Web Technology Experts Notes

Showing posts with label NodeJS-socket. Show all posts

Monday, 20 July 2020

Call socket event from router page in Node

Question: How to send socket notification from Node API/Router?

In App file (like index.js OR app.js)

//Express setup
var express = require('express');
var app = express();

//socketsetup setup
var io = require('socket.io')(https);    
app.set('io', io); //IMP this will let available io in router file

In Router or Controller file

exports.sendnotify = function(req, res) {
    var io = req.app.get('io');
    io.sockets["in"]('room_446').emit('session_end_notify', {vid:100,event_type:'live'});   //Send the Notification
    res.send('node is working fine');
};

Question: How decrypt a text which is encoded with base64?

let buff = Buffer.from('ENCRYPTED_TXT', 'base64');
print buff.toString('ascii');

Tuesday, 15 May 2018

io.emit vs socket.emit vs socket.broadcast.emit

Send message to one client, like New user come, we show him "welcome message"

socket.emit('message', "Welcome user to our Chat Group");

Sending to all clients except sender

socket.broadcast.emit('message', "New user i.e joy joined our chat group.");

Sending to all clients in 'game' room(channel) except sender

socket.broadcast.to('game').emit('message', 'sending to all clients in 'game' room(channel) except sender');

Sending to sender client, only if they are in 'game' room(channel)

socket.to('game').emit('message', 'sending to sender client, only if they are in game room');

Sending to individual socketid

socket.broadcast.to(socketid).emit('message', 'sending to individual socketid');

Sending to all clients, include sender

io.emit('message', "sending to all clients, include sender");

Sending to all clients in 'game' room(channel), include sender

io.in('game').emit('message', 'sending to all clients in game room');

sending to all clients in namespace 'myNamespace', include sender

io.of('myNamespace').emit('message', 'sending to all clients in namespace myNamespace');

for emiting to specific clients

io.sockets.socket('for emiting to specific clients');

send to all connected clients

io.sockets.emit('send to all connected clients');

Tuesday, 8 August 2017

Send Acknowledgment for socket.io event

Question: How to send Acknowledgment for socket.io event?
in node.js (Server side)

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

    /* Message Received from Client*/
    socket.on('chat_messsage', function(data, callback){        
        var responseData = { 'message':data.message, 'received':1};        
        callback(responseData); //Send Acknowledgment to the client
    });


});

Client Side JavaScript

var socket = io.connect('http://localhost:3000');
socket.on('connected', function (data) {    
    
    //Send message to Server with callback function
    socket.emit('chat_messsage', {message:"this is message"}, function(response){
        console.log(response); //console the Acknowledgment
    });

});

Question: How to Send additional data on socket connection?
Client side, connect with parameter

  var socket =  io.connect(chatURL,{ query: "req_from=browser" });

Sever side, Detect the client Connection.

io.on('connection', function (socket) {
  console.log(socket.handshake.query['req_from']);
});

Question: How to connect node with http and https?

var fs = require('fs');
var http = require('http');
var https = require('https');
var privateKey  = fs.readFileSync('cert/server.key', 'utf8');
var certificate = fs.readFileSync('cert/server.crt', 'utf8');

var credentials = {key: privateKey, cert: certificate};
var express = require('express');
var app = express();

var httpServer = http.createServer(app);
var httpsServer = https.createServer(credentials, app);

//http connect
httpServer.listen(8080);
//https connect
httpsServer.listen(8443);

Tuesday, 20 June 2017

Socket.IO module with nodeJs tutorial

How to send message from Node(server) to browser(client) and vice versa? How to connect/disconnect to the room.

Question: What is socket.io module?
Socket.IO is a JavaScript library for realtime web applications.
It enables realtime, bi-directional communication between web clients and servers.
It has two parts
a) client-side library that runs in the browser.
b) server side that run in browser.

Question: Give example of real time application?

Instant messengers like facebook notification/message.
Push Notifications like when someone tags you in a picture on facebook, you receive an instant notification.
Collaboration applications like multiple user editing same file.
Online gaming

Question: Why we use socket.io?

bi-directional communication channel between a client and a server.
When an event occur, socket get notify and let to know the single client OR all clients.
It is trust application and used by Microsoft Office, Yammer, Zendesk, Trello, and numerous other organizations.

Question: How to install socket.io in Web and Server?
In Browser (client)

<script src="https://cdnjs.cloudflare.com/ajax/libs/socket.io/2.0.3/socket.io.js"></script>

In NodeJS

npm install socket.io

var io = require('socket.io')

Question: How get to know, if user is connect/disconnect?
In Server(Node)

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

app.get('/', function(req, res){
  res.sendfile('index.html');
});

//Whenever someone connects (execute when come in Web page)
io.on('connection', function(socket){
  console.log('A user connected');

  //Whenever someone disconnects (execute when Leave the web page)
  socket.on('disconnect', function () {
    console.log('A user disconnected');
  });

});

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

In Browser

 var socket = io.connect('http://127.0.0.1:3000');

Question: How to get to know, when new user comes in browse?

OR
Question: How to send message from Client(Browser) to Server(Node)?
In Server

 
socket.on('adduser', function(name, email, uid) {
    //name, email, and uid of user
    console.log('New user comes in web page');
});

In Browser>

 
socket.emit('adduser', 'Robin Sharma','robinsharma@no-spam.ws',2555);

Question: How to send message from Server(Node) to Client(Browser)?
In Server

socket.emit('newRequestCome', 'name','myself send request'); //Send message to socket (Same window)
socket.broadcast.to(roomName).emit( 'newRequestCome','name','message'); //Send message to all socket (Other windows in same Room)