/**
* Validates the input value according to this attribute.
*
* @param InputInterface $input The input to validate
*
* @throws InvalidValueException If the value is not valid
*/
public static function validate(InputInterface $input)
{
if (!($value = $input->val())) {
return;
}
if ($input->attr('multiple')) {
if (array_keys(array_diff_key(array_flip($value), $input->options()))) {
throw new InvalidValueException(sprintf(static::$error_message));
}
} elseif (!isset($input[$value])) {
throw new InvalidValueException(sprintf(static::$error_message));
}
}