diff core/lib/Drupal/Component/Plugin/PluginManagerBase.php @ 17:129ea1e6d783

Update, including to Drupal core 8.6.10

--- a/core/lib/Drupal/Component/Plugin/PluginManagerBase.php	Tue Jul 10 15:07:59 2018 +0100
+++ b/core/lib/Drupal/Component/Plugin/PluginManagerBase.php	Thu Feb 28 13:21:36 2019 +0000
@@ -29,7 +29,7 @@
   /**
    * 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 @@
         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 {
@@ -86,9 +85,28 @@
   }
 
   /**
+   * 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);
   }