How to parse a CSS file with ExCSS in .NET Core?

Use the StylesheetParser class to read CSS text from a file; parse it into a queryable object model. For example, load the file content as a string and pass it to the parser for easy access to rules and properties.

ExCSS vs CSSAgilityPack for parsing CSS in .NET?

ExCSS focuses on CSS 3 compliance and LINQ integration, making it better for standards-based analysis, while CSSAgilityPack is more general-purpose for HTML/CSS but may lack ExCSS's specific parsing precision.

Does ExCSS support modern CSS features like Grid or Flexbox?

ExCSS handles CSS 3 selectors and rules via its grammar; it parses properties like Grid or Flexbox as standard CSS if they fit the syntax, but check the object model for specific property support as CSS evolves.

How to extract all class names from CSS using ExCSS?

Query the parsed stylesheet's StyleRules collection with LINQ to access SelectorText properties, filtering for class selectors (e.g., .className) to extract them programmatically.

ExCSS performance with large stylesheets?

The parsing engine is efficient, but large CSS files increase memory usage due to the full object model; performance is generally good for web-scale stylesheets, but test with your specific workload.

Can ExCSS modify and save CSS back to a file?

ExCSS parses CSS into a modifiable object model, but saving requires serializing the object back to CSS text, which isn't built-in and may need custom implementation for reliable output.

Open-Awesome

ExCSS

MITC#v4.3.1

A CSS 2.1 and CSS 3 parser for .NET that provides a LINQ-friendly object model for reading and manipulating stylesheets.

GitHub

377 stars128 forks0 contributors

What is ExCSS?

ExCSS is a CSS parser for .NET that reads and parses CSS 2.1 and CSS 3 stylesheets into a friendly, queryable object model. It solves the problem of programmatically accessing and manipulating CSS within .NET applications by providing a LINQ-compatible interface to stylesheet data.

Target Audience

.NET developers who need to programmatically read, analyze, or modify CSS stylesheets in their applications, such as those building web tools, design systems, or CSS preprocessors.

Value Proposition

Developers choose ExCSS for its robust CSS 3 compatibility, LINQ-friendly object model, and modern .NET framework support, making it a reliable and efficient solution for CSS parsing in .NET environments.

Overview

A CSS Parser for .NET. It's BADA55!

Use Cases

Best For

Parsing and analyzing CSS stylesheets programmatically in .NET applications
Building tools that manipulate or transform CSS within .NET projects
Integrating CSS processing into .NET-based web development workflows
Creating custom CSS preprocessors or post-processors in .NET
Testing CSS compliance or extracting stylesheet data in .NET
Developing design systems or style guide tools that require CSS introspection

Not Ideal For

Projects requiring CSS generation or minification from scratch, as ExCSS focuses on parsing and querying, not creating or optimizing CSS.
Applications that need real-time browser CSS rendering or integrated styling frameworks, since it's a .NET parser without browser context.
Teams looking for an all-in-one CSS-in-JS solution in .NET, as ExCSS is limited to parsing and lacks styling runtime features.
Simple tasks where only basic CSS reading is needed without deep manipulation, as the full object model adds unnecessary complexity.

Pros & Cons

Pros

CSS 3 Compliance

Passes all CSS Level 3 selector tests based on W3C specifications, ensuring accurate and standards-compliant parsing for modern stylesheets.

LINQ Query Support

Provides a fully queryable .NET object model using LINQ to Objects, enabling easy data extraction and manipulation without custom loops.

Future-Proof .NET Support

Targets .NET Core 3.1, .NET 4.8, and upcoming unified .NET versions, ensuring long-term compatibility with modern and future frameworks.

Robust Parsing Engine

Uses a CSS3-specific grammar with improved white space handling and support for unknown rules, adapting to evolving CSS without breaking.

Cons

No CSS Generation

Lacks built-in features for generating or minifying CSS from scratch, limiting its use for CSS authoring tools without additional libraries.

Niche Use Dependency

Best suited for parsing and analysis; for broader CSS workflows like preprocessing or transformations, custom code or other tools are required.

Overhead for Simple Use

The full object model and LINQ integration may add complexity for applications that only need to read CSS without deep querying or manipulation.

Frequently Asked Questions

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