2018-10-10 22:03:03 +00:00
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---
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id: 5a24c314108439a4d4036165
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challengeType: 6
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2020-09-17 16:13:42 +00:00
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forumTopicId: 301420
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2020-10-01 15:54:21 +00:00
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title: 使用 React 渲染嵌套组件
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2018-10-10 22:03:03 +00:00
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---
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## Description
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2020-09-17 16:13:42 +00:00
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<section id='description'>
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上一个挑战显示了组合两个组件的简单方法,但是有许多不同的方法可以把 React 组件组合在一起。
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组件组合是 React 的强大功能之一。当你使用 React 时,应当先用组件的思路考虑清楚用户界面的结构(如上一个挑战中的 App 示例)。可以将 UI 分解为基本的构建块,这些构建块就是组件。这样做有助于将负责 UI 的代码与负责处理应用程序逻辑的代码分开,并可以大大简化复杂项目的开发和维护。
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</section>
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2018-10-10 22:03:03 +00:00
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## Instructions
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2020-09-17 16:13:42 +00:00
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<section id='instructions'>
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代码编辑器中定义了两个功能组件,分别是<code>TypesOfFruit</code>和<code>Fruits</code>。请把<code>TypesOfFruit</code>组件放到<code>Fruits</code>组件中,然后把<code>Fruits</code>组件放到<code>TypesOfFood</code>组件中。结果应该是子组件嵌套在父组件中,父组件嵌套在它本身的父组件中!
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</section>
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2018-10-10 22:03:03 +00:00
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## Tests
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<section id='tests'>
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```yml
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tests:
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2020-09-17 16:13:42 +00:00
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- text: <code>TypesOfFood</code>组件应该返回单个<code>div</code>元素。
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2020-02-17 16:40:55 +00:00
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testString: assert(Enzyme.shallow(React.createElement(TypesOfFood)).type() === 'div');
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2020-09-17 16:13:42 +00:00
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- text: <code>TypesOfFood</code>组件应该返回<code>Fruits</code>组件。
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2020-02-17 16:40:55 +00:00
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testString: assert(Enzyme.shallow(React.createElement(TypesOfFood)).props().children[1].type.name === 'Fruits');
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2020-09-17 16:13:42 +00:00
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- text: <code>Fruits</code>组件应该返回<code>TypesOfFruit</code>组件。
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2020-02-17 16:40:55 +00:00
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testString: assert(Enzyme.mount(React.createElement(TypesOfFood)).find('h2').html() === '<h2>Fruits:</h2>');
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2020-09-17 16:13:42 +00:00
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- text: <code>TypesOfFruit</code>组件应该返回<code>h2</code>和<code>ul</code>元素。
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2020-02-17 16:40:55 +00:00
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testString: assert(Enzyme.mount(React.createElement(TypesOfFood)).find('ul').text() === 'ApplesBlueberriesStrawberriesBananas');
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2018-10-10 22:03:03 +00:00
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```
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</section>
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## Challenge Seed
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<section id='challengeSeed'>
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<div id='jsx-seed'>
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```jsx
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const TypesOfFruit = () => {
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return (
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<div>
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<h2>Fruits:</h2>
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<ul>
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<li>Apples</li>
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<li>Blueberries</li>
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<li>Strawberries</li>
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<li>Bananas</li>
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</ul>
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</div>
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);
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};
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const Fruits = () => {
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return (
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<div>
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{ /* change code below this line */ }
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{ /* change code above this line */ }
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</div>
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);
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};
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class TypesOfFood 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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<h1>Types of Food:</h1>
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{ /* change code below this line */ }
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{ /* change code above this line */ }
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</div>
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);
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}
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};
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```
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</div>
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### After Test
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<div id='jsx-teardown'>
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```js
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2020-09-17 16:13:42 +00:00
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ReactDOM.render(<TypesOfFood />, document.getElementById('root'))
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2018-10-10 22:03:03 +00:00
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```
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</div>
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</section>
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## Solution
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<section id='solution'>
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2020-09-17 16:13:42 +00:00
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2018-10-10 22:03:03 +00:00
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```js
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2020-09-17 16:13:42 +00:00
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const TypesOfFruit = () => {
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return (
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<div>
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<h2>Fruits:</h2>
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<ul>
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<li>Apples</li>
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<li>Blueberries</li>
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<li>Strawberries</li>
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<li>Bananas</li>
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</ul>
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</div>
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);
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};
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const Fruits = () => {
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return (
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<div>
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{ /* change code below this line */ }
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<TypesOfFruit />
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{ /* change code above this line */ }
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</div>
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);
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};
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class TypesOfFood 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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<h1>Types of Food:</h1>
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{ /* change code below this line */ }
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<Fruits />
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{ /* change code above this line */ }
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</div>
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);
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}
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};
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2018-10-10 22:03:03 +00:00
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```
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2020-08-13 15:24:35 +00:00
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2020-09-17 16:13:42 +00:00
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</section>
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