Develop Reference

socket.io not sending to client

I am trying to create a simple script to send data from a file every to the client every time the file is updated. I have tested and found that the file is read, but the client doesn't receive anything. there are no errors in the console. I am fairly new to socket.io.
node.js code
var app = require('express')();
var http = require('http').Server(app);
var io = require('socket.io')(http);
var fs = require("fs");
var port = process.env.PORT || 3000;
app.get('/', function(req, res){
res.sendFile(__dirname + '/popup.html');
});
fs.watchFile("assets/popup.json", {interval:100}, function(curr, prev)
{
fs.readFile("assets/popup.json",{encoding:"utf8"}, function(err, data){
io.emit("popup", data)
})
});
http.listen(port, function(){
console.log('listening on *:' + port);
});
client code
var socket = io();
socket.on('popup', function(msg){
alert("hello")
});

Whenever things aren't working right like this, you need to resort to "debug mode". In that mode, you need to gather all possible events that might be happening and see what you learn from that. To that end, add this code to the client:
var socket = io();
socket.on('popup', function(msg){
console.log("hello: ", msg)
});
socket.on('connection', function() {
console.log("client connected");
});
socket.on('connect_error', function(err) {
console.log("client connect_error: ", err);
});
socket.on('connect_timeout', function(err) {
console.log("client connect_timeout: ", err);
});
These messages are all documented in the client-side doc on the socket.io Github site which you can find by Googling "socket.io github" at any time.
Then, see what you see in the browser console when the page loads. If you don't know how to open the browser console in whichever browser you are using, google it to find out. You need to be looking at the debug console when the page loads.
FYI, we're assuming that you've loaded socket.io into the page via a script tag before this code. If not, that error will show in the console too.
The OP then gets this error:
client connect_error:
Error: server error at Socket.onPacket (socket.io-1.2.0.js:1)
at XHR.<anonymous> (socket.io-1.2.0.js:1)
at XHR.Emitter.emit (socket.io-1.2.0.js:1)
at XHR.Transport.onPacket (socket.io-1.2.0.js:1)
at callback (socket.io-1.2.0.js:2)
at Object.exports.decodePayload (socket.io-1.2.0.js:2)
at XHR.Polling.onData (socket.io-1.2.0.js:2)
at Request.<anonymous> (socket.io-1.2.0.js:2)
at Request.Emitter.emit (socket.io-1.2.0.js:1)
at Request.onData (socket.io-1.2.0.js:2)
OK, progress. How are you loading socket.io in the client page? This seems like it might be that you have mismatched versions of socket.io in client and server. You should be doing:
<script src="/socket.io/socket.io.js"></script>
and then your server will be feeding the client page the exact same version of socket.io. Also, since this error reports client-side socket.io 1.2.0, what version of socket.io is installed on the server?

try this
socket.on('popup', function(msg){
socket.emit('message',"popup");
});

The issue appears to be you don't actually connect to a local socket.io server. By running node server.js with the code below you can start a web server. Then navigate to localhost in your browser to see the changes in console made to popup.json.
server.js
var app = require('http').createServer(handler);
var io = require('socket.io')(app);
var fs = require('fs');
app.listen(80);
function handler (req, res) {
fs.readFile(__dirname + '/index.html',
function (err, data) {
if (err) {
res.writeHead(500);
return res.end('Error loading index.html');
}
res.writeHead(200);
res.end(data);
});
}
fs.watchFile("popup.json", {interval: 100}, function (curr, prev) {
fs.readFile("popup.json", {encoding: "utf8"}, function (err, data) {
io.emit("popup", JSON.parse(data));
})
});
index.html
<script src="/socket.io/socket.io.js"></script>
<script>
var socket = io('http://localhost');
socket.on('popup', function (data) {
console.log(data);
});
</script>

How do I properly emit data to server from client using Node.js?

When the client connects to the server a message is supposed to be emitted to the console. I'm not getting any errors so I'm confused as to what my problem actually is.
Server: As you can see the client connects.
Client: The message doesn't appear in the console.
(Forgive me for the links, I don't have 10 reputation)
How do I get the message to print to the console?
I've read other posts like this one, but they weren't helpful :(

When you do io.connect(), that call is asynchronous and not immediate. You cannot immediately emit to the server until the client generates the connect event:
var socket = io.connect()
socket.on('connect', function() {
// it is safe to call `.emit()` here
socket.emit("sndMsg", someData);
});

index.html
<html>
<head>
<script src='/socket.io/socket.io.js'></script>
<script>
var socket = io();
socket.on('welcome', function(data) {
addMessage(data.message);
// Respond with a message including this clients' id sent from the server
socket.emit('i am client', {data: 'foo!', id: data.id});
});
socket.on('time', function(data) {
addMessage(data.time);
});
socket.on('error', console.error.bind(console));
socket.on('message', console.log.bind(console));
function addMessage(message) {
var text = document.createTextNode(message),
el = document.createElement('li'),
messages = document.getElementById('messages');
el.appendChild(text);
messages.appendChild(el);
}
</script>
</head>
<body>
<ul id='messages'></ul>
</body>
</html>
server.js
var http = require('http'),
fs = require('fs'),
// NEVER use a Sync function except at start-up!
index = fs.readFileSync(__dirname + '/index.html');
// Send index.html to all requests
var app = http.createServer(function(req, res) {
res.writeHead(200, {'Content-Type': 'text/html'});
res.end(index);
});
// Socket.io server listens to our app
var io = require('socket.io').listen(app);
// Send current time to all connected clients
function sendTime() {
io.emit('time', { time: new Date().toJSON() });
}
// Send current time every 10 secs
setInterval(sendTime, 10000);
// Emit welcome message on connection
io.on('connection', function(socket) {
// Use socket to communicate with this particular client only, sending it it's own id
socket.emit('welcome', { message: 'Welcome!', id: socket.id });
socket.on('i am client', console.log);
});
app.listen(3000);

Node.js socket.io webserver provide other file than index.html

I started learn socket.io and use this example of chat.
When I go to ip:8080/public/index.html, I also need access to other files, for example other JS scripts, which will be used on client side in the browser. But when I put script load like this:
<script src="/js/phaser.js" type="text/javascript"></script>
the web server does not return it, and I need it on this handler code.
I have this code:
var app = require('http').createServer(handler)
var io = require('socket.io')(app);
var fs = require('fs');
app.listen(8080);
function handler (req, res) {
console.log(req.headers.referer);
fs.readFile(__dirname + '/public/index.html', // <--- I need here put filename which client wants it, but when I console.log to req it return HUGE data, I not found anythink usefull
function (err, data) {
if (err) {
res.writeHead(500);
return res.end('Error loading index.html');
}
res.writeHead(200);
res.end(data);
});
}
io.on('connection', function (socket) {
socket.emit('news', { hello: 'world' });
socket.on('my other event', function (data) {
socket.broadcast.emit('new message', data);
console.log(data);
});
socket.on('msg', function(data){
console.log(data);
})
});

You can use Express static for serving static files like your *.js files.

socket.io doesn't receive data

I have a simple client server web app that is using web sockets to send / receive information. The client can connect and receives properly the config file but then when I try to send a "test' message from the client using "socket.emit('message', {my: 'data'});" it doesn't display on the server. I did check with wireshark and the packets are arriving at the server.
var sIoPort = 8181;
var host = '192.168.4.111';
var fs = require('fs');
var iniMsg = fs.readFileSync('data.json','utf8');
var http = require("http").createServer(function (req, res) {
res.writeHead(200, {'Content-Type': 'text/html'});
res.end(index);
});
http.listen(sIoPort,host);
var browserServer = require('socket.io').listen(http);
browserServer.on('connection', function (socket) {
console.log('Client websocket connected');
// send the config file if available
browserServer.sockets.emit('msg',iniMsg.toString());
});
browserServer.on('message', function (message) {
console.log('received message: ' + message);
});
client side
///////////////////////////////////////////////////////////////////////////////
socket = io.connect("192.168.4.111",{"port":8181});
socket.on('connect',function() {if(DEBUG) console.log('Socket Connected');});
socket.emit('message', {my: 'data'}); // test if server receives message
socket.on('msg',function(data) {
var json = JSON.parse(data);
// add the maps to the the GUI
switch(json.type) {
case 'maps': add_maps_from_json(json, null);
break;
}
});
socket.on('disconnect',function() {if(DEBUG) console.log('Socket Disconnected');});
/////////////////////////////////////////////////////////////////////////////////

Modify the serverside listener so it's paying attention to events on a socket:
browserServer.on('connection', function (socket) {
console.log('Client websocket connected');
// send the config file if available
browserServer.sockets.emit('msg',iniMsg.toString());
socket.on('message', function (message) {
console.log('received message: ' + message);
});
});

Insert getusermedia to node.js and socket.io based chat engine

I have this code running in
Client side:
$(function(){
var iosocket = io.connect();
iosocket.on('connect', function () {
$('#incomingChatMessages').append($('<li>Connected</li>'));
iosocket.on('message', function(message) {
$('#incomingChatMessages').append($('<li></li>').text(message));
});
iosocket.on('disconnect', function() {
$('#incomingChatMessages').append('<li>Disconnected</li>');
});
});
$('#outgoingChatMessage').keypress(function(event) {
if(event.which == 13) {
event.preventDefault();
iosocket.send($('#outgoingChatMessage').val());
$('#incomingChatMessages').append($('<li></li>').text($('#outgoingChatMessage').val()));
$('#outgoingChatMessage').val('');
}
});
});
Server Side
var fs = require('fs'), http = require('http'), socketio = require('socket.io');
var server = http.createServer(function(req, res) {
res.writeHead(200, { 'Content-type': 'text/html'});
res.end(fs.readFileSync(__dirname + '/index.html'));
}).listen(8080, function() {
console.log('Listening at: localhost');
});
socketio.listen(server).on('connection', function (socket) {
socket.on('message', function (msg) {
console.log('Message Received: ', msg);
socket.broadcast.emit('message', msg);
});
});
Question :
How can I include the getUserMedia and other WEBRTC API's to create a simple video application ?

Have you looked at, or found, an opensource code set named webrtc.io. If you look at the example code (in the webrtc.io-demo project), you will find a really good example of how to use the getusermedia and peerconnection API's. This code does implement node.js but websocket.io instead of socket.io. I do not know that much about either, so I am not sure if there exists any compatibility between them.