npm i themed-jss

Features:

• Theme-based styling based on JSS
• Integrates with callbag-jsx and react
• Can be used with other frameworks or without any frameworks
• Automatic dark mode support
• Type safe

👉 Read the Docs

Usage

Create your styles based on a theme:

// styles.ts

import { style, when } from 'themed-jss'

export const btnStyle = style(theme => ({
  background: theme.primaryColor,
  color: theme.backgroundColor,

  borderRadius: 3,
  cursor: 'pointer',
  border: '2px solid transparent',
  padding: 8,
  fontSize: 14,

  [when(':hover')]: {
    background: 'transparent',
    color: theme.primaryColor,
    border: `2px solid ${theme.primaryColor}`
  }
}))

Then use a theme object to add your styles to the document:

import { theme } from 'themed-jss'
import { btnStyle } from './styles'

const btn = document.getElementById('btn')

const myTheme = theme({
  primaryColor: '#00917c',
  backgroundColor: 'white',
  textColor: '#424242',
})

btn.classList.add(myTheme.class(btnStyle))

►Playground

👉 Global styles:

import { global } from 'themed-jss'

myTheme.add(global(theme => ({
  body: {
    display: 'flex',
    alignItems: 'center',
    justifyContent: 'center',
    width: '100vw',
    height: '100vh',
    padding: 0,
    margin: 0,
    background: theme.backgroundColor,
  }
})))

►Playground

Dark Mode

Add some overrides to your theme for dark mode, themed-jss takes care of the rest automatically:

const myTheme = theme(
  {
    primaryColor: '#00917c',
    backgroundColor: '#fde8cd',
    textColor: '#424242',
  },
  // --> overrides for dark mode:
  {
    backgroundColor: '#0f3057',
    textColor: 'white',
  }
)

►Playground

👉 Dark mode by default is read from system settings. You can also assume manual control:

import { DarkMode } from 'themed-jss/dark-mode'

DarkMode.initialize()

// ...

btn.addEventListener('click', () => DarkMode.toggle())

►Playground

☝️ When you manually override dark mode settings, the preference is automatically stored in local storage and loaded on next page load (thats what DarkMode.initialize() does basically).

👉 themed-jss automatically injects additional CSS rules for properties that would change in dark mode. However, sometimes it is necessary to enforce some CSS properties to appear in these dark-mode rules despite them not changing between dark and light mode, for example as it would be superceded by some other rule otherwise. You can enforce CSS properties to be repeated in dark-mode rules by adding a !darkmode at the end of your property value:

const btnStyle = style(theme => ({
  // ...
  [when(':hover')]: {
    background: 'transparent !darkmode',
    color: `${theme.primaryColor} !darkmode`,
    border: `2px solid ${theme.primaryColor}`
  }
}))

👉 Read the Docs

Callbag JSX

👉 Use themePlug() to plug themes into callbag-jsx renderers:

import { makeRenderer } from 'callbag-jsx'
import { themePlug } from 'themed-jss/jsx'

const myTheme = theme({ ... })
const renderer = makeRenderer().plug(themePlug(myTheme))

Now components can use this.theme for accessing the theme:

import { style } from 'themed-jss'
import { DarkMode } from 'themed-jss/dark-mode'


const BtnStyle = style(theme => ({ ... }))

export function MyBtn(_, renderer) {
  const cls = this.theme.class(BtnStyle)

  return (
    <button class={cls} onclick={() => DarkMode.toggle()}>
      Toggle Dark Mode
    </button>
  )
}

►Playground

👉 themePlug() returns a ComponentProcessor, so it can be used to plug themes into any render-jsx based renderers.

👉 Read the Docs

React

👉 Use <Themed/> component and useThemedStyle() hook for utilizing themed styles in your components:

// my-btn.jsx
import { useThemedStyle } from 'themed-jss/react'

const BtnStyle = style(theme => ({ ... }))

export function MyBtn() {
  const cls = useThemedStyle(BtnStyle)

  return (
    <button className={cls} onClick={() => DarkMode.toggle()}>
      Switch Dark Mode
    </button>
  )
}

// app.jsx

import { theme } from 'themed-jss'
import { DarkMode } from 'themed-jss/dark-mode'
import { Themed } from 'themed-jss/react'

DarkMode.initialize()

const myTheme = theme({ ... })

export default function App() {
  return (
    <Themed theme={myTheme}>
      <MyBtn/>
    </Themed>
  )
}

►Playground

👉 Read the Docs

Type Safety

👉 You can specify the theme object type that a style() would accept:

const myStyle = style<MyThemeType>(theme => ({
  // ...
}))

👉 You can specify the theme object type that a theme() object should produce:

const myTheme = theme<MyThemeType>({
  ...
})

👉 You can specify the this argument for callbag-jsx (in general render-jsx) components:

import { ThemedComponentThis } from 'themed-jss/jsx'

// ...

function MyBtn(this: ThemedComponentThis, ...) {
   // ...
}

👉 You can even specify the theme type that a particular component will be expecting:

import { ThemedComponentThis } from 'themed-jss/jsx'

// ...

function MyBtn(this: ThemedComponentThis<MyThemeType>, ...) {
   // ...
}

Contribution

Be nice to each other. Here are some useful commands for development:

git clone https://github.com/loreanvictor/themed-jss.git

npm i                    # --> installs dependencies

npm start                # --> servers `samples/index.tsx` on `localhost:3000`

npm test                 # --> runs tests

npm run cov:view         # --> view coverage

npm i -g @codedoc/cli    # --> install CODEDOC cli (for working on docs)

codedoc install          # --> install CODEDOC dependencies (for working on docs)

codedoc serve            # --> serve docs on `localhost:3000/themed-jss` (from `docs/md/`)