ConstraintValidatorFactory.php

<?php


/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */
namespace Symfony\Component\Validator;

use Symfony\Component\Validator\Constraints\ExpressionValidator;

/**
 * Default implementation of the ConstraintValidatorFactoryInterface.
 *
 * This enforces the convention that the validatedBy() method on any
 * Constraint will return the class name of the ConstraintValidator that
 * should validate the Constraint.
 *
 * @author Bernhard Schussek <bschussek@gmail.com>
 */
class ConstraintValidatorFactory implements ConstraintValidatorFactoryInterface {
    public function __construct(array $validators = []) {
    }
    public function getInstance(Constraint $constraint) : ConstraintValidatorInterface {
        if ('validator.expression' === ($name = $class = $constraint->validatedBy())) {
            $class = ExpressionValidator::class;
        }
        return $this->validators[$name] ??= new $class();
    }

}