jss-plugin-compose.md

Enables classes composition

This plugin allows you to use CSS frameworks and legacy code together with JSS as well as reuse Rules more granularly.

Compose with global classes.

To combine JSS with CSS framework like Material Design Lite or Bootstrap and others.

const styles = {
  button: {
    // Using space separated class names.
    composes: 'btn btn-primary',
    color: 'red'
  },
  buttonActive: {
    // Using an array of class names.
    composes: ['btn', 'btn-primary'],
    color: 'blue'
  }
}

Compiles to:

.button-123456 {
  color: red;
}
.buttonActive-123456 {
  color: blue;
}

When you use it:

import React from 'react'

const classes = {
  button: 'button-123456 btn',
  buttonActive: 'buttonActive-123456 btn btn-primary'
}

const button1 = <button className={classes.button}>Button</button>
const button2 = <button className={classes.buttonActive}>Active Button</button>

It renders to:

<button class="button-123456 btn">Button</button>
<button class="buttonActive-123456 btn btn-primary">Active Button</button>

Compose with local classes.

Manage element states without rules duplication. To reference a local rule, prefix the rule name with the $ symbol.

const styles = {
  button: {
    color: 'black'
  },

  // You can chain compositions
  buttonActive: {
    composes: '$button',
    color: 'red'
  },
  buttonActiveDisabled: {
    composes: '$buttonActive',
    opacity: 0.5
  },

  // Or use arrays
  disabled: {
    opacity: 0.5
  },
  active: {
    color: 'red'
  },
  buttonDisabled: {
    composes: ['$button', '$active', '$disabled']
  }
}

Compiles to:

.button-123456 {
  color: black;
}
.buttonActive-123456 {
  color: red;
}
.buttonActiveDisabled-123456 {
  opacity: 0.5;
}
.disabled-123456 {
  opacity: 0.5;
}
.active-123456 {
  color: red;
}
/* Rule `buttonDisabled` is not compiled to CSS, because it has no own properties. */

When you use it:

import React from 'react'

const classes = {
  buttonActiveDisabled: 'buttonActiveDisabled-123456 buttonActive-123456 button-123456',
  buttonDisabled: 'buttonDisabled-123456 button-123456 active-123456 disabled-123456'
}

const button1 = <button className={classes.buttonActiveDisabled}>Active Disabled Button</button>
const button2 = (
  <button className={classes.buttonDisabled}>Disabled Button with active state</button>
)

It renders to:

<button class="buttonActiveDisabled-123456 buttonActive-123456 button-123456">Active Disabled Button</button>
<button class="buttonDisabled-123456 button-123456 active-123456 disabled-123456">Disabled Button with active state</button>

Mix global and local classes.

You can compose both local and global classes at the same time.

const styles = {
  active: {
    color: 'red'
  },
  button: {
    composes: ['$active', 'btn', 'btn-primary'],
    color: 'blue'
  }
}

Compiles to:

.active-123456 {
  color: red;
}
.button-123456 {
  color: blue;
}

When you use it:

import React from 'react'

const classes = {button: 'button-123456 active-123456 btn btn-primary'}

const button = <button className={classes.button}>Button</button>

It renders to:

<button class="button-123456 active-123456 btn btn-primary">Button</button>

Caveats

• It doesn't work within global Style Sheets.
• It does not work inside of nested rules.
• When composing local rules, they need to be defined first. Otherwise, you get wrong CSS selector order and specificity.

Demo

CodeSandbox