OptionsAllowedValues.php

<?php

declare (strict_types=1);
namespace Drupal\options_test;

use Drupal\Core\Entity\FieldableEntityInterface;
use Drupal\Core\Field\FieldStorageDefinitionInterface;

/**
 * Provide allowed values callback.
 */
class OptionsAllowedValues {
  
  /**
   * Implements callback_allowed_values_function().
   *
   * @see options_allowed_values()
   */
  public static function simpleValues(FieldStorageDefinitionInterface $definition, ?FieldableEntityInterface $entity = NULL) : array {
    return [
      'Group 1' => [
        0 => 'Zero',
      ],
      1 => 'One',
      'Group 2' => [
        2 => 'Some <script>dangerous</script> & unescaped <strong>markup</strong>',
      ],
      'More <script>dangerous</script> markup' => [
        3 => 'Three',
      ],
    ];
  }
  
  /**
   * Implements callback_allowed_values_function().
   *
   * @todo This function violates the recommendation in options_allowed_values()
   *   to return a list of all possible values in any context when $items is
   *   NULL. Since this is not yet used for testing Views integration, that is
   *   alright for now. Fix this in https://www.drupal.org/node/2012130.
   *
   * @see options_allowed_values()
   */
  public static function dynamicValues(FieldStorageDefinitionInterface $definition, ?FieldableEntityInterface $entity = NULL, &$cacheable = NULL) : array {
    $values = [];
    if (isset($entity)) {
      $cacheable = FALSE;
      $values = [
        $entity->label(),
        $entity->toUrl()
          ->toString(),
        $entity->uuid(),
        $entity->bundle(),
      ];
    }
    // We need the values of the entity as keys.
    return array_combine($values, $values);
  }

}