Node js Socket.iO accessing socket outside for multiple client - node.js

Question

How can we access socket object outside for multiple socket connection. I created a object globally and tried to do this. But it always works for last connected socket.
'use strict';
const path = require('path')
const express = require('express');
const http = require('http');
const chalk = require('chalk');
const socketio = require('socket.io');
var connectionString = '';
const eventHubConsumerGroup = ""
const app = express()
const server = http.createServer(app ,() => {
console.log(chalk.green('Server created'))
})
const io = socketio(server)
const port = process.env.port || 3000
const publicDirectoryPath = path.join(__dirname , '../public')
var server_token = "1234567890";
app.use(express.static(publicDirectoryPath))
var localSocket;
io.on('connection',function(socket){
localSocket = socket;
console.log(socket.handshake.query.deviceID)
console.log('on user connected '+socket.id);
//report = new Report(socket);
socket.auth = false;
socket.on('authenticate',function(token){
console.log('token recieved is '+token);
if(server_token == token){
socket.auth = true;
console.log('connection is authenticated '+socket.id);
socket.emit("authenticate",true);
} else {
console.log("Connection not established")
socket.emit("authenticate",false);
}
})
socket.on('sendSocketEvent' , message => {
console.log(chalk.yellowBright(`Message recieved from ${socket.id} + ${message}`));
io.to(socket.id).emit('recieveSocketEvent', `Hello test`);
})
socket.on('disconnect',function(){
console.log('one user disconnected '+socket.id);
})
setTimeout(function(){
if(!socket.auth){
console.log('disconnecting the socket '+socket.id);
socket.emit("timeOut");
socket.disconnect();
}
},1000);
})
server.listen(port,() => {
console.log(chalk.redBright(`Server is up on port ${port}`))
})
var printMessage = function (message) {
console.log(JSON.stringify(message));
console.log(message.DeviceId);
if (localSocket != null){
if (message.DeviceId == localSocket.handshake.query.deviceID) {
localSocket.emit('recieveSocketEvent', message);
}
}
};
class EventHubReader {
constructor(connectionString, consumerGroup) {
this.connectionString = connectionString;
this.consumerGroup = consumerGroup;
this.eventHubClient = undefined;
this.receiveHandlers = undefined;
}
async startReadMessage(startReadMessageCallback) {
try {
console.log(this.connectionString)
const client = await EventHubClient.createFromIotHubConnectionString(this.connectionString);
console.log('Successfully created the EventHub Client from IoT Hub connection string.');
this.eventHubClient = client;
const partitionIds = await this.eventHubClient.getPartitionIds();
console.log('The partition ids are: ', partitionIds);
const onError = (err) => {
console.error(err.message || err);
};
const onMessage = (message) => {
const deviceId = message.annotations['iothub-connection-device-id'];
return startReadMessageCallback(message.body, message.enqueuedTimeUtc, deviceId);
};
this.receiveHandlers = partitionIds.map(id => this.eventHubClient.receive(id, onMessage, onError, {
eventPosition: EventPosition.fromEnqueuedTime(Date.now()),
consumerGroup: this.consumerGroup,
}));
} catch (ex) {
console.error(ex.message || ex);
}
}
// Close connection to Event Hub.
async stopReadMessage() {
const disposeHandlers = [];
this.receiveHandlers.forEach((receiveHandler) => {
disposeHandlers.push(receiveHandler.stop());
});
await Promise.all(disposeHandlers);
this.eventHubClient.close();
}
}
var { EventHubClient, EventPosition } = require('#azure/event-hubs');
const eventHubReader = new EventHubReader(connectionString, eventHubConsumerGroup);
(async () => {
console.log("Step1")
await eventHubReader.startReadMessage((message, date, deviceId) => {
console.log("Here getting called");
try {
const payload = {
IotData: message,
MessageDate: date || Date.now().toISOString(),
DeviceId: deviceId,
};
printMessage(payload);
} catch (err) {
console.error('Error broadcasting: [%s] from [%s].', err, message);
}
});
})().catch();
the problem is in condition "printMessage" . here I am trying to restrict the emit based on socket deviceID, but it's only working for last connected socket.
Can You please help me in this.

Answer 1

var localSocket;
io.on('connection',function(socket){
localSocket = socket;
})
You're overwriting the same variable, on each new connection, which means it will always point to the last socket connected.
What exactly do you want to do? To send this message to all connected sockets?