css-var-theme

A small, dependency-free utility to enable efficient theming with css variables.

Repo / Demo / npm

Installation

npm i css-var-theme

Usage

A theme is basically a JS object implementing the Theme interface:

export interface Theme {
  meta?: object
  theme: object
}

It contains optional meta information (like a name) and the actual theme which can be any JS object.

Once a theme is defined the css-var-theme utility can be initialized with it:

import { useTheme } from 'css-var-theme'

const my_theme = {
  meta: {
    name: 'my theme',
  },
  theme: {
    color: {
      background: '#eee',
      text: '#333',
    },
  },
}

const theme_store = useTheme({ initial: my_theme })

During initialization a <style>-Tag is added to the head which will map this theme to the following css-variables:

:root {
  --color-background: #eee;
  --color-text: #333;
}

with theme_store.set(new_theme) the current theme can be changed and theme_store.subscribe(() => ...) you can subscribe to updates on the theme.

API

The useTheme function consumes an object implementing the ThemingOptions interface: