https://github.com/visualon/cssparser

CSS Parser for .NET
https://github.com/visualon/cssparser

csharp css dotnet

Last synced: 6 months ago
JSON representation

CSS Parser for .NET

• Host: GitHub
• URL: https://github.com/visualon/cssparser
• Owner: visualon
• License: mit
• Created: 2018-12-05T08:38:38.000Z (about 7 years ago)
• Default Branch: main
• Last Pushed: 2025-04-14T23:15:09.000Z (9 months ago)
• Last Synced: 2025-05-08T03:07:35.051Z (8 months ago)
• Topics: csharp, css, dotnet
• Language: C#
• Homepage:
• Size: 672 KB
• Stars: 7
• Watchers: 2
• Forks: 2
• Open Issues: 6
• Metadata Files:
  • Readme: README.md
  • License: LICENSE.txt

Awesome Lists containing this project

README

          
# CSS Parser

[![build](https://github.com/visualon/cssparser/actions/workflows/build.yml/badge.svg)](https://github.com/visualon/cssparser/actions/workflows/build.yml)

[![VisualOn.CSSParser](https://img.shields.io/nuget/v/VisualOn.CSSParser?label=VisualOn.CSSParser)](https://www.nuget.org/packages/VisualOn.CssParser)

[![VisualOn.CSSParser.ExtendedLESSParser](https://img.shields.io/nuget/v/VisualOn.CSSParser.ExtendedLESSParser?label=VisualOn.CSSParser.ExtendedLESSParser)](https://www.nuget.org/packages/VisualOn.CssParser.ExtendedLESSParser)

[![codecov](https://codecov.io/gh/visualon/cssparser/branch/main/graph/badge.svg?token=EEGfq3zpqS)](https://codecov.io/gh/visualon/cssparser)

![LICENSE](https://img.shields.io/github/license/visualon/cssparser)

This is a fork from [Dan Roberts](https://bitbucket.org/DanRoberts/cssparser).

A simple CSS and LESS parser to categorise strings of content and optionally generate a hierarchical representation of it.

## Changes

See [Releases](https://github.com/visualon/cssparser/releases)

## License

[MIT License](LICENSE.txt)

### Howto

This was written to fulfill a need I had to run quickly through a string of CSS and identify what "type" each character was. With an optional ability to parse it into hierarchical data describing nested selectors and/or media queries (most applicable to LESS rather than vanilla CSS since LESS supports nesting of selectors whereas CSS only supports single nesting of a selector within a media query).

    IEnumerable ParseCSS(string content)

and

    IEnumerable ParseLESS(string content)

(within the static class **CSSParser.Parser**) do the basic parsing work where **CategorisedCharacterString** has the properties

    public class CategorisedCharacterString

    {

      /// 

      /// This will never be null or an empty string

      /// 

      public string Value { get; }

      /// 

      /// This is the location of the start of the string in the source data

      /// 

      public int IndexInSource { get; }

      public CharacterCategorisationOptions CharacterCategorisation { get; }

    }

    public enum CharacterCategorisationOptions

    {

      Comment,

      CloseBrace,

      OpenBrace,

      SemiColon,

      SelectorOrStyleProperty,

      StylePropertyColon,

      Value,

      Whitespace

    }

so calling ParseCSS on

    /* Test */ .Content { color: black; }

will return **CategorisedCharacterString** instances with the data

    "/* Test */"     Comment (IndexInSource 0)

    " "              Whitespace (IndexInSource 10)

    ".Content"       SelectorOrStyleProperty (IndexInSource 11)

    " "              Whitespace (IndexInSource 19)

    "{"              OpenBrace (IndexInSource 20)

    " "              Whitespace (IndexInSource 19)

    "color"          SelectorOrStyleProperty (IndexInSource 22)

    ":"              StylePropertyColon (IndexInSource 27)

    " "              Whitespace (IndexInSource 28)

    "black"          Value (IndexInSource 29)

    ";"              SemiColon (IndexInSource 34)

    " "              Whitespace (IndexInSource 35)

    "}"              CloseBrace (IndexInSource 36)

This analysis can be done very cheaply as it is only a very simple representation. It does not, for example, differentiate between the type of the ".Content" value or "color", they are both considered to be of type **SelectorOrStyleProperty**.

To arrange in a hierchical manner and to categorise more strictly, the data return from ParseCSS or ParseLess can be passed into

    IEnumerable ParseIntoStructuredData(

      IEnumerable segments

    )

(within the static class **CSSParser.ExtendedLESSParser.LessCssHierarchicalParser**) which transforms the data again. The interface **ICSSFragment** is implemented by the classes **Import** (describing an import statement for another stylesheet), a **MediaQuery** or a **Selector** (both of which have a "ChildFragments" set as they may contain other media queries, selectors and/or properties), a **StylePropertyName** or **StylePropertyValue**. Note that comments and whitespace are not included in this data.

So content such as

    // Example

    html

    {

      h1

      {

        color: black;

        background: white url("background.jpg") no-repeat top left;

      }

      p.Intro { padding: 8px; }

    }

becomes something like

    html

      h1

        color

          black

        background

          white

          url("background.jpg")

          no-repat

          top

          left

      p.Intro

        padding

          8px

_(Above: "html" represent a Selector instance with a ChildFragments property containing Selector instances for the "h1" and "p", each with ChildFragments data made up of StylePropertyValue and StylePropertyValue instances)._