System.Xml.XmlDocument.CreateNavigator C# (CSharp) Method

        public override XPathNavigator CreateNavigator()
        {
            return CreateNavigator(this);
        }

        public void Apply (XmlDocument targetDocument, IXmlNamespaceResolver context) {

            XPathExpression local_file_expression = file_expression.Clone();
            local_file_expression.SetContext(context);

            XPathExpression local_source_expression = source_expression.Clone();
            local_source_expression.SetContext(context);

            XPathExpression local_target_expression = target_expression.Clone();
            local_target_expression.SetContext(context);

            string file_name = (string) targetDocument.CreateNavigator().Evaluate(local_file_expression);
            string file_path = Path.Combine(root_directory, file_name);

            if (!File.Exists(file_path)) return;
            XPathDocument sourceDocument = new XPathDocument(file_path);

            XPathNavigator target_node = targetDocument.CreateNavigator().SelectSingleNode(local_target_expression);
            if (target_node == null) return;

            XPathNodeIterator source_nodes = sourceDocument.CreateNavigator().Select(local_source_expression);
            foreach (XPathNavigator source_node in source_nodes) {
                target_node.AppendChild(source_node);
            }
       
        }