Websockets: send messages and notifications to all clients except sender - javascript

I am developing chat based on websockets and webrtc. I would like to send messages to all connected users except sender but I cannot find suitable solution. To be more specific, I would like to send notifications to other connected users that new user has joined to the chat.
I am trying to give a unique ID to every connected user, but the first assigned ID is re-writed by every new user and I cannot diferentiate users.
Server:
// list of users
var CLIENTS=[];
var id;
// web server is using 8081 port
var webSocketServer = new WebSocketServer.Server({ port: 8081 });
// check if connection is established
webSocketServer.on('connection', function(ws) {
id = Math.random();
CLIENTS[id] = ws;
CLIENTS.push(ws);
ws.on('message', function(message) {
console.log('received: %s', message);
var received = JSON.parse(message);
if(received.type == "login"){
ws.send(message); // send message to itself
/* *********************************************************** */
/* *** Here I trying to check if message comes from sender *** */
sendNotes(JSON.stringify({
user: received.name,
type: "notes"
}), ws, id);
/* *********************************************************** */
}else if(received.type == "message"){
sendAll(message); // broadcast messages to everyone including sender
}
});
ws.on('close', function() {
console.log('user ' + CLIENTS[ws] + ' left chat');
delete CLIENTS[ws];
});
});
function sendNotes(message, ws, id) {
console.log('sendNotes : ', id);
if (CLIENTS[id] !== ws) {
console.log('IF : ', message);
for (var i = 0; i < CLIENTS.length; i++) {
CLIENTS[i].send(message);
}
}else{
console.log('ELSE : ', message);
}
}
function sendAll(message) {
for (var i=0; i < CLIENTS.length; i++) {
CLIENTS[i].send(message); // broadcast messages to everyone including sender
}
}
Client:
loginButton.addEventListener("click", function(){
name = usernameInput.value;
if(name.length > 0){
socket.send(JSON.stringify({
type: "login",
name: name
}));
}
});
function sendData() {
var data = dataChannelSend.value;
var userName = document.getElementById('greetingUser').innerHTML;
socket.send(JSON.stringify({
username : userName, // fetch user name from browser, after login
type : "message",
message : data
}));
}
socket.onmessage = function(message) {
var envelope = JSON.parse(message.data);
switch(envelope.type) {
case "login":
onLogin(envelope);
break;
case "message":
showMessage(envelope);
break;
}
};
I would highly appreciate If you could give me any hint. Thanks

Here is a very simple way of sending to everyone connected except the sender.
Create a broadcast function on your webSocketServer instance that will
take two params.
...
var webSocketServer = new WebSocketServer.Server({ port: 8081 });
...
/*
* method: broadcast
* #data: the data you wanna send
* #sender: which client/ws/socket is sending
*/
webSocketServer.broadcast = function(data, sender) {
webSocketServer.clients.forEach(function(client) {
if (client !== sender) {
client.send(data)
}
})
}
...
// On your message callback.
ws.on('message', function(message) {
...
// Note that we're passing the (ws) here
webSocketServer.broadcast(message, ws);
})
That's it, the broadcast method will send to each connected client
except the one who is sending.

Ok, so we are now storing the CLIENTS in a way that allows us to uniquely identify each client that is connecting, and store arbitrary information about them for later retrieval.
The code below will send the "notes" message to all clients, and THEN add the newly connecting client to the "all clients" list.
SERVER.JS:
var http = require('http'),
Static = require('node-static'),
WebSocketServer = new require('ws'),
// list of users
/*
We are now storing client data like this:
CLIENTS = {
uniqueRandomClientID: {
socket: {}, // The socket that this client is connected on
clientDetails: { // Any details you might wish to store about this client
username: "",
etc: "etc"
}
}
};
So now to get at the socket for a client, it'll be: CLIENTS[uniqueRandomClientID].socket.
Or to show a client's username, it'll be: CLIENTS[uniqueRandomClientID].clientDetails.username.
You might want to write a 'getClientByUsername' function that iterates the CLIENTS array and returns the client with that username.
*/
CLIENTS = {},
// web server is using 8081 port
webSocketServer = new WebSocketServer.Server({ port: 8081 });
// check if connection is established
webSocketServer.on('connection', function(ws) {
console.log('connection is established');
// Now using a randomly generated ID to reference a client. Probably should be better than Math.random :D
var wsID = Math.floor(Math.random() * 1000);
ws.on('message', function(message) {
console.log('received: %s', message);
var received = JSON.parse(message);
if(received.type == "login"){
// If a client with this login name doesnt exist already, its a new client
if(!CLIENTS[wsID]) {
doBroadcast(
{
"newuser": received.name,
type: "notes"
}
);
// Now add this new client to the list
CLIENTS[wsID] = {
socket: ws,
clientDetails: {
username: received.name
}
};
}
} else if(received.type == "message") {
doBroadcast(message); // broadcast messages to everyone including sender
}
});
ws.on('close', function(_event) {
if(CLIENTS[wsID]) {
console.log('user ' + CLIENTS[wsID].clientDetails.username + ' left chat');
delete CLIENTS[wsID];
}
});
/*
* Added this to 'catch' errors rather than just red dump to console. I've never actually done anything with this myself (I *like* red text in my console), but I know this handler should be here :P
*/
ws.on('error', function(_error) {
console.log("error!");
console.log(_error);
});
/*
* Send an object to a client
*
* #param WebSocketClient _to - The client you want to send to (generally an index in the CLIENTS array, i.e CLIENTS["bobsusername123"]
* #param Object _message - A stringifyable JSON object. Complex ones can screw things up, but your basic key/value pairs are usually fine to send.
*/
function doSend(_to, _message) {
_to.send(JSON.stringify(_message));
};
// Added broadcast function to replace sendAll
// Notice how it JSON stringifies the data before sending
/*
* Broadcast a message to all clients
*
* #param Object _message - A stringifyable JSON object. Complex ones can screw things up, but your basic key/value pairs are usually fine to send.
*/
function doBroadcast(_message) {
for(var client in CLIENTS) {
if(!CLIENTS.hasOwnProperty(client)) continue;
doSend(CLIENTS[client].socket, _message);
}
};
});
var fileServer = new Static.Server('.');
http.createServer(function (req, res) {
fileServer.server(req, res);
}).listen(8080, function(){
console.log("Server is listening 8080 port.");
});
console.log("Server is running on 8080 and 8081 ports");
MY CLIENT.JS (for your reference):
var loginButton = document.getElementById("loginbutton"),
usernameInput = document.getElementById("usernameInput");
var SocketClient = function(_uri, _callbacks) {
this.uri = _uri;
this.callbacks = _callbacks;
};
SocketClient.prototype = {
send: function(_message) {
this.socket.send(_message);
},
connect: function() {
try {
this.socket = new WebSocket("ws://" + this.uri);
} catch(e) { return false; }
for(var callback in this.callbacks) {
if(!this.callbacks.hasOwnProperty(callback)) continue;
this.socket["on" + callback] = this.callbacks[callback];
}
return true;
}
};
var socketClient = new SocketClient(
"127.0.0.1:8081",
{
open: function() {
console.log("connected.");
},
message: function(_message) {
console.log("received data:");
console.log(_message);
},
close: function() {
console.log("closed.");
},
error: function(_error) {
console.log("error: ");
console.log(_error);
}
}
);
socketClient.connect();
loginButton.addEventListener("click", function(){
name = usernameInput.value;
if(name.length > 0){
socketClient.send(JSON.stringify({
type: "login",
name: name
}));
}
});
AND THE CLIENT.HTML TO GO WITH IT:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8"/>
</head>
<body>
<input type="text" id="usernameInput"/>
<button type="button" id="loginbutton">Login</button>
<script src="client.js"></script>
</body>
</html>
Ive tested this with NWJS v0.12.3 running the server and Firefox on the client.

This should work
const WebSocket = require('ws');
// Websocket variables
const wss = new WebSocket.Server({
port: 3000
});
console.log('Websocket active on port 3000...');
// New WebSocket Connection
wss.on('connection', function connection(ws) {
console.log('new connection')
// On Message Received
ws.on('message', function incoming(message) {
console.log(message)
// Send To Everyone Except Sender
wss.clients.forEach(function(client) {
if (client !== ws) client.send(message);
});
});
});

Related

How to use html5 websockets within sharedworkers

After checking similar questions on stackoverflow I did not find anything much helpful for what I want to do in my project. Reading and researching I successfully made the application work having multiple connections to my Ratchet PHP websocket server, but I noticed every time the user reloaded a page or opened a link in a new tab, the client websocket got disconnected and then reconnected again.
So, I wonder how to get only one persistent connection to a WebSocket Server, for multiple users, in a web application using a Sharedworker.
What I have in the client side is this:
<script>
$(document).ready(function($) {
let socket = new WebSocket("ws://realtime:8090");
socket.onopen = function(e) {
console.log("Browser client connected to websocket server");
socket.send("Greetings from the browser!");
};
socket.onmessage = function(event) {
console.log('Data received from server: ' + event.data);
};
socket.onclose = function(event) {
if (event.wasClean) {
console.log(`Connection closed cleanly, code=${event.code} reason=${event.reason}`);
}
else {
// e.g. server process killed or network down
// event.code is usually 1006 in this case
console.log('Connection closed unexpectedly.');
}
};
socket.onerror = function(error) {
alert(error.message);
};
});
</script>
Ok after reading, researching and trying different things and code samples, I came to this solution:
The client side (browser) should have the connection to a Sharedworker.
The sharedworker is a separated javascript file containing the core of the sharedworker and whatever other JS code that needs to be executed within it.
I first tested the sharedworker to work fine with the browser tabs, counting the number of opened tabs per user and sharing messages to one user, and then to a group of users.
Once the communication between the browser and the Sharedworker passed those tests I added the websocket code to the body of the Sharedworker JS file.
In the end, the client side (browser) looks like this:
<script>
$(document).ready(function($) {
var currentUser = "{{ Auth::user()->name }}";
let worker = new SharedWorker('worker.js');
worker.port.start();
worker.port.postMessage({
action: 'connect',
username: currentUser
});
worker.port.onmessage = function(message) {
console.log(message.data);
};
});
</script>
The Sharedworker looks like this:
// All this code is executed only once, until the onconnect() function.
//---------------------------------------------------------------------
// The array AllPorts contains objects with the format {user:<string>, port:<MessagePort>}
let AllPorts = [];
var socket = new WebSocket("ws://ssa:8090");
// Called when the WebSocket Server accepts the connection.
socket.onopen = function(e) {
//
};
// Event handler fired when the WebSocket Server sends a message to this client.
socket.onmessage = function(e) {
var message = JSON.parse(e.data);
// This loop sends a message to each tab opened by the given user.
for (var i = 0; i < AllPorts.length; i++) {
if (AllPorts[i].user == message.to) {
AllPorts[i].port.postMessage(message.msg);
}
}
};
socket.onclose = function(event) {
if (event.wasClean) {
console.log('Connection closed normally');
}
else {
console.log('Connection closed unexpectedly.');
}
};
socket.onerror = function(error) {
console.log(error.message);
};
// This event handler is fired every time a new tab is opened on the web browser.
onconnect = function(ev) {
let port = ev.ports[0];
port.onmessage = function(e) {
console.log(e.data.action);
let currentUser = e.data.username;
let userIsConnected = false;
switch (e.data.action) {
case "connect":
for (var i = 0; i < AllPorts.length; i++) {
if (AllPorts[i].user == currentUser) {
userIsConnected = true;
}
}
// Add new connected tab to AllPorts array.
AllPorts.push({user: currentUser, port: port});
if (!userIsConnected) {
// New users are added to the list of the WebSocket Server.
setTimeout(() => {
socket.send(JSON.stringify({action: 'connect', username: currentUser}));
}, 600);
}
break;
case "close":
console.log(AllPorts);
var index;
// This is also executed when the user reloads the Tab.
for (var i = 0; i < AllPorts.length; i++) {
if (AllPorts[i].port == port) {
index = i;
currentUser = AllPorts[i].user;
}
}
AllPorts.splice(index, 1);
userIsConnected = false;
// Check for any connected tab.
for (var i = 0; i < AllPorts.length; i++) {
if (AllPorts[i].user == currentUser) {
userIsConnected = true;
}
}
if (!userIsConnected) {
// User doen't have more tabs opened. Remove user from WebSocket Server.
socket.send(JSON.stringify({action: 'disconnect', username: currentUser}));
}
break;
case "notify":
// Check if given user is connected.
for (var i = 0; i < AllPorts.length; i++) {
if (AllPorts[i].user == currentUser) {
userIsConnected = true;
}
}
if (userIsConnected) {
socket.send(JSON.stringify({action: 'notify', to: currentUser, message: e.data.message}));
}
} // switch
} // port.onmessage
} // onconnect

Running node-rdkafka code in server

I'm running the below node-rdkafka code in Eclipse as Node.js application. This is the sample code from https://blizzard.github.io/node-rdkafka/current/tutorial-producer_.html
I want to run this in a test server and call from iOS Mobile application.
I knew about running node.js app in AWS.
Question I: Is there any other options to run in a free test server environment like Tomcat?
Question II: Even If I am able to run this node.js app in a server, how do i call from a mobile application? Do I need to call producer.on('ready', function(arg) (or) What function i need to call from Mobile app?
var Kafka = require('node-rdkafka');
//console.log(Kafka.features);
//console.log(Kafka.librdkafkaVersion);
var producer = new Kafka.Producer({
'metadata.broker.list': 'localhost:9092',
'dr_cb': true
});
var topicName = 'MyTest';
//logging debug messages, if debug is enabled
producer.on('event.log', function(log) {
console.log(log);
});
//logging all errors
producer.on('event.error', function(err) {
console.error('Error from producer');
console.error(err);
});
//counter to stop this sample after maxMessages are sent
var counter = 0;
var maxMessages = 10;
producer.on('delivery-report', function(err, report) {
console.log('delivery-report: ' + JSON.stringify(report));
counter++;
});
//Wait for the ready event before producing
producer.on('ready', function(arg) {
console.log('producer ready.' + JSON.stringify(arg));
for (var i = 0; i < maxMessages; i++) {
var value = new Buffer('MyProducerTest - value-' +i);
var key = "key-"+i;
// if partition is set to -1, librdkafka will use the default partitioner
var partition = -1;
producer.produce(topicName, partition, value, key);
}
//need to keep polling for a while to ensure the delivery reports are received
var pollLoop = setInterval(function() {
producer.poll();
if (counter === maxMessages) {
clearInterval(pollLoop);
producer.disconnect();
}
}, 1000);
});
/*
producer.on('disconnected', function(arg) {
console.log('producer disconnected. ' + JSON.stringify(arg));
});*/
//starting the producer
producer.connect();
First of all, you need an HTTP server. ExpressJS can be used. Then, just tack on the Express code basically at the end, but move the producer loop into the request route.
So, start with what you had
var Kafka = require('node-rdkafka');
//console.log(Kafka.features);
//console.log(Kafka.librdkafkaVersion);
var producer = new Kafka.Producer({
'metadata.broker.list': 'localhost:9092',
'dr_cb': true
});
var topicName = 'MyTest';
//logging debug messages, if debug is enabled
producer.on('event.log', function(log) {
console.log(log);
});
//logging all errors
producer.on('event.error', function(err) {
console.error('Error from producer');
console.error(err);
});
producer.on('delivery-report', function(err, report) {
console.log('delivery-report: ' + JSON.stringify(report));
counter++;
});
//Wait for the ready event before producing
producer.on('ready', function(arg) {
console.log('producer ready.' + JSON.stringify(arg));
});
producer.on('disconnected', function(arg) {
console.log('producer disconnected. ' + JSON.stringify(arg));
});
//starting the producer
producer.connect();
Then, you can add this in the same file.
var express = require('express')
var app = express()
app.get('/', (req, res) => res.send('Ready to send messages!'))
app.post('/:maxMessages', function (req, res) {
if (req.params.maxMessages) {
var maxMessages = parseInt(req.params.maxMessages);
for (var i = 0; i < maxMessages; i++) {
var value = new Buffer('MyProducerTest - value-' +i);
var key = "key-"+i;
// if partition is set to -1, librdkafka will use the default partitioner
var partition = -1;
producer.produce(topicName, partition, value, key);
} // end for
} // end if
}); // end app.post()
app.listen(3000, () => console.log('Example app listening on port 3000!'))
I don't think the poll loop is necessary since you don't care about the counter anymore.
Now, connect your mobile app to http://<your server IP>:3000/ and send test messages with a POST request to http://<your server IP>:3000/10, for example, and adjust to change the number of messages to send
I might be late on this but this is how I did using promises and found it better than have a time out etc.
const postMessageToPublisher = (req, res) => {
return new Promise((resolve, reject) => {
producer.connect();
producer.setPollInterval(globalConfigs.producerPollingTime);
const actualBody = requestBody.data;
const requestBody = req.body;
const topicName = req.body.topicName;
const key = requestBody.key || uuid();
const partition = requestBody.partition || undefined;
const data = Buffer.from(JSON.stringify(udpatedBody));
/**
* Actual messages are sent here when the producer is ready
*/
producer.on(kafkaEvents.READY, () => {
try {
producer.produce(
topic,
partition,
message,
key // setting key user provided or UUID
);
} catch (error) {
reject(error);
}
});
// Register listener for debug information; only invoked if debug option set in driver_options
producer.on(kafkaEvents.LOG, log => {
logger.info('Producer event log notification for debugging:', log);
});
// Register error listener
producer.on(kafkaEvents.ERROR, err => {
logger.error('Error from producer:' + JSON.stringify(err));
reject(err);
});
// Register delivery report listener
producer.on(kafkaEvents.PUBLISH_ACKNOWLEDGMENT, (err, ackMessage) => {
if (err) {
logger.error(
'Delivery report: Failed sending message ' + ackMessage.value
);
logger.error('and the error is :', err);
reject({ value: ackMessage.value, error: err });
} else {
resolve({
teamName: globalConfigs.TeamNameService,
topicName: ackMessage.topic,
key: ackMessage.key.toString()
});
}
});
});
};
Please note that kafkaEvents contains my constants for the events we listen to and it is just a reference such as kafkaEvents.LOG is same as event.log
and also the calling function is expecting this to a promise and accordingly we user .then(data => 'send your response to user from here') and .catch(error => 'send error response to user
this is how I achieved it using promises

Working with multiple tabs with Socket.io

I've the following code working in my server-side, it's all ok. But, I want to keep the same connection between n tabs, because when I open a new tab, looks like I've disconnected from the first tab... So, how can I keep the same connection?
client.js
socket.emit("connected", {user: inputUser.val()};
app.js
var express = require("express"),
app = express(),
http = require("http").Server(app),
io = require("socket.io")(http),
users = {};
io.on("connection", function(socket) {
socket.on("connected", function(data) {
socket.user = data.user;
users[socket.user] = socket;
updateUsers();
});
function updateUsers() {
io.emit("users", Object.keys(users));
}
socket.on("typing", function(data) {
var userMsg = data.user;
if(userMsg in users) {
users[userMsg].emit("typing", {user: socket.user});
}
});
socket.on("disconnect", function(data) {
if(!socket.user) {
return;
}
delete users[socket.user];
updateUsers();
});
});
var port = Number(process.env.PORT || 8000);
http.listen(port, function() {
console.log("Server running on 8000!");
});
Update:
The typing event above works fine... So I tried the typing event according to the answer:
var express = require("express"),
app = express(),
http = require("http").Server(app),
io = require("socket.io")(http),
users = {};
io.on("connection", function(socket) {
socket.on("connected", function(data) {
socket.user = data.user;
// add this socket to the Set of sockets for this user
if (!users[socket.user]) {
users[socket.user] = new Set();
}
users[socket.user].add(socket);
updateUsers();
});
function updateUsers() {
io.emit("users", Object.keys(users));
}
socket.on("typing", function(data) {
var userMsg = data.user;
if(userMsg in users) {
users[userMsg].emit("typing", {user: socket.user});
}
});
socket.on("disconnect", function(data) {
if(!socket.user) {
return;
}
// remove socket for this user
// and remove user if socket count hits zero
if (users[socket.user]) {
users[socket.user].delete(socket);
if (users[socket.user].size === 0) {
delete users[socket.user];
}
}
updateUsers();
});
});
var port = Number(process.env.PORT || 8000);
http.listen(port, function() {
console.log("Server running on 8000!");
});
But it is giving the following error:
users[userMsg].emit("typing", {user: socket.user});
^
TypeError: users[userMsg].emit is not a function
Update²:
To fix the typing event error, I just changed to:
socket.on("typing", function(data) {
var userMsg = data.user;
if(userMsg in users) {
for(let userSet of users[userMsg]) {
userSet.emit("typing", {user: socket.user});
}
}
});
There is no simple way to share a single socket.io connection among multiple tabs in the same browser. The usual model for multiple tabs would be that each tab just has its own socket.io connection.
The opening of a new tab and a new socket.io connection should not, on its own, cause your server to think anything was disconnected. If your code is doing that, then that is a fault in your code and it is probably easier to fix that particular fault.
In fact, if you want to explicitly support multiple tabs and be able to recognize that multiple tabs may all be used by the same user, then you may want to change your server side code so that it can keep track of multiple sockets for a single user, rather than how it is currently coded to only keep track of one socket per user.
If your server code is really just trying to keep track of which users online, then there's probably an easier way to do that by referencing counting each user. I will post a code example in a bit.
var express = require("express"),
app = express(),
http = require("http").Server(app),
io = require("socket.io")(http),
users = {};
io.on("connection", function(socket) {
socket.on("connected", function(data) {
socket.user = data.user;
// increment reference count for this user
if (!users[socket.user]) {
users[socket.user] = 0;
}
++users[socket.user];
updateUsers();
});
function updateUsers() {
io.emit("users", Object.keys(users));
}
socket.on("disconnect", function(data) {
if(!socket.user) {
return;
}
// decrement reference count for this user
// and remove user if reference count hits zero
if (users.hasOwnProperty(socket.user)) {
--users[socket.user];
if (users[socket.user] === 0) {
delete users[socket.user];
}
}
updateUsers();
});
});
var port = Number(process.env.PORT || 8000);
http.listen(port, function() {
console.log("Server running on 8000!");
});
If you need the users object to have the socket object in it, then you can change what is stored in the users object to be a Set of sockets like this:
var express = require("express"),
app = express(),
http = require("http").Server(app),
io = require("socket.io")(http),
users = {};
io.on("connection", function(socket) {
socket.on("connected", function(data) {
socket.user = data.user;
// add this socket to the Set of sockets for this user
if (!users[socket.user]) {
users[socket.user] = new Set();
}
users[socket.user].add(socket);
updateUsers();
});
function updateUsers() {
io.emit("users", Object.keys(users));
}
socket.on("disconnect", function(data) {
if(!socket.user) {
return;
}
// remove socket for this user
// and remove user if socket count hits zero
if (users[socket.user]) {
users[socket.user].delete(socket);
if (users[socket.user].size === 0) {
delete users[socket.user];
}
}
updateUsers();
});
});
var port = Number(process.env.PORT || 8000);
http.listen(port, function() {
console.log("Server running on 8000!");
});
For anyone still having this issue. here is how i fixed it.
let me explain.
once the page refreshes or a new tab is opened, socket dosen't really care so it opens a new connection every time . this is more of a advantage than disadvantage. the best way to tackle the issue is on the server side, once a user logs in with his or her user name , you can send that name along with the query options on the client so it can be used as a unique identifier. in my case i used a token
this.socket = io.connect(`${environment.domain}` , {
query: {token: this.authservice.authToken}
});
then on the server side you can create an empty array to a key and an array of values. the username of the user will be used as a key and the corresponding array of socket as the value. in my own case like i said i used a token
const users = [ ]
socket.nickname = (decoded token username);
users[socket.nickname] = [socket];
then you can perform a simple logic to check if a user already exists in an array, if it does, push the new socket to the array of the user
if ( user.username in users) {
console.log('already exists')
users[user.username].push(socket);
}
if it dosent, just create a new key and add the socket as the key.(make sure its an array because a user can always refresh or open a new tab with the same account and you dont want the chat message to deliver in one tab and not deliver in another)
else {
socket.nickname = username;
users[socket.nickname] = [socket];
}
then to emit a message you simply loop through the array and emit the message accordingly. this way each tab gets the message
socket.on('chat', (data) => {
if (data.to in users) {
for(let i = 0; i < users[data.to].length; i++) {
users[data.to][i].emit('chat', data)
}
for(let i = 0; i < users[data.user].length; i++) {
users[data.user][i].emit('chat', data)
}
}
})
you can add a disconnect logic to remove the socket from the users array too to save memory, so only currently open tabs acre active and closed tabs are removed. i hope it solved your problem
My solution is joining socket to a room with specific user Id.
io.on('connection', async (socket) => {
socket.join('user:' + socket.handshake.headers.uid) // The right way is getting `uid` from cookie/token and verifying user
})
One advantage is sending data to specific user (sending to all tabs)
io.to('user:' + uid).emit('hello');
Hope it's helpful!
I belive the best way is create a channel for the user and unique it by their ID, so, when you need to receive or send something you use the channel and every socket connected to it will receive.
Another solution is to save the flag to localStorage and use eventListener to change localStorage.
Do not connect when another connection exists.
and save message in local storage for send with master tab.

how to prevent new connection on every page refresh in sockjs

So, every time I refresh the page, it seems like sockjs is creating a new connection.
I am saving every message to my mongodb on every channel.onmessage, so if I refresh my page 7 times and send a message, I would save 7 messages of the same content into my mongodb.
This is very problematic because when I retrieve those messages when I go into the chat room, to see the log, I would see bunch of duplicate messages.
I want to keep track of all connections that are 'active', and if a user tries to make another connection, I want to terminate the old one so there is only one connection listening to each message at a time.
How do I do this ?
var connections = {};
//creating the sockjs server
var chat = sockjs.createServer();
//installing handlers for sockjs server instance, with the same url as client
chat.installHandlers(server, {prefix:'/chat/private'});
var multiplexer = new multiplexServer.MultiplexServer(chat);
var configChannel = function (channelId, userId, userName){
var channel = multiplexer.registerChannel(channelId);
channel.on('connection', function (conn) {
// console.log('connection');
console.log(connections);
connections[channelId] = connections[channelId] || {};
if (connections[channelId][userId]) {
//want to close the extra connection
} else {
connections[channelId][userId] = conn;
}
// }
// if (channels[channelId][userId]) {
// conn = channels[channelId][userId];
// } else {
// channels[channelId][userId] = conn;
// }
// console.log('accessing channel! ', channels[channelId]);
conn.on('new user', function (data, message) {
console.log('new user! ', data, message);
});
// var number = connections.length;
conn.on('data', function(message) {
var messageObj = JSON.parse(message);
handler.saveMessage(messageObj.channelId, messageObj.user, messageObj.message);
console.log('received the message, ', messageObj.message);
conn.write(JSON.stringify({channelId: messageObj.channelId, user: messageObj.user, message: messageObj.message }));
});
conn.on('close', function() {
conn.write(userName + ' has disconnected');
});
});
return channel;
};
The way I resolve a problem like yours was with a Closure and Promises, I don't know if that could help you. I let you the code that help me, this is with EventBus from Vertx:
window.Events = (function NewEvents() {
var eventBusUrl = $('#eventBusUrl').val();
var eventBus = null;
return new RSVP.Promise(function(resolve, reject) {
if(!eventBus) {
eventBus = new vertx.EventBus(eventBusUrl);
eventBus.onopen = function eventBusOpened() {
console.log('Event bus online');
resolve(eventBus);
}
eventBus.onclose = function() {
eventBus = null;
};
}
});
}());
And then in other script I call it in this way:
Events.then(function(eventBus) {
console.log("registering handlers for comments");
eventBus.registerHandler(address, function(incomingMessage) {
console.log(incomingMessage);
});
});
I hope this can help you.
Regards.

Dynamic Namespaces Socket.IO

How can I use dynamic namespaces in socket.io.
I'm looking in the (poor) documentation, and it says that namespaces must be used like this:
io.of('/news')
io.of('/akfda')
To use a namespace you do io.of("/namespace").
Do I need to register every single namespace in the server? Maybe I want a namespace for dynamic content.
How can I do something like :
io.of('/:somethign/:id')
Socket.IO supports 'rooms' (https://github.com/LearnBoost/socket.io/wiki/Rooms), you can use it instead of namespaces. Also when you need dynamic in routes (and you using express in your app) - best way is to use use route-engine from express box.
Best way to do dynamic routing with Express.js (node.js)
Using routes in Express-js
http://expressjs.com/api.html#app.routes
http://shtylman.com/post/expressjs-re-routing/
http://jordanhoff.com/post/22602013678/dynamic-express-routing
However, if you still think that you need dynamic in namespaces in socket.io, here is small example how it can be implemented:
User-side:
var connect = function (ns) {
return io.connect(ns, {
query: 'ns='+ns,
resource: "socket.io"
});
}
var socket = connect('/user/12');
Server-side:
var url = require('url');
, ev = new events.EventEmitter()
// <ns name>: <ns regexp>
var routes = {
// /user/:id
'user': '^\\/user\\/(\\d+)$',
// /:something/:id
'default': '^\\/(\\\w+)\\/(\\d+)$'
};
// global entry point for new connections
io.sockets.on('connection', function (socket) {
// extract namespace from connected url query param 'ns'
var ns = url.parse(socket.handshake.url, true).query.ns;
console.log('connected ns: '+ns)
//
for (var k in routes) {
var routeName = k;
var routeRegexp = new RegExp(routes[k]);
// if connected ns matched with route regexp
if (ns.match(routeRegexp)) {
console.log('matched: '+routeName)
// create new namespace (or use previously created)
io.of(ns).on('connection', function (socket) {
// fire event when socket connecting
ev.emit('socket.connection route.'+routeName, socket);
// #todo: add more if needed
// on('message') -> ev.emit(...)
});
break;
}
}
// when nothing matched
// ...
});
// event when socket connected in 'user' namespace
ev.on('socket.connection route.user', function () {
console.log('route[user] connecting..');
});
// event when socket connected in 'default' namespace
ev.on('socket.connection route.default', function () {
console.log('route[default] connecting..');
});
I hope this will help you!
I would use "rooms" to support your dynamic content.
Server Side
var server = require('http').createServer(),
io = require('socket.io')(server);
io.on('connection', function(socket){
var room = socket.handshake['query']['r_var'];
socket.join(room);
console.log('user joined room #'+room);
socket.on('disconnect', function() {
socket.leave(room)
console.log('user disconnected');
});
socket.on('chat message', function(msg){
io.to(room).emit('chat message', msg);
});
});
server.listen(3000);
Client Side
var socket_connect = function (room) {
return io('localhost:3000', {
query: 'r_var='+room
});
}
var random_room = Math.floor((Math.random() * 2) + 1);
var socket = socket_connect(random_room);
socket.emit('chat message', 'hello room #'+random_room);
....
As of version 2.1.1 I was able to make it work with this:
wss.of((nsp, query, next) => {
const { token } = query;
// Do your authentication or whatever here...
// If success
next(null, true);
}).on('connect', (socket) => {
// socket connected to your namespace
});
Server
var MAX_CLIENTS = 5;
var namespace_queue = [];
function searchObjectOnArray(nameKey, myArray) {
for (var i = 0; i < myArray.length; i++) {
if (myArray[i].id === nameKey) {
return myArray[i];
}
}
}
function createNamespace(data){
var ns = {
//id: require('node-uuid')(),
id : data.name,
clients: 0,
};
namespace_queue.push(ns);
return ns;
}
createNamespace({name: 'primer'});
io.of('').on('connection', function(socket){
console.log('-' + socket.id);
/// Welcome to the new client
socket.emit('Welcome', {SocketId : socket.id});
socket.on('JoinToApp', function (data, callback) {
var namespaceToConnect = searchObjectOnArray(data.namespace, namespace_queue)
if(namespaceToConnect.clients <= MAX_CLIENTS){
var dynamicNamespace = io.of('/' + namespaceToConnect.id);
dynamicNamespace.on('connection', function(ns_socket){
console.log('user connected to ' + namespaceToConnect.id);
dynamicNamespace.emit('hi', 'everyone!');
});
namespaceToConnect.clients++;
}
callback({namespaces:namespace_queue});
})
socket.on('createNamespace',function(data,join_cb){
createNamespace(data);
join_cb({message:'Namespace created'});
});
});
Client
<input id="namespaceInput" type="text" placeholder="New namespace name">
<input id="namespaceToConnect" type="text" placeholder="namespace to connect">
<button onclick="javascript: createNamespace()">Create Namespace</button>
<button onclick="javascript: joinToNamespace()">Connect to Namespace</button>
<script src="https://cdn.socket.io/socket.io-1.4.5.js"></script>
<script>
var socket = null;
(function(){
socket = io.connect('http://localhost:3000/');
})()
function createNamespace(){
var namespaceName = document.getElementById("namespaceInput").value;
socket.emit('createNamespace', {name : namespaceName}, function(data){
alert(data.message);
})
}
function joinToNamespace(){
var name = document.getElementById("namespaceToConnect").value;
socket.emit('JoinToApp', {namespace: name}, function(data){
console.log('Namespaces created:');
console.log(data)
var ns_socket = io.connect('http://localhost:3000/' + name);
ns_socket.on('connect',function(){
console.log('joined namespace ' + name);
});
ns_socket.on('hi', function(data){
console.log('hi ' + data)
})
});
}
</script>
More details on: https://ingcamilorodriguez.wordpress.com/2016/06/21/como-hacer-namespaces-dinamicos-en-socket-io/
Here is one way. Here is a socket.io subclass I created to solve the problem:
https://github.com/PencilCode/dynamic.io
That subclass adds dynamic namespaces as well as virtual hostname support (each host can go into its own namespace tree if you like). That repo has some examples.
Here is a universal socket.io listener that listens to every namespace requested, and logs a message for every socket that connects. You could listen to a different regexp to listen to any subset of namespaces.
It works with the standard socket.io client library without any modification.
var DynamicServer = require('dynamic.io');
io = DynamicServer({
host: true, // Enable virtual host handling
publicStatus: true // Enable /socket.io/status page.
});
// Any number of namespace patterns can be set up.
// This is an example of a single catch-all pattern.
io.setupNamespace(/.*/, function(nsp) {
nsp.on('connect', function(socket) {
console.log('a socket connected on', nsp.fullname());
});
nsp.expire(function() {
console.log(nsp.fullname(), 'is expiring');
});
});
io.listen(8888);
On newer versions you can use something like io.of(/^\/\w+$/).on('connection', (socket) where /^\/\w+$/ is a regular expression that will allow connection if it is a match.
Here is a full example on how to use this to setup many namespaces, here I suppose the only concerne is preventing emit diffusion from reaching other namespaces.
const workspaces = {}
io.of(/^\/\w+$/).on('connection', (socket) => {
const workspace = socket.nsp;
const namespace = workspace.name;
console.log("New Connection NameSpace", namespace);
// you can test here if "namespace" is allowed to be used
// if event handlers are set no need to got further
if (workspaces[namespace]) return;
// save workspace to prevent setting event handlers on each connection
workspaces[namespace] = workspace;
workspace.on("connection", (socket) => {
console.log(`${namespace} > connection from ${socket.id}`);
// set the event handlers same as normal socket
socket.on('event-1', (msg) => {
console.log("event-1", msg);
})
})
})

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