2018-10-10 22:03:03 +00:00
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---
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id: 5a24c314108439a4d4036165
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2021-03-05 15:43:24 +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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challengeType: 6
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2020-09-17 16:13:42 +00:00
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forumTopicId: 301420
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2021-01-13 02:31:00 +00:00
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dashedName: use-react-to-render-nested-components
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2018-10-10 22:03:03 +00:00
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---
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2020-12-16 07:37:30 +00:00
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# --description--
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2021-03-05 15:43:24 +00:00
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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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2018-10-10 22:03:03 +00:00
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2021-03-05 15:43:24 +00:00
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组件组合是 React 的强大功能之一。 当使用 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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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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# --instructions--
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2018-10-10 22:03:03 +00:00
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2021-03-05 15:43:24 +00:00
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代码编辑器中定义了两个功能组件,分别是 `TypesOfFruit` 和 `Fruits`。 请用组合或者*嵌套*把 `TypesOfFruit` 组件放到 `Fruits` 组件中, 然后把 `Fruits` 组件放到 `TypesOfFood` 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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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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# --hints--
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2018-10-10 22:03:03 +00:00
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2021-03-05 15:43:24 +00:00
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`TypesOfFood` 组件应该返回单个 `div` 元素。
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2018-10-10 22:03:03 +00:00
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```js
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2020-12-16 07:37:30 +00:00
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assert(Enzyme.shallow(React.createElement(TypesOfFood)).type() === 'div');
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2018-10-10 22:03:03 +00:00
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```
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2021-03-05 15:43:24 +00:00
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`TypesOfFood` 组件应该返回 `Fruits` 组件。
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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```js
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assert(
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Enzyme.shallow(React.createElement(TypesOfFood)).props().children[1].type
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.name === 'Fruits'
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);
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```
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2021-03-05 15:43:24 +00:00
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`Fruits` 组件应该返回 `TypesOfFruit` 组件。
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2018-10-10 22:03:03 +00:00
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2020-12-16 07:37:30 +00:00
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```js
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assert(
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Enzyme.mount(React.createElement(TypesOfFood)).find('h2').html() ===
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'<h2>Fruits:</h2>'
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);
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```
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2018-10-10 22:03:03 +00:00
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2021-03-05 15:43:24 +00:00
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`TypesOfFruit` 组件应该返回 `h2` 和 `ul` 元素。
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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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2020-12-16 07:37:30 +00:00
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assert(
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Enzyme.mount(React.createElement(TypesOfFood)).find('ul').text() ===
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'ApplesBlueberriesStrawberriesBananas'
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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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2021-01-13 02:31:00 +00:00
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# --seed--
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## --after-user-code--
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```jsx
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ReactDOM.render(<TypesOfFood />, document.getElementById('root'))
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```
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## --seed-contents--
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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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2020-12-16 07:37:30 +00:00
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# --solutions--
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2021-01-13 02:31:00 +00:00
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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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<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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```
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