React workground

by cadenzah

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.7.0-alpha.2/umd/react.development.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.7.0-alpha.2/umd/react-dom.production.min.js"></script>
<div id="app"></div>

CSS

body {
  background: #20262E;
  padding: 20px;
  font-family: Helvetica;
}

#app {
  background: #fff;
  border-radius: 4px;
  padding: 20px;
  transition: all 0.2s;
}

li {
  margin: 8px 0;
}

h2 {
  font-weight: bold;
  margin-bottom: 15px;
}

.done {
  color: rgba(0, 0, 0, 0.3);
  text-decoration: line-through;
}

input {
  margin-right: 5px;
}

Babel + JSX

const { useState, useEffect, useMemo, useCallback } = React;

let count = 0;

function Comp() {
	alert('render');
	const [data, setData] = useState(0);

	function listener(e) {
  	e.preventDefault();
    const element = document.getElementById('data');
    element.innerText = count+ 1;
  }

	return (
		<div>
      <p>{data}</p>
      <p id="data">{count}</p>
		  <button onClick={(e) => listener(e)}>click</button>
		</div>
  )
}

function App() {
	return (
  	<div>
      <Comp />
  	</div>
  )
}

ReactDOM.render(<App />, document.querySelector("#app"))