symfony/css-selector
Css Selector
This project is a PHP implementation of a CSS selector engine that transforms CSS selector strings into compatible XPath expressions for locating elements within documents. It serves as a converter and expression generator that maps CSS selection logic to the XPath query language.
The library processes selectors through a pipeline involving lexer-based tokenization and recursive descent parsing to create an abstract syntax tree. It utilizes pattern-matching logic to handle child and sibling relationships, translating CSS pseudo-classes and selectors into functional XPath logic.
These capabilities support document navigation and data extraction across HTML and XML structures, including applications in web scraping and automated browser testing.
Features
- CSS and XPath Query Engines - Provides a utility that transforms CSS selectors into XPath expressions for locating elements within documents.
- XML Parsing - Provides a way to query XML documents by translating CSS selectors into compatible XPath formats.
- Web Document Parsing - Facilitates navigating complex web page structures to locate target elements using CSS selection patterns.
- CSS Selector Engines - Provides a PHP-based CSS selector engine for querying and navigating DOM structures.
- Web Scraping Selectors - Enables high-precision element targeting for data extraction by converting CSS selectors to XPath.
- Recursive Descent Parsers - Uses a recursive descent parsing engine to translate token streams into internal syntax trees.
- Pattern Matching - Employs pattern-matching logic to handle complex CSS selector combinations and relationships.
- Query Expression Generators - Builds final XPath strings by concatenating mapped segments according to the document tree structure.
- Abstract Syntax Tree Parsing - Implements a transformation pipeline that converts parsed selector hierarchies into a structured tree representation.
- String Tokenization - Utilizes a lexer to break raw CSS selector strings into a stream of tokens based on character patterns.
