sheetjs

SheetJS

Easily create and manipulate CSSStyleDeclarations with javascript:

import { StyleSheet } from 'sheetjs';
const styleSheet = new StyleSheet();
const s = styleSheet.stylesForSelector;

// changes background color for all current and future matching elements
s('#content .my-selector').backgroundColor = 'green';

Good for when you have a dynamic number of elements that need dynamic styling.

jQuery .css() vs SheetJS

Imagine a web page with 1000 elements with class my-el, and you want to change their background-color to green.

Using jQuery:

// changes background color for all current matching elements
$('.my-el').css('background-color', 'green');
// took ~10ms
// new elements will not be green

Using SheetJS:

// changes background color for all current and future matching elements
s('.my-el').backgroundColor = 'green';
// took <1ms
// new elements will be green

Demo

http://codepen.io/jshanson7/pen/ojpbdm?editors=001

Installation

npm install sheetjs

Then reference either dist/sheet.js or dist/sheet.min.js in your html, or import 'sheetjs'. If a module environment is not detected, sheetjs will be exported to window.sheetjs.

Advanced Usage

import StyleSheet from 'sheetjs/StyleSheet';

const styleSheet = new StyleSheet({
  'html, body': {
    margin: 0,
    padding: 0
  },
  '.my-el': {
    backgroundColor: 'green'
  },
  '.my-el:hover': {
    backgroundColor: 'blue'
  }
});

API

import StyleSheet from 'sheetjs/StyleSheet';

const styleSheet = new StyleSheet();
const s = styleSheet.stylesForSelector;

// stylesForSelector - get CSSStyleDeclaration for selector (or create if it doesn't exist)
const styleDeclaration = styleSheet.stylesForSelector('.my-el');
styleDeclaration.backgroundColor = 'green';

// deleteStylesForSelector - delete CSSStyleDeclaration for selector
styleSheet.deleteStylesForSelector('.my-el'); // 'backgroundColor' is no longer green

// getStylesForSelector - get existing CSSStyleDeclaration for selector
const styleDeclaration2 = styleSheet.getStylesForSelector('.doesnt-exist');
styleDeclaration2 === undefined; // true

// disable - disables the stylesheet (and all generated styles)
styleSheet.disable();

// enable - enables the stylesheet (and all generated styles)
styleSheet.enable();

Contributing

Clone repo, cd into it.

npm install && npm start

Building

npm run build

Testing

Run the tests on your browser here.

npm test && npm run test-browser

License

MIT