79d9012432
* fix(curriculum): tests quotes * fix(curriculum): fill seed-teardown * fix(curriculum): fix tests and remove unneeded seed-teardown
107 lines
3.8 KiB
Markdown
107 lines
3.8 KiB
Markdown
---
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id: 5a24c314108439a4d4036172
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title: Render State in the User Interface Another Way
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challengeType: 6
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isRequired: false
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---
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## Description
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<section id='description'>
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There is another way to access <code>state</code> in a component. In the <code>render()</code> method, before the <code>return</code> statement, you can write JavaScript directly. For example, you could declare functions, access data from <code>state</code> or <code>props</code>, perform computations on this data, and so on. Then, you can assign any data to variables, which you have access to in the <code>return</code> statement.
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</section>
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## Instructions
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<section id='instructions'>
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In the <code>MyComponent</code> render method, define a <code>const</code> called <code>name</code> and set it equal to the name value in the component's <code>state</code>. Because you can write JavaScript directly in this part of the code, you don't have to enclose this reference in curly braces.
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Next, in the return statement, render this value in an <code>h1</code> tag using the variable <code>name</code>. Remember, you need to use the JSX syntax (curly braces for JavaScript) in the return statement.
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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: <code>MyComponent</code> should have a key <code>name</code> with value <code>freeCodeCamp</code> stored in its state.
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testString: assert(Enzyme.mount(React.createElement(MyComponent)).state('name') === 'freeCodeCamp', '<code>MyComponent</code> should have a key <code>name</code> with value <code>freeCodeCamp</code> stored in its state.');
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- text: <code>MyComponent</code> should render an <code>h1</code> header enclosed in a single <code>div</code>.
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testString: assert(/<div><h1>.*<\/h1><\/div>/.test(Enzyme.mount(React.createElement(MyComponent)).html()), '<code>MyComponent</code> should render an <code>h1</code> header enclosed in a single <code>div</code>.');
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- text: The rendered <code>h1</code> tag should include a reference to <code>{name}</code>.
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testString: getUserInput => assert(/<h1>\n*\s*\{\s*name\s*\}\s*\n*<\/h1>/.test(getUserInput('index')), 'The rendered <code>h1</code> tag should include a reference to <code>{name}</code>.');
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- text: The rendered <code>h1</code> header should contain text rendered from the component's state.
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testString: 'async () => { const waitForIt = (fn) => new Promise((resolve, reject) => setTimeout(() => resolve(fn()), 250)); const mockedComponent = Enzyme.mount(React.createElement(MyComponent)); const first = () => { mockedComponent.setState({ name: ''TestName'' }); return waitForIt(() => mockedComponent.html()) }; const firstValue = await first(); assert(firstValue === ''<div><h1>TestName</h1></div>'', ''The rendered <code>h1</code> header should contain text rendered from the component's state.''); };'
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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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class MyComponent extends React.Component {
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constructor(props) {
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super(props);
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this.state = {
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name: 'freeCodeCamp'
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}
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}
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render() {
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// change code below this line
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// change code above this line
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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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};
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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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ReactDOM.render(<MyComponent />, document.getElementById('root'))
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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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class MyComponent extends React.Component {
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constructor(props) {
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super(props);
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this.state = {
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name: 'freeCodeCamp'
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}
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}
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render() {
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// change code below this line
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const name = this.state.name;
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// change code above this line
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return (
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<div>
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{ /* change code below this line */ }
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<h1>{name}</h1>
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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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</section>
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