75 lines
2.5 KiB
Markdown
75 lines
2.5 KiB
Markdown
---
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id: 5a24c314108439a4d4036168
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title: Write a React Component from Scratch
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challengeType: 6
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isRequired: false
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forumTopicId: 301424
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---
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## Description
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<section id='description'>
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Now that you've learned the basics of JSX and React components, it's time to write a component on your own. React components are the core building blocks of React applications so it's important to become very familiar with writing them. Remember, a typical React component is an ES6 <code>class</code> which extends <code>React.Component</code>. It has a render method that returns HTML (from JSX) or <code>null</code>. This is the basic form of a React component. Once you understand this well, you will be prepared to start building more complex React projects.
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</section>
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## Instructions
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<section id='instructions'>
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Define a class <code>MyComponent</code> that extends <code>React.Component</code>. Its render method should return a <code>div</code> that contains an <code>h1</code> tag with the text: <code>My First React Component!</code> in it. Use this text exactly, the case and punctuation matter. Make sure to call the constructor for your component, too.
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Render this component to the DOM using <code>ReactDOM.render()</code>. There is a <code>div</code> with <code>id='challenge-node'</code> available for you to use.
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</section>
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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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- text: There should be a React component called <code>MyComponent</code>.
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testString: getUserInput => assert(getUserInput('index').replace(/\s/g, '').includes('classMyComponentextendsReact.Component{'));
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- text: <code>MyComponent</code> should contain an <code>h1</code> tag with text <code>My First React Component!</code> Case and punctuation matter.
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testString: assert((function() { const mockedComponent = Enzyme.mount(React.createElement(MyComponent)); return mockedComponent.find('h1').text() === 'My First React Component!'; })());
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- text: <code>MyComponent</code> should render to the DOM.
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testString: assert(document.getElementById('challenge-node').childNodes.length === 1);
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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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// change code below this line
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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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```js
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// change code below this line
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class MyComponent 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>My First React Component!</h1>
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</div>
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);
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}
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};
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ReactDOM.render(<MyComponent />, document.getElementById('challenge-node'));
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```
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</section>
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