styled.mdx

title
Styled Components

styled is a way to create React components that have styles attached to them. It's available from @emotion/styled. styled was heavily inspired by styled-components and glamorous.

Styling elements and components

styled is very similar to css except you call it with an html tag or React component and then call that with a template literal for string styles or a regular function call for object styles.

// @live
import styled from '@emotion/styled'

const Button = styled.button`
  color: turquoise;
`

render(<Button>This my button component.</Button>)

Changing based on props

Any interpolations or arguments that are functions in styled are called with props, this allows you to change the styles of a component based on the props.

// @live
import styled from '@emotion/styled'

const Button = styled.button`
  color: ${props => (props.primary ? 'hotpink' : 'turquoise')};
`

const Container = styled.div(props => ({
  display: 'flex',
  flexDirection: props.column && 'column'
}))

render(
  <Container column>
    <Button>This is a regular button.</Button>
    <Button primary>This is a primary button.</Button>
  </Container>
)

Styling any component

styled can style any component as long as it accepts a className prop.

// @live
import styled from '@emotion/styled'

const Basic = ({ className }) => <div className={className}>Some text</div>

const Fancy = styled(Basic)`
  color: hotpink;
`

render(<Fancy />)

Change the rendered tag using withComponent

Sometimes you want to create some styles with one component but then use those styles again with another component, the withComponent method can be used for this. This was inspired by styled-components' withComponent.

// @live
import styled from '@emotion/styled'

const Section = styled.section`
  background: #333;
  color: #fff;
`

// this component has the same styles as Section but it renders an aside
const Aside = Section.withComponent('aside')

render(
  <div>
    <Section>This is a section</Section>
    <Aside>This is an aside</Aside>
  </div>
)

Targeting another emotion component

Similar to styled-components, emotion allows for emotion components to be targeted like regular CSS selectors when using @emotion/babel-plugin.

// @live
import styled from '@emotion/styled'

const Child = styled.div`
  color: red;
`

const Parent = styled.div`
  ${Child} {
    color: green;
  }
`

render(
  <div>
    <Parent>
      <Child>Green because I am inside a Parent</Child>
    </Parent>
    <Child>Red because I am not inside a Parent</Child>
  </div>
)

Component selectors can also be used with object styles.

// @live
import styled from '@emotion/styled'

const Child = styled.div({
  color: 'red'
})

const Parent = styled.div({
  [Child]: {
    color: 'green'
  }
})

render(
  <div>
    <Parent>
      <Child>green</Child>
    </Parent>
    <Child>red</Child>
  </div>
)

Object styles

// @live
import styled from '@emotion/styled'

const H1 = styled.h1(
  {
    fontSize: 20
  },
  props => ({ color: props.color })
)

render(<H1 color="lightgreen">This is lightgreen.</H1>)

This API was inspired by glamorous. ❤️

Customizing prop forwarding

By default, Emotion passes all props (except for theme) to custom components and only props that are valid html attributes for string tags. You can customize this by passing a custom shouldForwardProp function. You can also use @emotion/is-prop-valid (which is used by emotion internally) to filter out props that are not valid as html attributes.

// @live
import isPropValid from '@emotion/is-prop-valid'
import styled from '@emotion/styled'

const H1 = styled('h1', {
  shouldForwardProp: prop => isPropValid(prop) && prop !== 'color'
})(props => ({
  color: props.color
}))

render(<H1 color="lightgreen">This is lightgreen.</H1>)

Composing dynamic styles

You can create dynamic styles that are based on props and use them in styles.

// @live
import styled from '@emotion/styled'
import { css } from '@emotion/react'

const dynamicStyle = props =>
  css`
    color: ${props.color};
  `

const Container = styled.div`
  ${dynamicStyle};
`
render(<Container color="lightgreen">This is lightgreen.</Container>)

as prop

To use styles from a styled component but change the element that's rendered, you can use the as prop.

// @live
import styled from '@emotion/styled'

const Button = styled.button`
  color: hotpink;
`

render(
  <Button as="a" href="https://github.com/emotion-js/emotion">
    Emotion on GitHub
  </Button>
)

This API was inspired by styled-components. ❤️

The as prop is only used by styled when it's not forwarded to the underlying element. By default, this means that the as prop is used for html tags and forwarded for components. To change this, you can pass a custom shouldForwardProp which returns true for 'as' to forward it or returns false for 'as' to use it and not forward it.

Nesting components

We can nest selectors using &:

// @live

import styled from '@emotion/styled'

const Example = styled('span')`
  color: lightgreen;

  & > strong {
    color: hotpink;
  }
`

render(
  <Example>
    This is <strong>nested</strong>.
  </Example>
)