My goal is to create a one to one chat based on two different users. The only way that I could think of is to use socket.io rooms
But the problem right now is that how do i create unique room?
For example
socket.on('join', function(room) {
socket.join(room);
});
Do i need to emit the room from the client, if so , how do I make it unique. Imagine there are thousands of users.
The chat application, is similar like facebook chat application. Where you can chat one on one.
Do i need redis or mongodb to store the room? Anyone of you who have experience using socket.io in scale, please do share your opinion
Thanks!
A room always will be unique, when you do socket.join('roomname') if the room not exist it will created and this socket will join it, if exist the socket just will join it.
So if you want that client A join in the room where is client B for example, from client A you can send a event like:
socket.emit('joinroom', roomname);
On sever:
socket.on('joinroom', function(data){
socket.join(data)
})
Anyway when a socket connect , it create and join his own room automatically , the name of this room will be the id of the socket, so i think is not neccessary create new rooms for a chat based on two different users.
Everything that you need is link the socket id with a permanent property of the user.
EDIT:
I leave you here a simple chat app example where you can open multiple conversations:
server.js: https://gist.github.com/pacmanmulet/b30d26b9e932316f54b2
index.html: https://gist.github.com/pacmanmulet/6481791089effb79f25f
You can test it here :https://chat-socket-io-example.herokuapp.com/
I did not use rooms, it have more sense when you want emit to a group of sockets, not to a only one.
Hope you can understand better my idea with that.
you need to store the room number somewhere(any database).You have to do this because you have to keep your server stateless.
Let us assume that you are creating a private chat only for two people.The room number has to be unique. so one approach is to use the user's email id and join them to create a new string and emit it back to the users.this is tricky because we don't know the order in which the strings are joined. so we join them by a string not used in normal email name(eg :'"#!#!#!!#!#!#!').we can split it on the server side and compare emit the results.
The actual message body will be
{
room:a#gmail.comb#gmail.com,
from:a,
message:'hi buddy how are you?'
}
CLIENT side code
const roomName = a#gmail.com+'#!#!2!#!#"+b#gmail.com
socket.emit('room', { room: roomName });
this.socket.on('joined', data => {
console.log('i have joined', data.room)
store the room name room: data.room })
})
socket.on('chat',data=>console.log(`received chat from ${data.from} from the message room ${data.room}`)
used '#!#!2#!#' just because we can separate them on the server side and check if the room already exists.
SERVER side code
const room =[]//this variable you have store in database and retrieve it when needed.
socket.on('room',data=>{
if(room.length!=0){
const temp = data.room.split('!#!#2#!#!').reverse().join('!#!#2#!#!');
if(room.includes(temp)){
socket.join(temp)
console.log('joined room',temp)
socket.emit('joined',{room:temp})
console.log(room);
} else if(room.includes(data.room)){
socket.join(data.room)
console.log('joined room', data.room)
socket.emit('joined', { room: data.room})
console.log(room);
}
}else{
socket.join(data.room);
room.push(data.room)
console.log('joined room',data.room);
socket.emit('joined', { room: data.room })
console.log(room);
}
})
I tried to do a minimal example of where you can only be in one room at a time (apart from your default socket.id room) and only other sockets in the same room as you will receive your messages. Also you can change rooms.
The basic premise is, if socket A is in room 'xyz' and so is socket B, on the server side you can do socket.to('xyz').emit('message', 'hello') for socket A, and socket B will receive the message, but another connected socket C which isn't in room 'xyz' won't.
You can create room at server runtime, I used both users id as room id, Ex : '100-200' for demo purpose. May be you can use some more complex approach.
I just started learning NodeJS and Socket.io. Until now I have this demo code, from official socket.io site:
http://socket.io/demos/chat/
I am able to get the unique client's ID of each user (socket) which connects, I am still trying to figure out, How can I make my code to only connect with 1 random user at a time when somebody runs the application. I just want to make random chat like Omegle (http://www.omegle.com/).
Only two users should randomly connect and chat with each other till they re-run the app, if they come back they should get connected with someone else who is in the online queue.
What changes do I need to do to have a similar behaviour?
Update
Added Client site code, main.js
$(function() {
var FADE_TIME = 150; // ms
var TYPING_TIMER_LENGTH = 400; // ms
var COLORS = [
'#e21400', '#91580f', '#f8a700', '#f78b00',
'#58dc00', '#287b00', '#a8f07a', '#4ae8c4',
'#3b88eb', '#3824aa', '#a700ff', '#d300e7'
];
// Initialize variables
var $window = $(window);
var $usernameInput = $('.usernameInput'); // Input for username
var $messages = $('.messages'); // Messages area
var $inputMessage = $('.inputMessage'); // Input message input box
var $loginPage = $('.login.page'); // The login page
var $chatPage = $('.chat.page'); // The chatroom page
// Prompt for setting a username
var username;
var connected = false;
var typing = false;
var lastTypingTime;
var $currentInput = $usernameInput.focus();
//Own Global
var room = '';
var socket = io();
function addParticipantsMessage (data) {
var message = '';
if (data.numUsers === 1) {
// message += "there's 1 participant";
// Status Message
message += "Waiting to connect with someone";
} else {
// message += "there are " + data.numUsers + " participants";
//Status message update
message = "You are connected to a stranger! Say Hey!";
}
log(message);
}
// Sets the client's username
function setUsername () {
username = cleanInput($usernameInput.val().trim());
// If the username is valid
if (username) {
$loginPage.fadeOut();
$chatPage.show();
$loginPage.off('click');
$currentInput = $inputMessage.focus();
// Tell the server your username
socket.emit('add user', username);
// Own
socket.emit('login', {'username' : 'Faizan'});
}
}
Although I would close this question because it's too vague, I feel obliged to give you some insight since I worked way too much with websockets in the last years (although not that much with socketio & nodejs). I suppose some simple guide and relevant links could help you. So first,
Kind of relevant intro
You should already know that Socket.io is a WebSocket implementation.
WebSockets (WS) allow server to send data whenever it wants, as long as the connection is still open, as opposed to old way: client querying all the time asking, if there is an update on the server.
You can imagine a woman and a man at the end of a party: "Thanks for tonight, I'd love to repeat it sometimes soon. Would you give me your number?" - asks the old man. "Ughhh, you know what, better give me yours, I promise I will call you!"
If the girl were to give him her number, he'd call a few times a day asking if she'd go somewhere (and she'd reply no). The other way around, she would call him only if she wanted to go and he would go. Of course he would.
I got a bit carried away, but you get the picture. The woman is a server, the guy is a client.
What is important to understand
(Absolute basic, you should know this =>)
When client connect to your server, (s)he should be served a html page and some javascript, which establishes connection to your WS server. In the code you've posted, Express is used as http server. Check this example to see how you should give user html&js.
You'll also notice namespaces and rooms in most of these tutorials. These are used for separating users into subcategories. One server may contain multiple namespaces (by default only one) and each namespace may contain multiple rooms. You probably won't need to bother with namespaces, one is just enough for your case. You will, however, need to understand rooms (more on that later).
Next thing, taken from your code
io.on('connection', function (socket) {
It's important to know, that socket here basically represent one connected client (in one namespace, but possibly in multiple rooms). You can do all sort of stuff with it, most notably:
install event handlers on it (that's what you do when you call socket.on(event, handler(data))
send events to it with socket.emit(event, data)
send broadcast event to all users with socket.broadcast.emit(event, data)
add/remove it to/from room with socket.join(room), socket.leave(room) respectively.
work with it as with an ordinary variable - store it wherever you want and then reuse it
Do you see the definition of numUsers in your code? That's a global variable which is shared with all clients, since nodejs is single-threaded. In the example it is being incremented inside one of the event handlers. Think we could use something like that? YES.
We can define global variable, queue for example. Or Q if you want. Point is, it can be an array used to store sockets, or rather clients, which are not currently in chat room.
At the end of this section I'd like to point out another obvious thing.
io.on('connection', handler); defines an event handler for 'connection' event happening on the io object (WS server). This is triggered each time client makes connection to your WS server (in your case, through javascript ran inside client's browser). Argument to the method is socket and it is this method where you should add event listeners for each client (that you already do in the code, particularly handling events 'new message', 'add user', 'typing', 'stop typing' and 'disconnect').
What events shall you need
That really depends on how complex you want your app to be. In my opinion, the bare minimum would be (note that you can change the event names, but 'disconnect' should stay 'disconnect'):
event name -> data given
Events handled on server side
login -> username (how the user should be called), possibly password if you want to enable registration
message -> text (content of the message being sent)
leave room -> room name
disconnect
Event handled on client side
connect
chat start -> name (second client's name), room (so we can leave it)
chat end -> no data required if you want to allow only one chat at the same time. In case of multiple chats you should also include which chat got closed
disconnect
Last note before we get started
This is only a rough sketch. There are multiple different crossroads along the way and which path you take mostly depends on your idea of the app. If you want to have multiple chats opened at the same time, you'll need to do some modifications. The same goes if you want to have more than two people connected to the same chat. Here I'll describe the simplest case possible, one chat, to people, no registration. Possibly what you want, judging from your post. Could be wrong.
Workflow
User opens your page in their web browser. You serve them html and javascript. The javascript will start new connection to your websocket server. Also, handlers for desired events should be defined at this point.
When the connection is established, this will be happening:
ON SERVER SIDE
io.on('connection', handler) will be fired. Only appropriate handlers for new socket will be installed, not doing anything else at this point.
ON CLIENT SIDE
socket.on('connect', handler) will be fired. Client should at that point have username stored somewhere. If not, no problem. The connection will be alive for quite some time. You can just call socket.emit('login', {'username':name) any time you wish after you are connected (in the example below I set up variable connected, which defaults to false but will be set to true as soon as connection is established.)
After you send login event from client, server registers it and saves it somewhere. Possibilities are endless, in this case I'll create global dictionary which maps socket.id to username. After that, user socket should be either paired with another one or added to queue.
So, if the queue is empty, simply append socket to global variable (it doesn't have to be an array, since we will pair the first available sockets together, however you may want to implement some history of users so they won't get connected to the same person again). If the queue is not empty, we pull one socket out of the Q and add them to the same room. Room name can be random or whatever you want, I'll use (socket1.id+'#'+socket2.id (if you wanted to have more users in one chat, this would have to be changed).
After you add them both, you'll need to notify them that their chat has started and send them the other peer's name. You will emit event 'chat start'.
Clients will catch the event and open new window. After that, whenever user types something and sends it, client emits event 'message' with payload {'message': user_inserted_text}. Server will capture it in the .on('message' handler and broadcast it to the room. Note:
Broadcasting means sending a message to everyone else except for the socket that starts it.
Note: I am really confused about socketio code right now. Look at this and tell me, if socket.rooms is an array or an object (socket.rooms[room] = room; ?? why?)
To avoid dealing with this not-straightforward code, lets create another global object, rooms, which will store the room names for us. We will map socket.id -> roomName there.
So when message comes, we can get name of the room by calling rooms[socket.id]. Then we broadcast the message like this:
socket.broadcast.to(room).emit('message', data);
Where data is what we received from the sender, therefore object {'text': 'some nice message'}. Your peer will then receive it (you won't) and display it (you should display it when you are sending it).
So the chat continues like this for a while, then one of the users decides (s)he wants to leave / chat with somebody else. They will close window and client will emit event 'leave room'. Server will capture it and send to the other party that her/his peer has disconnected. The same should happen if the client disconnects. After everything is closed, add both users to queue (or only one, if the other has disconnected from the server). In my code I will not make sure they won't get paired again. That is for the OP to code (can't be hard).
So, if you read this far, you deserve some actual code. Although I say actual, it's actually untested. But you know, it should work like this.
Some code
Client side
var connected = false;
var username = 'Faizan';
var room = '';
var socket = io('http://localhost');
socket.on('connect', function (data) { // we are connected, should send our name
connected = true;
if (username) socket.emit('login', {'username' : username});
});
socket.on('chat start', function(data) {
room = data.room;
show_chat_window(data.name); // some method which will show chat window
});
socket.on('chat end', function(data) {
hide_chat_window(); // this will close chat window and alert user that the peer ended chat
socket.leave(room); // it's possible to leave from both server and client, hoever it is better to be done by the client in this case
room = '';
});
socket.on('disconnect', function(data) { // handle server/connection falling
console.log('Connection fell or your browser is closing.');
});
var send_message = function(text) { // method, which you will call when user hits enter in input field
if (connected) socket.emit('message', {'text': text});
};
var leave_chat = function() { // call this when user want to end current chat
if (connected) {
socket.emit('leave room');
socket.leave(room);
room = '';
}
};
Server side
Not including initial requires and html/js serving., only global definitions and main io handler.
var queue = []; // list of sockets waiting for peers
var rooms = {}; // map socket.id => room
var names = {}; // map socket.id => name
var allUsers = {}; // map socket.id => socket
var findPeerForLoneSocket = function(socket) {
// this is place for possibly some extensive logic
// which can involve preventing two people pairing multiple times
if (queue) {
// somebody is in queue, pair them!
var peer = queue.pop();
var room = socket.id + '#' + peer.id;
// join them both
peer.join(room);
socket.join(room);
// register rooms to their names
rooms[peer.id] = room;
rooms[socket.id] = room;
// exchange names between the two of them and start the chat
peer.emit('chat start', {'name': names[socket.id], 'room':room});
socket.emit('chat start', {'name': names[peer.id], 'room':room});
} else {
// queue is empty, add our lone socket
queue.push(socket);
}
}
io.on('connection', function (socket) {
console.log('User '+socket.id + ' connected');
socket.on('login', function (data) {
names[socket.id] = data.username;
allUsers[socket.id] = socket;
// now check if sb is in queue
findPeerForLoneSocket(socket);
});
socket.on('message', function (data) {
var room = rooms[socket.id];
socket.broadcast.to(room).emit('message', data);
});
socket.on('leave room', function () {
var room = rooms[socket.id];
socket.broadcast.to(room).emit('chat end');
var peerID = room.split('#');
peerID = peerID[0] === socket.id ? peerID[1] : peerID[0];
// add both current and peer to the queue
findPeerForLoneSocket(allUsers[peerID]);
findPeerForLoneSocket(socket);
});
socket.on('disconnect', function () {
var room = rooms[socket.id];
socket.broadcast.to(room).emit('chat end');
var peerID = room.split('#');
peerID = peerID[0] === socket.id ? peerID[1] : peerID[0];
// current socket left, add the other one to the queue
findPeerForLoneSocket(allUsers[peerID]);
});
});
P.S.
The code above got a bit messy in the end. It can be done better and I encourage you to do better job than I did. Having this material at hand, go through it step by step and try to understand. I think I commented most, if not all of it. Good luck.
Tl;dr
I am not even surprised. Here, read a comic
I have a Node / Express based server that uses Mongodb / Mongoose as it's data store. The clients are iOS apps that mostly access data (posts) using a REST API on the server. However, the client user can also start a chat on individuals posts in the app, which require that the user find out immediately if a new message is posted for that specific chat/post. This is handled by opening a websocket between the iOS app (socketrocket) and the server (Einaros WS socket).
Each chat involves only a handful of the total number of users on the system (e.g. 2 - 5 of the thousands of active users), and there are many concurrent chats on different posts. When a new message is received by the server (using an HTML POST), I need to figure out how to inform just the corresponding websockets of that message. Ideally I would like to only iterate through the 2-5 users that are connected to one post rather than the full list of all open sockets.
What would be the best way to store and access this list of sockets (for a post) without going through all of the open sockets, and blocking the event loop? Are there better ways to do this without using sockets at all, since I only care about the notification from server to client that a new message is available? I debated using long polling as well but ran into issues when trying to store the Express response object.
I'm thinking that the incoming message handler would look something like below where I can access the list of sockets for each story, but storing sockets in the database feels strange to me.
app.post('/api/message', isLoggedInAPI, function(req, res) {
var story_id = req.body.story_id;
var text = req.body.message;
var message = {text: text, sender: req.user._id};
Story.findByIdAndUpdate(story_id, {$push: {messages: message}}, {safe: true, upset: true})
.execAsync()
.catch(function(err) {
res.status(404).end();
Promise.resolve();
})
.then(function(story){
// console.log(story, story_id);
if(story)
{
//console.log(story, story_id);
res.status(200).json({count: story.messages.length});
for (var i=0; i< story.pendingResponses.length; i++)
{
socket = story.pendingResponses[i];
// Send message to socket
});
}
story.pendingResponses.length = 0;
story.update({$set: {pendingResponses: []}}, {safe: true, upset: true})
.execAsync()
.then(function(){
})
.catch(function(err) {
});
}
else res.status(404).end();
}).catch(function(err) {
res.status(501).send(err).end();
});
});
I was able to solve this by doing the following. When I get a new socket, I store it in an array using the user_id which is unique for each connection.
var clients = [];
store socket with user ID (could store res for long polling the same way)
clients[req.user.id]=socket;
I store the user_id in an array of pendingResponses for each post / Story, at the same time.
And in my POST api,
for (var i=0; i< story.pendingResponses.length; i++)
{
id = story.pendingResponses[i];
do something with clients[id] to talk to thesocket
}
This means that for each POST, the event loop will look through pending sockets for that specific story only. I do worry about the scenario of what happens if there are many users connected to the same story, in which case this loop becomes problematic.
To scale this as the number of users grow requires using some sort of messaging queue (such as ZMQ, RabbitMQ, Redis Pub Sub), so that messages from one server instance can be shared with users connected to other instances.
I'm trying to learn express and socket.io and haven't been able to find an answer to my question. I need to reference clients and not sockets, and since I have multiple pages connecting to the server it creates different sockets so I can't keep track of users. What is the proper way to do this? I haven't been able to find a solution that made sense
In essence all I want to do is be able to reference the same client no matter what page they are on with my server. But if I have two separate snippets of code like this to keep track of users it doesn't work
socket.on('set name', function (name) {
console.log("set name My socket id is " + socket.id);
socket.set('username', name);
socket.get('username', function (error, value) {
console.log("set name Socket.username " + value);
});
});
and later
socket.on('getusername', function () {
console.log("getusername My socket id is " + socket.id);
socket.get('username', function (error, value) {
console.log("getusername Socket.username " + value);
});
});
The second code being called from a different page, what are my options to reference the client rather than the sockets?
You can use the concept of rooms in socket.io.
All sockets with same name can going a room.
Something like this:
socket.on('set name', function (name) {
socket.join(name);
});
and later
socket.on('getusername', function () {
// get all the rooms socket is part of and use the
// first room he is in.
var room = io.sockets.manager.roomClients[socket.id][0];
});
You can try set the browser cookie on the client (the one that will be deleted when user closes the browser) and send its value in message payload when you initialize the socket connection.
Straight to the point:
I am using node.js, socket.io and redis for a private chat system.
On connect user passes his website id (userID) to node.js server. He may have multiple connections so I have to pair socketID (of each connection) and userID somehow. I has thinking about using redis to store userID->sessionID pairs. However, when user disconnects I need to remove that pair from redis.. but I have only socketID not userID so I can't select by that key..
Now, am I approaching this the wrong way or should I store both userID->socketID and socketID->userID pairs? Maybe someone could offer more elegant solution?
A more elegant solution would be to make each socket connect to the channel userID, for example:
io.sockets.on('connection', function (socket) {
socket.join(userID);
});
// when you want somebody to send a message to userID you can do:
io.sockets.in(userID).emit(message);
There are two things you need to take care of here:
Make sure that only userID can connect to his channel, thus verify the session ( read more here: http://www.danielbaulig.de/socket-ioexpress/ )
On connection increase the value for userID in redis (so that you know a new connection for that user is listening) and on disconnect decrease the userID value (so that you know the number of connections still listening). If the value is 0 then you emit a message to the chat stating that userID has left (since the number of connections listening to the userID channel is 0).
When other users will want to send a message to userID, they don't need to connect to the userID channel, they can send a message to the chat channel and pass userID as a property. For example:
var chat = io
.of('/chat')
.on('connection', function (socket) {
// connected to public chat
})
.on('message', function (data) {
if (data.userID && data.message) {
io.sockets.in(userID).emit('UserX: ' + data.message);
}
});