| | left | center | right ] [ | | top | center | bottom ]? ] | [ // this signifies that the vertical and horizontal adjectives // can be arbitrarily ordered, however, there can only be two, // one of each, or none at all [ left | center | right ] || [ top | center | bottom ] ] top, left = 0% center, (none) = 50% bottom, right = 100% */ /* QuirksMode says: keyword + length/percentage must be ordered correctly, as per W3C Internet Explorer and Opera, however, support arbitrary ordering. We should fix it up. Minor issue though, not strictly necessary. */ // control freaks may appreciate the ability to convert these to // percentages or something, but it's not necessary /** * Validates the value of background-position. */ class HTMLPurifier_AttrDef_CSS_BackgroundPosition extends HTMLPurifier_AttrDef { /** * @type HTMLPurifier_AttrDef_CSS_Length */ protected $length; /** * @type HTMLPurifier_AttrDef_CSS_Percentage */ protected $percentage; public function __construct() { $this->length = new HTMLPurifier_AttrDef_CSS_Length(); $this->percentage = new HTMLPurifier_AttrDef_CSS_Percentage(); } /** * @param string $string * @param HTMLPurifier_Config $config * @param HTMLPurifier_Context $context * @return bool|string */ public function validate($string, $config, $context) { $string = $this->parseCDATA($string); $bits = explode(' ', $string); $keywords = array(); $keywords['h'] = false; // left, right $keywords['v'] = false; // top, bottom $keywords['ch'] = false; // center (first word) $keywords['cv'] = false; // center (second word) $measures = array(); $i = 0; $lookup = array( 'top' => 'v', 'bottom' => 'v', 'left' => 'h', 'right' => 'h', 'center' => 'c' ); foreach ($bits as $bit) { if ($bit === '') { continue; } // test for keyword $lbit = ctype_lower($bit) ? $bit : strtolower($bit); if (isset($lookup[$lbit])) { $status = $lookup[$lbit]; if ($status == 'c') { if ($i == 0) { $status = 'ch'; } else { $status = 'cv'; } } $keywords[$status] = $lbit; $i++; } // test for length $r = $this->length->validate($bit, $config, $context); if ($r !== false) { $measures[] = $r; $i++; } // test for percentage $r = $this->percentage->validate($bit, $config, $context); if ($r !== false) { $measures[] = $r; $i++; } } if (!$i) { return false; } // no valid values were caught $ret = array(); // first keyword if ($keywords['h']) { $ret[] = $keywords['h']; } elseif ($keywords['ch']) { $ret[] = $keywords['ch']; $keywords['cv'] = false; // prevent re-use: center = center center } elseif (count($measures)) { $ret[] = array_shift($measures); } if ($keywords['v']) { $ret[] = $keywords['v']; } elseif ($keywords['cv']) { $ret[] = $keywords['cv']; } elseif (count($measures)) { $ret[] = array_shift($measures); } if (empty($ret)) { return false; } return implode(' ', $ret); } } // vim: et sw=4 sts=4