5.5 KiB
5.5 KiB
id | title | challengeType | isRequired | forumTopicId |
---|---|---|---|---|
5a24c314108439a4d4036189 | Change Inline CSS Conditionally Based on Component State | 6 | false | 301380 |
Description
Instructions
3px solid red
. You can try it out by entering text in the input.
Tests
tests:
- text: The <code>GateKeeper</code> component should render a <code>div</code> element.
testString: assert((function() { const mockedComponent = Enzyme.mount(React.createElement(GateKeeper)); return mockedComponent.find('div').length === 1; })());
- text: The <code>GateKeeper</code> component should be initialized with a state key <code>input</code> set to an empty string.
testString: assert((function() { const mockedComponent = Enzyme.mount(React.createElement(GateKeeper)); return mockedComponent.state().input === ''; })());
- text: The <code>GateKeeper</code> component should render an <code>h3</code> tag and an <code>input</code> tag.
testString: assert((function() { const mockedComponent = Enzyme.mount(React.createElement(GateKeeper)); return mockedComponent.find('h3').length === 1 && mockedComponent.find('input').length === 1; })());
- text: The <code>input</code> tag should initially have a style of <code>1px solid black</code> for the <code>border</code> property.
testString: assert((function() { const mockedComponent = Enzyme.mount(React.createElement(GateKeeper)); return mockedComponent.find('input').props().style.border === '1px solid black'; })());
- text: 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.
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''); }; '
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
ReactDOM.render(<GateKeeper />, document.getElementById('root'))
Solution
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'
};
if (this.state.input.length > 15) {
inputStyle.border = '3px solid red';
};
return (
<div>
<h3>Don't Type Too Much:</h3>
<input
type="text"
style={inputStyle}
value={this.state.input}
onChange={this.handleChange} />
</div>
);
}
};