Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Core\Theme;
Chris@0: 
Chris@0: use Drupal\Component\Render\MarkupInterface;
Chris@0: use Drupal\Core\Render\Markup;
Chris@0: use Drupal\Core\Routing\RouteMatchInterface;
Chris@0: use Drupal\Core\Routing\StackedRouteMatchInterface;
Chris@0: use Drupal\Core\Extension\ModuleHandlerInterface;
Chris@0: use Drupal\Core\Template\Attribute;
Chris@0: 
Chris@0: /**
Chris@0:  * Provides the default implementation of a theme manager.
Chris@0:  */
Chris@0: class ThemeManager implements ThemeManagerInterface {
Chris@0: 
Chris@0:   /**
Chris@0:    * The theme negotiator.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Theme\ThemeNegotiatorInterface
Chris@0:    */
Chris@0:   protected $themeNegotiator;
Chris@0: 
Chris@0:   /**
Chris@0:    * The theme registry used to render an output.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Theme\Registry
Chris@0:    */
Chris@0:   protected $themeRegistry;
Chris@0: 
Chris@0:   /**
Chris@0:    * Contains the current active theme.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Theme\ActiveTheme
Chris@0:    */
Chris@0:   protected $activeTheme;
Chris@0: 
Chris@0:   /**
Chris@0:    * The theme initialization.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Theme\ThemeInitializationInterface
Chris@0:    */
Chris@0:   protected $themeInitialization;
Chris@0: 
Chris@0:   /**
Chris@0:    * The module handler.
Chris@0:    *
Chris@0:    * @var \Drupal\Core\Extension\ModuleHandlerInterface
Chris@0:    */
Chris@0:   protected $moduleHandler;
Chris@0: 
Chris@0:   /**
Chris@0:    * The app root.
Chris@0:    *
Chris@0:    * @var string
Chris@0:    */
Chris@0:   protected $root;
Chris@0: 
Chris@0:   /**
Chris@0:    * Constructs a new ThemeManager object.
Chris@0:    *
Chris@0:    * @param string $root
Chris@0:    *   The app root.
Chris@0:    * @param \Drupal\Core\Theme\ThemeNegotiatorInterface $theme_negotiator
Chris@0:    *   The theme negotiator.
Chris@0:    * @param \Drupal\Core\Theme\ThemeInitializationInterface $theme_initialization
Chris@0:    *   The theme initialization.
Chris@0:    * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
Chris@0:    *   The module handler.
Chris@0:    */
Chris@0:   public function __construct($root, ThemeNegotiatorInterface $theme_negotiator, ThemeInitializationInterface $theme_initialization, ModuleHandlerInterface $module_handler) {
Chris@0:     $this->root = $root;
Chris@0:     $this->themeNegotiator = $theme_negotiator;
Chris@0:     $this->themeInitialization = $theme_initialization;
Chris@0:     $this->moduleHandler = $module_handler;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Sets the theme registry.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Theme\Registry $theme_registry
Chris@0:    *   The theme registry.
Chris@0:    *
Chris@0:    * @return $this
Chris@0:    */
Chris@0:   public function setThemeRegistry(Registry $theme_registry) {
Chris@0:     $this->themeRegistry = $theme_registry;
Chris@0:     return $this;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function getActiveTheme(RouteMatchInterface $route_match = NULL) {
Chris@0:     if (!isset($this->activeTheme)) {
Chris@0:       $this->initTheme($route_match);
Chris@0:     }
Chris@0:     return $this->activeTheme;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function hasActiveTheme() {
Chris@0:     return isset($this->activeTheme);
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function resetActiveTheme() {
Chris@0:     $this->activeTheme = NULL;
Chris@0:     return $this;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function setActiveTheme(ActiveTheme $active_theme) {
Chris@0:     $this->activeTheme = $active_theme;
Chris@0:     if ($active_theme) {
Chris@0:       $this->themeInitialization->loadActiveTheme($active_theme);
Chris@0:     }
Chris@0:     return $this;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function render($hook, array $variables) {
Chris@0:     static $default_attributes;
Chris@0: 
Chris@0:     $active_theme = $this->getActiveTheme();
Chris@0: 
Chris@0:     // If called before all modules are loaded, we do not necessarily have a
Chris@0:     // full theme registry to work with, and therefore cannot process the theme
Chris@0:     // request properly. See also \Drupal\Core\Theme\Registry::get().
Chris@0:     if (!$this->moduleHandler->isLoaded() && !defined('MAINTENANCE_MODE')) {
Chris@0:       throw new \Exception('The theme implementations may not be rendered until all modules are loaded.');
Chris@0:     }
Chris@0: 
Chris@0:     $theme_registry = $this->themeRegistry->getRuntime();
Chris@0: 
Chris@0:     // If an array of hook candidates were passed, use the first one that has an
Chris@0:     // implementation.
Chris@0:     if (is_array($hook)) {
Chris@0:       foreach ($hook as $candidate) {
Chris@0:         if ($theme_registry->has($candidate)) {
Chris@0:           break;
Chris@0:         }
Chris@0:       }
Chris@0:       $hook = $candidate;
Chris@0:     }
Chris@0:     // Save the original theme hook, so it can be supplied to theme variable
Chris@0:     // preprocess callbacks.
Chris@0:     $original_hook = $hook;
Chris@0: 
Chris@0:     // If there's no implementation, check for more generic fallbacks.
Chris@0:     // If there's still no implementation, log an error and return an empty
Chris@0:     // string.
Chris@0:     if (!$theme_registry->has($hook)) {
Chris@0:       // Iteratively strip everything after the last '__' delimiter, until an
Chris@0:       // implementation is found.
Chris@0:       while ($pos = strrpos($hook, '__')) {
Chris@0:         $hook = substr($hook, 0, $pos);
Chris@0:         if ($theme_registry->has($hook)) {
Chris@0:           break;
Chris@0:         }
Chris@0:       }
Chris@0:       if (!$theme_registry->has($hook)) {
Chris@0:         // Only log a message when not trying theme suggestions ($hook being an
Chris@0:         // array).
Chris@0:         if (!isset($candidate)) {
Chris@0:           \Drupal::logger('theme')->warning('Theme hook %hook not found.', ['%hook' => $hook]);
Chris@0:         }
Chris@0:         // There is no theme implementation for the hook passed. Return FALSE so
Chris@0:         // the function calling
Chris@0:         // \Drupal\Core\Theme\ThemeManagerInterface::render() can differentiate
Chris@0:         // between a hook that exists and renders an empty string, and a hook
Chris@0:         // that is not implemented.
Chris@0:         return FALSE;
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     $info = $theme_registry->get($hook);
Chris@0: 
Chris@0:     // If a renderable array is passed as $variables, then set $variables to
Chris@0:     // the arguments expected by the theme function.
Chris@0:     if (isset($variables['#theme']) || isset($variables['#theme_wrappers'])) {
Chris@0:       $element = $variables;
Chris@0:       $variables = [];
Chris@0:       if (isset($info['variables'])) {
Chris@0:         foreach (array_keys($info['variables']) as $name) {
Chris@0:           if (isset($element["#$name"]) || array_key_exists("#$name", $element)) {
Chris@0:             $variables[$name] = $element["#$name"];
Chris@0:           }
Chris@0:         }
Chris@0:       }
Chris@0:       else {
Chris@0:         $variables[$info['render element']] = $element;
Chris@0:         // Give a hint to render engines to prevent infinite recursion.
Chris@0:         $variables[$info['render element']]['#render_children'] = TRUE;
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     // Merge in argument defaults.
Chris@0:     if (!empty($info['variables'])) {
Chris@0:       $variables += $info['variables'];
Chris@0:     }
Chris@0:     elseif (!empty($info['render element'])) {
Chris@0:       $variables += [$info['render element'] => []];
Chris@0:     }
Chris@0:     // Supply original caller info.
Chris@0:     $variables += [
Chris@0:       'theme_hook_original' => $original_hook,
Chris@0:     ];
Chris@0: 
Chris@0:     // Set base hook for later use. For example if '#theme' => 'node__article'
Chris@0:     // is called, we run hook_theme_suggestions_node_alter() rather than
Chris@0:     // hook_theme_suggestions_node__article_alter(), and also pass in the base
Chris@0:     // hook as the last parameter to the suggestions alter hooks.
Chris@0:     if (isset($info['base hook'])) {
Chris@0:       $base_theme_hook = $info['base hook'];
Chris@0:     }
Chris@0:     else {
Chris@0:       $base_theme_hook = $hook;
Chris@0:     }
Chris@0: 
Chris@0:     // Invoke hook_theme_suggestions_HOOK().
Chris@0:     $suggestions = $this->moduleHandler->invokeAll('theme_suggestions_' . $base_theme_hook, [$variables]);
Chris@0:     // If the theme implementation was invoked with a direct theme suggestion
Chris@0:     // like '#theme' => 'node__article', add it to the suggestions array before
Chris@0:     // invoking suggestion alter hooks.
Chris@0:     if (isset($info['base hook'])) {
Chris@0:       $suggestions[] = $hook;
Chris@0:     }
Chris@0: 
Chris@0:     // Invoke hook_theme_suggestions_alter() and
Chris@0:     // hook_theme_suggestions_HOOK_alter().
Chris@0:     $hooks = [
Chris@0:       'theme_suggestions',
Chris@0:       'theme_suggestions_' . $base_theme_hook,
Chris@0:     ];
Chris@0:     $this->moduleHandler->alter($hooks, $suggestions, $variables, $base_theme_hook);
Chris@0:     $this->alter($hooks, $suggestions, $variables, $base_theme_hook);
Chris@0: 
Chris@0:     // Check if each suggestion exists in the theme registry, and if so,
Chris@0:     // use it instead of the base hook. For example, a function may use
Chris@0:     // '#theme' => 'node', but a module can add 'node__article' as a suggestion
Chris@0:     // via hook_theme_suggestions_HOOK_alter(), enabling a theme to have
Chris@0:     // an alternate template file for article nodes.
Chris@0:     foreach (array_reverse($suggestions) as $suggestion) {
Chris@0:       if ($theme_registry->has($suggestion)) {
Chris@0:         $info = $theme_registry->get($suggestion);
Chris@0:         break;
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     // Include a file if the theme function or variable preprocessor is held
Chris@0:     // elsewhere.
Chris@0:     if (!empty($info['includes'])) {
Chris@0:       foreach ($info['includes'] as $include_file) {
Chris@0:         include_once $this->root . '/' . $include_file;
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     // Invoke the variable preprocessors, if any.
Chris@0:     if (isset($info['base hook'])) {
Chris@0:       $base_hook = $info['base hook'];
Chris@0:       $base_hook_info = $theme_registry->get($base_hook);
Chris@0:       // Include files required by the base hook, since its variable
Chris@0:       // preprocessors might reside there.
Chris@0:       if (!empty($base_hook_info['includes'])) {
Chris@0:         foreach ($base_hook_info['includes'] as $include_file) {
Chris@0:           include_once $this->root . '/' . $include_file;
Chris@0:         }
Chris@0:       }
Chris@0:       if (isset($base_hook_info['preprocess functions'])) {
Chris@0:         // Set a variable for the 'theme_hook_suggestion'. This is used to
Chris@0:         // maintain backwards compatibility with template engines.
Chris@0:         $theme_hook_suggestion = $hook;
Chris@0:       }
Chris@0:     }
Chris@0:     if (isset($info['preprocess functions'])) {
Chris@0:       foreach ($info['preprocess functions'] as $preprocessor_function) {
Chris@0:         if (function_exists($preprocessor_function)) {
Chris@0:           $preprocessor_function($variables, $hook, $info);
Chris@0:         }
Chris@0:       }
Chris@0:       // Allow theme preprocess functions to set $variables['#attached'] and
Chris@0:       // $variables['#cache'] and use them like the corresponding element
Chris@0:       // properties on render arrays. In Drupal 8, this is the (only) officially
Chris@0:       // supported method of attaching bubbleable metadata from preprocess
Chris@0:       // functions. Assets attached here should be associated with the template
Chris@0:       // that we are preprocessing variables for.
Chris@0:       $preprocess_bubbleable = [];
Chris@0:       foreach (['#attached', '#cache'] as $key) {
Chris@0:         if (isset($variables[$key])) {
Chris@0:           $preprocess_bubbleable[$key] = $variables[$key];
Chris@0:         }
Chris@0:       }
Chris@0:       // We do not allow preprocess functions to define cacheable elements.
Chris@0:       unset($preprocess_bubbleable['#cache']['keys']);
Chris@0:       if ($preprocess_bubbleable) {
Chris@0:         // @todo Inject the Renderer in https://www.drupal.org/node/2529438.
Chris@0:         \Drupal::service('renderer')->render($preprocess_bubbleable);
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     // Generate the output using either a function or a template.
Chris@0:     $output = '';
Chris@0:     if (isset($info['function'])) {
Chris@0:       if (function_exists($info['function'])) {
Chris@0:         // Theme functions do not render via the theme engine, so the output is
Chris@0:         // not autoescaped. However, we can only presume that the theme function
Chris@0:         // has been written correctly and that the markup is safe.
Chris@0:         $output = Markup::create($info['function']($variables));
Chris@0:       }
Chris@0:     }
Chris@0:     else {
Chris@0:       $render_function = 'twig_render_template';
Chris@0:       $extension = '.html.twig';
Chris@0: 
Chris@0:       // The theme engine may use a different extension and a different
Chris@0:       // renderer.
Chris@0:       $theme_engine = $active_theme->getEngine();
Chris@0:       if (isset($theme_engine)) {
Chris@0:         if ($info['type'] != 'module') {
Chris@0:           if (function_exists($theme_engine . '_render_template')) {
Chris@0:             $render_function = $theme_engine . '_render_template';
Chris@0:           }
Chris@0:           $extension_function = $theme_engine . '_extension';
Chris@0:           if (function_exists($extension_function)) {
Chris@0:             $extension = $extension_function();
Chris@0:           }
Chris@0:         }
Chris@0:       }
Chris@0: 
Chris@0:       // In some cases, a template implementation may not have had
Chris@0:       // template_preprocess() run (for example, if the default implementation
Chris@0:       // is a function, but a template overrides that default implementation).
Chris@0:       // In these cases, a template should still be able to expect to have
Chris@0:       // access to the variables provided by template_preprocess(), so we add
Chris@0:       // them here if they don't already exist. We don't want the overhead of
Chris@0:       // running template_preprocess() twice, so we use the 'directory' variable
Chris@0:       // to determine if it has already run, which while not completely
Chris@0:       // intuitive, is reasonably safe, and allows us to save on the overhead of
Chris@0:       // adding some new variable to track that.
Chris@0:       if (!isset($variables['directory'])) {
Chris@0:         $default_template_variables = [];
Chris@0:         template_preprocess($default_template_variables, $hook, $info);
Chris@0:         $variables += $default_template_variables;
Chris@0:       }
Chris@0:       if (!isset($default_attributes)) {
Chris@0:         $default_attributes = new Attribute();
Chris@0:       }
Chris@0:       foreach (['attributes', 'title_attributes', 'content_attributes'] as $key) {
Chris@0:         if (isset($variables[$key]) && !($variables[$key] instanceof Attribute)) {
Chris@0:           if ($variables[$key]) {
Chris@0:             $variables[$key] = new Attribute($variables[$key]);
Chris@0:           }
Chris@0:           else {
Chris@0:             // Create empty attributes.
Chris@0:             $variables[$key] = clone $default_attributes;
Chris@0:           }
Chris@0:         }
Chris@0:       }
Chris@0: 
Chris@0:       // Render the output using the template file.
Chris@0:       $template_file = $info['template'] . $extension;
Chris@0:       if (isset($info['path'])) {
Chris@0:         $template_file = $info['path'] . '/' . $template_file;
Chris@0:       }
Chris@0:       // Add the theme suggestions to the variables array just before rendering
Chris@0:       // the template for backwards compatibility with template engines.
Chris@0:       $variables['theme_hook_suggestions'] = $suggestions;
Chris@0:       // For backwards compatibility, pass 'theme_hook_suggestion' on to the
Chris@0:       // template engine. This is only set when calling a direct suggestion like
Chris@0:       // '#theme' => 'menu__shortcut_default' when the template exists in the
Chris@0:       // current theme.
Chris@0:       if (isset($theme_hook_suggestion)) {
Chris@0:         $variables['theme_hook_suggestion'] = $theme_hook_suggestion;
Chris@0:       }
Chris@0:       $output = $render_function($template_file, $variables);
Chris@0:     }
Chris@0: 
Chris@0:     return ($output instanceof MarkupInterface) ? $output : (string) $output;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * Initializes the active theme for a given route match.
Chris@0:    *
Chris@0:    * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
Chris@0:    *   The current route match.
Chris@0:    */
Chris@0:   protected function initTheme(RouteMatchInterface $route_match = NULL) {
Chris@0:     // Determine the active theme for the theme negotiator service. This includes
Chris@0:     // the default theme as well as really specific ones like the ajax base theme.
Chris@0:     if (!$route_match) {
Chris@0:       $route_match = \Drupal::routeMatch();
Chris@0:     }
Chris@0:     if ($route_match instanceof StackedRouteMatchInterface) {
Chris@0:       $route_match = $route_match->getMasterRouteMatch();
Chris@0:     }
Chris@0:     $theme = $this->themeNegotiator->determineActiveTheme($route_match);
Chris@0:     $this->activeTheme = $this->themeInitialization->initTheme($theme);
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    *
Chris@0:    * @todo Should we cache some of these information?
Chris@0:    */
Chris@0:   public function alterForTheme(ActiveTheme $theme, $type, &$data, &$context1 = NULL, &$context2 = NULL) {
Chris@0:     // Most of the time, $type is passed as a string, so for performance,
Chris@0:     // normalize it to that. When passed as an array, usually the first item in
Chris@0:     // the array is a generic type, and additional items in the array are more
Chris@0:     // specific variants of it, as in the case of array('form', 'form_FORM_ID').
Chris@0:     if (is_array($type)) {
Chris@0:       $extra_types = $type;
Chris@0:       $type = array_shift($extra_types);
Chris@0:       // Allow if statements in this function to use the faster isset() rather
Chris@0:       // than !empty() both when $type is passed as a string, or as an array with
Chris@0:       // one item.
Chris@0:       if (empty($extra_types)) {
Chris@0:         unset($extra_types);
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@18:     $theme_keys = array_keys($theme->getBaseThemeExtensions());
Chris@0:     $theme_keys[] = $theme->getName();
Chris@0:     $functions = [];
Chris@0:     foreach ($theme_keys as $theme_key) {
Chris@0:       $function = $theme_key . '_' . $type . '_alter';
Chris@0:       if (function_exists($function)) {
Chris@0:         $functions[] = $function;
Chris@0:       }
Chris@0:       if (isset($extra_types)) {
Chris@0:         foreach ($extra_types as $extra_type) {
Chris@0:           $function = $theme_key . '_' . $extra_type . '_alter';
Chris@0:           if (function_exists($function)) {
Chris@0:             $functions[] = $function;
Chris@0:           }
Chris@0:         }
Chris@0:       }
Chris@0:     }
Chris@0: 
Chris@0:     foreach ($functions as $function) {
Chris@0:       $function($data, $context1, $context2);
Chris@0:     }
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function alter($type, &$data, &$context1 = NULL, &$context2 = NULL) {
Chris@0:     $theme = $this->getActiveTheme();
Chris@0:     $this->alterForTheme($theme, $type, $data, $context1, $context2);
Chris@0:   }
Chris@0: 
Chris@0: }