@nx-kit/styling

The @nx-kit/styling package contains the design system and a few utility functions. It is based on styled-components and reexports all of its functions.

babel-plugin-styled-components is also already included.

Installation

npm install @nx-kit/styling

yarn add @nx-kit/styling

Theme

The design system values and component skin styles are all inside the theme. You are free to choose the keys and values, but for the design system to work, the theme must have a certain format.

Example theme:

const theme = {
  global: {
    styles: css`
      body {
        font-size: ${({ theme }) => theme?.global?.fontSize?.['16']};
        line-height: ${({ theme }) => theme?.global?.lineHeight?.default};
        ${({ theme }) => theme?.global?.font?.trebuchetNormal};
        color: ${({ theme }) => theme?.global?.color?.gray500};
      }
    `,
    color: {
      black: '#000',
      gray500: '#ccc',
    },
    breakpoint: {
      xs: { min: 0, max: 575.98 },
      sm: { min: 576, max: 767.98 },
      md: { min: 768, max: 991.98 },
      lg: { min: 992, max: 1199.98 },
      xl: { min: 1200, max: null },
    },
    spacing: {
      5: '5px',
      10: '10px',
      20: '20px',
      40: '40px',
    },
    font: {
      trebuchetNormal: `
        font-family: 'Trebuchet MS', Helvetica, sans-serif;
        font-weight: normal;
      `,
    },
    fontSize: {
      14: '14px',
      16: '16px',
      18: '18px',
    },
    lineHeight: {
      default: 1.5,
    },
    zIndex: {
      1: 1,
      10: 10,
      50: 50,
      100: 100,
    },
    // ... more global values
  },
  component: {
    button: {
      global: css`
        position: relative;
        display: inline-flex;
      `,
      skin: {
        primary: css`
          color: ${({ theme }) => theme.global.color.black};
        `
      },
    },
    // ... more components
  },
};

As you see the theme consists of global and component values/styles. You can use the global values in the styled components but they are also used for the design system.

Design System

Most of the nx-kit components have a special styles prop. With this prop you are able to set some styles directly on the component. These are not inline styles like the style prop and you can also use the global values from the theme.

Example:

<Button
  onPress={(e: any) => console.log(e)}
  skin="primary"
  styles={{ padding: 40, marginTop: { xs: 20, md: 40 } }}
>
  Press me
</Button>

As you can see, you are also able to use the breakpoints, but only "up" media queries. Because the keys for spacing (20, 40) exists in the theme, the corresponding values are used. Else it would use the value directly for the css.

For consistency it is recommend to also use the global values in the styled components where possible.

Example styled:

import { styled } from '@nx-kit/styling';

const Example = styled.div`
  ${({ theme }) => `
    color: ${theme?.global?.color?.gray500};
    ${theme?.global?.font?.trebuchetNormal};
  `};
`;

In the styles prop only a subset of css is possible because it should be only used for small tweaks. The following table shows what is possible and which global values are used.

styles prop | global theme prop ------------ | ------------- marginTop, marginBottom, marginLeft, marginRight, margin, marginX, marginY, paddingTop, paddingBottom, paddingLeft, paddingRight, padding, paddingX, paddingY, gap | spacing zIndex | zIndex color, backgroundColor | color font | font fontSize | fontSize lineHeight | lineHeight flexGrow, flexShrink, flexBasis, flex, alignSelf, order | - position, top, right, bottom, left | - opacity | - width, height, minWidth, maxWidth, minHeight, maxHeight, display, verticalAlign, overflow, overflowX, overflowY | - letterSpacing, textAlign, fontStyle, textTransform, textDecoration, textOverflow | -

media Helper

@nx-kit/styling exports a media function that can be used for media queries. You can use the breakpoint keys from the theme. First parameter is min (uses the min value from the breakpoint), second optional is max (uses the max value from the breakpoint).

import { styled, media } from '@nx-kit/styling';

const Example = styled.div`
  margin-top: 10px;

  ${media('md')} {
    margin-top: 20px;
  }

  ${media('lg', 'xl')} {
    color: red;
  }
`;

Sorted breakpoints

If you need the breakpoints sorted you can use the useBreakpointsSorted hook. It is a low level functionality and is used by @nx-kit/breakpoint.

import { useBreakpointsSorted } from '@nx-kit/styling';

const Example = () => {
  const sortedBreakpoints = useBreakpointsSorted();

  // returns array like { min: number; max: number | null; breakpoint: string | number }[]
};

reset CSS

@nx-kit/styling also exports a lightweight reset CSS string:

import { resetCSS } from '@nx-kit/styling';