CSSParser++

A C++ CSS Parser

This is a fork of luojilab´s DDCSSParser.
Full credits goes to luojilab for writing the CSS Parser and Gumbo code.

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CSSParser++ is a C++ CSS parser and selector, that can read full CSS stylesheets or standalone CSS strings and match the rules with a custom node tree provided by the implementing library/application.

Please check the CustomNodeExample project for a full example.

Changes from DDCSSParser

• Project has been converted to a Visual Studio solution
• Code has been split into 3 Visual Studio projects
  • A CSSParser library - this outputs a lib file that can be used by implementing libraries/applications
  • A CustomNodeExample console application - Example that showcases how to provide a custom node class to the CSSParser and retrieve the matching style rules for each node
  • A GumboExample console application - the original example from DDCSSParser
• The CSSParser library is no longer dependent on Gumbo
• A new API based on the INodeSelector interface has been added, allowing implementing libraries/applications to provide their own custom node tree to the node-selector resolvers.
• Various minor changes and fixes

Installation

Using the Code

• Clone the source code into a working directory git clone https://github.com/Xanashi/CSSParser.git
• Open the Visual Studio solution
• Build the CSSParser library (in Release mode)
• Link the compiled cssparser.lib in your project, and add the "CssParser\include" directory to your include path.

Running the example Apps

• Open the Visual Studio solution
• Build All
• Run either the CustomNodeExample or the GumboExample

Features

• Parse CSS files or strings
• Easily iterate through the CSS selectors and rules
• CSS rules is provided as raw string or std::map key/value pairs
• Use INodeSelector interface to match a custom node tree automatically with the CSS selectors.

Supported CSS Selectors:

• Simple Selector:
  • Type Selector
  • Universal Selector
  • Attribute Selector
  • Class Selector
  • ID Selector
  • Pseudo Class
• Selector Sequence
• Selector Group
• Combinators:
  • Descendant combinator
  • Child combinators
  • Sibling combinators

Basic Usage

• Parse CSS files or strings

  // Parse CSS file
  future::CSSParser* parser = new future::CSSParser();
  parser->parseByFile("/Path/to/CssFile");
  std::vector<future::Selector *>selectors = parser>getSelectors();
  
  // Parse CSS string
  parser->parseByString("body #id { color: black; }");
  std::vector<future::Selector *>selectors = parser>getSelectors();

• Print all selector descriptions and rules

  int i = 1;
  printf("\n\n********** All Selectors **********\n\n");
  for (future::Selector* s : selectors) {
      printf("#%i\n\n", i++);
      printf("%s\n\n", s->description().c_str());
      printf("specificity: %i\n\n\n", s->weight());
  
      auto ruleMap = s->getRuleDataMap();
      for (const auto& rule : ruleMap) {
          printf("%s: %s\n", rule.first.c_str(), rule.second.c_str());
      }
  
      printf("\n----------------------\n\n");
  }
  printf("\n");

• Match custom node with selector and handle selector rules and specificity if the node macthes a selector (See the CustomNodeExample for the full code)

  int selIdx = 1;
  CustomNode* node = new CustomNode(); // <-- Your custom node 
  for (future::Selector* s : selectors) {
      if (future::NodeSelectorResolver::DoesNodeMatchSelector(node, s)) {
          auto spec = s->weight();
          auto ruleMap = s->getRuleDataMap();
  
          ApplyStyleRules(node, ruleMap, spec);
  
          printf("node %s%s %s matched with selector #%i\n", 
          node->tag.c_str(), node->GetIdDesc().c_str(), node->GetClassesDesc().c_str(), selIdx);
      }
      selIdx++;
  }

Applicability

The code has been tested on Windows