2018-10-10 18:03:03 -04:00
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---
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id: 5a24c314108439a4d403616f
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2020-12-16 00:37:30 -07:00
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title: 复习如何使用 Props 和无状态函数组件
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2018-10-10 18:03:03 -04:00
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challengeType: 6
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2020-09-18 00:13:42 +08:00
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forumTopicId: 301411
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2021-01-13 03:31:00 +01:00
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dashedName: review-using-props-with-stateless-functional-components
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2018-10-10 18:03:03 -04:00
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---
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2020-12-16 00:37:30 -07:00
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# --description--
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2020-09-18 00:13:42 +08:00
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除了上一个挑战,你一直在将 props 传递给无状态的函数组件。这些组件就像纯函数,它们接收 props 作为输入,并在每次传递相同 props 时返回相同的视图。你可能会想知道什么是状态,下一个挑战将会更详细地讲述它。在此之前,我们先来回顾一下组件的术语。
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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*无状态函数组件*是一个函数,它接收 props 作为输入并返回 JSX。另一方面,*无状态组件*是一个类,它扩展了`React.Component`,但是不使用内部状态(下一个挑战中讨论)。最后,*状态组件*是指维护其自身内部状态的组件,它简称组件或 React 组件。
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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一种常见的应用模式是尽可能减少状态组件并创建无状态的函数组件。这有助于将状态管理包含到应用程序的特定区域。反过来,通过更容易地跟踪状态变化如何影响其行为,可以改进应用程序的开发和维护。
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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# --instructions--
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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在代码编辑器中有一个`CampSite`组件,它把`Camper`组件渲染为自己的子组件。定义`Camper`组件,并为其分配默认 props`{ name: 'CamperBot' }`。你可以在`Camper`组件内部渲染任何你想要的代码,但是要确保有一个`p`元素,它只包含作为`prop`传递的`name`值。最后,在`Camper`组件上定义`propTypes`,要求提供`name`作为 prop,并验证它是`string`类型。
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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# --hints--
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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应该渲染`CampSite`组件。
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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```js
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assert(
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(function () {
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const mockedComponent = Enzyme.mount(React.createElement(CampSite));
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return mockedComponent.find('CampSite').length === 1;
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})()
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);
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```
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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应该渲染`Camper`组件。
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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```js
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assert(
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(function () {
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const mockedComponent = Enzyme.mount(React.createElement(CampSite));
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return mockedComponent.find('Camper').length === 1;
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})()
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);
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2018-10-10 18:03:03 -04:00
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```
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2020-12-16 00:37:30 -07:00
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`Camper`组件应该包含默认 props,它将字符串`CamperBot`赋值给关键字`name`。
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2018-10-10 18:03:03 -04:00
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```js
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2020-12-16 00:37:30 -07:00
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assert(
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/Camper.defaultProps={name:(['"`])CamperBot\1,?}/.test(
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code.replace(/\s/g, '')
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)
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);
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2018-10-10 18:03:03 -04:00
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```
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2020-12-16 00:37:30 -07:00
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`Camper`组件应该包含`string`类型的`name`prop。
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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```js
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assert(
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/Camper.propTypes={name:PropTypes.string.isRequired,?}/.test(
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code.replace(/\s/g, '')
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)
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);
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```
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2018-10-10 18:03:03 -04:00
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2020-12-16 00:37:30 -07:00
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`Camper`组件应该包含一个`p`元素,元素内是来自prop`name`的唯一文本。
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2020-09-18 00:13:42 +08:00
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2018-10-10 18:03:03 -04:00
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```js
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2020-12-16 00:37:30 -07:00
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assert(
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(function () {
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const mockedComponent = Enzyme.mount(React.createElement(CampSite));
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2020-09-18 00:13:42 +08:00
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return (
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2020-12-16 00:37:30 -07:00
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mockedComponent.find('p').text() ===
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mockedComponent.find('Camper').props().name
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2020-09-18 00:13:42 +08:00
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);
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2020-12-16 00:37:30 -07:00
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})()
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);
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2018-10-10 18:03:03 -04:00
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```
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2020-08-13 17:24:35 +02:00
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2021-01-13 03:31:00 +01:00
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# --seed--
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## --before-user-code--
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```jsx
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var PropTypes = {
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string: { isRequired: true }
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};
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```
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## --after-user-code--
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```jsx
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ReactDOM.render(<CampSite />, document.getElementById('root'))
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```
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## --seed-contents--
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```jsx
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class CampSite extends React.Component {
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constructor(props) {
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super(props);
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}
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render() {
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return (
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<div>
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<Camper/>
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</div>
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);
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}
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};
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// Change code below this line
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```
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2020-12-16 00:37:30 -07:00
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# --solutions--
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2021-01-13 03:31:00 +01:00
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```jsx
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class CampSite extends React.Component {
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constructor(props) {
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super(props);
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}
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render() {
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return (
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<div>
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<Camper/>
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</div>
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);
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}
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};
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// Change code below this line
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const Camper = (props) => {
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return (
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<div>
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<p>{props.name}</p>
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</div>
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);
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};
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Camper.propTypes = {
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name: PropTypes.string.isRequired
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};
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Camper.defaultProps = {
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name: 'CamperBot'
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};
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```
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