/** * @param string $string * @param HTMLPurifier_Config $config * @param HTMLPurifier_Context $context * @return bool|string */ public function validate($string, $config, $context) { $string = trim($string); if ($string === '') { return false; } $parent_result = parent::validate($string, $config, $context); if ($parent_result !== false) { return $parent_result; } $length = strlen($string); $last_char = $string[$length - 1]; if ($last_char !== '%') { return false; } $points = substr($string, 0, $length - 1); if (!is_numeric($points)) { return false; } $points = (int) $points; if ($points < 0) { return '0%'; } if ($points > 100) { return '100%'; } return (string) $points . '%'; }