balazimichal/gist:15b1bd01bb7db4284af5c84b305e2358

## gistfile1.txt
<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <title>Hello World</title>
    <script src="https://unpkg.com/react@16/umd/react.development.js"></script>
    <script src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script>
    <script src="https://unpkg.com/babel-standalone@6.15.0/babel.min.js"></script>
  </head>
  <body>
    <div id="root"></div>
    <script type="text/babel">

    class Clock extends React.Component {
      constructor(props) {
        super(props);
        this.state = {date: new Date()};
        this.stopTimer = this.stopTimer.bind(this);
        this.startTimer = this.startTimer.bind(this);
      }

      componentDidMount() {
        this.timerID = setInterval(
          () => this.tick(),
          1000
        );
      }

      componentWillUnmount() {
        clearInterval(this.timerID);
      }

      tick() {
        this.setState({
          date: new Date()
        });
      }

      stopTimer() {
        clearInterval(this.timerID);
      }

      startTimer() {
        this.timerID = setInterval(
          () => this.tick(),
          1000
        );
      }

      render() {
        return (
          <div>
            <h1>Hello, world!</h1>
            <h2>It is {this.state.date.toLocaleTimeString()}.</h2>
            <button onClick={this.stopTimer} color='red'>Stop timer</button>
            <button onClick={this.startTimer}>Start timer</button>
          </div>
        );
      }
    }

    ReactDOM.render(
      <Clock />,
      document.getElementById('root')
    );

    </script>
    <!--
      Note: this page is a great way to try React but it's not suitable for production.
      It slowly compiles JSX with Babel in the browser and uses a large development build of React.

      To set up a production-ready React build environment, follow these instructions:
      * https://reactjs.org/docs/add-react-to-a-new-app.html
      * https://reactjs.org/docs/add-react-to-an-existing-app.html

      You can also use React without JSX, in which case you can remove Babel:
      * https://reactjs.org/docs/react-without-jsx.html
      * https://reactjs.org/docs/cdn-links.html
    -->
  </body>
</html>
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="UTF-8" />
	<title>Hello World</title>
	<script src="https://unpkg.com/react@16/umd/react.development.js"></script>
	<script src="https://unpkg.com/react-dom@16/umd/react-dom.development.js"></script>
	<script src="https://unpkg.com/babel-standalone@6.15.0/babel.min.js"></script>
	</head>
	<body>
	<div id="root"></div>
	<script type="text/babel">

	class Clock extends React.Component {
	constructor(props) {
	super(props);
	this.state = {date: new Date()};
	this.stopTimer = this.stopTimer.bind(this);
	this.startTimer = this.startTimer.bind(this);
	}

	componentDidMount() {
	this.timerID = setInterval(
	() => this.tick(),
	1000
	);
	}

	componentWillUnmount() {
	clearInterval(this.timerID);
	}

	tick() {
	this.setState({
	date: new Date()
	});
	}

	stopTimer() {
	clearInterval(this.timerID);
	}

	startTimer() {
	this.timerID = setInterval(
	() => this.tick(),
	1000
	);
	}

	render() {
	return (
	<div>
	<h1>Hello, world!</h1>
	<h2>It is {this.state.date.toLocaleTimeString()}.</h2>
	<button onClick={this.stopTimer} color='red'>Stop timer</button>
	<button onClick={this.startTimer}>Start timer</button>
	</div>
	);
	}
	}

	ReactDOM.render(
	<Clock />,
	document.getElementById('root')
	);

	</script>
	<!--
	Note: this page is a great way to try React but it's not suitable for production.
	It slowly compiles JSX with Babel in the browser and uses a large development build of React.

	To set up a production-ready React build environment, follow these instructions:
	* https://reactjs.org/docs/add-react-to-a-new-app.html
	* https://reactjs.org/docs/add-react-to-an-existing-app.html

	You can also use React without JSX, in which case you can remove Babel:
	* https://reactjs.org/docs/react-without-jsx.html
	* https://reactjs.org/docs/cdn-links.html
	-->
	</body>
	</html>