class ComplexDataConstraint

class ComplexDataConstraint extends Constraint {

  /**
   * An array of constraints for contained properties, keyed by property name.
   *
   * @var array
   */
  public $properties;

  /**
   * {@inheritdoc}
   */
  public function __construct($options = NULL) {

    // Allow skipping the 'properties' key in the options.
    if (is_array($options) && !array_key_exists('properties', $options)) {
      $options = array(
        'properties' => $options,
      );
    }
    parent::__construct($options);
    $constraint_manager = \Drupal::service('validation.constraint');

    // Instantiate constraint objects for array definitions.
    foreach ($this->properties as &$constraints) {
      foreach ($constraints as $id => $options) {
        if (!is_object($options)) {
          $constraints[$id] = $constraint_manager
            ->create($id, $options);
        }
      }
    }
  }

  /**
   * {@inheritdoc}
   */
  public function getDefaultOption() {
    return 'properties';
  }

  /**
   * {@inheritdoc}
   */
  public function getRequiredOptions() {
    return array(
      'properties',
    );
  }

}