Horde_Kolab_Format_Xml_Helper::findNodesRelativeTo PHP Method

    public function findNodesRelativeTo($query, DOMNode $context)
    {
        return $this->_xpath->query($query, $context);
    }

 /**
  * Update the specified attribute.
  *
  * @param string                        $name        The name of the the
  *                                                   attribute to be updated.
  * @param array                         $attributes  The data array that holds
  *                                                   all attribute values.
  * @param DOMNode                       $parent_node The parent node of the
  *                                                   node that should be
  *                                                   updated.
  * @param Horde_Kolab_Format_Xml_Helper $helper      A XML helper instance.
  * @param array                         $params      Additional parameters
  *                                                   for this write operation.
  *
  * @return DOMNode|boolean The new/updated child node or false if this
  *                         failed.
  *
  * @throws Horde_Kolab_Format_Exception If converting the data to XML failed.
  */
 public function save($name, $attributes, $parent_node, Horde_Kolab_Format_Xml_Helper $helper, $params = array())
 {
     $children = $helper->findNodesRelativeTo('./' . $name, $parent_node);
     if (!isset($attributes[$name])) {
         if ($children->length == 0) {
             if ($this->value == Horde_Kolab_Format_Xml::VALUE_MAYBE_MISSING || $this->value == Horde_Kolab_Format_Xml::VALUE_NOT_EMPTY && $this->isRelaxed($params)) {
                 return false;
             }
         } else {
             if ($this->value == Horde_Kolab_Format_Xml::VALUE_MAYBE_MISSING) {
                 /** Client indicates that the value should get removed */
                 $helper->removeNodes($parent_node, $name);
                 return false;
             } else {
                 return $children;
             }
         }
     }
     //@todo What is required to get around this overwriting of the old values?
     $helper->removeNodes($parent_node, $name);
     return $this->_writeMultiple($parent_node, $name, $this->generateWriteValue($name, $attributes, $params), $helper, $params);
 }