I encounter an issue with my code when using socket.removeAllListeners();
I'm using express, socket.io and socket.io-client: this server is linked to another one, represented by matchmaking which is sending the information that the game has stopped.
var express = require('express');
var url = require('url');
var app = express();
var server = require('http').Server(app);
var io = require('socket.io')(server);
var matchmaking = require("socket.io-client")('http://localhost:1610');
io.on('connection',function(socket){
var page = 'lobby';
show_page(page);
matchmaking.on('ChangePage',function(value){
//switch lobby to game
show_page(value.Page);
});
function show_page(page){
//The user goes here to login and sends info to the matchmaking server
if(page == 'lobby')
{
//If more than 2 players are waiting , the matchmaking server generate a game server, put the waiting players in it and sends it to this server.
}
//If the player joined a game, he's redirected here
else if(page == 'game')
{
socket.on('PlayerMove',function(value){
// The game Code
})
matchmaking.once('END',function(value){
//The game is ended and the user go back to lobby in the players queue where he will be put in another game
socket.removeAllListeners("PlayerMove");
show_page('lobby');
})
}
}
})
When the game is ended, the user will join another game and will pass by (page == 'game')where he will be affected with another listener. So the first time , the game works perfecly but then each time he joins a new server, the code inside the listenner is multiplied.
The only way I found to fix it is to make the code like that which doesn't fit with my idea.
socket.on('PlayerMove',function(value){
// code inside
}
socket.removeAllListeners("PlayerMove");
matchmaking.once('END',function(value){
})
Is there any solution to my problem ?
Thanks in advance
I've finaly resolved the problem on my own : this multiplication was caused because i forgot to remove socket on the clients too.
Related
So i've been making a realtime E2EE chatting application in node.js and socket.io, and I've ran into an issue
I'm using a recent socket.io version, specifically 4.2.0 and I've been attempting to find out the number of clients within a room, in order to create a check to either allow, or block access to a chat area, since it doesn't support more than 2 clients in 1 room.
My variables/includes for socket.io
var socket = require("socket.io")
var io = socket(server)
var chat = io.of('/socket').on('connection', function (socket) {
socket.on('loginchat', async function(data){
io.in(data.id).allSockets().then(result=>{
console.log(result.size) })
});
});
data.id is a randomly generated string and used to create a room server side, so my idea was to use allSockets() to get a count of sockets connected to that room, but it returns zero even with 2 clients connected.
allSockets() idea from https://stackoverflow.com/a/66065685/16140221
I can't find a working solution on stack overflow, or anything inside the docs that is an obvious method to do so. I'm not the best at socket.io since I simply picked it up to use for this project, so any help is appreciated :)
Given the example you provided, you don't seem to ever make a socket to join a room. So your room is forever empty.
According the socket.io documentation you must first listen for the connection event, then you must use join to add users to the room.
const socket = require("socket.io")
const io = socket(server)
io.on("connection", socket => {
socket.on('loginchat', async data => {
//Assuming data.id is the room identifier
const roomUsers = await io.in(data.id).allSockets();
//There, you make your socket join the room if room users are not exceeding
//your maximum
if(roomUsers.size < 2) socket.join(data.id);
});
});
var socket = require("socket.io")
var io = socket(server)
var chat = io.of('/socket').on('connection', function (socket) {
socket.on('loginchat', async function(data){
const sockets = await io.of("/socket").in(data.id).fetchSockets();
console.log(sockets.length)
if(sockets.length <= 1){
socket.room = data.id;
socket.join(data.id);
}else{
//attempting to join a room with greater than 2 users
console.log("too many")
}
});
});
https://socket.io/docs/v3/migrating-from-3-x-to-4-0/
Using the fetchSockets() and checking the length of the object, you are able to check the length or numbers of users in a room.
Working in Socket.io v4.3.1 but most likely functioning in any v4.x
I have spent a long on Google but I didn't found any solution. I saw many questions related to my problem on stack overflow but I didn't get any solution.
Explaining in brief, I am coding for real time chat room and it works fine when I continuously send messages from either room but when I left it for a short period mean (when message is not send from either side) it automatically gets disconnect inside the browser is still opened. And messages send from one room didn't transferred to other room. Please help me.
var express = require('express'); // node code
var app = express();
var server = require('http').createServer(app);
var io = require('socket.io').listen(server);
var redis = require('redis');
var redis_client = redis.createClient(6379,'192.168.43.49');
redis_client.auth('rajesh');
redis_client.select(1);
io.sockets.on('connection',function(socket){
/* used for transfering message from one node to other node */
socket.on('node_message',function(data){
// sending message to other end
redis_client.smembers(data.user_hash,function(err,reply){
if(reply!=null){
reply.forEach(function(value){
var res = {'user_hash':socket.user_hash,'msg':data.msg};
io.to(value).emit('node_message',res); // i am sending sender user_hash also so that while getting message in second end i will validate second party {cause problem in multi-page to show message in every panel}
});
}
});
});
socket.on('disconnect', function (){
console.log('lost connection',socket.user_hash);
})
});
I've started writing a node.js websocket solution using socket.io.
The browsers connects to the node server successfully and I get see the socket.id and all config associated with console.log(socket). I also pass a userid back with the initial connection and can see this on the server side to.
Question: I'm not sure the best way to associate a user with a connection. I can see the socket.id changes every page change and when a tab is opened up. How can I track a user and send 'a message' to all required sockets. (Could be one page or could be 3 tabs etc).
I tried to have a look at 'express-socket.io-session' but I'm unsure how to code for it and this situation.
Question: I have 'io' and 'app' variables below. Is it possible to use the 2 together? app.use(io);
Essentially I want to be able to track users (I guess by session - but unsure of how to handle different socket id's for tabs etc) and know how to reply to user or one or more sockets.
thankyou
The best way to handle the situation is rely on SocketIO's rooms. Name the room after the user's unique ID. This will support multiple connections out of the box. Then, whenever you need to communicate with a particular user, simply call the message function and pass in their id, the event, and any relevant data. You don't need to worry about explicitly leaving a room, SocketIO does that for you whenever their session times out or they close their browser tab. (We do explicitly leave a room whenever they log out though obviously)
On the server:
var express = require('express');
var socketio = require('socket.io');
var app = express();
var server = http.createServer(app);
var io = socketio(server);
io.on('connect', function (socket) {
socket.on('userConnected', socket.join); // Client sends userId
socket.on('userDisconnected', socket.leave); // Cliend sends userId
});
// Export this function to be used throughout the server
function message (userId, event, data) {
io.sockets.to(userId).emit(event, data);
}
On the client:
var socket = io('http://localhost:9000'); // Server endpoint
socket.on('connect', connectUser);
socket.on('message', function (data) {
console.log(data);
});
// Call whenever a user logs in or is already authenticated
function connectUser () {
var userId = ... // Retrieve userId somehow
if (!userId) return;
socket.emit('userConnected', userId);
}
// Call whenever a user disconnects
function disconnectUser () {
var userId = ... // Retrieve userId somehow
if (!userId) return;
socket.emit('userDisconnected', userId);
}
This must have been asked already a thousand times, but I do not find any of the answers satisfying, so I'll try having another go, being as clear as possible.
I am starting out with a clean Express; the one that is usually done via the following terminal commands:
user$ express
user$ npm install
then I proceed installing socket.io, this way:
user$ npm install socket.io --save
on my main.js file I then have the following:
//app.js
var express = require('express'),
http = require('http'),
path = require('path'),
io = require('socket.io'),
routes = require('./routes');
var app = express();
I start my socket.io server by attaching it to my express one:
//app.js
var server = http.createServer(app).listen(app.get('port'), function(){
console.log('express server started!');
});
var sIo = io.listen(server);
What I do now is to set the usual routes for Express to work with:
//app.js
app.get('/', routes.index);
app.get('/send/:recipient/:text', routes.sendMessage);
Now, Since I like to keep things organized, I want to put my socket.io code in another file, so instead of using the usual code:
//app.js
sIo.sockets.on('connection', function(socket){
console.log('got a connection');
});
I use the following to be able to access both the socket and the sIo object (as that object contains all the connections infos (important)):
//app.js
sIo.sockets.on('connection', function(socket){
routes.connection(sIo, socket);
});
// index.js (./routes)
exports.connection = function(sIo, socket){
console.log('got a connection.');
};
This way I can do all my socket.io jobs in here. I know that I can access all my clients information now from the sIo object, but of course, they do not contain any information about their session data.
My questions now are the following:
Suppose a user makes an HTTP request to send a message and the handler in my routes is like this:
exports.sendMessage = function(req, res){
//do stuff here
};
How can I get this to "fire" something in my socket.io to send a message? I do not want to know all the underlying work that needs to be done, like keeping track of messages, users, etc. I only want to understand how to "fire" socket.io to do something.
How can I make sure that socket.io sends the message only to a person in particular and be 100% sure that nobody else gets it? From what I can see, there is no way to get the session infos from the sIo object.
Thanks in advance.
question one: The cleanest way to separate the two would probably be to use an EventEmitter. You create an EventEmitter that emits when an http message comes in. You can pass session information along with the event to tie it back to the user who sent the message if necessary.
// index.js (./routes)
var EventEmitter = require('events').EventEmitter;
module.exports.messageEmitter = messageEmitter = new EventEmitter();
module.exports.sendMessage = function(req, res) {
messageEmitter.emit('private_message', req.params.recipient, req.params.text);
};
question 2: You can access the socket when the initial connection is made. An example mostly borrowed from this answer:
var connect = require('connect'),
userMap = {};
routes.messageEmitter.on('private_message', function(recipient, text) {
userMap[recipient].emit('private_message', text);
});
io.on('connection', function(socket_client) {
var cookie_string = socket_client.request.headers.cookie;
var parsed_cookies = connect.utils.parseCookie(cookie_string);
var connect_sid = parsed_cookies['connect.sid'];
if (connect_sid) {
session_store.get(connect_sid, function (error, session) {
userMap[session.username] = socket_client;
});
}
socket_client.on('private_message', function(username, message) {
userMap[username].emit(private_message, message)
});
});
So we're just creating a map between a session's username and a socket connection. Now whenever you need to send a message you can easily lookup what socket is associated with that user and send a message to them using their socket. Just make sure to handle disconnects, and reconnects and connecting in multiple tabs, etc.
I have built something like what you are saying. If a user can make a socket request, it pushes the message via the socket, and then the server does a broadcast or emit of it. But, if a user can't connect to the socket, it then does the http post, like what you are saying by calling the sendMessage. What I have done, rather than having sendMessage shoot off a socket is that I also have my clients doing an ajax request every 5 seconds or so. That will bring back new messages, and if any of the messages were not received via socket.io, I then add them to my clientside array. This acts as sort of a safety net, so I don't have to always fully trust socket.io.
see below in pseudo code
client
if canSendSocketMessage()
sendSocketMessage(message)
else
sendAjaxMessage(message)
setInterval( ->
// ajax call
getNewMessages()
), 5000
server
socket stuff
socket.on 'message' ->
saveMessage()
socket.emit(message)
ajax endpoints
app.post 'sendMessage'
saveMessage()
app.get 'getNewMessages'
res.send getNewMessages()
I'm writing a two player card game, (say it's regular poker for simplicity) in Node.js and Express js. There's a couple of things I'm having trouble with. First, how do I make sure that there are only 2 players that can access an instance of the game, and is it possible to have them reconnect if they lose the connection? Second, how do send a message from the server to the client? I can send it within the "socket.on" listener call, but within the normal scope of the program I can't get it to work.
var socket = io.listen(app);
socket.on('connection', function(client){
player++;
if(player <= 2) {
var messageout = "player " + player + " connected";
client.broadcast(messageout);
client.on('message', function(data){console.log(data); })
client.on('disconnect', function(){console.log('disconnected');})
}
else {
socket.end;
}
});
I'm having trouble conceptually what's going on here and how to approach the problem. For example, do I do it all with sockets? Or do I return a web page with the updated state of the game (cards, bets, etc.) every turn?
First, how do I make sure that there
are only 2 players that can access an
instance of the game?
Create an array of instance objects.
When a new player joins either create a new instance and set them as player1, or add them to an existing instance as player two.
var instances = [];
function Instance () {
return {
name = 'game' + instances.length + 1,
gameVariables = defaults,
player1 = null,
player2 = null,
player1UUID = UUID(),
player2UUID = UUID()
}
}
Is it possible to have them reconnect
if they lose the connection?
If you send each player a UUID when they initially connect you can have them use it to authenticate when they reconnect.
How do I send a message from the
server to the client?
client.send({ gameState: gameState() });
of if you've saved the client into an object: instances[ 'game1' ].player1.send( data );
I do it all with sockets?
I would deal with all dynamic interactions with web sockets.
Do I return a web page with the updated state of the game (cards, bets, etc.) every turn?
I wouldn't send html over web sockets. Instead send json and use a client side template to render it.
Try now.
// server
var nowjs = require("now")
var everyone = nowjs.initialize(app);
everyone.connected(function() {
if (users.length < 2) {
users.push(this);
}
});
everyone.now.sendMessage = function(message, cb) {
gameLogic(message);
users.forEach(function(user) {
user.update(gameLogic.getState());
});
};
//client
$("#action").click(function() {
now.sendMessage($(this).data("action"));
});
now.update = function(data) {
// update UI
};