Resin CSS

the resin logo: two bottles labeled CSS and JS

A small css-in-js library works with Deno and Fresh.

The core concept is build a decorated component by writing jsx and css parts and combine(solidify) them. Easy and clean inline code helps making a well-styled apps.

Usage

import

import {
  css,
  ResinCssEmitter,
  solidify,
} from "https://deno.land/x/resin/mod.ts";

Just import the code from your Deno+Fresh app. No configurations required.

Styling a component

Here is a basic function component using Resin CSS.

function HelloComponent() {
  return solidify(
    <div>
      <span class="sun">🔆</span>
      Hello World
    </div>,
    css`
      color: blue;
      font-size: 80px;
      font-weight: bold;
      > .sun {
        font-size: 90px;
      }
    `,
  );
}

css() and solidify() are core API used for applying scoped css to the resulting vdom of a function component. css() takes a string literal. The syntax of css text is basically compatible to SCSS. Multi-stage nesting is supported.

solidify() internally creates a unique class name for the css and add the class prop to the vdom. It also creates a converted css texts prefixed with the class selector. The css definitions are collected and they are awaiting for the emission.

Embed collected CSS to the page

export default function HelloPage() {
  return (
    <>
      <Head>
        <title>Fresh App</title>
        <ResinCssEmitter />
      </Head>
      <HelloComponent />
    </>
  );
}

Here is a page component for a route. <ResinCssEmitter /> embeds the collected css definitions into <head> tag. A single <style> tag is created and all css are settled in this tag.

Global Style

If you want to write a global css, refer the code below.

const globalCss = css`
  * {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
  }
`;

export default function HelloPage() {
  return (
    <>
      <Head>
        <title>Fresh App</title>
        <ResinCssEmitter />
        <ResinCssGlobalStyle css={globalCss} />
      </Head>
      <HelloComponent />
    </>
  );
}

<ResinCssGlobalStyle /> embeds given css definition to the page without prefix. So the definition is regarded as global-scoped.

createFC API

There is a component wrapper function createFC. It wraps a function component and provide class prop to the caller. It's convenient when customizing the style of child elements in the parent context.

//create wrapped component, it accepts additional class prop
const AnimalSprite = createFC<{ iconText: string }>((props) => {
  return solidify(
    <div>{props.iconText}</div>,
    css`
      font-size: 200px;
    `,
  );
});

function ZooComponent() {
  //apply customized style to children in parent component
  return solidify(
    <div>
      <AnimalSprite iconText="🐈" class="cat" />
      <AnimalSprite iconText="🐇" class="rabbit" />
    </div>,
    css`
      position: relative;
      > * {
        position: absolute;
      }
      > .cat {
        left: 10px;
        top: 40px;
        transform: scaleX(-1);
      }
      > .rabbit {
        right: 10px;
        top: 10px;
      }
    `,
  );
}

Style compotion

A style definition can be embed into another by string interpolatiton.

const base = css`
    color: red;
    font-size: 20px;
  `;

const extended = css`
    ${base};
    background: blue;
  `;

License

MIT License