socket io 실시간 알림

import React, { useEffect, useState } from 'react';
import io from 'socket.io-client';

const socket = io.connect('http://localhost:3000');

function App() {
  const [notifications, setNotifications] = useState([]);

  useEffect(() => {
    socket.on('display_notification', (data) => {
      setNotifications([...notifications, data]);
    });
  }, [notifications]);

  return (
    <div className="App">
      <button onClick={() => socket.emit('new_notification', '새로운 알림')}>알림 보내기</button>
      <h2>알림 목록:</h2>
      <ul>
        {notifications.map((notification, index) => (
          <li key={index}>{notification}</li>
        ))}
      </ul>
    </div>
  );
}

export default App;