Issue #1963340 by amateescu, dags, andypost, agentrickard, mgifford, yoroy,...

Issue #1963340 by amateescu, dags, andypost, agentrickard, mgifford, yoroy, pguillard, jibran, YesCT, xjm, LewisNyman, swentel, Hydra, yched, tim.plunkett, rteijeiro, ainz, Xano, Bojhan, Berdir: Change field UI so that adding a field is a separate task

core/modules/comment/comment.module

@@ -311,17 +311,16 @@ function comment_view_multiple($comments, $view_mode = 'full', $langcode = NULL)
 }
 
 /**
- * Implements hook_form_FORM_ID_alter() for field_ui_field_overview_form.
+ * Implements hook_form_FORM_ID_alter() for field_ui_field_storage_add_form.
  */
-function comment_form_field_ui_field_overview_form_alter(&$form, FormStateInterface $form_state) {
+function comment_form_field_ui_field_storage_add_form_alter(&$form, FormStateInterface $form_state) {
   $request = \Drupal::request();
-  if ($form['#entity_type'] == 'comment' && $request->attributes->has('commented_entity_type')) {
+  if ($form_state->get('entity_type_id') == 'comment' && $request->attributes->has('commented_entity_type')) {
     $form['#title'] = \Drupal::service('comment.manager')->getFieldUIPageTitle($request->attributes->get('commented_entity_type'), $request->attributes->get('field_name'));
   }
-  $entity_type_id = $form['#entity_type'];
-  if (!_comment_entity_uses_integer_id($entity_type_id)) {
+  if (!_comment_entity_uses_integer_id($form_state->get('entity_type_id'))) {
     // You cannot use comment fields on entity types with non-integer IDs.
-    unset($form['fields']['_add_new_field']['type']['#options']['comment']);
+    unset($form['add']['new_storage_type']['#options']['comment']);
   }
 }
 

core/modules/comment/src/Tests/CommentNonNodeTest.php

@@ -408,24 +408,24 @@ public function testsNonIntegerIdEntities() {
       'administer entity_test_string_id fields',
     ));
     $this->drupalLogin($limited_user);
-    // Visit the Field UI overview.
-    $this->drupalGet('entity_test_string_id/structure/entity_test/fields');
+    // Visit the Field UI field add page.
+    $this->drupalGet('entity_test_string_id/structure/entity_test/fields/add-field');
     // Ensure field isn't shown for string IDs.
-    $this->assertNoOption('edit-fields-add-new-field-type', 'comment');
+    $this->assertNoOption('edit-new-storage-type', 'comment');
     // Ensure a core field type shown.
-    $this->assertOption('edit-fields-add-new-field-type', 'boolean');
+    $this->assertOption('edit-new-storage-type', 'boolean');
 
     // Create a bundle for entity_test_no_id.
     entity_test_create_bundle('entity_test', 'Entity Test', 'entity_test_no_id');
     $this->drupalLogin($this->drupalCreateUser(array(
       'administer entity_test_no_id fields',
     )));
-    // Visit the Field UI overview.
-    $this->drupalGet('entity_test_no_id/structure/entity_test/fields');
+    // Visit the Field UI field add page.
+    $this->drupalGet('entity_test_no_id/structure/entity_test/fields/add-field');
     // Ensure field isn't shown for empty IDs.
-    $this->assertNoOption('edit-fields-add-new-field-type', 'comment');
+    $this->assertNoOption('edit-new-storage-type', 'comment');
     // Ensure a core field type shown.
-    $this->assertOption('edit-fields-add-new-field-type', 'boolean');
+    $this->assertOption('edit-new-storage-type', 'boolean');
   }
 
 }

core/modules/contact/src/Tests/ContactSitewideTest.php

@@ -247,6 +247,8 @@ function testSiteWideContact() {
 
     $this->clickLink(t('Manage fields'), $i);
     $this->assertResponse(200);
+    $this->clickLink(t('Add field'));
+    $this->assertResponse(200);
 
     // Create a simple textfield.
     $field_name = Unicode::strtolower($this->randomMachineName());

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

@@ -7,6 +7,7 @@
 
 namespace Drupal\entity_reference\Tests;
 
+use Drupal\field_ui\Tests\FieldUiTestTrait;
 use Drupal\simpletest\WebTestBase;
 use Drupal\taxonomy\Entity\Vocabulary;
 
@@ -17,6 +18,8 @@
  */
 class EntityReferenceAdminTest extends WebTestBase {
 
+  use FieldUiTestTrait;
+
   /**
    * Modules to install.
    *
@@ -55,11 +58,11 @@ public function testFieldAdminHandler() {
     $bundle_path = 'admin/structure/types/manage/' . $this->type;
 
     // First step: 'Add new field' on the 'Manage fields' page.
-    $this->drupalPostForm($bundle_path . '/fields', array(
-      'fields[_add_new_field][label]' => 'Test label',
-      'fields[_add_new_field][field_name]' => 'test',
-      'fields[_add_new_field][type]' => 'entity_reference',
-    ), t('Save'));
+    $this->drupalPostForm($bundle_path . '/fields/add-field', array(
+      'label' => 'Test label',
+      'field_name' => 'test',
+      'new_storage_type' => 'entity_reference',
+    ), t('Save and continue'));
 
     // Node should be selected by default.
     $this->assertFieldByName('field_storage[settings][target_type]', 'node');
@@ -198,24 +201,13 @@ public function createEntityReferenceField($target_type, $bundle = NULL) {
     // Generate a random field name, must be only lowercase characters.
     $field_name = strtolower($this->randomMachineName());
 
-    // Create the initial entity reference.
-    $this->drupalPostForm($bundle_path . '/fields', array(
-      'fields[_add_new_field][label]' => $this->randomMachineName(),
-      'fields[_add_new_field][field_name]' => $field_name,
-      'fields[_add_new_field][type]' => 'entity_reference',
-    ), t('Save'));
-
-    // Select the correct target type given in the parameters and save field settings.
-    $this->drupalPostForm(NULL, array('field_storage[settings][target_type]' => $target_type), t('Save field settings'));
-
-    // Select required fields if there are any.
-    $edit = array();
-    if($bundle) {
-      $edit['field[settings][handler_settings][target_bundles][' . $bundle . ']'] = TRUE;
+    $storage_edit = $field_edit = array();
+    $storage_edit['field_storage[settings][target_type]'] = $target_type;
+    if ($bundle) {
+      $field_edit['field[settings][handler_settings][target_bundles][' . $bundle . ']'] = TRUE;
     }
 
-    // Save settings.
-    $this->drupalPostForm(NULL, $edit, t('Save settings'));
+    $this->fieldUIAddNewField($bundle_path, $field_name, NULL, 'entity_reference', $storage_edit, $field_edit);
 
     // Returns the generated field name.
     return $field_name;

core/modules/field_ui/css/field_ui.admin.css

@@ -3,37 +3,28 @@
  * Stylesheet for the Field UI module.
  */
 
-/* 'Manage fields' and 'Manage display' overviews */
-.field-ui-overview .add-new .label-input {
-  float: left; /* LTR */
+/* Add new field page. */
+.field-ui-field-storage-add-form .field-type-wrapper .form-item {
+  float: left;
+  margin-right: 1em;
+  vertical-align: text-bottom;
 }
-[dir="rtl"] .field-ui-overview .add-new .label-input {
+[dir="rtl"] .field-ui-field-storage-add-form .field-type-wrapper .form-item {
   float: right;
+  margin-left: 1em;
+  margin-right: 0;
 }
-.field-ui-overview .add-new .description {
-  margin-bottom: 0;
-  max-width: 250px;
-}
-.field-ui-overview .add-new .form-type-machine-name .description {
-  white-space: normal;
-}
-.field-ui-overview .add-new .add-new-placeholder {
-  font-weight: bold;
-  padding-bottom: .5em;
+.field-ui-field-storage-add-form .field-type-wrapper .form-item-separator {
+  margin-top: 2.3em;
 }
+
+/* 'Manage fields' and 'Manage display' overviews */
 .field-ui-overview .region-title td {
   font-weight: bold;
 }
 .field-ui-overview .region-message td {
   font-style: italic;
 }
-.field-ui-overview .region-add-new-title {
-  display: none;
-}
-.field-ui-overview .add-new td {
-  vertical-align: top;
-  white-space: nowrap;
-}
 
 /* 'Manage form display' and 'Manage display' overview */
 .field-ui-overview .field-plugin-summary-cell {

core/modules/field_ui/field_ui.js

@@ -3,10 +3,53 @@
  * Attaches the behaviors for the Field UI module.
  */
 
-(function ($) {
+(function ($, Drupal, drupalSettings) {
 
   "use strict";
 
+  Drupal.behaviors.fieldUIFieldStorageAddForm = {
+    attach: function (context) {
+      var $form = $(context).find('#field-ui-field-storage-add-form').once('field_ui_add');
+      if ($form.length) {
+        // Add a few 'form-required' css classes here. We can not use the Form API
+        // '#required' property because both label elements for "add new" and
+        // "re-use existing" can never be filled and submitted at the same time.
+        // The actual validation will happen server-side.
+        $form.find(
+          '.form-item-label label,' +
+          '.form-item-field-name label,' +
+          '.form-item-existing-storage-label label')
+          .addClass('form-required');
+
+        var $newFieldType = $form.find('select[name="new_storage_type"]');
+        var $existingStorageName = $form.find('select[name="existing_storage_name"]');
+
+        // When the user selects a new field type, clear the "existing field"
+        // selection.
+        $newFieldType.change(function () {
+          if ($(this).val() != '') {
+            // Reset the "existing storage name" selection.
+            $existingStorageName.val('').change();
+          }
+        });
+
+        // When the user selects an existing storage name, clear the "new field
+        // type" selection and populate the 'existing_storage_label' element.
+        $existingStorageName.change(function () {
+          if ($(this).val() != '') {
+            // Reset the "new field type" selection.
+            $newFieldType.val('').change();
+
+            // Pre-populate the "existing storage label" element.
+            if (drupalSettings.existingFieldLabels[$(this).val()] !== undefined) {
+              $(context).find('input[name="existing_storage_label"]').val(drupalSettings.existingFieldLabels[$(this).val()]);
+            }
+          }
+        });
+      }
+    }
+  };
+
   Drupal.behaviors.fieldUIDisplayOverview = {
     attach: function (context, settings) {
       $(context).find('table#field-display-overview').once('field-display-overview', function () {
@@ -249,4 +292,4 @@
     }
   };
 
-})(jQuery);
+})(jQuery, Drupal, drupalSettings);

core/modules/field_ui/field_ui.links.action.yml

@@ -11,3 +11,7 @@ field_ui.entity_form_mode_add:
   weight: 1
   appears_on:
     - field_ui.entity_form_mode_list
+
+field_ui.field_storage_config_add:
+  class: \Drupal\Core\Menu\LocalActionDefault
+  deriver: \Drupal\field_ui\Plugin\Derivative\FieldUiLocalAction

core/modules/field_ui/src/Controller/FieldConfigListController.php

+<?php
+
+/**
+ * @file
+ * Contains \Drupal\field_ui\Controller\FieldConfigListController.
+ */
+
+namespace Drupal\field_ui\Controller;
+
+use Drupal\Core\Entity\Controller\EntityListController;
+use Symfony\Component\HttpFoundation\Request;
+
+/**
+ * Defines a controller to list field instances.
+ */
+class FieldConfigListController extends EntityListController {
+
+  /**
+   * Shows the 'Manage fields' page.
+   *
+   * @param string $entity_type_id
+   *   The entity type.
+   * @param string $bundle
+   *   The entity bundle.
+   * @param \Symfony\Component\HttpFoundation\Request $request
+   *   The current request.
+   *
+   * @return array
+   *   A render array as expected by drupal_render().
+   */
+  public function listing($entity_type_id = NULL, $bundle = NULL, Request $request = NULL) {
+    if (!$bundle) {
+      $entity_info = $this->entityManager()->getDefinition($entity_type_id);
+      $bundle = $request->attributes->get('_raw_variables')->get($entity_info->getBundleEntityType());
+    }
+    return $this->entityManager()->getListBuilder('field_config')->render($entity_type_id, $bundle, $request);
+  }
+
+}

core/modules/field_ui/src/DisplayOverview.php

@@ -204,7 +204,7 @@ protected function getTableHeader() {
    */
   protected function getOverviewRoute($mode) {
     return Url::fromRoute('field_ui.display_overview_view_mode_' . $this->entity_type, [
-      $this->bundleEntityType => $this->bundle,
+      $this->bundleEntityTypeId => $this->bundle,
       'view_mode_name' => $mode,
     ]);
   }

core/modules/field_ui/src/DisplayOverviewBase.php

@@ -9,6 +9,7 @@
 
 use Drupal\Component\Plugin\Factory\DefaultFactory;
 use Drupal\Component\Plugin\PluginManagerBase;
+use Drupal\Component\Utility\Html;
 use Drupal\Component\Utility\String;
 use Drupal\Core\Config\ConfigFactoryInterface;
 use Drupal\Core\Entity\Display\EntityDisplayInterface;
@@ -16,13 +17,51 @@
 use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Field\FieldTypePluginManagerInterface;
 use Drupal\Core\Field\PluginSettingsInterface;
+use Drupal\Core\Form\FormBase;
 use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Render\Element;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
  * Field UI display overview base class.
  */
-abstract class DisplayOverviewBase extends OverviewBase {
+abstract class DisplayOverviewBase extends FormBase {
+
+  /**
+   * The name of the entity type.
+   *
+   * @var string
+   */
+  protected $entity_type = '';
+
+  /**
+   * The entity bundle.
+   *
+   * @var string
+   */
+  protected $bundle = '';
+
+  /**
+   * The name of the entity type which provides bundles for the entity type
+   * defined above.
+   *
+   * @var string
+   */
+  protected $bundleEntityTypeId;
+
+  /**
+   * The entity view or form mode.
+   *
+   * @var string
+   */
+  protected $mode = '';
+
+  /**
+   * The entity manager.
+   *
+   * @var \Drupal\Core\Entity\EntityManagerInterface
+   */
+  protected $entityManager;
 
   /**
    * The display context. Either 'view' or 'form'.
@@ -65,8 +104,7 @@ abstract class DisplayOverviewBase extends OverviewBase {
    *   The configuration factory.
    */
   public function __construct(EntityManagerInterface $entity_manager, FieldTypePluginManagerInterface $field_type_manager, PluginManagerBase $plugin_manager, ConfigFactoryInterface $config_factory) {
-    parent::__construct($entity_manager);
-
+    $this->entityManager = $entity_manager;
     $this->fieldTypes = $field_type_manager->getDefinitions();
     $this->pluginManager = $plugin_manager;
     $this->configFactory = $config_factory;
@@ -85,7 +123,23 @@ public static function create(ContainerInterface $container) {
   }
 
   /**
-   * {@inheritdoc}
+   * Get the regions needed to create the overview form.
+   *
+   * @return array
+   *   Example usage:
+   *   @code
+   *     return array(
+   *       'content' => array(
+   *         // label for the region.
+   *         'title' => $this->t('Content'),
+   *         // Indicates if the region is visible in the UI.
+   *         'invisible' => TRUE,
+   *         // A message to indicate that there is nothing to be displayed in
+   *         // the region.
+   *         'message' => $this->t('No field is displayed.'),
+   *       ),
+   *     );
+   *   @endcode
    */
   public function getRegions() {
     return array(
@@ -101,6 +155,20 @@ public function getRegions() {
     );
   }
 
+  /**
+   * Returns an associative array of all regions.
+   *
+   * @return array
+   *   An array containing the region options.
+   */
+  public function getRegionOptions() {
+    $options = array();
+    foreach ($this->getRegions() as $region => $data) {
+      $options[$region] = $data['title'];
+    }
+    return $options;
+  }
+
   /**
    * Collects the definitions of fields whose display is configurable.
    *
@@ -118,8 +186,16 @@ protected function getFieldDefinitions() {
    * {@inheritdoc}
    */
   public function buildForm(array $form, FormStateInterface $form_state, $entity_type_id = NULL, $bundle = NULL, $mode = 'default') {
-    parent::buildForm($form, $form_state, $entity_type_id, $bundle);
+    $entity_type = $this->entityManager->getDefinition($entity_type_id);
+    $this->bundleEntityTypeId = $entity_type->getBundleEntityType();
+
+    if (!$form_state->get('bundle')) {
+      $bundle = $bundle ?: $this->getRequest()->attributes->get('_raw_variables')->get($this->bundleEntityTypeId);
+      $form_state->set('bundle', $bundle);
+    }
 
+    $this->entity_type = $entity_type_id;
+    $this->bundle = $form_state->get('bundle');
     $this->mode = $mode;
 
     $field_definitions = $this->getFieldDefinitions();
@@ -689,6 +765,120 @@ public function multistepAjax($form, FormStateInterface $form_state) {
     return $form['fields'];
   }
 
+  /**
+   * Performs pre-render tasks on field_ui_table elements.
+   *
+   * This function is assigned as a #pre_render callback in
+   * field_ui_element_info().
+   *
+   * @param array $elements
+   *   A structured array containing two sub-levels of elements. Properties
+   *   used:
+   *   - #tabledrag: The value is a list of $options arrays that are passed to
+   *     drupal_attach_tabledrag(). The HTML ID of the table is added to each
+   *     $options array.
+   *
+   * @see drupal_render()
+   * @see \Drupal\Core\Render\Element\Table::preRenderTable()
+   */
+  public function tablePreRender($elements) {
+    $js_settings = array();
+
+    // For each region, build the tree structure from the weight and parenting
+    // data contained in the flat form structure, to determine row order and
+    // indentation.
+    $regions = $elements['#regions'];
+    $tree = array('' => array('name' => '', 'children' => array()));
+    $trees = array_fill_keys(array_keys($regions), $tree);
+
+    $parents = array();
+    $children = Element::children($elements);
+    $list = array_combine($children, $children);
+
+    // Iterate on rows until we can build a known tree path for all of them.
+    while ($list) {
+      foreach ($list as $name) {
+        $row = &$elements[$name];
+        $parent = $row['parent_wrapper']['parent']['#value'];
+        // Proceed if parent is known.
+        if (empty($parent) || isset($parents[$parent])) {
+          // Grab parent, and remove the row from the next iteration.
+          $parents[$name] = $parent ? array_merge($parents[$parent], array($parent)) : array();
+          unset($list[$name]);
+
+          // Determine the region for the row.
+          $region_name = call_user_func($row['#region_callback'], $row);
+
+          // Add the element in the tree.
+          $target = &$trees[$region_name][''];
+          foreach ($parents[$name] as $key) {
+            $target = &$target['children'][$key];
+          }
+          $target['children'][$name] = array('name' => $name, 'weight' => $row['weight']['#value']);
+
+          // Add tabledrag indentation to the first row cell.
+          if ($depth = count($parents[$name])) {
+            $children = Element::children($row);
+            $cell = current($children);
+            $indentation = array(
+              '#theme' => 'indentation',
+              '#size' => $depth,
+            );
+            $row[$cell]['#prefix'] = drupal_render($indentation) . (isset($row[$cell]['#prefix']) ? $row[$cell]['#prefix'] : '');
+          }
+
+          // Add row id and associate JS settings.
+          $id = Html::getClass($name);
+          $row['#attributes']['id'] = $id;
+          if (isset($row['#js_settings'])) {
+            $row['#js_settings'] += array(
+              'rowHandler' => $row['#row_type'],
+              'name' => $name,
+              'region' => $region_name,
+            );
+            $js_settings[$id] = $row['#js_settings'];
+          }
+        }
+      }
+    }
+    // Determine rendering order from the tree structure.
+    foreach ($regions as $region_name => $region) {
+      $elements['#regions'][$region_name]['rows_order'] = array_reduce($trees[$region_name], array($this, 'reduceOrder'));
+    }
+
+    $elements['#attached']['drupalSettings']['fieldUIRowsData'] = $js_settings;
+
+    // If the custom #tabledrag is set and there is a HTML ID, add the table's
+    // HTML ID to the options and attach the behavior.
+    // @see \Drupal\Core\Render\Element\Table::preRenderTable()
+    if (!empty($elements['#tabledrag']) && isset($elements['#attributes']['id'])) {
+      foreach ($elements['#tabledrag'] as $options) {
+        $options['table_id'] = $elements['#attributes']['id'];
+        drupal_attach_tabledrag($elements, $options);
+      }
+    }
+
+    return $elements;
+  }
+
+  /**
+   * Determines the rendering order of an array representing a tree.
+   *
+   * Callback for array_reduce() within
+   * \Drupal\field_ui\DisplayOverviewBase::tablePreRender().
+   */
+  public function reduceOrder($array, $a) {
+    $array = !isset($array) ? array() : $array;
+    if ($a['name']) {
+      $array[] = $a['name'];
+    }
+    if (!empty($a['children'])) {
+      uasort($a['children'], array('Drupal\Component\Utility\SortArray', 'sortByWeightElement'));
+      $array = array_merge($array, array_reduce($a['children'], array($this, 'reduceOrder')));
+    }
+    return $array;
+  }
+
   /**
    * Returns the entity display object used by this form.
    *

core/modules/field_ui/src/FieldConfigListBuilder.php

@@ -7,10 +7,15 @@
 
 namespace Drupal\field_ui;
 
+use Drupal\Component\Utility\Html;
+use Drupal\Component\Utility\String;
 use Drupal\Core\Config\Entity\ConfigEntityListBuilder;
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\EntityManagerInterface;
 use Drupal\Core\Entity\EntityTypeInterface;
+use Drupal\Core\Field\FieldTypePluginManagerInterface;
+use Drupal\Core\Url;
+use Drupal\field\FieldConfigInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
 
 /**
@@ -18,6 +23,20 @@
  */
 class FieldConfigListBuilder extends ConfigEntityListBuilder {
 
+  /**
+   * The name of the entity type the listed fields are attached to.
+   *
+   * @var string
+   */
+  protected $targetEntityTypeId;
+
+  /**
+   * The name of the bundle the listed fields are attached to.
+   *
+   * @var string
+   */
+  protected $targetBundle;
+
   /**
    * The entity manager.
    *
@@ -25,6 +44,13 @@ class FieldConfigListBuilder extends ConfigEntityListBuilder {
    */
   protected $entityManager;
 
+  /**
+   * The field type plugin manager.
+   *
+   * @var \Drupal\Core\Field\FieldTypePluginManagerInterface
+   */
+  protected $fieldTypeManager;
+
   /**
    * Constructs a new class instance.
    *
@@ -32,27 +58,103 @@ class FieldConfigListBuilder extends ConfigEntityListBuilder {
    *   The entity type definition.
    * @param \Drupal\Core\Entity\EntityManagerInterface $entity_manager
    *   The entity manager.
+   * @param \Drupal\Core\Field\FieldTypePluginManagerInterface $field_type_manager
+   *   The field type manager
    */
-  public function __construct(EntityTypeInterface $entity_type, EntityManagerInterface $entity_manager) {
+  public function __construct(EntityTypeInterface $entity_type, EntityManagerInterface $entity_manager, FieldTypePluginManagerInterface $field_type_manager) {
     parent::__construct($entity_type, $entity_manager->getStorage($entity_type->id()));
+
     $this->entityManager = $entity_manager;
+    $this->fieldTypeManager = $field_type_manager;
   }
 
   /**
    * {@inheritdoc}
    */
   public static function createInstance(ContainerInterface $container, EntityTypeInterface $entity_type) {
-    return new static($entity_type, $container->get('entity.manager'));
+    return new static($entity_type, $container->get('entity.manager'), $container->get('plugin.manager.field.field_type'));
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function render($target_entity_type_id = NULL, $target_bundle = NULL) {
+    $this->targetEntityTypeId = $target_entity_type_id;
+    $this->targetBundle = $target_bundle;
+
+    $build = parent::render();
+    $build['#attributes']['id'] = 'field-overview';
+    $build['#empty'] = $this->t('No fields are present yet.');
+
+    return $build;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function load() {
+    $entities = array_filter($this->entityManager->getFieldDefinitions($this->targetEntityTypeId, $this->targetBundle), function ($field_definition) {
+      return $field_definition instanceof FieldConfigInterface;
+    });
+
+    // Sort the entities using the entity class's sort() method.
+    // See \Drupal\Core\Config\Entity\ConfigEntityBase::sort().
+    uasort($entities, array($this->entityType->getClass(), 'sort'));
+    return $entities;
   }
 
   /**
    * {@inheritdoc}
    */
-  public function render() {
-    // The actual field config overview is rendered by
-    // \Drupal\field_ui\FieldOverview, so we should not use this class to build
-    // lists.
-    throw new \Exception('This class is only used for operations and not for building lists.');
+  public function buildHeader() {