Issue #2651418 by vasike, DieterHolvoet, smustgrave, Xano, rpayanm, quietone,...

Issue #2651418 by vasike, DieterHolvoet, smustgrave, Xano, rpayanm, quietone, alexpott, larowlan, catch, lauriii: Non-array values for #ajax

(cherry picked from commit fe3aa496)

core/lib/Drupal/Core/Entity/Plugin/EntityReferenceSelection/DefaultSelection.php

@@ -183,6 +183,9 @@ public function buildConfigurationForm(array $form, FormStateInterface $form_sta
         '#size' => 6,
         '#multiple' => TRUE,
         '#element_validate' => [[static::class, 'elementValidateFilter']],
+        // Use a form process callback to build #ajax property properly and also
+        // to avoid code duplication.
+        // @see \Drupal\Core\Field\Plugin\Field\FieldType\EntityReferenceItem::fieldSettingsAjaxProcess()
         '#ajax' => TRUE,
         '#limit_validation_errors' => [],
       ];
@@ -232,6 +235,9 @@ public function buildConfigurationForm(array $form, FormStateInterface $form_sta
         '#type' => 'select',
         '#title' => $this->t('Sort by'),
         '#options' => $fields,
+        // Use a form process callback to build #ajax property properly and also
+        // to avoid code duplication.
+        // @see \Drupal\Core\Field\Plugin\Field\FieldType\EntityReferenceItem::fieldSettingsAjaxProcess()
         '#ajax' => TRUE,
         '#empty_value' => '_none',
         '#sort_options' => TRUE,

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

@@ -2,11 +2,11 @@
 
 namespace Drupal\Core\Field\Plugin\Field\FieldType;
 
+use Drupal\Component\Plugin\Exception\PluginNotFoundException;
 use Drupal\Component\Render\FormattableMarkup;
 use Drupal\Component\Utility\Html;
 use Drupal\Core\Entity\ContentEntityStorageInterface;
 use Drupal\Core\Entity\EntityInterface;
-use Drupal\Component\Plugin\Exception\PluginNotFoundException;
 use Drupal\Core\Entity\EntityTypeInterface;
 use Drupal\Core\Entity\FieldableEntityInterface;
 use Drupal\Core\Entity\TypedData\EntityDataDefinition;
@@ -477,6 +477,9 @@ public function fieldSettingsForm(array $form, FormStateInterface $form_state) {
       '#options' => $handlers_options,
       '#default_value' => $field->getSetting('handler'),
       '#required' => TRUE,
+      // Use a form process callback to build #ajax property properly and also
+      // to avoid code duplication.
+      // @see \Drupal\Core\Field\Plugin\Field\FieldType\EntityReferenceItem::fieldSettingsAjaxProcess()
       '#ajax' => TRUE,
       '#limit_validation_errors' => [],
     ];
@@ -703,6 +706,7 @@ public static function fieldSettingsAjaxProcess($form, FormStateInterface $form_
    * @see static::fieldSettingsAjaxProcess()
    */
   public static function fieldSettingsAjaxProcessElement(&$element, $main_form) {
+    // Elements are marked as TRUE ('#ajax' => TRUE,), so not empty.
     if (!empty($element['#ajax'])) {
       $element['#ajax'] = [
         'trigger_as' => ['name' => 'handler_settings_submit'],

core/modules/user/src/Plugin/EntityReferenceSelection/UserSelection.php

@@ -117,6 +117,9 @@ public function buildConfigurationForm(array $form, FormStateInterface $form_sta
         '_none' => $this->t('- None -'),
         'role' => $this->t('User role'),
       ],
+      // Use a form process callback to build #ajax property properly and also
+      // to avoid code duplication.
+      // @see \Drupal\Core\Field\Plugin\Field\FieldType\EntityReferenceItem::fieldSettingsAjaxProcess()
       '#ajax' => TRUE,
       '#limit_validation_errors' => [],
       '#default_value' => $configuration['filter']['type'],