services:
  app.twig.demo_extension:
    class: LkBundle\Twig\Extension\AppDocsExtension
    tags:
      - { name: twig.extension }


 
<?php
namespace LkBundle\Twig\Extension;

/**
 * Class AppDocsExtension
 * @package LkBundle\Twig\Extension
 */
class AppDocsExtension extends \Twig_Extension
{
    /**
     * @return string
     */
    public function getName()
    {
       return 'app_documentation_extension';
    }

    /**
     * @return array|\Twig_Function[]
     */
    public function getFunctions()
    {
        return array(
            new \Twig_SimpleFunction(
                'show_docs',
                array($this,'ShowPagerFunction'),
                array(
                    'is_safe' => array('html'),
                    'needs_environment' => true,
                )
            ),
        );
    }

    /**
     * @param \Twig_Environment $environment
     * @param $docs
     * @return string
     * @throws \Twig_Error_Loader
     * @throws \Twig_Error_Runtime
     * @throws \Twig_Error_Syntax
     */
    public function ShowPagerFunction(\Twig_Environment $environment, $documentation)
    {
        return $environment->render('LkBundle:TwigExtension:docs.html.twig', array('documentation' => $documentation));
    }

}