/**
  * Return the content of the document in plain text
  *
  * @param string $encoding The encoding, default UTF-8
  *
  * @return string
  */
 function getPlainText($encoding = "UTF-8")
 {
     if (!$this->_source) {
         $this->loadContent(true);
     }
     return CMbString::htmlToText($this->_source, $encoding);
 }