Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Core\Template;
Chris@0: 
Chris@0: use Drupal\Core\Cache\CacheBackendInterface;
Chris@0: use Drupal\Core\Render\Markup;
Chris@0: use Drupal\Core\State\StateInterface;
Chris@0: 
Chris@0: /**
Chris@0:  * A class that defines a Twig environment for Drupal.
Chris@0:  *
Chris@0:  * Instances of this class are used to store the configuration and extensions,
Chris@0:  * and are used to load templates from the file system or other locations.
Chris@0:  *
Chris@0:  * @see core\vendor\twig\twig\lib\Twig\Environment.php
Chris@0:  */
Chris@0: class TwigEnvironment extends \Twig_Environment {
Chris@0: 
Chris@0:   /**
Chris@0:    * Static cache of template classes.
Chris@0:    *
Chris@0:    * @var array
Chris@0:    */
Chris@0:   protected $templateClasses;
Chris@0: 
Chris@0:   protected $twigCachePrefix = '';
Chris@0: 
Chris@0:   /**
Chris@0:    * Constructs a TwigEnvironment object and stores cache and storage
Chris@0:    * internally.
Chris@0:    *
Chris@0:    * @param string $root
Chris@0:    *   The app root.
Chris@0:    * @param \Drupal\Core\Cache\CacheBackendInterface $cache
Chris@0:    *   The cache bin.
Chris@0:    * @param string $twig_extension_hash
Chris@0:    *   The Twig extension hash.
Chris@0:    * @param \Drupal\Core\State\StateInterface $state
Chris@0:    *   The state service.
Chris@0:    * @param \Twig_LoaderInterface $loader
Chris@0:    *   The Twig loader or loader chain.
Chris@0:    * @param array $options
Chris@0:    *   The options for the Twig environment.
Chris@0:    */
Chris@0:   public function __construct($root, CacheBackendInterface $cache, $twig_extension_hash, StateInterface $state, \Twig_LoaderInterface $loader = NULL, $options = []) {
Chris@0:     // Ensure that twig.engine is loaded, given that it is needed to render a
Chris@0:     // template because functions like TwigExtension::escapeFilter() are called.
Chris@0:     require_once $root . '/core/themes/engines/twig/twig.engine';
Chris@0: 
Chris@0:     $this->templateClasses = [];
Chris@0: 
Chris@0:     $options += [
Chris@0:       // @todo Ensure garbage collection of expired files.
Chris@0:       'cache' => TRUE,
Chris@0:       'debug' => FALSE,
Chris@0:       'auto_reload' => NULL,
Chris@0:     ];
Chris@0:     // Ensure autoescaping is always on.
Chris@0:     $options['autoescape'] = 'html';
Chris@0: 
Chris@0:     $policy = new TwigSandboxPolicy();
Chris@0:     $sandbox = new \Twig_Extension_Sandbox($policy, TRUE);
Chris@0:     $this->addExtension($sandbox);
Chris@0: 
Chris@0:     if ($options['cache'] === TRUE) {
Chris@0:       $current = $state->get('twig_extension_hash_prefix', ['twig_extension_hash' => '']);
Chris@0:       if ($current['twig_extension_hash'] !== $twig_extension_hash || empty($current['twig_cache_prefix'])) {
Chris@0:         $current = [
Chris@0:           'twig_extension_hash' => $twig_extension_hash,
Chris@0:           // Generate a new prefix which invalidates any existing cached files.
Chris@0:           'twig_cache_prefix' => uniqid(),
Chris@0: 
Chris@0:         ];
Chris@0:         $state->set('twig_extension_hash_prefix', $current);
Chris@0:       }
Chris@0:       $this->twigCachePrefix = $current['twig_cache_prefix'];
Chris@0: 
Chris@0:       $options['cache'] = new TwigPhpStorageCache($cache, $this->twigCachePrefix);
Chris@0:     }
Chris@0: 
Chris@0:     $this->loader = $loader;
Chris@0:     parent::__construct($this->loader, $options);
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Get the cache prefixed used by \Drupal\Core\Template\TwigPhpStorageCache
Chris@0:    *
Chris@0:    * @return string
Chris@0:    *   The file cache prefix, or empty string if the cache is disabled.
Chris@0:    */
Chris@0:   public function getTwigCachePrefix() {
Chris@0:     return $this->twigCachePrefix;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Gets the template class associated with the given string.
Chris@0:    *
Chris@0:    * @param string $name
Chris@0:    *   The name for which to calculate the template class name.
Chris@0:    * @param int $index
Chris@0:    *   The index if it is an embedded template.
Chris@0:    *
Chris@0:    * @return string
Chris@0:    *   The template class name.
Chris@0:    */
Chris@0:   public function getTemplateClass($name, $index = NULL) {
Chris@0:     // We override this method to add caching because it gets called multiple
Chris@0:     // times when the same template is used more than once. For example, a page
Chris@0:     // rendering 50 nodes without any node template overrides will use the same
Chris@0:     // node.html.twig for the output of each node and the same compiled class.
Chris@0:     $cache_index = $name . (NULL === $index ? '' : '_' . $index);
Chris@0:     if (!isset($this->templateClasses[$cache_index])) {
Chris@0:       $this->templateClasses[$cache_index] = $this->templateClassPrefix . hash('sha256', $this->loader->getCacheKey($name)) . (NULL === $index ? '' : '_' . $index);
Chris@0:     }
Chris@0:     return $this->templateClasses[$cache_index];
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Renders a twig string directly.
Chris@0:    *
Chris@0:    * Warning: You should use the render element 'inline_template' together with
Chris@0:    * the #template attribute instead of this method directly.
Chris@0:    * On top of that you have to ensure that the template string is not dynamic
Chris@0:    * but just an ordinary static php string, because there may be installations
Chris@0:    * using read-only PHPStorage that want to generate all possible twig
Chris@0:    * templates as part of a build step. So it is important that an automated
Chris@0:    * script can find the templates and extract them. This is only possible if
Chris@0:    * the template is a regular string.
Chris@0:    *
Chris@0:    * @param string $template_string
Chris@0:    *   The template string to render with placeholders.
Chris@0:    * @param array $context
Chris@0:    *   An array of parameters to pass to the template.
Chris@0:    *
Chris@0:    * @return \Drupal\Component\Render\MarkupInterface|string
Chris@0:    *   The rendered inline template as a Markup object.
Chris@0:    *
Chris@0:    * @see \Drupal\Core\Template\Loader\StringLoader::exists()
Chris@0:    */
Chris@0:   public function renderInline($template_string, array $context = []) {
Chris@0:     // Prefix all inline templates with a special comment.
Chris@0:     $template_string = '{# inline_template_start #}' . $template_string;
Chris@0:     return Markup::create($this->loadTemplate($template_string, NULL)->render($context));
Chris@0:   }
Chris@0: 
Chris@0: }