CHAT-APPLICATIONS (using socket.io, express and Nodejs )

(1)First of All install Nodejs  on your Windows system:

https://nodejs.org/en/download/

(2)After  That create a folder into your D: drive and name it "chat code" & now you need to  Open your command Prompt:

& perform following  command in command prompt

step 1:

D:\>cd chat code

step 2: to install socket.io

D:\chat code>npm   install  socket.io


step 3:to install  express


D:\chat code>npm   install   express

step 4: Prepare a file name it  as   "package.json " write given code below:

{
  "name": "socket-chat-example",
  "version": "0.0.1",
  "description": "my first socket.io app",
  "dependencies": {
    "express": "4.10.2",
    "socket.io": "1.2.0"
  }
}

& save it.

(3)Now write code for    "om.js"    file code which act as server program at server side keep this file  inside "chat code" folder :

var express = require('express')
  , app = express()
  , http = require('http')
  , server = http.createServer(app)
  , io = require('socket.io').listen(server);

server.listen(8080);

// routing
app.get('/', function (req, res) {
  res.sendfile(__dirname + '/om.html');
});

// usernames which are currently connected to the chat
var usernames = {};

io.sockets.on('connection', function (socket) {

  // when the client emits 'sendchat', this listens and executes
  socket.on('sendchat', function (data) {
    // we tell the client to execute 'updatechat' with 2 parameters
    io.sockets.emit('updatechat', socket.username, data);
  });

  // when the client emits 'adduser', this listens and executes
  socket.on('adduser', function(username){
    // we store the username in the socket session for this client
    socket.username = username;
    // add the client's username to the global list
    usernames[username] = username;
    // echo to client they've connected
    socket.emit('updatechat', 'SERVER', 'you have connected');
    // echo globally (all clients) that a person has connected
    socket.broadcast.emit('updatechat', 'SERVER', username + ' has connected');
    // update the list of users in chat, client-side
    io.sockets.emit('updateusers', usernames);
  });

  // when the user disconnects.. perform this
  socket.on('disconnect', function(){
    // remove the username from global usernames list
    delete usernames[socket.username];
    // update list of users in chat, client-side
    io.sockets.emit('updateusers', usernames);
    // echo globally that this client has left
    socket.broadcast.emit('updatechat', 'SERVER', socket.username + ' has disconnected');
  });
});

(4)Now write code for file "om.html" client side   "userinterface"  keep this file inside "chat code " folder :

<style>
.button { width: 9%; background: rgb(130, 224, 255); border: none; padding: 10px; }
</style>
<script src="/socket.io/socket.io.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.6.4/jquery.min.js"></script>
<script>

    //var socket = io.connect('http://Localhost:8080');

   //var socket = io.connect('http://vissicomp.evennode.com:8080');
   var socket=io.connect();
   //var socket = io.connect('http://192.168.1.4:8080');
 
  // on connection to server, ask for user's name with an anonymous callback

  socket.on('connect', function()
  {
    // call the server-side function 'adduser' and send one parameter (value of prompt)
    socket.emit('adduser', prompt("What's your name?"));

  });
  // listener, whenever the server emits 'updatechat', this updates the chat body
  socket.on('updatechat', function (username, data) {
    $('#conversation').append('<b>'+username + ':</b> ' + data + '<br>');
  });
  // listener, whenever the server emits 'updateusers', this updates the username list
  socket.on('updateusers', function(data) {
    $('#users').empty();
    $.each(data, function(key, value) {
      $('#users').append('<div>' + key + '</div>');
    });
  });
  // on load of page
  $(function(){
    // when the client clicks SEND
    $('#datasend').click( function() {
      var message = $('#data').val();
      $('#data').val('');
      // tell server to execute 'sendchat' and send along one parameter
      socket.emit('sendchat', message);
    });
    // when the client hits ENTER on their keyboard
    $('#data').keypress(function(e) {
      if(e.which == 13) {
        $(this).blur();
        $('#datasend').focus().click();
      }
    });
  });
</script>
<div style="float:left;width:100px;border-right:1px solid black;height:300px;padding:10px;overflow:scroll-y;">
  <b>USERS</b>
  <div id="users"></div>
</div>
<div style="float:left;width:300px;height:250px;overflow:scroll-y;padding:10px;">
  <div id="conversation"></div>
  <input id="data" style="width:200px;" />
  <input type="button" id="datasend" value="send" />
  </div>


(5)Now  run your  "om.js"  server file first:


D:\chat code>node  om.js

(6)Then  Run   client side file open any browser and type on address bar "Localhost:8080 :

"Localhost:8080"