I'm quite new to Redis Pub/sub so please bear with me. I'm trying to create an IRC where users can create their own chat rooms, kinda like Gitter. Below is what I've done so far.. I'm subscribing the users to different channels by their username only just for testing.. Thing is that when I publish to channel x, a client who's subbed to channel y still gets the same message.. I'm publishing using redis-cli and PUBLISH command.
function handleIO(socket){
function disconnect(){
console.log("Client disconnected");
socket.broadcast.emit("user d/c", socket.username+" has left!");
}
socket.on("new user", function(username){
socket.username = username;
if(socket.username == "chat"){
redisClient.subscribe("chat");
}else{
redisClient.subscribe("other");
}
socket.userColor = '#'+(Math.random()*0xFFFFFF<<0).toString(16);
socket.emit("new_user", username);
emitter.lrange("messages", 0, -1, function(err, messages){
//reversing to be in correct order
messages = messages.reverse();
messages.forEach(function(message){
message = JSON.parse(message);
socket.emit("messages", message);
});
});
socket.broadcast.emit("user connection", username+" has connected to the Haven!");
});
socket.on("disconnect", disconnect);
socket.on("send", function(msg){
var msg = JSON.stringify( { name: socket.username, messageText: msg, color: socket.userColor } );
emitter.lpush("messages", msg, function(err, response){
//keep newest 10 items
emitter.ltrim("messages", 0, 9);
});
io.sockets.emit("receive", msg, socket.userColor);
});
redisClient.on("message", function (channel, message) {
console.log(channel+":"+message);
socket.emit("message", channel, message);
});
}
For the lost wanderer out there... What I did is implement another event on the client to basically check whether that client is 'entitled' to the message (i.e. whether the message's channel belongs in the client's list of subbed channels if that makes sense).
Client-side
socket.on("message", function(channel, message){
socket.emit("entitled", channel, message);
});
socket.on("entitled", function(reply, channel, message){
if(reply == 1){
$("#msgArea").append(message+"<br/>");
$("#msgArea").prop({ scrollTop: $("#msgArea").prop("scrollHeight") });
}
});
Server-side
socket.on("entitled", function(channel, message){
//check that user is subbed
emitter.sismember('channels:'+socket.username, channel, function(err, reply){
if(err) throw err;
socket.emit("entitled", reply, channel, message);
});
});
What I purposely left out is that I didn't keep using socket.username but started using sessions for persistence.. My word of advice would be to stick with redis store since it's one of the most popular on github.
Related
I am new to socket.io, and trying to figure out how to send multiple messages. Here is the scenario I am working on,
function setupServer(server) {
var socketIO = require("socket.io").listen(server);
socketIO.sockets.on('connection', function (socket) {
console.log("client is connected");
socket.emit('update', { progress: "starting..." })
});
}
I have to call setupServer(server) from another method, and I am receiving "starting..." on client side.
But the problem is, i want to send more/multiple messages LATER ON. Can not send array of messages as my application is building messages strings in say every 10 milliseconds (in a callback function) and i want to send as soon as they are created.
Any solution? Is it possible to get the socket object reference to reuse outside this function?
From socket.io docs: http://socket.io/docs/#broadcasting-messages
To broadcast, simply add a broadcast flag to emit and send method calls. Broadcasting means sending a message to everyone else except for the socket that starts it.
function setupServer(server) {
var socketIO = require("socket.io").listen(server);
socketIO.on('connection', function (socket) {
console.log("client is connected");
socket.emit('update', { progress: "starting..." });
startBroadCastFromSocket(socket, 3);
socket.on('disconnect', function(){
stopBroadcastFromSocket(socket);
});
});
// broadcast message to all sockets
setInteval(function() {
broadcastMessageToEveryone(socketIO, {body: 'Hello everyone (FROM SERVER)', timestamp: new Date());
}, 1000);
}
function broadcastMessageToEveryone(io, body) {
io.emit('message', {body: body, timestamp: new Date()});
}
function broadcastMessageFromSocket(socket, body) {
socket.broadcast.emit('message', {body: body, timestamp: new Date()});
}
var socketIntervals = {};
function stopBroadcastFromSocket(socket) {
if(socketIntervals[socket.id]) {
clearInterval(socketIntervals[socket.id]);
}
}
function startBroadcastFromSocket(socket, seconds) {
socketIntervals[socket.id] = setInterval(function(){
broadcastMessageFromSocket(socket, 'Hello!');
}, seconds*1000);
}
I'm trying to learn Socket.io by building a set of dynamically created chatrooms that emit 'connected' and 'disconnected' messages when users enter and leave. After looking at a couple of questions I've put together something functional but most of the response linked are from people who admit they've hacked together answers and I've noticed there's a more general - and recent - discussion about the right way to do this on the Socket.io repo (notably here and here)
As I'm such a novice I don't know if the work below is an acceptable way to do things or it just happens to incidentally function but will cause performance issues or result in too many listeners. If there's an ideal - and official - way to join and leave rooms that feels less clunky than this I'd love to learn about it.
Client
var roomId = ChatRoomData._id // comes from a factory
function init() {
// Make sure the Socket is connected
if (!Socket.socket) {
Socket.connect();
}
// Sends roomId to server
Socket.on('connect', function() {
Socket.emit('room', roomId);
});
// Remove the event listener when the controller instance is destroyed
$scope.$on('$destroy', function () {
Socket.removeListener('connect');
});
}
init();
Server
io.sockets.once('connection', function(socket){
socket.on('room', function(room){ // take room variable from client side
socket.join(room) // and join it
io.sockets.in(room).emit('message', { // Emits a status message to the connect room when a socket client is connected
type: 'status',
text: 'Is now connected',
created: Date.now(),
username: socket.request.user.username
});
socket.on('disconnect', function () { // Emits a status message to the connected room when a socket client is disconnected
io.sockets.in(room).emit({
type: 'status',
text: 'disconnected',
created: Date.now(),
username: socket.request.user.username
});
})
});
Socket.IO : recently released v2.0.3
Regarding joining / leaving rooms [read the docs.]
To join a room is as simple as socket.join('roomName')
//:JOIN:Client Supplied Room
socket.on('subscribe',function(room){
try{
console.log('[socket]','join room :',room)
socket.join(room);
socket.to(room).emit('user joined', socket.id);
}catch(e){
console.log('[error]','join room :',e);
socket.emit('error','couldnt perform requested action');
}
})
and to leave a room, simple as socket.leave('roomName'); :
//:LEAVE:Client Supplied Room
socket.on('unsubscribe',function(room){
try{
console.log('[socket]','leave room :', room);
socket.leave(room);
socket.to(room).emit('user left', socket.id);
}catch(e){
console.log('[error]','leave room :', e);
socket.emit('error','couldnt perform requested action');
}
})
Informing the room that a room user is disconnecting
Not able to get the list of rooms the client is currently in on disconnect event
Has been fixed (Add a 'disconnecting' event to access to socket.rooms upon disconnection)
socket.on('disconnect', function(){(
/*
socket.rooms is empty here
leaveAll() has already been called
*/
});
socket.on('disconnecting', function(){
// socket.rooms should isn't empty here
var rooms = socket.rooms.slice();
/*
here you can iterate over the rooms and emit to each
of those rooms where the disconnecting user was.
*/
});
Now to send to a specific room :
// sending to all clients in 'roomName' room except sender
socket.to('roomName').emit('event', 'content');
Socket.IO Emit Cheatsheet
This is how I inform users of a "disconnecting user"
socket.on('disconnecting', function(){
console.log("disconnecting.. ", socket.id)
notifyFriendOfDisconnect(socket)
});
function notifyFriendOfDisconnect(socket){
var rooms = Object.keys(socket.rooms);
rooms.forEach(function(room){
socket.to(room).emit('connection left', socket.id + ' has left');
});
}
Here is a working method.
I am using socketio "socket.io": "^2.3.0" on server side. On Client side is android
// SocketIO
implementation('io.socket:socket.io-client:1.0.0') {
// excluding org.json which is provided by Android
exclude group: 'org.json', module: 'json'
}
Following is the code that is working for me.
// Join Chat Room
socket.on('ic_join', function(data) {
// Json Parse String To Access Child Elements
let messageJson = JSON.parse(data)
let room1 = messageJson.room1
console.log('======Joined Room========== ')
console.log(room1)
socket.join(room1, function(err) {
console.log(io.sockets.adapter.rooms[room1].length);
console.log(err)
})
})
// Leave Chat Room
socket.on('ic_leave', function(data) {
// Json Parse String To Access Child Elements
let messageJson = JSON.parse(data)
let room1 = messageJson.room1
console.log('======Left Room========== ')
console.log(room1)
socket.leave(room1, function(err) {
if (typeof io.sockets.adapter.rooms[room1] !== 'undefined' && io.sockets.adapter.rooms[room1] != null) {
console.log(io.sockets.adapter.rooms[room1].length);
console.log(err)
} else{
console.log("room is deleted")
}
})
})
For anyone reading this beyond 2/1/2021, using socket.io 3.1.0 and hopefully later, you can reference my example. I have found that the example on how to do this in socket.io's documentation is incorrect. They claim that in the disconnect event that socket.rooms is an object. While is uses the block container and is comma separated, there are no key pairs, meaning their demonstration of const rooms = Object.keys(socket.rooms) returns an empty value. It's creating an array out of an object that is really just an array. To my knowledge {} can only be used for block statements and objects. By some quirk, NodeJS is treating it like a normal array. I assign custom, 4 digit rooms on each connect event. So I have on the disconnect event I have the server skim through all the rooms, and if it encounters a room name with a length of 4, it tells everyone in the room that the size of the room decreased by one. On the client side, I have a socket event listener monitoring for this and when it's detected, updates a innerHTML property so that the clients can display the number of connected users.
//client side code:
socket.on('roomSize', (roomSize) => {
document.getElementById('clientCount').innerHTML = roomSize + ' clients connected';
});
//Server side code:
io.on("connection", (socket) => {
socket.on('createRoom', () => {
let ID = makeID(4)
while (io.sockets.adapter.rooms.has(ID)) {
ID = makeID(4)
}
socket.join(ID);
socket.emit('setID', ID);
});
socket.on("joinRoom", (room) => {
socket.join(room);
let roomSize = io.sockets.adapter.rooms.get(room).size
io.in(room).emit('roomSize', roomSize);
socket.emit('roomJoined', room, roomSize);
});
socket.on('disconnecting', function() {
let rooms = socket.rooms;
rooms.forEach(function(room) {
if (room.length === 4) {
let roomSize = io.sockets.adapter.rooms.get(room).size - 1
io.in(room).emit('roomSize', roomSize);
}
});
});
function makeID(length) {
var result = '';
var characters = '0123456789';
var charactersLength = characters.length;
for (var i = 0; i < length; i++) {
result += characters.charAt(Math.floor(Math.random() * charactersLength));
}
return result;
}
})
I am trying to build a live chat, I am using mongodb and socket.io to store the messages and users.
When a new user is created that user is stored in the mongodb and in the socket object.
If a user refreshes the page the user is removed from the socket object, meaning now in order for that person to get back in they have to create a new username and that generates a new socket.
Here is what my server side code looks like
/*
|--------------------------------------------------------------------------
| Live socket communication with front end:
|--------------------------------------------------------------------------
|
|
*/
var users = {};
io.sockets.on('connection', function (socket) {
// Listen to a new user then emit the user to all clients
socket.on('new user', function (data) {
// Check mongodb to see if the user exists and emit proper message
models.Message.findOne({username:data},function(err,user){
if(err){
console.log('something went wrong')
}
else if(user){
socket.emit('username taken', 'something');
}
else{
socket.emit('create user', data);
socket.userName = data;
socket.connected = true;
users[socket.userName] = socket;
io.sockets.emit('user name', Object.keys(users));
}
});
});
socket.on('facebook id', function(data) {
models.User.findOne({username:data.name}, function(err, user) {
if (user) {
console.log('User already exists');
socket.userName = data.name;
socket.facebook_id = data.id;
socket.connected = true;
users[socket.userName] = socket;
io.sockets.emit('user name', Object.keys(users));
}
else {
var newUser = new models.User({
username: data.name,
facebook_id: data.id
});
newUser.save(function(err, user) {
console.log('successfully inserted user/user: ' + user._id);
});
}
});
});
// Listen to a new message then emit the message to all clients
socket.on('send message', function (data, callback) {
io.sockets.emit('new message', {message: data, username: socket.userName, facebook_id: socket.facebook_id});
});
// Logic when client disconnects
socket.on('disconnect', function (data) {
if(!socket.userName) return;
seeder.disconnect(socket.userName);
delete users[socket.userName]
io.sockets.emit('user disconnected', Object.keys(users));
});
});
You see in my disconnect I remove the socket from the users object.
My question would be is there a way to save the socket info on disconnect then if the same socket tries to connect have it recognize the user and continue?
Additonal: I am thinking maybe I need to focus on creating a user login with mongodb first, then using that log in session data and pass that to the socket, creating a socket object with current database details? Does that sound like something that makes more sense, is that possible?
You can use cookies to identify users. Generate a random hash, put it in cookies, and thus this data will be transferred when establishing connection between client and server.
The client code may look like:
function generateHash(len) {
var symbols = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890';
var hash = '';
for (var i = 0; i < len; i++) {
var symIndex = Math.floor(Math.random() * symbols.length);
hash += symbols.charAt(symIndex);
}
return hash;
}
if (!/\buser_id=/.test(document.cookie)) { //if no 'user_id' in cookies
document.cookie = 'user_id=' + generateHash(32); //add cookie 'user_id'
}
//here goes establishing connection to server via `io.connect`
On the server-side you can write:
io.sockets.on('connection', function (socket) {
var cookie = socket.handshake.headers.cookie;
var match = cookie.match(/\buser_id=([a-zA-Z0-9]{32})/); //parse cookie header
var userId = match ? match[1] : null;
//...
Thus you have userId variable which is unique for each user. Then you can comment this line:
delete users[socket.userName]
because you should keep the user data.
You may now store your users object with userId (not username) as a key, and on each connection check whether users[userId] != null. And if such user exists, use their socket info
So I am building, a chat app and need help figuring out how to send private messages. This is the code I have, to 'send a message'.
users = {}
socket.on('send message', function(data, callback){
var msg = data.trim();
console.log(users);
console.log('after trimming message is: ' + msg);
var name = req.params.posteruname;//reciever
var msg = msg;
if(name in users){
var message = new Chat({
msg : msg,
sender : req.user.username,
reciever : name
}).save(function(err, savedMessage){
if(err) {
users[name].emit('whisper', {msg: "Error, some tried sending you a message but something went wrong", nick: socket.nickname});
} else {
users[name].emit('whisper', {
reciever: name,
sender:req.user.username,
msg:msg
});
}
});
} else{
callback("Something went wrong");
}
});
This code isn't working very well. When I try to send message, it still displays to all users.
Take a look in this document. You should specify rooms. Every one will be a "room", when you send a message with event and room specified the correct user will receive it.
Your users object is just a plain object, don't reflect what I'm talking about.
I have a node.js application subscribed to a channel listening for an event. When it hears that event it publishes another event to a new channel. I have been using MubSub for my publish/subscriptions. My issue is that no matter what I do every time the page is reloaded there are two listeners and two publishes, then 3,4,5,6 etc..
I dont understand why they do not get disconnected?
if (curURL == '/handwash') {
db2.handwash.find({
"event": "handwash"
}).sort({
"message.time": -1
}).limit(10).forEach(function(error, x) {
if (error || !x) {
console.log("error getting items");
} else {
socket.emit('archive', x.message);
}
});
channel2.subscribe('dealer out', function(message) {
console.log("new dealer event " + message);
db.events.find({
"event": "wash"
}).sort({
"message.time": -1
}).limit(1).forEach(function(error, x) {
if (error || !x) {
console.log("error getting items");
} else {
console.log("found last handwash..." + x.message.type + "....publishing");
var message = ({
'tableid': 123,
'time': Date(),
'type': x.message.type,
})
channel.publish('handwash', message );
socket.emit('message', message);
}
});
//socket.emit('message', message);
});
socket.on("disconnect", function(s) {
console.log("Disconnected from global handler");
});
}
The problem was that I was using MubSub for subscription and publishing messages. Fixed it by creating a varaible for my connection and then closing it with a unsubscribe();
var subscription = channelEvents.subscribe('pocket', function(message) {}
subscription.unsubscribe();