php-htmlpurifier/library/HTMLPurifier/AttrDef/CSS/Length.php

<?php

require_once 'HTMLPurifier/Length.php';
require_once 'HTMLPurifier/UnitConverter.php';

HTMLPurifier_ConfigSchema::define(
    'CSS', 'MaxImgLength', '1200px', 'string/null', '
<p>
 This parameter sets the maximum allowed length on <code>img</code> tags,
 effectively the <code>width</code> and <code>height</code> properties.
 Only absolute units of measurement (in, pt, pc, mm, cm) and pixels (px) are allowed. This is
 in place to prevent imagecrash attacks, disable with null at your own risk.
 This directive is similar to %HTML.MaxImgLength, and both should be
 concurrently edited, although there are
 subtle differences in the input format (the CSS max is a number with
 a unit).
</p>
');

/**
 * Represents a Length as defined by CSS.
 */
class HTMLPurifier_AttrDef_CSS_Length extends HTMLPurifier_AttrDef
{
    
    var $min, $max;
    
    /**
     * @param HTMLPurifier_Length $max Minimum length, or null for no bound. String is also acceptable.
     * @param HTMLPurifier_Length $max Maximum length, or null for no bound. String is also acceptable.
     */
    function HTMLPurifier_AttrDef_CSS_Length($min = null, $max = null) {
        $this->min = $min !== null ? HTMLPurifier_Length::make($min) : null;
        $this->max = $max !== null ? HTMLPurifier_Length::make($max) : null;
    }
    
    function validate($string, $config, $context) {
        $string = $this->parseCDATA($string);
        
        // Optimizations
        if ($string === '') return false;
        if ($string === '0') return '0';
        if (strlen($string) === 1) return false;
        
        $length = HTMLPurifier_Length::make($string);
        if (!$length->isValid()) return false;
        
        if ($this->min) {
            $c = $length->compareTo($this->min);
            if ($c === false) return false;
            if ($c < 0) return false;
        }
        if ($this->max) {
            $c = $length->compareTo($this->max);
            if ($c === false) return false;
            if ($c > 0) return false;
        }
        
        return $length->toString();
    }
    
}