Integratedstyle NPM

IntegratedStyle

After integrating HTML into JavaScript by React.js, a logical next step is to do the same for CSS.

Build with help of the awesome recast library.

Example

var React           = require('react/addons')
var IntegratedStyle = require('integratedstyle')
var vars            = require('./vars')

var Button = React.createClass({

  normalStyle: IntegratedStyle(function() {
    return {
      backgroundColor: vars.orange
    }
  }),

  activeStyle: IntegratedStyle(function() {
    if (this.state.active) {
      return {
        color: 'yellow',
        padding: '10px'
      }
    }
  }),

  getInitialState: function() {
    return {
      active: false
    }
  },

  render: function() {
    var styles = [
      this.normalStyle(),
      this.activeStyle()
    ]
    return (
      <div styles={styles} onClick={this.onClick}>
        Hello, I'm styled
      </div>
    )
  },

  onClick: function() {
    this.setState({active: !this.state.active})
  }

})

Turns into the following CSS:

.a {
  background-color: 'orange';
}

while the JavaScript code itself gets transformed into:

var React           = require('react/addons')
var IntegratedStyle = require('integratedstyle')
var vars            = require('./vars')

var Button = React.createClass({

  normalStyle: function() {
    return " a"
  },

  activeStyle: IntegratedStyle(function() {
    if (this.state.active) {
      return {
        color: 'yellow',
        padding: '10px'
      }
    }
  }),

  getInitialState: function() {
    return {
      active: false
    }
  },

  render: function() {
    var styles = [
      this.normalStyle(),
      this.activeStyle()
    ]
    return (
      <div styles={styles} onClick={this.onClick}>
        Hello, I'm styled
      </div>
    )
  },

  onClick: function() {
    this.setState({active: !this.state.active})
  }

})

Note how normalStyle style declaration is extracted into CSS class.

Motivation

CSS is problematic to maintain and components give all the borders you actually need.

What does it actually do?

At runtime:

It adds style declaration to React components. Style declarations are regular methods which are decorated with IntegratedStyle decorator and return regular style rules.
It adds styles prop to all React.DOM components which allows to add styles to a component from a style declaration.

At code transformation:

It finds all component methods wrapped into IntegratedStyle() decorator.
It checks if such methods have references to this.
2.1. If method has no reference to this it is executed and result is used to generated CSS class with a corresponding ruleset.
2.2. If method has reference to this it is left as is, as it will be used to generate inline styles.