Constraint.php

<?php

namespace Drupal\Core\Validation\Attribute;

use Drupal\Component\Plugin\Attribute\Plugin;
use Drupal\Core\StringTranslation\TranslatableMarkup;

/**
 * Defines a Constraint attribute object.
 *
 * Plugin Namespace: Plugin\Validation\Constraint
 *
 * For a working example, see
 * \Drupal\Core\Validation\Plugin\Validation\Constraint\LengthConstraint
 *
 * @see \Drupal\Core\Validation\ConstraintManager
 * @see \Symfony\Component\Validator\Constraint
 * @see hook_validation_constraint_alter()
 * @see plugin_api
 */
class Constraint extends Plugin {
    
    /**
     * Constructs a Constraint attribute.
     *
     * @param string $id
     *   The constraint plugin ID.
     * @param \Drupal\Core\StringTranslation\TranslatableMarkup|null $label
     *   (optional) The human-readable name of the constraint plugin.
     * @param string|string[]|false $type
     *   (optional) DataType plugin IDs for which this constraint applies. Valid
     *   values are any types registered by the typed data API, or an array of
     *   multiple type names. For supporting all types, FALSE may be specified.
     *   The key defaults to an empty array, which indicates no types are
     *   supported.
     * @param class-string|null $deriver
     *   (optional) The deriver class.
     */
    public function __construct(string $id, ?TranslatableMarkup $label = NULL, string|array|false $type = [], ?string $deriver = NULL) {
    }

}