styled.md

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;
`
// 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 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 babel-plugin-emotion.

// @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>
)

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 will pass all props to custom components and only props that are valid html attributes for string tags. This is can be customized by passing a custom shouldForwardProp function. You can also use @emotion/is-prop-valid to filter out props that are not valid as html attributes, it is what emotion uses internally.

// @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: 'hotpink'
}))

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