<?php/** * Validates a number as defined by the CSS spec. */class HTMLPurifier_AttrDef_CSS_Number extends HTMLPurifier_AttrDef{        /**     * Bool indicating whether or not only positive values allowed.     */    var $non_negative = false;        /**     * @param $non_negative Bool indicating whether negatives are forbidden     */    function HTMLPurifier_AttrDef_CSS_Number($non_negative = false) {        $this->non_negative = $non_negative;    }        /**     * @warning Some contexts do not pass $config, $context. These     *          variables should not be used without checking HTMLPurifier_Length.     *          This might not work properly in PHP4.     */    function validate($number, $config, &$context) {                $number = $this->parseCDATA($number);                if ($number === '') return false;                $sign = '';        switch ($number[0]) {            case '-':                if ($this->non_negative) return false;                $sign = '-';            case '+':                $number = substr($number, 1);        }                if (ctype_digit($number)) {            $number = ltrim($number, '0');            return $number ? $sign . $number : '0';        }        if (!strpos($number, '.')) return false;                list($left, $right) = explode('.', $number, 2);                if (!ctype_digit($left)) return false;        $left = ltrim($left, '0');                $right = rtrim($right, '0');                if ($right === '') {            return $left ? $sign . $left : '0';        } elseif (!ctype_digit($right)) {            return false;        }                return $sign . $left . '.' . $right;            }    }