/**
  * Get path for item with specific purpose.
  *
  * @param	int		$a_mob_id		media object id
  */
 static function _lookupItemPath($a_mob_id, $a_url_encode = false, $a_web = true, $a_purpose = "")
 {
     if ($a_purpose == "") {
         $a_purpose = "Standard";
     }
     $location = ilMediaItem::_lookupLocationForMobId($a_mob_id, $a_purpose);
     if (preg_match("/https?\\:/i", $location)) {
         return $location;
     }
     if ($a_url_encode) {
         $location = rawurlencode($location);
     }
     $path = $a_web ? ILIAS_HTTP_PATH : ".";
     return $path . "/data/" . CLIENT_ID . "/mobs/mm_" . $a_mob_id . "/" . $location;
 }