Issue #2436835 by amateescu, alexpott: Unable to create config schema for entity type specific entity reference selection plugin

core/config/schema/core.data_types.schema.yml

@@ -552,7 +552,7 @@ field.value.changed:
 
 field.storage_settings.entity_reference:
   type: mapping
-  label: 'Entity reference settings'
+  label: 'Entity reference field storage settings'
   mapping:
     target_type:
       type: string
@@ -560,14 +560,14 @@ field.storage_settings.entity_reference:
 
 field.field_settings.entity_reference:
   type: mapping
-  label: 'Entity reference settings'
+  label: 'Entity reference field settings'
   mapping:
     handler:
       type: string
       label: 'Reference method'
     handler_settings:
-      type: entity_reference.[%parent.handler].handler_settings
+      type: entity_reference_selection.[%parent.handler]
-      label: 'Reference method settings'
+      label: 'Entity reference selection plugin settings'
 
 field.value.entity_reference:
   type: mapping
@@ -750,3 +750,32 @@ text_format:
       label: 'Text format'
       # The text format should not be translated as part of the string
       # translation system, so this is not marked as translatable.
+
+# Schema for the configuration of the Entity reference selection plugins.
+
+entity_reference_selection:
+  type: mapping
+  label: 'Entity reference selection plugin configuration'
+  mapping:
+    target_bundles:
+      type: sequence
+      label: 'types'
+      sequence:
+        type: string
+        label: 'Type'
+    sort:
+      type: mapping
+      label: 'Sort settings'
+      mapping:
+        field:
+          type: string
+          label: 'Sort by'
+        direction:
+          type: string
+          label: 'Sort direction'
+    auto_create:
+      type: boolean
+      label: 'Create referenced entities if they don''t already exist'
+
+entity_reference_selection.*:
+  type: entity_reference_selection

core/lib/Drupal/Core/Entity/EntityReferenceSelection/SelectionPluginManager.php

@@ -45,21 +45,37 @@ class SelectionPluginManager extends DefaultPluginManager implements SelectionPl
 
     // Initialize default options.
     $options += array(
-      'handler' => 'default',
+      'handler' => $this->getPluginId($options['target_type'], 'default'),
       'handler_settings' => array(),
     );
 
-    // Get all available selection plugins for this entity type.
+    // A specific selection plugin ID was already specified.
-    $selection_handler_groups = $this->getSelectionGroups($options['target_type']);
+    if (strpos($options['handler'], ':') !== FALSE) {
-
+      $plugin_id = $options['handler'];
-    // Sort the selection plugins by weight and select the best match.
+    }
-    uasort($selection_handler_groups[$options['handler']], array('Drupal\Component\Utility\SortArray', 'sortByWeightElement'));
+    // Only a selection group name was specified.
-    end($selection_handler_groups[$options['handler']]);
+    else {
-    $plugin_id = key($selection_handler_groups[$options['handler']]);
+      $plugin_id = $this->getPluginId($options['target_type'], $options['handler']);
+    }
 
     return $this->createInstance($plugin_id, $options);
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public function getPluginId($target_type, $base_plugin_id) {
+    // Get all available selection plugins for this entity type.
+    $selection_handler_groups = $this->getSelectionGroups($target_type);
+
+    // Sort the selection plugins by weight and select the best match.
+    uasort($selection_handler_groups[$base_plugin_id], array('Drupal\Component\Utility\SortArray', 'sortByWeightElement'));
+    end($selection_handler_groups[$base_plugin_id]);
+    $plugin_id = key($selection_handler_groups[$base_plugin_id]);
+
+    return $plugin_id;
+  }
+
   /**
    * {@inheritdoc}
    */
@@ -86,7 +102,7 @@ class SelectionPluginManager extends DefaultPluginManager implements SelectionPl
     $options = array(
       'target_type' => $field_definition->getFieldStorageDefinition()->getSetting('target_type'),
       'handler' => $field_definition->getSetting('handler'),
-      'handler_settings' => $field_definition->getSetting('handler_settings'),
+      'handler_settings' => $field_definition->getSetting('handler_settings') ?: array(),
       'entity' => $entity,
     );
     return $this->getInstance($options);

core/lib/Drupal/Core/Entity/EntityReferenceSelection/SelectionPluginManagerInterface.php

@@ -16,6 +16,19 @@ use Drupal\Core\Field\FieldDefinitionInterface;
  */
 interface SelectionPluginManagerInterface extends PluginManagerInterface {
 
+  /**
+   * Gets the plugin ID for a given target entity type and base plugin ID.
+   *
+   * @param string $target_type
+   *   The target entity type.
+   * @param string $base_plugin_id
+   *   The base plugin ID (e.g. 'default' or 'views').
+   *
+   * @return string
+   *   The plugin ID.
+   */
+  public function getPluginId($target_type, $base_plugin_id);
+
   /**
    * Returns selection plugins that can reference a specific entity type.
    *

core/lib/Drupal/Core/Field/Plugin/Field/FieldType/EntityReferenceItem.php

@@ -59,7 +59,8 @@ class EntityReferenceItem extends FieldItemBase {
    */
   public static function defaultFieldSettings() {
     return array(
-      'handler' => 'default',
+      'handler' => 'default:' . (\Drupal::moduleHandler()->moduleExists('node') ? 'node' : 'user'),
+      'handler_settings' => array(),
     ) + parent::defaultFieldSettings();
   }
 

core/modules/entity_reference/config/schema/entity_reference.schema.yml

@@ -1,41 +0,0 @@
-# Schema for the configuration files of the Entity Reference module.
-
-entity_reference.default.handler_settings:
-  type: mapping
-  label: 'View handler settings'
-  mapping:
-    target_bundles:
-      type: sequence
-      label: 'types'
-      sequence:
-        type: string
-        label: 'Type'
-    sort:
-      type: mapping
-      label: 'Sort settings'
-      mapping:
-        field:
-          type: string
-          label: 'Sort by'
-        direction:
-          type: string
-          label: 'Sort direction'
-    filter:
-      type: mapping
-      label: 'Filter settings'
-      mapping:
-        type:
-          type: string
-          label: 'Filter by'
-        role:
-          type: sequence
-          label: 'Restrict to the selected roles'
-          sequence:
-            type: string
-            label: 'Role'
-    auto_create:
-      type: boolean
-      label: 'Create referenced entities if they don''t already exist'
-    include_anonymous:
-      type: boolean
-      label: 'Include the anonymous user in the matched entities.'

core/modules/entity_reference/entity_reference.module

@@ -13,6 +13,7 @@ use Drupal\Core\Routing\RouteMatchInterface;
 use Drupal\field\Entity\FieldStorageConfig;
 use Drupal\field\Entity\FieldConfig;
 use Drupal\field\FieldStorageConfigInterface;
+use Drupal\field\FieldConfigInterface;
 
 /**
  * Implements hook_help().
@@ -84,20 +85,33 @@ function entity_reference_field_storage_config_update(FieldStorageConfigInterfac
     return;
   }
 
-  if (empty($field_storage->bundles)) {
+  foreach ($field_storage->getBundles() as $bundle) {
-    // Field storage has no fields.
+    $field = FieldConfig::loadByName($field_storage->getTargetEntityTypeId(), $bundle, $field_storage->getName());
-    return;
-  }
-
-  $field_name = $field_storage->getName();
-
-  foreach ($field_storage->bundles() as $entity_type => $bundles) {
-    foreach ($bundles as $bundle) {
-      $field = FieldConfig::loadByName($entity_type, $bundle, $field_name);
     $field->settings['handler_settings'] = array();
     $field->save();
   }
+}
+
+/**
+ * Implements hook_ENTITY_TYPE_presave() for 'field_config'.
+ *
+ * Determine the selection handler plugin ID for an entity reference field.
+ */
+function entity_reference_field_config_presave(FieldConfigInterface $field) {
+  if ($field->getType() != 'entity_reference') {
+    // Only act on entity reference fields.
+    return;
   }
+
+  if ($field->isSyncing()) {
+    // Don't change anything during a configuration sync.
+    return;
+  }
+
+  $target_type = $field->getFieldStorageDefinition()->getSetting('target_type');
+  $selection_manager = \Drupal::service('plugin.manager.entity_reference_selection');
+  list($current_handler) = explode(':', $field->getSetting('handler'), 2);
+  $field->settings['handler'] = $selection_manager->getPluginId($target_type, $current_handler);
 }
 
 /**

core/modules/entity_reference/src/ConfigurableEntityReferenceItem.php

@@ -42,15 +42,6 @@ class ConfigurableEntityReferenceItem extends EntityReferenceItem implements Opt
     return $settings;
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  public static function defaultFieldSettings() {
-    return array(
-      'handler_settings' => array(),
-    ) + parent::defaultFieldSettings();
-  }
-
   /**
    * {@inheritdoc}
    */
@@ -149,7 +140,7 @@ class ConfigurableEntityReferenceItem extends EntityReferenceItem implements Opt
       }
       elseif (array_key_exists($selection_group_id . ':' . $this->getSetting('target_type'), $selection_plugins[$selection_group_id])) {
         $selection_group_plugin = $selection_group_id . ':' . $this->getSetting('target_type');
-        $handlers_options[$selection_group_id] = String::checkPlain($selection_plugins[$selection_group_id][$selection_group_plugin]['base_plugin_label']);
+        $handlers_options[$selection_group_plugin] = String::checkPlain($selection_plugins[$selection_group_id][$selection_group_plugin]['base_plugin_label']);
       }
     }
 

core/modules/entity_reference/src/Tests/EntityReferenceAdminTest.php

@@ -78,7 +78,7 @@ class EntityReferenceAdminTest extends WebTestBase {
     $this->drupalPostForm(NULL, array(), t('Save field settings'));
 
     // The base handler should be selected by default.
-    $this->assertFieldByName('field[settings][handler]', 'default');
+    $this->assertFieldByName('field[settings][handler]', 'default:node');
 
     // The base handler settings should be displayed.
     $entity_type_id = 'node';

core/modules/field/src/Tests/EntityReference/EntityReferenceItemTest.php

@@ -11,6 +11,8 @@ use Drupal\Component\Utility\Unicode;
 use Drupal\Core\Field\FieldItemListInterface;
 use Drupal\Core\Field\FieldItemInterface;
 use Drupal\Core\Language\LanguageInterface;
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
 use Drupal\field\Tests\FieldUnitTestBase;
 use Drupal\taxonomy\Entity\Term;
 use Drupal\taxonomy\Entity\Vocabulary;
@@ -27,7 +29,7 @@ class EntityReferenceItemTest extends FieldUnitTestBase {
    *
    * @var array
    */
-  public static $modules = array('entity_reference', 'taxonomy', 'text', 'filter');
+  public static $modules = array('entity_reference', 'taxonomy', 'text', 'filter', 'views');
 
   /**
    * The taxonomy vocabulary to test with.
@@ -214,4 +216,36 @@ class EntityReferenceItemTest extends FieldUnitTestBase {
     $this->assertEqual($entity->field_test_taxonomy_term->entity->id(), $term->id());
   }
 
+  /**
+   * Tests that the 'handler' field setting stores the proper plugin ID.
+   */
+  public function testSelectionHandlerSettings() {
+    $field_name = Unicode::strtolower($this->randomMachineName());
+    $field_storage = FieldStorageConfig::create(array(
+      'field_name' => $field_name,
+      'entity_type' => 'entity_test',
+      'type' => 'entity_reference',
+      'settings' => array(
+        'target_type' => 'entity_test'
+      ),
+    ));
+    $field_storage->save();
+
+    // Do not specify any value for the 'handler' setting in order to verify
+    // that the default value is properly used.
+    $field = FieldConfig::create(array(
+      'field_storage' => $field_storage,
+      'bundle' => 'entity_test',
+    ));
+    $field->save();
+
+    $field = FieldConfig::load($field->id());
+    $this->assertTrue($field->getSetting('handler') == 'default:entity_test');
+
+    $field->settings['handler'] = 'views';
+    $field->save();
+    $field = FieldConfig::load($field->id());
+    $this->assertTrue($field->getSetting('handler') == 'views');
+  }
+
 }

core/modules/file/config/schema/file.schema.yml

@@ -46,6 +46,9 @@ base_file_field_field_settings:
     handler:
       type: string
       label: 'Reference method'
+    handler_settings:
+      type: entity_reference_selection.[%parent.handler]
+      label: 'Entity reference selection settings'
     file_directory:
       type: string
       label: 'File directory'

core/modules/migrate_drupal/src/Tests/d6/MigrateFieldInstanceTest.php

@@ -134,12 +134,17 @@ class MigrateFieldInstanceTest extends MigrateDrupal6TestBase {
       'display_field' => FALSE,
       'display_default' => FALSE,
       'uri_scheme' => 'public',
-      'handler' => 'default',
+      // This value should be 'default:file' but the test does not migrate field
+      // storages so we end up with the default value for this setting.
+      'handler' => 'default:node',
+      'handler_settings' => array(),
       'target_bundle' => NULL,
     );
+    $field_settings = $field->getSettings();
+    ksort($expected);
+    ksort($field_settings);
     // This is the only way to compare arrays.
-    $this->assertFalse(array_diff_assoc($field->getSettings(), $expected));
+    $this->assertIdentical($expected, $field_settings);
-    $this->assertFalse(array_diff_assoc($expected, $field->getSettings()));
 
     // Test a link field.
     $field = FieldConfig::load('node.story.field_test_link');

core/modules/taxonomy/config/schema/taxonomy.schema.yml

@@ -62,6 +62,9 @@ field.field_settings.taxonomy_term_reference:
     handler:
       type: string
       label: 'Reference method'
+    handler_settings:
+      type: entity_reference_selection.[%parent.handler]
+      label: 'Entity reference selection settings'
 
 field.value.taxonomy_term_reference:
   type: mapping

core/modules/taxonomy/src/Plugin/Field/FieldType/TaxonomyTermReferenceItem.php

@@ -47,6 +47,15 @@ class TaxonomyTermReferenceItem extends EntityReferenceItem implements OptionsPr
     ) + parent::defaultStorageSettings();
   }
 
+  /**
+   * {@inheritdoc}
+   */
+  public static function defaultFieldSettings() {
+    return array(
+      'handler' => 'default:taxonomy_term',
+    ) + parent::defaultFieldSettings();
+  }
+
   /**
    * {@inheritdoc}
    */

core/modules/user/config/schema/user.schema.yml

@@ -174,3 +174,23 @@ condition.plugin.user_role:
       type: sequence
       sequence:
         type: string
+
+entity_reference_selection.default:user:
+  type: entity_reference_selection
+  mapping:
+    filter:
+      type: mapping
+      label: 'Filter settings'
+      mapping:
+        type:
+          type: string
+          label: 'Filter by'
+        role:
+          type: sequence
+          label: 'Restrict to the selected roles'
+          sequence:
+            type: string
+            label: 'Role'
+    include_anonymous:
+      type: boolean
+      label: 'Include the anonymous user in the matched entities.'

core/modules/views/config/schema/views.entity_reference.schema.yml

@@ -1,6 +1,6 @@
 # Schema for the views entity reference selection plugins.
 
-entity_reference.views.handler_settings:
+entity_reference_selection.views:
   type: mapping
   label: 'View handler settings'
   mapping: