getOverviewRouteInfo example

    // deleted too, notify the user about dependencies.     if (count($field_storage->getBundles()) <= 1) {
      $config_names[] = $field_storage->getConfigDependencyName();
    }
    return $config_names;
  }

  /** * {@inheritdoc} */
  public function getCancelUrl() {
    return FieldUI::getOverviewRouteInfo($this->entity->getTargetEntityTypeId(), $this->entity->getTargetBundle());
  }

  /** * {@inheritdoc} */
  public function submitForm(array &$form, FormStateInterface $form_state) {
    $field_storage = $this->entity->getFieldStorageDefinition();
    $bundles = $this->entityTypeBundleInfo->getBundleInfo($this->entity->getTargetEntityTypeId());
    $bundle_label = $bundles[$this->entity->getTargetBundle()]['label'];

    if ($field_storage && !$field_storage->isLocked()) {
      

public function save(array $form, FormStateInterface $form_state) {
    $field_label = $form_state->get('field_config')->label();
    try {
      $this->entity->save();
      $this->messenger()->addStatus($this->t('Updated field %label field settings.', ['%label' => $field_label]));
      $request = $this->getRequest();
      if (($destinations = $request->query->all('destinations')) && $next_destination = FieldUI::getNextDestination($destinations)) {
        $request->query->remove('destinations');
        $form_state->setRedirectUrl($next_destination);
      }
      else {
        $form_state->setRedirectUrl(FieldUI::getOverviewRouteInfo($form_state->get('entity_type_id'), $form_state->get('bundle')));
      }
    }
    catch (\Exception $e) {
      $this->messenger()->addStatus($this->t('Attempt to update field %label failed: %message.', ['%label' => $field_label, '%message' => $e->getMessage()]));
    }
  }

  /** * Returns the cardinality enforced by the field type. * * Some field types choose to enforce a fixed cardinality. This method * returns that cardinality or NULL if no cardinality has been enforced. * * @return int|null */

    $entity_type_id = $field_storage->getTargetEntityTypeId();
    // Adding the entity type.     $row['data']['entity_type'] = $entity_type_id;

    $field_type = $this->fieldTypes[$field_storage->getType()];
    $row['data']['type'] = $this->t('@type (module: @module)', ['@type' => $field_type['label'], '@module' => $field_type['provider']]);

    $usage = [];
    foreach ($field_storage->getBundles() as $bundle) {
      if ($route_info = FieldUI::getOverviewRouteInfo($entity_type_id, $bundle)) {
        $usage[] = Link::fromTextAndUrl($this->bundles[$entity_type_id][$bundle]['label'], $route_info)->toRenderable();
      }
      else {
        $usage[] = $this->bundles[$entity_type_id][$bundle]['label'];
      }
    }
    $row['data']['usage']['data'] = [
      '#theme' => 'item_list',
      '#items' => $usage,
      '#context' => ['list_style' => 'comma-list'],
    ];
    

$field_definitions = $this->getFieldDefinitions();
    $extra_fields = $this->getExtraFields();

    $form += [
      '#entity_type' => $this->entity->getTargetEntityTypeId(),
      '#bundle' => $this->entity->getTargetBundle(),
      '#fields' => array_keys($field_definitions),
      '#extra' => array_keys($extra_fields),
    ];

    if (empty($field_definitions) && empty($extra_fields) && $route_info = FieldUI::getOverviewRouteInfo($this->entity->getTargetEntityTypeId(), $this->entity->getTargetBundle())) {
      $this->messenger()->addWarning($this->t('There are no fields yet added. You can add new fields on the <a href=":link">Manage fields</a> page.', [':link' => $route_info->toString()]));
      return $form;
    }

    $table = [
      '#type' => 'field_ui_table',
      '#header' => $this->getTableHeader(),
      '#regions' => $this->getRegions(),
      '#attributes' => [
        'class' => ['field-ui-overview'],
        'id' => 'field-display-overview',
      ],

public function save(array $form, FormStateInterface $form_state) {
    $this->entity->save();

    $this->messenger()->addStatus($this->t('Saved %label configuration.', ['%label' => $this->entity->getLabel()]));

    $request = $this->getRequest();
    if (($destinations = $request->query->all('destinations')) && $next_destination = FieldUI::getNextDestination($destinations)) {
      $request->query->remove('destinations');
      $form_state->setRedirectUrl($next_destination);
    }
    else {
      $form_state->setRedirectUrl(FieldUI::getOverviewRouteInfo($this->entity->getTargetEntityTypeId(), $this->entity->getTargetBundle()));
    }
  }

  /** * The _title_callback for the field settings form. * * @param \Drupal\field\FieldConfigInterface $field_config * The field. * * @return string * The label of the field. */