NodeJS和Websockets

Question

Today is my first time using NodeJS, and Socket.io more particularly. I developed a website with a PHP framework and would like to add notification and chat features. I'm following the tutorial on the Socket.io website trying to adapt it to my needs, but I have a few questions.

• First, I see that they are creating an HTTP server. What I want is the website to keep working as usual, meaning HTTP requests to be handled the same way, but on top of that I would like a websocket to be created whenever a page is loaded. So instead of

   var http = require('http').Server(app); http.listen(3000, function(){ console.log('listening on *:3000'); }); 

could we create a websocket server and use the WS protocol instead? I've seen a few libraries online but I would like to know if there is a standard one or a better way to do it.

• The other thing is I can't find the right path to the server-side Socket.io script. Therefore the connection can't be established. From I saw online, it should look like DOMAIN/socket.io:3000 . Now I'm getting lost since it's my first time using Node: where can I find this "socket.io" file on the server? In my project folder, all I see is a node_modules folder (which does include a socket.io folder but I'm not sure how to use it).

Please note that my script on the server runs without any errors, even though I haven't had a chance to establish a connection

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

http.listen(3000, function(){
    console.log('listening on *:3000');
});

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

Here's the current code on the client side:

var socket = io('<?php echo base_url(); ?>:3000, {path: "/sockets/socket.io"}');

Answer 1

NodeJS is a webserver. Unlike PHP, you can run multiple servers on different ports from one server. So this creates a webserver:

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

http.get("/",(req,res)=>res.write("Hello World"));

http.listen(3000, function(){
console.log('listening on *:3000');
});

And this is the socket:

var io = require('socket.io')(http);
io.on('connection', function(socket){
console.log('a user connected');
});

Note that Socket.io needs a webserver for their handshake,so an additional http server is neccessary. However, you dont need to use this server for serving pages, so you can do:

var io = require("socket.io")(8000);//creates a webserver on port 8000, no need to do more with the pure http server
io.on('connection', function(socket){
console.log('a user connected');
});

---

Unlike PHP you dont need to embed scripts, you can import them:

var so=require("socket.io");//works if socket.io is installed in modules