EntityHasFieldConstraint.php

<?php

namespace Drupal\Core\Entity\Plugin\Validation\Constraint;

use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\Core\Validation\Attribute\Constraint;
use Symfony\Component\Validator\Constraint as SymfonyConstraint;

/**
 * Checks if a value is an entity that has a specific field.
 */
class EntityHasFieldConstraint extends SymfonyConstraint {
    
    /**
     * The default violation message.
     *
     * @var string
     */
    public $message = 'The entity must have the %field_name field.';
    
    /**
     * The violation message for non-fieldable entities.
     *
     * @var string
     */
    public $notFieldableMessage = 'The entity does not support fields.';
    
    /**
     * The field name option.
     *
     * @var string
     */
    // phpcs:ignore Drupal.NamingConventions.ValidVariableName.LowerCamelName
    public $field_name;
    
    /**
     * {@inheritdoc}
     *
     * @return ?string
     *   Name of the default option.
     *
     * @todo Add method return type declaration.
     * @see https://www.drupal.org/project/drupal/issues/3425150
     */
    public function getDefaultOption() {
        return 'field_name';
    }
    
    /**
     * {@inheritdoc}
     *
     * @return array
     *   The names of the required options.
     *
     * @todo Add method return type declaration.
     * @see https://www.drupal.org/project/drupal/issues/3425150
     */
    public function getRequiredOptions() {
        return (array) $this->getDefaultOption();
    }

}