Как правильно загружать дерево из базы данных(вопрос по пхп) - Модификации расширений для Joomla

		$ids = array();
		$ids[0] = true;
		$last = null;
		$unresolved = array();
		// pop the first item until the array is empty if there is any item
		if ( is_array($rows)) {
			while (count($rows) && !is_null($row = array_shift($rows)))
			{
				if (array_key_exists($row->parent, $ids)) {
					$row->ionly = $params->get('menu_images_link');
					$menu->addNode($params, $row);

					// record loaded parents
					$ids[$row->id] = true;
				} else {
					// no parent yet so push item to back of list
					// SAM: But if the key isn't in the list and we dont _add_ this is infinite, so check the unresolved queue
					if(!array_key_exists($row->id, $unresolved) || $unresolved[$row->id] < $maxdepth) {
						array_push($rows, $row);
						// so let us do max $maxdepth passes
						// TODO: Put a time check in this loop in case we get too close to the PHP timeout
						if(!isset($unresolved[$row->id])) $unresolved[$row->id] = 1;
						else $unresolved[$row->id]++;
					}
				}
			}
		}

* Main Menu Tree Class.
 *
 * @package		Joomla
 * @subpackage	Menus
 * @since		1.5
 */
class JMenuTree extends JTree
{
	/**
	 * Node/Id Hash for quickly handling node additions to the tree.
	 */
	var $_nodeHash = array();

	/**
	 * Menu parameters
	 */
	var $_params = null;

	/**
	 * Menu parameters
	 */
	var $_buffer = null;

	function __construct(&$params)
	{
		$this->_params		=& $params;
		$this->_root		= new JMenuNode(0, 'ROOT');
		$this->_nodeHash[0]	=& $this->_root;
		$this->_current		=& $this->_root;
	}

	function addNode(&$params, $item)
	{
		// Get menu item data
		$data = $this->_getItemData($params, $item);

		// Create the node and add it
		$node = new JMenuNode($item->id, $item->name, $item->access, $data);

		if (isset($item->mid)) {
			$nid = $item->mid;
		} else {
			$nid = $item->id;
		}
		$this->_nodeHash[$nid] =& $node;
		$this->_current =& $this->_nodeHash[$item->parent];

		if ($item->type == 'menulink' && !empty($item->query['Itemid'])) {
			$node->mid = $item->query['Itemid'];
		}

		if ($this->_current) {
			$this->addChild($node, true);
		} else {
			// sanity check
			JError::raiseError( 500, 'Orphan Error. Could not find parent for Item '.$item->id );
		}
	}

	function toXML()
	{
.............
	}

	function _getLevelXML($depth)
	{
........
	}

	function _getItemData(&$params, $item)
	{
	.............
	}
}

/**
 * Main Menu Tree Node Class.
 *
 * @package		Joomla
 * @subpackage	Menus
 * @since		1.5
 */
class JMenuNode extends JNode
{
	/**
	 * Node Title
	 */
	var $title = null;

	/**
	 * Node Link
	 */
	var $link = null;

	/**
	 * CSS Class for node
	 */
	var $class = null;

	function __construct($id, $title, $access = null, $link = null, $class = null)
	{
		$this->id		= $id;
		$this->title	= $title;
		$this->access	= $access;
		$this->link		= $link;
		$this->class	= $class;
	}
}

SELECT CONCAT(
 if( c1.id, CONCAT(
 if( c2.id, CONCAT(
 if( c3.id, CONCAT(
 if( c4.id, CONCAT(
 if( c5.id, CONCAT(
 if( c6.id, CONCAT(
 if( c7.id, 
 CONCAT( REPLACE( c7.alias, '/', '-' ), '/' ),'')
 , CONCAT(  REPLACE( c6.alias, '/', '-' ), '/' ) ), '' )
 , CONCAT(  REPLACE( c5.alias, '/', '-' ), '/' ) ), '' )
 , CONCAT(  REPLACE( c4.alias, '/', '-' ), '/' ) ), '' )
 , CONCAT(  REPLACE( c3.alias, '/', '-' ), '/' ) ), '' )
 , CONCAT(  REPLACE( c2.alias, '/', '-' ), '/' ) ), '' )
 , CONCAT(  REPLACE( c1.alias, '/', '-' ), '/' ) ), '' ), CONCAT( c0.id, '-', REPLACE( c0.alias, '/', '-' ))) AS path
  FROM #__xxx as c0
 LEFT JOIN `#__xxx` as `c1` ON c1.id = c0.parent
 LEFT JOIN `#__xxx` as `c2` ON c2.id = c1.parent
 LEFT JOIN `#__xxx` as `c3` ON c3.id = c2.parent
 LEFT JOIN `#__xxx` as `c4` ON c4.id = c3.parent
 LEFT JOIN `#__xxx` as `c5` ON c5.id = c4.parent
 LEFT JOIN `#__xxx` as `c6` ON c6.id = c5.parent
 LEFT JOIN `#__xxx` as `c7` ON c7.id = c6.parent
 WHERE c0.id = <id_текущей_категории>