/**
  * Sets default document to $id. Document has to be loaded prior
  * to using this method.
  * $id can be retrived via getDocumentID() or getDocumentIDRef().
  *
  * @param unknown_type $id
  */
 public static function selectDocument($id)
 {
     $id = self::getDocumentID($id);
     self::debug("Selecting document '{$id}' as default one");
     self::$defaultDocumentID = self::getDocumentID($id);
 }
 /**
  * Enter description here...
  *
  * @param unknown_type $html
  * @param unknown_type $domId
  * @return unknown New DOM ID
  * @todo support PHP tags in input
  * @todo support passing DOMDocument object from self::loadDocument
  */
 protected static function createDocumentWrapper($html, $contentType = null, $documentID = null)
 {
     if (function_exists('domxml_open_mem')) {
         throw new Exception("Old PHP4 DOM XML extension detected. phpQuery won't work until this extension is enabled.");
         return null;
     }
     $id = $documentID ? $documentID : md5(microtime());
     $document = null;
     if ($html instanceof DOMDOCUMENT) {
         // TODO support cloning of DOMDocumentWrapper
         if (self::getDocumentID($html)) {
             // document already exists in phpQuery::$documents, make a copy
             $document = clone $html;
         } else {
             // new document, add it to phpQuery::$documents
             $wrapper = new DOMDocumentWrapper($html, $contentType);
         }
     } else {
         $wrapper = new DOMDocumentWrapper($html, $contentType);
     }
     $wrapper->id = $id;
     // create document
     phpQuery::$documents[$id] = $wrapper;
     // remember last loaded document
     return self::$defaultDocumentID = $id;
 }