Walks the XPathNavigator tree recursively

Description

Demo Code


using System;/* www . j a v  a2  s  .c o  m*/
using System.Diagnostics;
using System.IO;
using System.Text;

using System.Xml.XPath;

namespace iLabs.UtilLib
{
   /// <summary>
   /// A wrapped XPathDocument.
   /// </summary>
   public class XmlQueryDoc
   {
      XPathDocument pathDocument = null;
      public XPathNavigator pathNavigator = null;


      public XmlQueryDoc()
      {
         //
         // TODO: Add constructor logic here
         //
      }

      public XmlQueryDoc(String input)

      {
         UTF8Encoding utf8 = new UTF8Encoding();
          MemoryStream mStream = new MemoryStream(utf8.GetBytes(input),false);

         pathDocument = new XPathDocument(mStream);
         pathNavigator = pathDocument.CreateNavigator();

         
      }

      // Get all the book prices
      //Query( "descendant::book/price");

      // Get the ISBN of the last book
      // "bookstore/book[3]/@ISBN");
        /// <summary>
        /// Returns the values within the queried element, only should be used with a single element without children as only the text is returned.
        /// </summary>
        /// <param name="xpathexpr"></param>
        /// <returns></returns>
      public string Query( string xpathexpr )
      {
         StringBuilder buf = new StringBuilder();
         try
         {

            // Create a node interator to select nodes and move through them (read-only)
            XPathNodeIterator pathNodeIterator =  pathNavigator.Select (xpathexpr);

            while (pathNodeIterator.MoveNext())
            {
               buf.Append(pathNodeIterator.Current.Value);
            }
            
         }
         catch (Exception e)
         {
            Console.WriteLine ("Exception: {0}", e.ToString());
         }
         return buf.ToString();
      }

        /// <summary>
        /// Test to see if the requested node is found.
        /// </summary>
        /// <param name="xpathexpr"></param>
        /// <returns></returns>
        public bool Found(string xpathexpr)
        {
            bool status = false;
            try
            {
                // Create a node interator to select nodes and move through them (read-only)
                XPathNodeIterator pathNodeIterator = pathNavigator.Select(xpathexpr);
                status = true;
            }
            catch (XPathException e)
            {
                status = false;
            }
            return status;
        }
        /// <summary>
        /// Create a node interator to select nodes and move through them (read-only)
        /// </summary>
        /// <param name="xpathexpr"></param>
        /// <returns></returns>
        public XPathNodeIterator Select(string xpathexpr)
        {
            XPathNodeIterator pathNodeIterator = null;
            try
            {
                // Create a node interator to select nodes and move through them (read-only)
                pathNodeIterator = pathNavigator.Select(xpathexpr);
                
            }
            catch (XPathException e)
            {
                Trace.WriteLine("XPath not found: " + xpathexpr); 
            }
            return pathNodeIterator;
        }

        //public string Select(string xpathexpr)
        //{
        //    StringBuilder buf = new StringBuilder();
        //    try
        //    {

        //        // Create a node interator to select all child nodes
        //        XPathNodeIterator pathNodeIterator = pathNavigator.Select(xpathexpr);
        //        buf.Append(pathNodeIterator.Current.InnerXml);
                
        //    }
        //    catch (Exception e)
        //    {
        //        Console.WriteLine("Exception: {0}", e.ToString());
        //    }
        //    return buf.ToString();
        //}

        /// <summary>
        /// This does not work
        /// </summary>
        /// <returns></returns>
        public string GetTopName(){
            string str;
            pathNavigator.MoveToRoot();
            pathNavigator.MoveToFirstChild();
            str = pathNavigator.Name;
           return str;
        }

       

        /// <summary>
        /// This does not work
        /// </summary>
        /// <param name="xpathexpr"></param>
        /// <returns></returns>
        public string LocalName(string xpathexpr)
        {
            string name = null;
            try
            {
                // Create a node interator to select nodes and move through them (read-only)
                XPathNodeIterator iter = pathNavigator.Select(xpathexpr);
                name = iter.Current.LocalName;
            
            }
            catch (Exception e)
            {
                Console.WriteLine("Exception: {0}", e.ToString());
            }
            return name;

        }
        
        /// <summary>
        /// Walks the XPathNavigator tree recursively
        /// </summary>
        /// <param name="myXPathNavigator"></param>
 
        public static void DisplayTree(XPathNavigator myXPathNavigator)
        {
            if (myXPathNavigator.HasChildren)
            {
                myXPathNavigator.MoveToFirstChild();

                Format(myXPathNavigator);
                DisplayTree(myXPathNavigator);

                myXPathNavigator.MoveToParent();
            }
            while (myXPathNavigator.MoveToNext())
            {
                Format(myXPathNavigator);
                DisplayTree(myXPathNavigator);
            }
        }


        /// <summary>
        /// Format the output
        /// </summary>
        /// <param name="myXPathNavigator"></param>
        private static void Format(XPathNavigator myXPathNavigator)
        {
            if (!myXPathNavigator.HasChildren)
            {
                if (myXPathNavigator.NodeType == XPathNodeType.Text)
                    Console.WriteLine(myXPathNavigator.Value);
                else if (myXPathNavigator.Name != String.Empty)
                    Console.WriteLine("<" + myXPathNavigator.Name + ">");
                else
                    Console.WriteLine();
            }
            else
            {
                Console.WriteLine("<" + myXPathNavigator.Name + ">");

                // Show the attributes if there are any
                if (myXPathNavigator.HasAttributes)
                {
                    Console.WriteLine("Attributes of <" + myXPathNavigator.Name + ">");

                    while (myXPathNavigator.MoveToNextAttribute())
                        Console.Write("<" + myXPathNavigator.Name + "> " + myXPathNavigator.Value + " ");

                    // Return to the 'Parent' node of the attributes
                    myXPathNavigator.MoveToParent();
                }
            }
        }



   }
}
Walks the XPathNavigator tree recursively - CSharp System.Xml

Description

Demo Code

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