polished
Version:
A lightweight toolset for writing styles in Javascript.
57 lines (54 loc) • 1.63 kB
Flow
// @flow
import constructGradientValue from '../internalHelpers/_constructGradientValue'
import PolishedError from '../internalHelpers/_errors'
import type { LinearGradientConfiguration } from '../types/linearGradientConfiguration'
import type { Styles } from '../types/style'
/**
* CSS for declaring a linear gradient, including a fallback background-color. The fallback is either the first color-stop or an explicitly passed fallback color.
*
* @example
* // Styles as object usage
* const styles = {
* ...linearGradient({
colorStops: ['#00FFFF 0%', 'rgba(0, 0, 255, 0) 50%', '#0000FF 95%'],
toDirection: 'to top right',
fallback: '#FFF',
})
* }
*
* // styled-components usage
* const div = styled.div`
* ${linearGradient({
colorStops: ['#00FFFF 0%', 'rgba(0, 0, 255, 0) 50%', '#0000FF 95%'],
toDirection: 'to top right',
fallback: '#FFF',
})}
*`
*
* // CSS as JS Output
*
* div: {
* 'backgroundColor': '#FFF',
* 'backgroundImage': 'linear-gradient(to top right, #00FFFF 0%, rgba(0, 0, 255, 0) 50%, #0000FF 95%)',
* }
*/
export default function linearGradient({
colorStops,
fallback,
toDirection = '',
}: LinearGradientConfiguration): Styles {
if (!colorStops || colorStops.length < 2) {
throw new PolishedError(56)
}
return {
backgroundColor:
fallback
|| colorStops[0]
.replace(/,\s+/g, ',')
.split(' ')[0]
.replace(/,(?=\S)/g, ', '),
backgroundImage: constructGradientValue`linear-gradient(${toDirection}${colorStops
.join(', ')
.replace(/,(?=\S)/g, ', ')})`,
}
}