('http').Server(app);
var io = require('socket.io')(server);

var port = process.env.PORT || 8080;
server.listen(port);

io.sockets.on('connection', newConnection);
function newConnection(socket){
   console.log('new connection');
   console.log(socket);
}

Upvotes: 2

ThatBrianDude
ThatBrianDude

Reputation: 3190

You initialized io incorrectly. Try like this:

var io = socket(http);

Upvotes: 1

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