htmlpurifier/library/HTMLPurifier/AttrDef/HTML/MultiLength.php

<?php

/**
 * Validates a MultiLength as defined by the HTML spec.
 * 
 * A multilength is either a integer (pixel count), a percentage, or
 * a relative number.
 */
class HTMLPurifier_AttrDef_HTML_MultiLength extends HTMLPurifier_AttrDef_HTML_Length
{
    
    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;
        
        $int = substr($string, 0, $length - 1);
        
        if ($int == '') return '*';
        if (!is_numeric($int)) return false;
        
        $int = (int) $int;
        
        if ($int < 0) return false;
        if ($int == 0) return '0';
        if ($int == 1) return '*';
        return ((string) $int) . '*';
        
    }
    
}