CurrencyValidator.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\Constraints;

use Symfony\Component\Intl\Intl;
use Symfony\Component\Validator\Constraint;
use Symfony\Component\Validator\ConstraintValidator;
use Symfony\Component\Validator\Exception\UnexpectedTypeException;

/**
 * Validates whether a value is a valid currency
 *
 * @author Miha Vrhovnik <miha.vrhovnik@pagein.si>
 *
 * @api
 */
class CurrencyValidator extends ConstraintValidator {

  /**
   * {@inheritDoc}
   */
  public function validate($value, Constraint $constraint) {
    if (null === $value || '' === $value) {
      return;
    }
    if (!is_scalar($value) && !(is_object($value) && method_exists($value, '__toString'))) {
      throw new UnexpectedTypeException($value, 'string');
    }
    $value = (string) $value;
    $currencies = Intl::getCurrencyBundle()
      ->getCurrencyNames();
    if (!isset($currencies[$value])) {
      $this->context
        ->addViolation($constraint->message, array(
        '{{ value }}' => $value,
      ));
    }
  }

}