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Toggle between light and dark mode in Storybook

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Storybook Dark Mode

A Storybook v9-optimized addon that enables users to toggle between dark and light modes. For support with earlier Storybook versions, see the original addon.

The project is supported and maintained by the Vueless UI core team. | See the demo 🌗

Example

Installation

Install the following npm module:

npm i -D @vueless/storybook-dark-mode

Then, add following content to .storybook/main.js

export default {
  addons: ['@vueless/storybook-dark-mode']
};

Configuration

Configure the dark and light mode by adding the following to your .storybook/preview.js file:

import { themes } from 'storybook/theming';

export const parameters = {
  darkMode: {
    // Override the default dark theme
    dark: { ...themes.dark, appBg: 'black' },
    // Override the default light theme
    light: { ...themes.normal, appBg: 'red' }
  }
};

Default Theme

Order of precedence for the initial color scheme:

  1. If the user has previously set a color theme it's used
  2. The value you have configured for current parameter in your storybook
  3. The OS color scheme preference

Once the initial color scheme has been set, subsequent reloads will use this value. To clear the cached color scheme you have to localStorage.clear() in the chrome console.

export const parameters = {
  darkMode: {
    // Set the initial theme
    current: 'light'
  }
};

Dark/Light Class

This plugin will apply a dark and light class name to the manager. This allows you to easily write dark mode aware theme overrides for the storybook UI.

You can override the classNames applied when switching between light and dark mode using the darkClass and lightClass parameters.

export const parameters = {
  darkMode: {
    darkClass: 'lights-out',
    lightClass: 'lights-on'
  }
};

You can also pass an array to apply multiple classes.

export const parameters = {
  darkMode: {
    darkClass: ['lights-out', 'foo'],
    lightClass: ['lights-on', 'bar']
  }
};

Preview class target

This plugin will apply the dark/light class to the <body> element of the preview iframe. This can be configured with the classTarget parameter. The value will be passed to a querySelector() inside the iframe.

This is useful if the <body> is styled according to a parent's class, in that case it can be set to html.

export const parameters = {
  darkMode: {
    classTarget: 'html'
  }
};

Story integration

Preview ClassName

This plugin will apply the darkClass and lightClass classes to the preview iframe if you turn on the stylePreview option.

export const parameters = {
  darkMode: {
    stylePreview: true
  }
};

React

If your components use a custom Theme provider, you can integrate it by using the provided hook.

import { useDarkMode } from '@vueless/storybook-dark-mode';

// your theme provider
import ThemeContext from './theme';

// create a component that uses the dark mode hook
function ThemeWrapper(props) {
  // render your custom theme provider
  return (
    <ThemeContext.Provider value={useDarkMode() ? darkTheme : defaultTheme}>
      {props.children}
    </ThemeContext.Provider>
  );
}

export const decorators = [renderStory => <ThemeWrapper>{renderStory()}</ThemeWrapper>];

Theme Knobs

If you want to have you UI's dark mode separate from you components' dark mode, implement this global decorator:

import { themes } from 'storybook/theming';

// Add a global decorator that will render a dark background when the
// "Color Scheme" knob is set to dark
const knobDecorator = storyFn => {
  // A knob for color scheme added to every story
  const colorScheme = select('Color Scheme', ['light', 'dark'], 'light');

  // Hook your theme provider with some knobs
  return React.createElement(ThemeProvider, {
    // A knob for theme added to every story
    theme: select('Theme', Object.keys(themes), 'default'),
    colorScheme,
    children: [
      React.createElement('style', {
        dangerouslySetInnerHTML: {
          __html: `html { ${
            colorScheme === 'dark' ? 'background-color: rgb(35,35,35);' : ''
          } }`
        }
      }),
      storyFn()
    ]
  });
};

export const decorators = [knobDecorator];

Events

You can also listen for the DARK_MODE event via the addons channel.

Listening for events

You can listen for events on the channel with React hooks:

import { useState, useEffect } from 'react';
import { addons } from 'storybook/preview-api';
import { DARK_MODE_EVENT_NAME } from '@vueless/storybook-dark-mode';

const channel = addons.getChannel()

/**
 * Use this hook if you want to pass in your own callback, e.g. Mantine's `setColorScheme`
 **/
export function useOnDarkModeEvent(callback) {
  useEffect(function () {
    channel.on(DARK_MODE_EVENT_NAME, callback)
    return () => channel.off(DARK_MODE_EVENT_NAME, callback)
  })
}

/**
 * Use this hook if you only need to know whether dark mode is toggled on
 **/
export function useIsDarkMode() {
  const [isDarkMode, setIsDarkMode] = useState()
  useOnDarkModeEvent(setIsDarkMode)
  return isDarkMode
}

You can then use these hooks to theme stories and docs (see below).

Theming stories

You can use the hooks above with your ThemeContext:

import { useIsDarkMode } from './hooks'; // the hook we defined above
// your theme provider
import ThemeContext from './theme';

// create a component that uses the dark mode hook
function ThemeWrapper(props) {
  const isDarkMode = useIsDarkMode();

  // render your custom theme provider
  return (
    <ThemeContext.Provider value={isDarkMode ? darkTheme : defaultTheme}>
      {props.children}
    </ThemeContext.Provider>
  );
}

export const decorators = [
  (renderStory) => <ThemeWrapper>{renderStory()}</ThemeWrapper>,
];

Some UI libraries expose hooks for controlling the theme. E.g., if you are using Mantine, you can use this component:

import { useOnDarkModeEvent } from './hooks'; // the hook we defined above
import { useMantineColorScheme } from '@mantine/core'

/**
 * Custom story wrapper that handles Mantine's dark mode
 **/
function ThemeWrapper({ children }: { children: React.ReactNode }) {
  const { setColorScheme } = useMantineColorScheme()
  const handleColorScheme = useCallback((value) => setColorScheme(value ? 'dark' : 'light'), [setColorScheme])
  useOnDarkModeEvent(handleColorScheme)

  return children
}

export const decorators = [
  (renderStory) => <ThemeWrapper>{renderStory()}</ThemeWrapper>,
];

Theming docs

Docs have a dedicated container component which will not be themed unless you explicitly configure it:

import { useIsDarkMode } from './hooks'; // the hook we defined above

function ThemedDocsContainer(props) {
  const isDarkMode = useIsDarkMode() // the hook we defined above

  return (
    <DocsContainer theme={isDarkMode ? themes.dark : themes.light} context={props.context}>
      {props.children}
    </DocsContainer>
  )
}

export const parameters = {
  docs: {
    container: ThemedDocsContainer,
  },
},

Emit event in docs mode

Since in docs mode, Storybook will not display its toolbar, You can also trigger the UPDATE_DARK_MODE event via the addons channel if you want to control that option in docs mode, By editing your .storybook/preview.js.

import React from 'react';
import { addons } from 'storybook/preview-api';
import { DocsContainer } from '@storybook/addon-docs';
import { themes } from 'storybook/theming';

import {
  DARK_MODE_EVENT_NAME,
  UPDATE_DARK_MODE_EVENT_NAME
} from '@vueless/storybook-dark-mode';

const channel = addons.getChannel();

export const parameters = {
  darkMode: {
    current: 'light',
    dark: { ...themes.dark },
    light: { ...themes.light }
  },
  docs: {
    container: props => {
      const [isDark, setDark] = React.useState();

      const onChangeHandler = () => {
        channel.emit(UPDATE_DARK_MODE_EVENT_NAME);
      };

      React.useEffect(() => {
        channel.on(DARK_MODE_EVENT_NAME, setDark);
        return () => channel.removeListener(DARK_MODE_EVENT_NAME, setDark);
      }, [channel, setDark]);

      return (
        <div>
          <input type="checkbox" onChange={onChangeHandler} />
          <DocsContainer {...props} />
        </div>
      );
    }
  }
};