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Why my socketio is not connecting with my socketio-client?

i am working on a chatapp project that needs a real time chatting so i have used socketio in my server side which is written in nodejs and than used socketio-client in my main chatapp react-native project.
But now a problem is coming my socket is not initializing. I'm not able to connect my server with my main app. I am using socketio and socketio client my both the socket version are same 4.5.1 but it's not even connecting. I have tried to use old version of socket but its also not working and I have also tried to change my localhost port to 4000 but it's also not working.
My server code:
const express = require('express');
var bodyParser = require('body-parser');
const app = express();
const http = require('http');
const server = http.createServer(app);
const { Server } = require("socket.io");
const io = new Server(server);
const port = process.env.PORT || 3000;
require('./src/config/database')
const user_routes = require('./src/user/users.routes');
app.use(bodyParser.urlencoded({extended: true}))
app.use(express.json())
app.get('/', (req, res) => {
res.sendFile(__dirname + '/index.html');
});
app.use('/User', user_routes)
io.on('connection', (socket) => {
console.log('a user connected');
socket.on('send_message',(data)=>{
console.log("received message in server side",data)
io.emit('received_message',data)
})
socket.on('disconnect', () => {
console.log('user disconnected');
});
});
server.listen(port, () => {
console.log( `Server running at http://localhost:${port}/`);
});
My app socketservice file code:
import io from 'socket.io-client';
const SOCKET_URL = 'http://localhost:3000'
class WSService {
initializeSocket = async () => {
try {
this.socket = io(SOCKET_URL, {
transports: ['websocket']
})
console.log("initializing socket", this.socket)
this.socket.on('connect', (data) => {
console.log("=== socket connected ====")
})
this.socket.on('disconnect', (data) => {
console.log("=== socket disconnected ====")
})
this.socket.on('error', (data) => {
console.log("socekt error", data)
})
} catch (error) {
console.log("scoket is not inialized", error)
}
}
emit(event, data = {}) {
this.socket.emit(event, data)
}
on(event, cb) {
this.socket.on(event, cb)
}
removeListener(listenerName) {
this.socket.removeListener(listenerName)
}
}
const socketServcies = new WSService()
export default socketServcies
Where I have marked it should be connected = true but it's false in the dev console I have done console log so check that it's connecting or not and I can see that it's not connecting. How to make it connect?
There is no error in my app or server I have checked many times and my server is also running when I am running my app.

Answering my own question
The problem was i was using android emulator and android in an emulator can't connect to localhost you need to use the proxy ip so when i add http://10.0.2.2:3000 in const SOCKET_URL = 'http://10.0.2.2:3000' than its working fine
credit goes to gorbypark who told me this in discord

I'm assuming that your front and back runs in localhost. The documentation says that if the front-end is in the same domain as the back-end, you don't need to use the URL. Since you have the options parameter declared, you can use the default argument window.location in first place:
class WSService {
initializeSocket = async () => {
try {
this.socket = io(window.location, {
transports: ['websocket']
})
console.log("initializing socket", this.socket)
this.socket.on('connect', (data) => {
console.log("=== socket connected ====")
})
this.socket.on('disconnect', (data) => {
console.log("=== socket disconnected ====")
})
this.socket.on('error', (data) => {
console.log("socekt error", data)
})
} catch (error) {
console.log("scoket is not inialized", error)
}
}
emit(event, data = {}) {
this.socket.emit(event, data)
}
on(event, cb) {
this.socket.on(event, cb)
}
removeListener(listenerName) {
this.socket.removeListener(listenerName)
}
}

Don't specify the host/port for socket-io to connect to. It can figure it out on its own.
Per documentation, it tries to connect to window.location if no URL is specified as an argument.
So instead of
this.socket = io(SOCKET_URL, {
transports: ['websocket']
})
Just do
this.socket = io()
I am not sure it works with other arguments. You could try like this
this.socket = io(undefined, {
transports: ['websocket']
})

how to Get all connected clients in socket.io

I have socket.io v2.3 and I'm trying to get all connected sockets from a different file. Here's my setup:
const io = require('socket.io');
let IO;
let myNameIO;
module.exports = {
create: (server) => {
IO = io(server, { cors: { origin: '*' } });
const redisConnection = redisAdapter({ host: redisHost, port: redisPort });
IO.adapter(redisConnection);
IO.on('connection', (socket) => {
console.log('a user connected');
});
IO.on('disconnect', (socket) => {
console.log('disconnected');
});
myNameIO = IO.of('/my-name');
myNameIO.on('connection', function (socket) {
console.log('someone connected');
});
},
getIO: () => IO,
getMyNameIO: () => myNameIO,
};
IN a diff file I import getMyNameIO and I'm trying to get all connected clients but I'm having trouble with that. Tried doing
getMyNameIO().clients((error, clients) => {
console.log(clients, '-=--=-=');
});
But clients isn't a function. I then tried importing the socket.io and use.of, but that doesn't return anything. What am doing wrong and how can I fix it?

Give this a try. I suspect either a scope issue or order of operations issue. Either way this should resolve it or give you a more useful error. I've tried to maintain your naming scheme which gave me a small headache. =)
const io = require('socket.io');
const socketServer = {
_initialized: false,
_myNameIO: null,
_IO: null,
_myNameIOClients: new Map(),
get myNameIO() {
if (!socketServer._initialized) throw new Error('socketServer.create not called!')
return socketServer._myNameIO
},
get IO() {
if (!socketServer._initialized) throw new Error('socketServer.create not called!')
return socketServer._IO
},
create: (server) => {
IO = io(server, { cors: { origin: '*' } });
const redisConnection = redisAdapter({ host: redisHost, port: redisPort });
IO.adapter(redisConnection);
IO.on('connection', (socket) => {
console.log('a user connected');
});
IO.on('disconnect', (socket) => {
console.log('disconnected');
});
myNameIO = IO.of('/my-name');
myNameIO.on('connection', function (socket) {
console.log('someone connected');
socketServer._myNameIOClients.set(socket.id, socket)
});
},
//getIO: () => IO,
//getMyNameIO: () => myNameIO,
getIO: () => socketServer._IO,
getMyNameIO: () => socketServer._myNameIO,
get myNameIOClients() {
return socketServer._myNameIOClients
},
getClients: () => new Promise((resolve,reject)=>socketServer._myNameIO.clients((error, clients)=> error ? reject(error) : resolve(clients))
}),
};
module.exports = socketServer
when I do console.log(socketServer.myNameIO.sockets); I get an object with all the sockets. how can I get an array?
Looking at the API https://socket.io/docs/v2/server-api/#Namespace I don't see a reference to Namespace.sockets. That doesn't mean it doesn't exist. I added a getClients function that will return an array of client IDs.
const socketServer = require('./socketServer ')
socketServer.getClients()
.then(clients=>{
// clients an array of client IDs
})
.catch(e=>console.error('Error is socketServer.getClients()', e))
I think what you really want is to manage the connections. One way to do it is by mapping the connections as they come in.
const socketServer = require('./socketServer ')
// This is a Map
let myNameIOClients = socketServer.myNameIOClients
// We can easily turn it into an array if needed
let myNameIOClientsArray = Array.from(socketServer.myNameIOClients)

Socket.IO server to server connection doesn't work

I wrote a simple test case.
const socketioclient = require("socket.io-client");
const io = require("socket.io");
const server = io.listen(process.env.PORT);
server.on("connection", (client) => {
console.log("[SERVER] Client connected!");
client.emit("chat", "Bye!");
client.on("bye", () => {
console.log("[SERVER] Client goodbye'd us.");
client.disconnect();
})
});
const client = socketioclient("localhost:" + process.env.PORT);
client.once("connect", () => {
console.log("[CLIENT] Connected to remote server, identificating.")
this.sendIdentification();
});
client.on("chat", (msg) => {
console.log("[CLIENT] Server sends message:", msg);
if (msg.toLowerCase().indexOf("bye") != -1) {
client.emit("bye");
}
});
client.on("disconnected", () => {
console.log("[CLIENT] Disconnected.");
})
client.on("error", () => {
console.error("[CLIENT] Socket IO connection error.")
});
If you run it, nothing happens. Client does not connect to the server at all.

How to send broadcast to all connected client in node js

I'm a newbie working with an application with MEAN stack. It is an IoT based application and using nodejs as a backend.
I have a scenario in which I have to send a broadcast to each connected clients which can only open the Socket and can wait for any incoming data. unless like a web-browser they can not perform any event and till now I have already gone through the Socket.IO and Express.IO but couldn't find anything which can be helpful to achieve what I want send raw data to open socket connections'
Is there any other Node module to achieve this. ?
Here is the code using WebSocketServer,
const express = require('express');
const http = require('http');
const url = require('url');
const WebSocket = require('ws');
const app = express();
app.use(function (req, res) {
res.send({ msg: "hello" });
});
const server = http.createServer(app);
const wss = new WebSocket.Server({ server });
wss.on('connection', function connection(ws) {
ws.on('message', function(message) {
wss.broadcast(message);
}
}
wss.broadcast = function broadcast(msg) {
console.log(msg);
wss.clients.forEach(function each(client) {
client.send(msg);
});
};
server.listen(8080, function listening() {
console.log('Listening on %d', server.address().port);
});
Now, my query is when this code will be executed,
wss.on('connection', function connection(ws) {
ws.on('message', function(message) {
wss.broadcast(message);
}
}

var WebSocketServer = require("ws").Server;
var wss = new WebSocketServer({port:8100});
wss.on('connection', function connection(ws) {
ws.on('message', function(message) {
wss.broadcast(message);
}
}
wss.broadcast = function broadcast(msg) {
console.log(msg);
wss.clients.forEach(function each(client) {
client.send(msg);
});
};

Try the following code to broadcast message from server to every client.
wss.clients.forEach(function(client) {
client.send(data.toString());
});
Demo server code,
const WebSocket = require('ws')
const wss = new WebSocket.Server({ port: 2055 },()=>{
console.log('server started')
})
wss.on('connection', (ws) => {
ws.on('message', (data) => {
console.log('data received \n '+ data)
wss.clients.forEach(function(client) {
client.send(data.toString());
});
})
})
wss.on('listening',()=>{
console.log('listening on 2055')
})

Run client socket.io on terminal

I was searching a if there is a way to run a node.js & socket.io client on terminal. My goal its that both client & server run on terminal. It work in a webpage but no in a terminal, any ideas?

terminal based chat application using socket.io and readline
Server :
var app = require('express')();
var http = require('http').createServer(app);
var io = require('socket.io')(http);
io.on('connection', (socket) => {
console.log('a user connected');
socket.on('disconnect', () => {
console.log('user disconnected');
});
let eventName = 'simple chat message';
let broadcast = (msg) => socket.broadcast.emit(eventName, msg);
socket.on(eventName, (msg, ackFn) => {
console.log('message: ' + msg);
// broadcast to other clients after 1.5 seconds
setTimeout(broadcast, 1500, msg);
});
});
http.listen(3000, () => {
console.log('listening on *:3000');
});
Server opens connection on http://localhost:3000
Receive messages from client and broadcast to other client
Client :
const io = require("socket.io-client");
const readline = require('readline');
const rl = readline.createInterface({ input: process.stdin, output: process.stdout });
rl.question('What\'s your name ? ', (name) => {
const socket = io('http://localhost:3000');
const sendMsg = () => {
rl.question('> ', (reply) => {
console.log(`Sending message: ${reply}`);
socket.emit('simple chat message', `${name} says ${reply}`);
sendMsg();
});
}
socket.on('connect', () => {
console.log('Sucessfully connected to server.');
sendMsg();
});
socket.on('simple chat message', (message) => {
console.log(message);
});
socket.on('disconnect', () => {
console.log('Connection lost...')
});
});
Read text from terminal using rl.question()and send it to server using socket.emit()
send msg() is called recursively to read text from terminal and send it to server
socket.on() is used to receive messages from other clients

Simple use socket.io-client from node process
https://github.com/socketio/socket.io-client

You could use PhantomJS to run a headless browser on the terminal and have JavaScript for socket.io client in the page loaded to PhantomJS.