import { useEffect } from 'react'; import { useDispatch } from 'react-redux'; import { connect } from 'react-redux'; import { positionsActions, devicesActions } from './store'; const displayNotifications = events => { if ("Notification" in window) { if (Notification.permission === "granted") { for (const event of events) { const notification = new Notification(`Event: ${event.type}`); setTimeout(notification.close.bind(notification), 4 * 1000); } } else if (Notification.permission !== "denied") { Notification.requestPermission(permission => { if (permission === "granted") { displayNotifications(events); } }); } } }; const SocketController = () => { const dispatch = useDispatch(); const connectSocket = () => { const protocol = window.location.protocol === 'https:' ? 'wss:' : 'ws:'; const socket = new WebSocket(protocol + '//' + window.location.host + '/api/socket'); socket.onclose = () => { setTimeout(() => connectSocket(), 60 * 1000); }; socket.onmessage = (event) => { const data = JSON.parse(event.data); if (data.devices) { dispatch(devicesActions.update(data.devices)); } if (data.positions) { dispatch(positionsActions.update(data.positions)); } if (data.events) { displayNotifications(data.events); } }; } useEffect(() => { fetch('/api/devices').then(response => { if (response.ok) { response.json().then(devices => { dispatch(devicesActions.update(devices)); }); } connectSocket(); }); }, []); return null; } export default connect()(SocketController);