Twigエクステンションの作り方The document discusses the Twig templating language for PHP, providing an overview of its syntax like tags for logic and output and how to create custom extensions. It also describes how to register a Twig extension as a service in Symfony using dependency injection and create custom filters, functions, and tests for the extension using Twig_Function_Method, Twig_Filter_Method and Twig_Test_Method
