@svebass/flexbox

Flexbox

📦 Svelte layout and grid system, heavily inspired by and largely ported from rebass/reflexbox for React 🙏.

• Primitive components for all your layout needs
• Customize styles inline with the sx prop
• Ergonomic responsive array-based values
• Support for component variants
• Styled System props
• Themeable and compatible with the Theme Specification
• Built with Styled System
• Works with Theme UI
• Built with Emotion

Getting Started

yarn add @svebass/flexbox

<script>
  import { Box, Flex } from '@svebass/flexbox';
</script>

<Flex width={[ 1, 1/2]}>
  <Box p={2}>
    Box 1
  </Box>
  <Box p={2}>
    Box 2
  </Box>
</Flex>

sx Prop

The Box and Flex components both accept a sx prop that works with no additional setup required. The sx prop is similar to Emotion's css prop, but allows you to use values derived from the theme object.

Flexbox follows the Theme Specification, which means that any theme created for use with Theme UI, Styled System, or other similar libraries will work out-of-the-box. This allows you to share design constraints for typography, color, and layout throughout your application using a theming context.

<Box
  sx={{
    p: 4,
    color: 'primary',
  }}
/>

Note: to opt-out of theme-based styles, use the css prop instead, which will not transform values.

as Prop

Passing an as prop and a tagname will convert the resulting container into the tag. Until dynamic tags are supported in Svelte, only a select few tags are supported:

• div
• button
• a
• img

Theming

Because Flexbox follows the Theme Specification, all themes built for use with Styled System, Theme UI, or other related libraries are compatible with Flexbox.

Context

Adding a theme to your Svelte app is super simple with Svelte's context API.

// Parent.svelte
<script>
  import { setContext } from 'svelte';
  import Child from './Child.svelte';
  
  const theme = {
    breakpoints: [
      '40em', '52em', '64em',
    ],
    colors: {
      text: '#000',
      background: '#fff',
      primary: '#07c',
    },
    space: [
      0, 4, 8, 16, 32, 64, 128, 256,
    ],
  };

  // Set context for children
  setContext('theme', theme);
</script>

<Child />

// Child.svelte

<script>
  import { Box, Flex } from '@svebass/flexbox';
</script>

<Box
  sx={{
    p: 4,
    bg: 'primary',
  }}>
  Hello
</Box>

Prop

You can also pass a theme directly as a prop:

<script>
  import { Box, Flex } from '@svebass/flexbox';
  import theme from './theme.js';
</script>

<Box
  theme={theme}
  sx={{
    p: 4,
    bg: 'primary',
  }}
>
  Hello
</Box>

Variants

Flexbox components also accept a variant prop, which allows you to define commonly used styles, such as cards, badges, and CSS grid layouts, in your theme object for reuse.

Add a variants object to your theme and include any variants as style objects. These styles can reference other values in your theme such as colors, typographic styles, and more.

// example theme
export default {
  colors: {
    text: '#000',
    background: '#fff',
    primary: '#07c',
  },
  radii: {
    default: 4,
  },
  shadows: {
    card: '0 0 4px rgba(0, 0, 0, .125)',
  },
  variants: {
    card: {
      p: 3,
      borderRadius: 'default',
      bg: 'white',
      boxShadow: 'card',
    },
    badge: {
      color: 'white',
      bg: 'primary',
      p: 1,
      borderRadius: 'default',
    },
  },
}

To apply a variant to your component, pass the name to the variant prop.

<Box variant='card'>Card</Box>
<Box variant='badge'>Badge</Box>

Responsive Styles

Use array values to quickly and ergonomically add mobile-first responsive styles to specific properties. This works on all style props and the sx prop. See the Styled System docs for more.

// 100% width at the smallest viewport width
// 50% width at the next breakpoint
// 25% width at the next breakpoint
<Box width={[ '100%', '50%', '25%' ]} />

You can customize the widths used for each breakpoint by defining a theme.breakpoints array in your theme.

Styled System Props

Flexbox conforms to the Theme Specification and includes many common Styled System props. The Box and Flex components accept the following props:

Space Props

Prop	Theme Key
margin, m	space
marginTop, mt	space
marginRight, mr	space
marginBottom, mb	space
marginLeft, ml	space
marginX, mx	space
marginY, my	space
padding, p	space
paddingTop, pt	space
paddingRight, pr	space
paddingBottom, pb	space
paddingLeft, pl	space
paddingX, px	space
paddingY, py	space

Layout Props

Prop	Theme Key
width	sizes
height	sizes
minWidth	sizes
maxWidth	sizes
minHeight	sizes
maxHeight	sizes

Typography Props

Prop	Theme Key
fontFamily	fonts
fontSize	fontSizes
fontWeight	fontWeights
lineHeight	lineHeights
letterSpacing	letterSpacings
fontStyle	N/A
textAlign	N/A

Color Props

Prop	Theme Key
color	colors
backgroundColor, bg	colors
opacity	N/A

Flexbox Props

Prop	Theme Key
alignItems	N/A
alignContent	N/A
justifyItems	N/A
justifyContent	N/A
flexWrap	N/A
flexDirection	N/A
flex	N/A
flexGrow	N/A
flexShrink	N/A
flexBasis	N/A
justifySelf	N/A
alignSelf	N/A
order	N/A

About

This library is the result of consolidating and porting APIs and ergonomics from RebassJS, Flexbox library, Grid Styled, and Rebass Grid.

MIT License