CSSObject.js

A Parser CSS in Javascript Vanilla

Summary

• Overview
  • Usage
  • Supports
• Structure
  • Project Structure
  • CSSObject Structure
• Be a Contributor!

Overview

This project was started from the idea of reading CSS files, to implement an alternative functionality, which I call Pseudo-Event for dynamic styling of elements from CSS. Initially, it was just a gists, but as the code developed, the project expanded.

Usage

Simple Usage

The fast way is using UNPKG link:

<script src="https://unpkg.com/cssobjectjs@latest/cssobject.js"></script>

sample code:

// normal
const cssobj = new CSSObject()

// get local stylesheets
cssobj.local(style => {
    // parsed local style!
    console.log(style)
})

// get external stylesheets
cssobj.external(style => {
    // parsed external style!
    console.log(style)
})

// static stylesheet
cssobj.static(".blob { background-color: #d7d7d7; }", style => {
  // parsed static style
  console.log(style)
})

or use alias CSSObj to CSSObject instance:

// using alias
CSSObj.options({load_min: false})
  .local(style => console.log(style))
  .external(style => console.log(style))
  .static(".blob { background-color: #d7d7d7; }", style => console.log(style))

Full Usage Mode

In your html, use type="module" in <script> tag:

<script src="./main.js" type="module"></script>

In main.js you can use CSSObject to get local stylesheets, styles inside <style> tag in your HTML, or external stylesheets (link), see:

import CSSObject from "CSSObject/CSSObject.js"


// instace CSSObject
let cssobj = new CSSObject()

// get local stylesheets
cssobj.local(style => {
  // parsed local style!
  console.log(style)
})

// get external stylesheets
cssobj.external(style => {
  // parsed external style!
  console.log(style)
})

the external method use a callback in promise, so it has a short call delay...

You can use the method .options(), to filter external stylesheets

cssobj.options({
  load_min: false, // '.min.css' (default is `true`)
  ignore_files: [], // ignored if `only_files` not empty
  only_files: []
}).external(style => {
  console.log(style)
})

the options object can also be passed in CSSObject constructor, and haven't effect for local stylesheets

Supports

See on table, what statments and others things this parser supports:

CSS At-Rules

Statment	Example	Supports
Charset	@charset <type>	✅
Namespace	@namespace <prefix?> <URL>	❌
Import	@import <URL> <where?>	✅
Font Face	@font-face { <rules> }	✅
Keyframes	@keyframes <name> { <blocks> }	✅
Media Query	@media <query> { <blocks> }	✅
Support	@supports <where> { <blocks> }	❌
Font Feature	@font-feature-values <family-name> { <blocks> }	❌
Counter Style	@counter-style <name> { <rules> }	❌
Page	@page <where> { <rules> }	❌

see about this statments and others at-rules here

Others

Data URI	data:[<media-type>];[base64],<data>	✅
Comment	/*<text>*/	✅

Structure

Now, understand how the CSSObject, object class, and file and folder segments are structured

Project Structure

First, I need to show the organization of the project

CSSObject:
  enums: # auxiliary files as interfaces
    ICombiner.js
    ICSS.js
    ICSSStatments.js
    IMedia.js
    ISelector.js
    IPseudo.js
    IUnit.js
  parser: # files responsible for data processing
    BlocksParser.js
    CommentBlock.js
    ParserBlock.js
    StatmentsParser.js
    Stylesheet.js
  queries: # classes thats work of queries part
    Selector.js
    Pseudo.js
  rules: # classes thats work of rules statments
    BlockRule.js
    CharsetRule.js
    FontfaceRule.js
    FunctionRule.js
    ImportRule.js
    KeyframeRule.js
    MediaRule.js
    QuerieRule.js
    Rule.js
    VariableRule.js
  CSSObject.js
  CSSParser.js
example.css # example css code
index.html
main.js # usage of `CSSObject.js`

CSSObject Structure

See below, the objects and their properties that are returned

• CSSObject
• Stylesheet
  • BlockRule
  • CommentBlock
• Rule
  • VariableRule
  • FunctionRule
  • CharsetRule
  • ImportRule
  • FontFaceRule
  • KeyframeRule
  • MediaRule
  • QuerieRule
• Selector
  • Pseudo

CSSObject

CSSObject:
  options(options: object)
  static(text: string, callback: function)
  local(callback: function, all: boolean?)
  external(callback: function) # callback in promise

callbacks functions return Stylesheet object

Stylesheet

Stylesheet:
  cssText: string # contains break-lines and spaces
  css: string # clean string (without break-lines and spaces)
  comments: CommentBlock[]
  blocks: BlockRule[]
  variables: VariableRule[]
  filename: string | null
  statments: {
    charsets: CharsetRule[],
    imports: ImportRule[],
    fontfaces: FontfaceRule[],
    keyframes: KeyframeRule[],
    medias: MediaRule[],
  }

Block Rule

BlockRule:
  query: string
  selectors: Selector[]
  rules: Rule[]

Comment Block

CommentBlock:
  text: string
  comment: string # like `text` property (without break-lines and spaces)
  line: number | number[]

Rule

Rule:
  property: string
  value: string | string[] | FunctionRule
  values: object[] # ex.: "10px" => [{value: 10, unit: "PIXELS"}]
  prop: string # alias to `property`
  isImportant: boolean

Variable Rule

VariableRule:
  name: string
  value: string | string[] | FunctionRule
  scope: string
  statment: string

Function Rule

FunctionRule:
  name: string
  value: string | string[] # may contains FunctionRule object

Charset Rule

CharsetRule:
  type: string

Import Rule

ImportRule:
  url: string
  where: string[] # may contains Rule object

Font Face Rule

FontFaceRule:
  name: string # `font-family` value
  rules: Rule[]

Keyframe Rule

KeyframeRule:
  name: string
  blocks: BlockRule[]

Media Query Rule

MediaRule:
  query: string
  queries: QuerieRule[]
  blocks: BlockRule[]

Querie Rule

QuerieRule:
  rules: Rule[]
  types: string[]
  only: boolean
  not: boolean

Selector

Selector:
  name: string
  type: 'UniversalSelector' | 'IDSelector' | 'ClassSelector' | 'AttrSelector' | 'PseudoSelector' | 'HTMLSelector'
  hasCombiner: boolean
  pseudo?: Pseudo # has if `hasCombiner` is `false`
  selectors?: Selector[] # has if `hasCombiner` is `true`

Pseudo

Selector:
  name: string
  type: 'PseudoClass' | 'PseudoElement' | 'PseudoEvent'
  value?: string # has if pseudo contains parameters

the type PseudoEvent is a custom support of CSSObject not has on CSS language

Be a Contributor

• This project was plan, writted and develop by Kugi Haito 🍪
• Did you like my project? give star or fork to help, thanks 😁
• would you like to be a contributor? make me a Pull Request!