5.1 KiB
5.1 KiB
id | title | challengeType | isRequired | videoUrl | localeTitle |
---|---|---|---|---|---|
5a24c314108439a4d4036189 | Change Inline CSS Conditionally Based on Component State | 6 | false | 有条件地改变内联CSS基于组件状态 |
Description
Instructions
3px solid red
。您可以通过在输入中输入文本来尝试。 Tests
tests:
- text: <code>GateKeeper</code>组件应该呈现<code>div</code>元素。
testString: 'assert((function() { const mockedComponent = Enzyme.mount(React.createElement(GateKeeper)); return mockedComponent.find("div").length === 1; })(), "The <code>GateKeeper</code> component should render a <code>div</code> element.");'
- text: 应使用设置为空字符串的状态键<code>input</code>初始化<code>GateKeeper</code>组件。
testString: 'assert((function() { const mockedComponent = Enzyme.mount(React.createElement(GateKeeper)); return mockedComponent.state().input === ""; })(), "The <code>GateKeeper</code> component should be initialized with a state key <code>input</code> set to an empty string.");'
- text: <code>GateKeeper</code>组件应呈现<code>h3</code>标记和<code>input</code>标记。
testString: 'assert((function() { const mockedComponent = Enzyme.mount(React.createElement(GateKeeper)); return mockedComponent.find("h3").length === 1 && mockedComponent.find("input").length === 1; })(), "The <code>GateKeeper</code> component should render an <code>h3</code> tag and an <code>input</code> tag.");'
- text: <code>input</code>标记最初应为<code>border</code>属性的<code>1px solid black</code>样式。
testString: 'assert((function() { const mockedComponent = Enzyme.mount(React.createElement(GateKeeper)); return mockedComponent.find("input").props().style.border === "1px solid black"; })(), "The <code>input</code> tag should initially have a style of <code>1px solid black</code> for the <code>border</code> property.");'
- text: 如果状态中的输入值超过15个字符,则<code>input</code>标记应使用<code>3px solid red</code>边框进行样式设置。
testString: 'async () => { const waitForIt = (fn) => new Promise((resolve, reject) => setTimeout(() => resolve(fn()), 100)); const mockedComponent = Enzyme.mount(React.createElement(GateKeeper)); const simulateChange = (el, value) => el.simulate("change", {target: {value}}); let initialStyle = mockedComponent.find("input").props().style.border; const state_1 = () => { mockedComponent.setState({input: "this is 15 char" }); return waitForIt(() => mockedComponent.find("input").props().style.border )}; const state_2 = () => { mockedComponent.setState({input: "A very long string longer than 15 characters." }); return waitForIt(() => mockedComponent.find("input").props().style.border )}; const style_1 = await state_1(); const style_2 = await state_2(); assert(initialStyle === "1px solid black" && style_1 === "1px solid black" && style_2 === "3px solid red", "The <code>input</code> tag should be styled with a border of <code>3px solid red</code> if the input value in state is longer than 15 characters."); }; '
Challenge Seed
class GateKeeper extends React.Component {
constructor(props) {
super(props);
this.state = {
input: "
};
this.handleChange = this.handleChange.bind(this);
}
handleChange(event) {
this.setState({ input: event.target.value })
}
render() {
let inputStyle = {
border: '1px solid black'
};
// change code below this line
// change code above this line
return (
<div>
<h3>Don't Type Too Much:</h3>
<input
type="text"
style={inputStyle}
value={this.state.input}
onChange={this.handleChange} />
</div>
);
}
};
After Test
console.info('after the test');
Solution
// solution required