socket.js

/* 

this is the server.js file

*/


io.on('connection', (client) => {
  client.on('helloUser', () => {
    console.log('sending');
    client.emit('hello', 'hello world')
  });
});

const port = 8000;
io.listen(port);
console.log('listening on port ', port);


/* 

this is the main app.js file

*/

import React, { Component } from 'react';
import openSocket from 'socket.io-client';
const  socket = openSocket('http://localhost:8000');


class App extends Component {
  constructor(props) {
    super(props);

    this.state = {
      hello: "not hello"
    };
    socket.emit('helloUser');
    socket.on('hello', msg => this.setState({hello: msg}));
  }

  render() {
    return (
      <div>
        <p>
        {this.state.hello}
        </p>
      </div>
    );
  }
}

export default App;