<!DOCTYPE html>
<html>
<body>
<div id="root"></div>
<!-- ReactDom이 react element를 가져다 놓을 곳 -->
</body>
<script src="https://unpkg.com/react@17.0.2/umd/react.production.min.js"></script>
<script src="https://unpkg.com/react-dom@17.0.2/umd/react-dom.production.min.js"></script>
<script src="https://unpkg.com/@babel/standalone/babel.min.js"></script>
<script type="text/babel">
function App() {
const [amount, setAmount] = React.useState(0);
const [inverted, setInverted] = React.useState(false); //flip은 boolean타입의 변수
const onChange = (event) => {
setAmount(event.target.value);
};
const reset = () => setAmount(0); //minutes의 값을 0으로 초기화
const onInvert = () => {
reset(); //flip누르면 변화된 값 그대로 가져오므로
setInverted((current) => !current);
};
return (
<div>
<h1>Super Converter</h1>
<label for="minutes">Minutes</label>
<input
value={inverted ? amount * 60 : amount} //value값을 state와 연결, 외부에서도 값을 변경해주기 위해
onChange={onChange} //데이터를 업데이트
id="minutes"
placeholder="Minutes"//label의 for과 id가 같으면 연결됨
type="number"
disabled={inverted} //disabled={flipped===true}
/>
<div>
</div>
<label for="hours">Hours</label>
<input id="hours"
value={inverted ? amount : Math.round(amount / 60)}
placeholder="Hours"
type="number"
disabled={!inverted}
onChange={onChange}
/>
<div>
<button onClick={reset}>Reset</button>
<button onClick={onInvert}>{inverted ? "Turn back" : "Invert"}</button>
</div>
</div>
); //변수를 컴포넌트에 연결
}
const root = document.getElementById("root");
ReactDOM.render(<App />, root);
</script>
</html>
