// Originale Quelle: Zarko Gajic:
 // http://delphi.about.com/od/vclusing/qt/delphi-select-xml-nodes-ixmlnodelist-selectnodes-xpath-xmldom.htm, 18.06.2013
 // Erweitert um Rekursive Parents.

function XPathQuery(aNode: IXMLNode; aQuery: string): IXMLNodeList; overload;
var
  XmlNodeAccess: IXmlNodeAccess;
  XmlDocAccess: IXmlDocumentAccess;
  XmlDomNodeSelect: IDomNodeSelect;
  DomNodeList: IDomNodeList;
  Document: TXMLDocument;
  i: integer;
  OwnerDoc: TXMLDocument;
  DomDoc2: IXMLDOMDocument2;

  function CreateWithParentNode(const aDomNode: IDOMNode; const aOwnerDoc: TXMLDocument): TXmlNode;
  begin
    if assigned(aDomNode) then
      Result := TXMLNode.Create(aDomNode, CreateWithParentNode(aDomNode.parentNode, aOwnerDoc), aOwnerDoc)
    else
      Result := nil;
  end;

begin
  Result := nil;
  if not assigned(aNode) then
    Exit;
  if not Supports(aNode, IXmlNodeAccess, XmlNodeAccess) then
    raise Exception.Create('Interface IXmlNodeAccess not found.');
  if not Supports(aNode.DOMNode, IDomNodeSelect, XmlDomNodeSelect) then
    raise Exception.Create('Interface IDomNodeSelect not found.');
  if Supports(aNode.OwnerDocument, IXmlDocumentAccess, XmlDocAccess) then
    OwnerDoc := XmlDocAccess.DocumentObject
  else
    OwnerDoc := nil; // if Owner is nil this is a possble Memory Leak!

  //>>> if XPath is not enabled
  if assigned(OwnerDoc) then
    if Supports(OwnerDoc.DOMDocument, IXMLDOMDocument2, DomDoc2) then
      DomDoc2.setProperty('SelectionLanguage', 'XPath');
  //<<< if XPath is not enabled


  DomNodeList := XmlDomNodeSelect.selectNodes(aQuery);
  if assigned(DomNodeList) then
  begin
    Result := TXMLNodeList.Create(XmlNodeAccess.GetNodeObject, '', nil);
    Document := OwnerDoc;
    for i := 0 to pred(DomNodeList.length) do
    begin
      Result.Add(CreateWithParentNode(DomNodeList.item[i], Document));
    end;
  end
end;