React integration of JSS

There is a number of benefits when using react-jss instead of JSS directly:

Lazy evaluation - sheet is created only when component will mount.
Auto attach/detach - sheet will be rendered to the dom when component is about to mount and will be removed when no element needs it.
A sheet gets shared between all elements.
You want to use it with React Hot Loader.

Also you may need this module if you build a big application where leaving all styles in the DOM or compiling all styles at once may have a performance overhead or you are going to hit IE limits.

Usage

You can use it as a higher-order component to inject JSS. It can act both as a simple wrapping function and as a ES7 decorator.

React JSS wraps your React component and injects props.classes and props.sheet, which is a regular JSS StyleSheet, as props into your component. This is a common pattern that is used for composition in React instead of mixins, and works equally well with old-style createClass classes, as well as the ES6 classes.

Because JSS class names are namespaced by default, you will need to reach into this.props.classes to get their real names. For example, if you define a button class in your JSS stylesheet, its real name will be available as props.classes.button.

By default react-jss comes with jss and presets.

import React from 'react'
import injectSheet from 'react-jss'

const styles = {
  button: {
    background: props => props.color
  },
  label: {
    fontWeight: 'bold'
  }
}

const Button = ({classes, children}) => (
  <button className={classes.button}>
    <span className={classes.label}>
      {children}
    </span>
  </button>
)

export default injectSheet(styles)(Button)

Custom setup.

If you want to specify a jss version and plugins to use, you should create your own jss instance, setup plugins and create a injectSheet function which has your jss version bound.

import {create as createJss} from 'jss'
import {create as createInjectSheet} from 'react-jss'
import vendorPrefixer from 'jss-vendor-prefixer'

const jss = createJss()
jss.use(vendorPrefixer())

export const injectSheet = createInjectSheet(jss)

You can also access the Jss instance being used by default.

import {jss} from 'react-jss'

Using decorators.

You can use ES7 with decorators (using babel-plugin-transform-decorators-legacy).

import React, {Component} from 'react'
import injectSheet from 'react-jss'

const styles = {
  button: {
    backgroundColor: 'yellow'
  },
  label: {
    fontWeight: 'bold'
  }
}

@injectSheet(styles)
export default class Button extends Component {
  render() {
    const {classes, children} = this.props
    return (
      <button className={classes.button}>
        <span className={classes.label}>
          {children}
        </span>
      </button>
    )
  }
}

Reuse same StyleSheet in different Components.

Sometimes you may need to reuse the same StyleSheet in different components, without generating new styles for each. You can pass StyleSheet instance to the injectSheet? function instead of styles object.

import React, {Component} from 'react'
import injectSheet from 'react-jss'
import jss from 'jss'

const sheet = jss.createStyleSheet({
  button: {
    color: 'red'
  }
})

@injectSheet(sheet)
class Button extends Component {
  render() {
    const {classes} = this.props
    return <button className={classes.button}></button>
  }
}

Using classNames helper.

You can use classNames together with JSS same way you do it with global CSS.

import classNames from 'classnames'

const Component = ({classes, children, isActive}) => (
  <div
    className={classNames({
      [classes.normal]: true,
      [classes.active]: isActive
    })}>
    {children}
  </div>
)

Using `SheetsRegistryProvider` for server-side rendering

import {renderToString} from 'react-dom/server'
import {SheetsRegistryProvider, SheetsRegistry} from 'react-jss'
import MyApp from './MyApp'

export default function render(req, res) {
  const sheets = new SheetsRegistry()

  const body = renderToString(
    <SheetsRegistryProvider registry={sheets}>
      <MyApp />
    </SheetsRegistryProvider>
  )

  // any instances of `injectStyle` within `<MyApp />` will have gotten `sheets`
  // from `context` and added their style sheets to it by now.

  return res.send(renderToString(
    <html>
      <head>
        <style type="text/css">
          {sheets.toString()}
        </style>
      </head>
      <body>
        {body}
      </body>
    </html>
  ))
}

Accessing the inner component

const InnerComponent = () => null
const StyledComponent = injectSheet(styles, InnerComponent)
console.log(StyledComponent.InnerComponent) // Prints out the inner component.

Installation.

npm install --save react-jss

Contributing

See our contribution guidelines.

License

MIT

SerjoPepper/react-jss