Node.js how to use socket.io in express route – iTecNote - Kiến Thức Cho Người lao Động Việt Nam

expressnode.jsroutessocket.io

In one of my node.js script i am trying to use socket.io in express route. I found many similar questions and tried to implement the solution as suggested but nothing worked out. May be because of my lack of understanding of express routes. I followed below links,

How use socket.io in express routes with node.js

Use socket.io in expressjs routes instead of in main server.js file

This is my app.js

const express = require('express');
const app = express();
const server = require('http').createServer(app);
const io = require('socket.io').listen(server);

const PORT = 3000;
server.listen(PORT);
console.log('Server is running');
var api = require('./routes/api');

//app.use('/api', api);
app.use('/api', (req, res) => {
res.sendFile(__dirname + '/api.html');
});

app.get('/', (req, res) => {
   res.send("this is home location");
});

And route file api.js in ./routes folder

var express = require('express');
var router = express.Router();
var fs = require("fs");
var bodyParser = require('body-parser');

const app = express();
const server = require('http').createServer(app);
const io = require('socket.io').listen(server);

console.log("inside api route");

router.get('/', function(req, res, next) {
console.log("api route called");

const connections = [];
var jsonobj = [{name:"john",score:345},{name:"paul",score:678}]

io.sockets.on('connection',(socket) => {
    connections.push(socket);
    console.log(' %s sockets is connected', connections.length); // this is not printing

    socket.on('disconnect', () => {
       connections.splice(connections.indexOf(socket), 1);
    });

    socket.emit('server message', jsonobj);

 }); 
    //res.send(jsonobj) 
});

module.exports = router;

Socket.emit is not showing data on html page i am rendering on route use. My html code is,

//api.html

<!DOCTYPE html>
<html lang="en">

<body>
   <div class="container">
      <h1 class="jumbotron">
         Node js Socket io with  socket route example
      </h1>
      <div class="results">results</div>      
   </div>
   <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
   <script src="https://cdnjs.cloudflare.com/ajax/libs/socket.io/2.0.4/socket.io.js"></script>
   <script>
    jQuery(document).ready(function() {
       var socket = io.connect();
       var jsondata = "";

       socket.on('server message', function(data){
         console.log('got data from server',data)
         jsondata = JSON.stringify(data);
         //console.log('jsondata',jsondata)
         $('.results').html(jsondata);
       });
    });   
 </script>
</body>
</html>

Please suggest what i am supposed to get route socket data in html page.
Thanks