www.aleph1.co.uk Git - yaffs-website/blob - web/core/lib/Drupal/Core/Theme/ThemeNegotiator.php

   1 <?php
   2
   3 namespace Drupal\Core\Theme;
   4
   5 use Drupal\Core\DependencyInjection\ClassResolverInterface;
   6 use Drupal\Core\Routing\RouteMatchInterface;
   7
   8 /**
   9  * Provides a class which determines the active theme of the page.
  10  *
  11  * It therefore uses ThemeNegotiatorInterface objects which are passed in
  12  * using the 'theme_negotiator' tag.
  13  */
  14 class ThemeNegotiator implements ThemeNegotiatorInterface {
  15
  16   /**
  17    * Holds an array of theme negotiator IDs, sorted by priority.
  18    *
  19    * @var string[]
  20    */
  21   protected $negotiators = [];
  22
  23   /**
  24    * The access checker for themes.
  25    *
  26    * @var \Drupal\Core\Theme\ThemeAccessCheck
  27    */
  28   protected $themeAccess;
  29
  30   /**
  31    * The class resolver.
  32    *
  33    * @var \Drupal\Core\DependencyInjection\ClassResolverInterface
  34    */
  35   protected $classResolver;
  36
  37   /**
  38    * Constructs a new ThemeNegotiator.
  39    *
  40    * @param \Drupal\Core\Theme\ThemeAccessCheck $theme_access
  41    *   The access checker for themes.
  42    * @param \Drupal\Core\DependencyInjection\ClassResolverInterface $class_resolver
  43    *   The class resolver.
  44    * @param string[] $negotiators
  45    *   An array of negotiator IDs.
  46    */
  47   public function __construct(ThemeAccessCheck $theme_access, ClassResolverInterface $class_resolver, array $negotiators) {
  48     $this->themeAccess = $theme_access;
  49     $this->negotiators = $negotiators;
  50     $this->classResolver = $class_resolver;
  51   }
  52
  53   /**
  54    * {@inheritdoc}
  55    */
  56   public function applies(RouteMatchInterface $route_match) {
  57     return TRUE;
  58   }
  59
  60   /**
  61    * {@inheritdoc}
  62    */
  63   public function determineActiveTheme(RouteMatchInterface $route_match) {
  64     foreach ($this->negotiators as $negotiator_id) {
  65       $negotiator = $this->classResolver->getInstanceFromDefinition($negotiator_id);
  66
  67       if ($negotiator->applies($route_match)) {
  68         $theme = $negotiator->determineActiveTheme($route_match);
  69         if ($theme !== NULL && $this->themeAccess->checkAccess($theme)) {
  70           return $theme;
  71         }
  72       }
  73     }
  74   }
  75
  76 }