<?php

class kXMLHelper extends kHelper {
	var $RootElement = null;

	/**
	 * Enter description here...
	 *
	 * @var kXMLNode
	 */
	var $CurrentElement = null;

	/**
	 * Parses XML data specified and returns root node
	 *
	 * @param string $xml
	 * @return kXMLNode
	 */
	function &Parse($xml = null)
	{
		$this->Clear(); // in case if Parse method is called more then one time
		$xml_parser = xml_parser_create();
		xml_set_element_handler( $xml_parser, Array(&$this, 'startElement'), Array(&$this, 'endElement') );
		xml_set_character_data_handler( $xml_parser, Array(&$this, 'characterData') );
		if (!xml_parse($xml_parser, $xml, 1)) {
    	    trigger_error(sprintf('XML error: %s at line %d'),
			xml_error_string(xml_get_error_code($xml_parser)),
			xml_get_current_line_number($xml_parser), E_USER_WARNING);
		}
		xml_parser_free($xml_parser);
		return $this->RootElement;
	}

	function startElement(&$Parser, &$Elem, $Attrs)
	{
		$parent =& $this->CurrentElement;
		$this->CurrentElement =& new kXMLNode($Elem, $Attrs);
		if (is_null($this->RootElement)) {
			$this->RootElement =& $this->CurrentElement;
		}
		if (!is_null($parent)) {
			$parent->AddChild($this->CurrentElement);
		}
	}

	function characterData($Parser, $Line)
	{
		$this->CurrentElement->AppendData($Line);
	}

	function endElement($Parser, $Elem)
	{
		if ($this->CurrentElement->Parent != null) {
			$this->CurrentElement =& $this->CurrentElement->Parent;
		}
	}

	function Clear()
	{
		$this->RootElement = null;
		$this->CurrentElement = null;
	}
}

class kXMLNode {
	var $Name = null;
	var $Attributes = array();
	var $Children = array();
	var $Data = null;
	
	var $firstChild = null;
	var $lastChild = null;
	/**
	 * Parent node
	 *
	 * @var kXMLNode
	 */
	var $Parent = null;
	/**
	 * Node position relative to other nodes of it's parent
	 *
	 * @var int
	 */
	var $Position = 0;
	
	function kXMLNode($name, $attrs = array())
	{
		$this->Name = $name;
		$this->Attributes = $attrs;
	}

	function SetParent(&$elem)
	{
		$this->Parent =& $elem;
	}

	/**
	 * Adds new child to current node
	 *
	 * @param kXMLNode $a_child
	 */
	function AddChild(&$a_child)
	{
		$node_count = count($this->Children);
		$a_child->Position = $node_count;
		
		if ($node_count == 0) {
			$this->firstChild =& $a_child;
			$this->lastChild =& $a_child;
		}
		else {
			$this->lastChild =& $a_child;
		}
		
		$this->Children[] =& $a_child;
		$a_child->SetParent($this);
	}

	function AppendData($data)
	{
		$this->Data .= $data;
	}

	function &GetChild($path)
	{
		$entries = explode('/', strtoupper($path));
		$cur = array_shift($entries);
		if ($cur == $this->Name) $cur = array_shift($entries);
		if (!$cur) return $this;
		if (!isset($this->Children[$cur])) return false;
		$left = implode('/', $entries);
		if (!$left) return $this->Children[$cur];
		return $this->Children[$cur]->GetChild($left);
	}

	function GetChildValue($path)
	{
		$child =& $this->GetChild($path);
		if ($child !== false) {
			return $child->Data;
		}
	}

	function &GetChildByPosition($position)
	{
		if ($position < count($this->Children) ) {
			return $this->Children[$position];
		}
		else {
			$false = false;
			return $false;
		}
	}
	
	function &FindChild($name)
	{
		$name = strtoupper($name);
		if ($this->Name == $name) return $this;
//		if (isset($this->Children[$name])) return $this->Children[$name];
//		$children = array_keys($this->Children);
		foreach ($this->Children as $elem)
		{
			$child =& $elem->FindChild($name);
			if ($child !== false)
			{
				return $child;
			}
		}
		return false;
	}

	function FindChildValue($name, $attr=null)
	{
		$child =& $this->FindChild($name);
		if ($child !== false) {
			if (isset($attr)) {
				return $child->Attributes[strtoupper($attr)];
			}
			return $child->Data;
		}
	}
	
	/**
	 * Returns next node to this, false in case of end list
	 *
	 * @return kXMLNode
	 */
	function &NextSibling()
	{
		if (!is_null($this->Parent)) {
			$ret =& $this->Parent->GetChildByPosition($this->Position + 1);
			return $ret;
		}
		else {
			$false = false;
			return $false;
		}
	}
}

?>