인프런 커뮤니티 질문&답변
작성한 질문수
답변 3
0
0
<html>
<head>
<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/babel.min.js"></script>
<!-- <script
crossorigin
src="https://unpkg.com/react@17/umd/react.development.js"
></script> -->
<!-- <script crossorigin src="https://unpkg.com/react@16/umd/react.production.js"></script> -->
<!-- <script
crossorigin
src="https://unpkg.com/react-dom@17/umd/react-dom.development.js"
></script> -->
<!-- <script crossorigin src="https://unpkg.com/react-dom@16/umd/react.production.js"></script> -->
<!-- <script src="https://unpkg.com/babel-standalone@6/babel.min.js"></script> -->
</head>
<body>
<div id="root"></div>
<!-- 결과: <div id="root"><button>Like</button></div> -->
<script type="text/babel">
// const e = React.createElement; [옛날버전]
class LikeButton extends React.Component {
constructor(props) {
super(props);
// 바뀔 여지가 있는 부분이 상태(state)입니다. 상태 = state
this.state = {
liked: false,
};
}
render() {
return (
<button type="submit" onClick={this.setState({ liked: true })}>
{this.state.liked === true ? "Liked" : "Like"}
</button>
);
// JSX ( JS + XML )
/** 변경전 [옛날버전]
e(
"button",
{
onClick: () => {
this.setState({ liked: true });
},
type: "submit",
},
this.state.liked === true ? "Liked" : "Like"
); **/
// <button onclick="() => {console.log('clicked')}" type="submit">Like</button>
// $('button').text('Liked'); 제이쿼리
}
}
</script>
<script type="text/babel">
ReactDOM.render(
<div>
<LikeButton />
<LikeButton />
<LikeButton />
<LikeButton />
</div>,
document.querySelector("#root")
);
</script>
</body>
</html>
0
element.style {
}
user agent stylesheet
body {
display: block;
margin: 8px;
}
Some messages have been moved to the Issues panel.
View issues
index.html:95 Live reload enabled.
babel.min.js:1 You are using the in-browser Babel transformer. Be sure to precompile your scripts for production - https://babeljs.io/docs/setup/
react-dom.development.js:82 Warning: Cannot update during an existing state transition (such as within `render`). Render methods should be a pure function of props and state.
in LikeButton
in div
react-dom.development.js:19662 The above error occurred in the <LikeButton> component:
in LikeButton
in div
Consider adding an error boundary to your tree to customize error handling behavior.
Visit https://fb.me/react-error-boundaries to learn more about error boundaries.
react-dom.development.js:11237 Uncaught Error: Maximum update depth exceeded. This can happen when a component repeatedly calls setState inside componentWillUpdate or componentDidUpdate. React limits the number of nested updates to prevent infinite loops.
at checkForNestedUpdates (react-dom.development.js:23228)
at scheduleUpdateOnFiber (react-dom.development.js:21299)
at Object.enqueueSetState (react-dom.development.js:12774)
at LikeButton.Component.setState (react.development.js:557)
at LikeButton.render (<anonymous>:49:23)
at finishClassComponent (react-dom.development.js:17295)
at updateClassComponent (react-dom.development.js:17245)
at beginWork (react-dom.development.js:18755)
at beginWork$1 (react-dom.development.js:23314)
at performUnitOfWork (react-dom.development.js:22289)