styled-transform-proxy

A wrapper function for extending styled-components via a custom transform function. The wrapper function is curried and takes two arguments - the transform function and the original styled function from styled-components. The transform receives the original strings & interpolations and is expected to return an array containing the strings and interpolations with any transformations applied.

Install

# Yarn
yarn add styled-transform-proxy

# npm
npm install --save styled-transform-proxy

Type Definitions

transform :: (Array<String> strings, ...* interpolations) -> [strings, ...interpolations]

styledTransformProxy :: transform -> styled -> styled

Examples

Transform strings

// src/styled.js
import styled from 'styled-components';
import styledTransformProxy from 'styled-transform-proxy';
import { map, replace } from 'ramda';

const transformStrings = map(replace(/\.foo\s/g, '.bar '));

const transform = (strings, ...interpolations) => [
  transformStrings([...strings]),
  ...interpolations
];

export default styledTransformProxy(transform, styled);

// src/components/MyComponent.js
import styled from '../styled';

// Results in `.foo` below being transformed to `.bar`
const MyComponent = styled.span`
  .foo {
    color: red;
  }
`;

Transform interpolations

// src/styled.js
import styled from 'styled-components';
import styledTransformProxy from 'styled-transform-proxy';
import { map, path, when, is } from 'ramda';

const transformInterpolations = map(when(is(Array), path));

const transform = (strings, ...interpolations) => [
  strings,
  ...transformInterpolations(interpolations),
];

export default styledTransformProxy(transform, styled);

// src/components/MyComponent.js
import styled from '../styled';

const MyComponent = styled.span`
  color: ${['colors', 'foreground']};
  background-color: ${['colors', 'background']}
`;

// The above is equivalent to:
const MyComponent = styled.span`
  color: ${(props) => props.colors.foreground};
  background-color: ${(props) => props.colors.background};
`;

Composing transforms

The wrapper function being curried means that composing multiple transformations together is simple:

// src/styled.js
import styled from 'styled-components';
import styledTransformProxy from 'styled-transform-proxy';
import { compose } from 'ramda';

const transformFoo = (strings, ...interpolations) => [...];
const transformBar = (strings, ...interpolations) => [...];

const applyTransforms = compose(
  styledTransformProxy(transformFoo),
  styledTransformProxy(transformBar),
);

export default applyTransforms(styled);

Third-party libraries

If you're creating a third-party package that utilizes styled-transform-proxy you can simplify things a bit compared to the above examples. In addition to the wrapper function being curried, it takes the original styled function as its last argument, meaning instead of this:

export default (styled) => styledTransformProxy(transform, styled);

...you can simply do this:

export default styledTransformProxy(transform);

Caveats

Currently there is no straightforward way to tap into the extend method on a styled component, so the transform function will not be applied when using extend. So instead of this:

const ChildComponent = ParentComponent.extend`...`;

...you'll need to do this:

const ChildComponent = styled(ParentComponent)`...`;