Fixing inheritance for entity reference fields.

recurring_events.module

@@ -40,6 +40,7 @@ function recurring_events_entity_base_field_info_alter(&$fields, EntityTypeInter
           'method' => $field->type(),
           'plugin' => $field->plugin(),
         ];
+
         if ($field->entityField()) {
           $settings['entity field'] = $field->entityField();
         }
@@ -51,12 +52,18 @@ function recurring_events_entity_base_field_info_alter(&$fields, EntityTypeInter
           $type = $field_definitions[$field->sourceField()]->getType();
         }
 
+        $settings = array_merge($settings, $field_definitions[$field->sourceField()]->getSettings());
+
+        $class = '\Drupal\recurring_events\FieldInheritanceFactory';
+        if ($type === 'entity_reference') {
+          $class = '\Drupal\recurring_events\EntityReferenceFieldInheritanceFactory';
+        }
         $fields[$field->id()] = BaseFieldDefinition::create($type)
           ->setLabel($field->label())
           ->setName($field->id())
           ->setDescription(t('The inherited field: @field', ['@field' => $field->label()]))
           ->setComputed(TRUE)
-          ->setClass('\Drupal\recurring_events\FieldInheritanceFactory')
+          ->setClass($class)
           ->setSettings($settings)
           ->setTargetEntityTypeId($entity_type->id())
           ->setDisplayConfigurable('view', TRUE);

src/EntityReferenceFieldInheritanceFactory.php

+<?php
+
+namespace Drupal\recurring_events;
+
+use Drupal\Core\Field\EntityReferenceFieldItemList;
+use Drupal\Core\TypedData\ComputedItemListTrait;
+use Drupal\Core\Field\BaseFieldDefinition;
+use Drupal\Core\TypedData\TypedDataInterface;
+
+/**
+ * The EntityReferenceFieldInheritanceFactory class.
+ *
+ * Note: This class exists separately to the FieldInheritanceFactor because
+ * when inheriting data from an entity_reference field we end up with type hints
+ * failing during calls to EntityReferenceFormatterBase::getEntitiesToView().
+ */
+class EntityReferenceFieldInheritanceFactory extends EntityReferenceFieldItemList {
+
+  use ComputedItemListTrait;
+
+  /**
+   * Constructs a TypedData object given its definition and context.
+   *
+   * @param \Drupal\Core\Field\BaseFieldDefinition $definition
+   *   The data definition.
+   * @param string $name
+   *   (optional) The name of the created property, or NULL if it is the root
+   *   of a typed data tree. Defaults to NULL.
+   * @param \Drupal\Core\TypedData\TypedDataInterface $parent
+   *   (optional) The parent object of the data property, or NULL if it is the
+   *   root of a typed data tree. Defaults to NULL.
+   *
+   * @see \Drupal\Core\TypedData\TypedDataManager::create()
+   */
+  public function __construct(BaseFieldDefinition $definition, $name = NULL, TypedDataInterface $parent = NULL) {
+    parent::__construct($definition, $name, $parent);
+
+    if ($this->getSetting('plugin') === NULL) {
+      throw new \InvalidArgumentException("The definition's 'plugin' key has to specify the plugin to use to inherit data.");
+    }
+
+    if ($this->getSetting('method') === NULL) {
+      throw new \InvalidArgumentException("The definition's 'method' key has to specify the method to use to inherit data. Valid options are inherit, prepend, replace, and append.");
+    }
+
+    if ($this->getSetting('source field') === NULL) {
+      throw new \InvalidArgumentException("The definition's 'source field' key has to specify the field from which to inherit data.");
+    }
+  }
+
+  /**
+   * Compute the field property from state.
+   */
+  protected function computeValue() {
+    $entity = $this->getEntity();
+    $manager = $this->getManager();
+    $configuration = $this->getSettings() + ['entity' => $entity];
+    $plugin = $manager->createInstance($this->getSetting('plugin'), $configuration);
+    $values = $plugin->computeValue();
+    if (!empty($values)) {
+      foreach ($values as $key => $value) {
+        $this->list[$key] = $this->createItem($key, $value);
+      }
+    }
+  }
+
+  /**
+   * Returns the FieldInheritancePluginManager plugin manager.
+   *
+   * @return \Drupal\recurring_events\FieldInheritancePluginManager
+   *   The FieldInheritancePluginManager plugin manager.
+   */
+  protected function getManager() {
+    return \Drupal::service('plugin.manager.field_inheritance');
+  }
+
+}

src/Plugin/FieldInheritance/MediaFieldInheritancePlugin.php → src/Plugin/FieldInheritance/EntityReferenceFieldInheritancePlugin.php

@@ -5,15 +5,15 @@ namespace Drupal\recurring_events\Plugin\FieldInheritance;
 use Drupal\recurring_events\FieldInheritancePluginInterface;
 
 /**
- * Media Inheritance plugin.
+ * Entity Reference Inheritance plugin.
  *
  * @FieldInheritance(
- *   id = "media_inheritance",
- *   name = @Translation("Media Field Inheritance"),
+ *   id = "entity_reference_inheritance",
+ *   name = @Translation("Entity Reference Field Inheritance"),
  *   types = {
- *     "field_ui:entity_reference:media"
+ *     "entity_reference"
  *   }
  * )
  */
-class MediaFieldInheritancePlugin extends FieldInheritancePluginBase implements FieldInheritancePluginInterface {
+class EntityReferenceFieldInheritancePlugin extends FieldInheritancePluginBase implements FieldInheritancePluginInterface {
 }

src/Plugin/FieldInheritance/TaxonomyFieldInheritancePlugin.php

-<?php
-
-namespace Drupal\recurring_events\Plugin\FieldInheritance;
-
-use Drupal\recurring_events\FieldInheritancePluginInterface;
-
-/**
- * Taxonomy Inheritance plugin.
- *
- * @FieldInheritance(
- *   id = "taxonomy_inheritance",
- *   name = @Translation("Taxonomy Field Inheritance"),
- *   types = {
- *     "field_ui:entity_reference:taxonomy_term"
- *   }
- * )
- */
-class TaxonomyFieldInheritancePlugin extends FieldInheritancePluginBase implements FieldInheritancePluginInterface {
-}