emotion
The emotion package is framework agnostic and the simplest way to use Emotion.
Table of Contents
Quick Start
Get up and running with a single import.
npm install --save emotionimport { css } from 'emotion'
const app = document.getElementById('root')
const myStyle = css`
color: rebeccapurple;
`
app.classList.add(myStyle)API
css
The css function accepts styles as a template literal, object, or array of objects and returns a class name. It is the foundation of emotion.
String Styles
// @live
import { css } from 'emotion'
const color = 'darkgreen'
render(
<div
className={css`
background-color: hotpink;
&:hover {
color: ${color};
}
`}
>
This has a hotpink background.
</div>
)Object Styles
// @live
import { css } from 'emotion'
const color = 'darkgreen'
render(
<div
className={css({
backgroundColor: 'hotpink',
'&:hover': {
color
}
})}
>
This has a hotpink background.
</div>
)Array of Object Styles
// @live
import { css } from 'emotion'
const color = 'darkgreen'
const isDanger = true
render(
<div
className={css([
{
backgroundColor: 'hotpink',
'&:hover': {
color
}
},
isDanger && {
color: 'red'
}
])}
>
This has a hotpink background.
</div>
)Global Styles
injectGlobal injects styles into the global scope and is useful for applications such as css resets or font faces.
import { injectGlobal } from 'emotion'
injectGlobal`
* {
box-sizing: border-box;
}
@font-face {
font-family: 'Patrick Hand SC';
font-style: normal;
font-weight: 400;
src: local('Patrick Hand SC'),
local('PatrickHandSC-Regular'),
url(https://fonts.gstatic.com/s/patrickhandsc/v4/OYFWCgfCR-7uHIovjUZXsZ71Uis0Qeb9Gqo8IZV7ckE.woff2)
format('woff2');
unicode-range: U+0100-024f, U+1-1eff,
U+20a0-20ab, U+20ad-20cf, U+2c60-2c7f,
U+A720-A7FF;
}
`Animation Keyframes
keyframes generates a unique animation name that can be used to animate elements with CSS animations.
String Styles
// @live
import { css, keyframes } from 'emotion'
const bounce = keyframes`
from, 20%, 53%, 80%, to {
transform: translate3d(0,0,0);
}
40%, 43% {
transform: translate3d(0, -30px, 0);
}
70% {
transform: translate3d(0, -15px, 0);
}
90% {
transform: translate3d(0,-4px,0);
}
`
render(
<img
className={css`
width: 96px;
height: 96px;
border-radius: 50%;
animation: ${bounce} 1s ease infinite;
transform-origin: center bottom;
`}
src={logoUrl}
/>
)Object Styles
// @live
import { css, keyframes } from 'emotion'
const bounce = keyframes({
'from, 20%, 53%, 80%, to': {
transform: 'translate3d(0,0,0)'
},
'40%, 43%': {
transform: 'translate3d(0, -30px, 0)'
},
'70%': {
transform: 'translate3d(0, -15px, 0)'
},
'90%': {
transform: 'translate3d(0, -4px, 0)'
}
})
render(
<img
src={logoUrl}
className={css({
width: 96,
height: 96,
borderRadius: '50%',
animation: `${bounce} 1s ease infinite`,
transformOrigin: 'center bottom'
})}
/>
)cx
cx is emotion's version of the popular classnames library. The key advantage of cx is that it detects emotion generated class names ensuring styles are overwritten in the correct order. Emotion generated styles are applied from left to right. Subsequent styles overwrite property values of previous styles.
Combining class names
import { cx, css } from 'emotion'
const cls1 = css`
font-size: 20px;
background: green;
`
const cls2 = css`
font-size: 20px;
background: blue;
`
<div className={cx(cls1, cls2)} />Conditional class names
const cls1 = css`
font-size: 20px;
background: green;
`
const cls2 = css`
font-size: 20px;
background: blue;
`
const foo = true
const bar = false
<div
className={cx(
{ [cls1]: foo },
{ [cls2]: bar }
)}
/>Using class names from other sources
const cls1 = css`
font-size: 20px;
background: green;
`
<div
className={cx(cls1, 'profile')}
/>