X-Git-Url: http://www.aleph1.co.uk/gitweb/?p=yaffs-website;a=blobdiff_plain;f=web%2Fcore%2Flib%2FDrupal%2FComponent%2FPlugin%2FPluginManagerBase.php;fp=web%2Fcore%2Flib%2FDrupal%2FComponent%2FPlugin%2FPluginManagerBase.php;h=d7342da2ed18c69bb05fe2b124aca55e88d616bd;hp=34416ff4371d84974984205b07b2cca8ffba0c69;hb=0bf8d09d2542548982e81a441b1f16e75873a04f;hpb=74df008bdbb3a11eeea356744f39b802369bda3c

diff --git a/web/core/lib/Drupal/Component/Plugin/PluginManagerBase.php b/web/core/lib/Drupal/Component/Plugin/PluginManagerBase.php
index 34416ff43..d7342da2e 100644
--- a/web/core/lib/Drupal/Component/Plugin/PluginManagerBase.php
+++ b/web/core/lib/Drupal/Component/Plugin/PluginManagerBase.php
@@ -29,7 +29,7 @@ abstract class PluginManagerBase implements PluginManagerInterface {
   /**
    * The object that returns the preconfigured plugin instance appropriate for a particular runtime condition.
    *
-   * @var \Drupal\Component\Plugin\Mapper\MapperInterface
+   * @var \Drupal\Component\Plugin\Mapper\MapperInterface|null
    */
   protected $mapper;
 
@@ -76,8 +76,7 @@ abstract class PluginManagerBase implements PluginManagerInterface {
         return $this->getFactory()->createInstance($plugin_id, $configuration);
       }
       catch (PluginNotFoundException $e) {
-        $fallback_id = $this->getFallbackPluginId($plugin_id, $configuration);
-        return $this->getFactory()->createInstance($fallback_id, $configuration);
+        return $this->handlePluginNotFound($plugin_id, $configuration);
       }
     }
     else {
@@ -85,10 +84,29 @@ abstract class PluginManagerBase implements PluginManagerInterface {
     }
   }
 
+  /**
+   * Allows plugin managers to specify custom behavior if a plugin is not found.
+   *
+   * @param string $plugin_id
+   *   The ID of the missing requested plugin.
+   * @param array $configuration
+   *   An array of configuration relevant to the plugin instance.
+   *
+   * @return object
+   *   A fallback plugin instance.
+   */
+  protected function handlePluginNotFound($plugin_id, array $configuration) {
+    $fallback_id = $this->getFallbackPluginId($plugin_id, $configuration);
+    return $this->getFactory()->createInstance($fallback_id, $configuration);
+  }
+
   /**
    * {@inheritdoc}
    */
   public function getInstance(array $options) {
+    if (!$this->mapper) {
+      throw new \BadMethodCallException(sprintf('%s does not support this method unless %s::$mapper is set.', static::class, static::class));
+    }
     return $this->mapper->getInstance($options);
   }