* * 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\Validator\Constraint; use Symfony\Component\Validator\ConstraintValidator; use Symfony\Component\Validator\Exception\UnexpectedTypeException; /** * Validates whether the value is a valid ISSN. * * @author Antonio J. García Lagar * * @see https://en.wikipedia.org/wiki/Issn */ class IssnValidator 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'); } // Compose regex pattern $digitsPattern = $constraint->requireHyphen ? '\d{4}-\d{3}' : '\d{4}-?\d{3}'; $checksumPattern = $constraint->caseSensitive ? '[\d|X]' : '[\d|X|x]'; $pattern = "/^".$digitsPattern.$checksumPattern."$/"; if (!preg_match($pattern, $value)) { $this->context->addViolation($constraint->message); } else { $digits = str_split(strtoupper(str_replace('-', '', $value))); $sum = 0; for ($i = 8; $i > 1; $i--) { $sum += $i * (int) array_shift($digits); } $checksum = 'X' == reset($digits) ? 10 : (int) reset($digits); if (0 != ($sum + $checksum) % 11) { $this->context->addViolation($constraint->message); } } } }