<?php
/**
* Validates Color as defined by CSS.
*/
class HTMLPurifier_AttrDef_CSS_Color extends HTMLPurifier_AttrDef
{
/**
* @type HTMLPurifier_AttrDef_CSS_AlphaValue
*/
protected $alpha;
public function __construct()
{
$this->alpha = new HTMLPurifier_AttrDef_CSS_AlphaValue();
}
/**
* @param string $color
* @param HTMLPurifier_Config $config
* @param HTMLPurifier_Context $context
* @return bool|string
*/
public function validate($color, $config, $context)
{
static $colors = null;
if ($colors === null) {
$colors = $config->get('Core.ColorKeywords');
}
$color = trim($color);
if ($color === '') {
return false;
}
$lower = strtolower($color);
if (isset($colors[$lower])) {
return $colors[$lower];
}
if (preg_match('#(rgb|rgba|hsl|hsla)\(#', $color, $matches) === 1) {
$length = strlen($color);
if (strpos($color, ')') !== $length - 1) {
return false;
}
// get used function : rgb, rgba, hsl or hsla
$function = $matches[1];
$parameters_size = 3;
$alpha_channel = false;
if (substr($function, -1) === 'a') {
$parameters_size = 4;
$alpha_channel = true;
}
/*
* Allowed types for values :
* parameter_position => [type => max_value]
*/
$allowed_types = array(
1 => array('percentage' => 100, 'integer' => 255),
2 => array('percentage' => 100, 'integer' => 255),
3 => array('percentage' => 100, 'integer' => 255),
);
$allow_different_types = false;
if (strpos($function, 'hsl') !== false) {
$allowed_types = array(
1 => array('integer' => 360),
2 => array('percentage' => 100),
3 => array('percentage' => 100),
);
$allow_different_types = true;
}
$values = trim(str_replace($function, '', $color), ' ()');
$parts = explode(',', $values);
if (count($parts) !== $parameters_size) {
return false;
}
$type = false;
$new_parts = array();
$i = 0;
foreach ($parts as $part) {
$i++;
$part = trim($part);
if ($part === '') {
return false;
}
// different check for alpha channel
if ($alpha_channel === true && $i === count($parts)) {
$result = $this->alpha->validate($part, $config, $context);
if ($result === false) {
return false;
}
$new_parts[] = (string)$result;
continue;
}
if (substr($part, -1) === '%') {
$current_type = 'percentage';
} else {
$current_type = 'integer';
}
if (!array_key_exists($current_type, $allowed_types[$i])) {
return false;
}
if (!$type) {
$type = $current_type;
}
if ($allow_different_types === false && $type != $current_type) {
return false;
}
$max_value = $allowed_types[$i][$current_type];
if ($current_type == 'integer') {
// Return value between range 0 -> $max_value
$new_parts[] = (int)max(min($part, $max_value), 0);
} elseif ($current_type == 'percentage') {
$new_parts[] = (float)max(min(rtrim($part, '%'), $max_value), 0) . '%';
}
}
$new_values = implode(',', $new_parts);
$color = $function . '(' . $new_values . ')';
} else {
// hexadecimal handling
if ($color[0] === '#') {
$hex = substr($color, 1);
} else {
$hex = $color;
$color = '#' . $color;
}
$length = strlen($hex);
if ($length !== 3 && $length !== 6) {
return false;
}
if (!ctype_xdigit($hex)) {
return false;
}
}
return $color;
}
}
// vim: et sw=4 sts=4