C# XML Directory Lister

using System;
using System.IO;
using System.Xml;
using System.Data;

namespace GregHack.XMLStuff.Cs
{

   /// <summary>
   /// This class generates a list of files in a directory as XML.  It can
   /// return the XML as a string, a W3C DOM document, or a DataSet.  I
   /// wrote this code to learn about the XML capabilities of the framework
   /// work specifically with the DataSets.
   /// </summary>
   public class XMLDirectoryLister
   {
      private Boolean m_bUseDOMCalls;

      /// <summary>
      /// Constructor
      /// </summary>
      /// <param name="bUseDOMCalls">Use W3C DOM calls to build XML?</param>
      /// <returns>None</returns>
      public XMLDirectoryLister( Boolean bUseDOMCalls )
      {
         m_bUseDOMCalls = bUseDOMCalls;
      }
      
      /// <summary>
      /// This method generates a list of files in a directory as XML and
      /// returns the XML as a string.
      /// </summary>
      /// <param name="strDirectory">List files in this directory</param>
      /// <returns>A XML string with the directory file list</returns>
      public string
      getXMLString( string strDirectory )
      {
         string strXML = "";
      
         XmlDocument doc = getXML( strDirectory );
         if ( doc != null )
         {
		      StringWriter writer = new StringWriter();
            doc.Save( writer );
            strXML = writer.ToString();
         }

         doc = null;
         return strXML;
      }
       

      /// <summary>
      /// This method generates a list of files in a directory as XML and
      /// returns the XML as a DataSet.
      /// </summary>
      /// <param name="strDirectory">List files in this directory</param>
      /// <returns>A DataSet with the directory file list</returns>
      public DataSet
      getXMLDataset( string strDirectory )
      {
         DataSet ds = null;
      
         string strXML = getXMLString( strDirectory );
         XmlDataDocument datadoc = new XmlDataDocument();
         datadoc.DataSet.ReadXml( new StringReader(strXML) );

         ds =  datadoc.DataSet;    
          
         return ds;
      }
       

      /// <summary>
      /// This public method generates a list of files in a directory as XML and
      /// returns the XML as a W3C DOM document.
      /// </summary>
      /// <param name="strDirectory">List files in this directory</param>
      /// <returns>A W3C DOM docuemnt with the directory file list</returns>
      public XmlDocument
      getXMLDocument( string strDirectory )
      {
         return getXML( strDirectory );
      }
   
      private XmlDocument
      getXML( string strDirectory )
      {
         XmlDocument xmlDoc;
         if ( m_bUseDOMCalls )
            xmlDoc = getXMLUsingDOMCalls( strDirectory );
         else
            xmlDoc = getXMLUsingTextWriterClass( strDirectory );
         
         return xmlDoc;
      }

      /// <summary>
      /// This private method generates a list of files in a directory as XML and
      /// returns the XML as a W3C DOM document using the DOM calls.
      /// </summary>
      /// <param name="strDirectory">List files in this directory</param>
      /// <returns>A W3C DOM docuemnt with the directory file list</returns>
      private XmlDocument
      getXMLUsingDOMCalls( string strDirectory )
      {
         // Create the document.
         XmlDocument doc = new XmlDocument();

         // Insert the xml processing instruction and the root node
         XmlDeclaration dec = 
            doc.CreateXmlDeclaration("1.0", "", "yes");
         doc.PrependChild ( dec );

         // Add the root element
         XmlElement nodeElem = 
            doc.CreateElement( "dirlist" );
         doc.AppendChild( nodeElem );
         
         Boolean bFirst = true;

         // Process the directory list
         DirectoryInfo dir = new DirectoryInfo( strDirectory );
         foreach ( FileSystemInfo entry in dir.GetFileSystemInfos() ) 
         {
            if ( bFirst == true )
            {
               // If we haven't added any elements yet, go ahead and add a text element which
               // contains the full directory path.
               XmlElement root = doc.DocumentElement;

               String strFullName = entry.FullName;
               String strFileName = entry.Name;
         
               String strDir = strFullName.Substring( 0, strFullName.Length - strFileName.Length );
               root.SetAttribute ("dir", strDir );

               bFirst = false;
            }   
            
            // Add a new text node with a tag entry.  There will be one added per
            // item encountered in the directory.
            XmlElement elem = doc.CreateElement("entry");
            doc.DocumentElement.AppendChild(elem);
            
            // Write out the things we are interested in about this entry in the
            // directory.
            addTextElement( doc, elem, "name", entry.Name );
            addTextElement( doc, elem, "created", entry.CreationTime.ToString() );
            addTextElement( doc, elem, "lastaccess", entry.LastAccessTime.ToString() );
            addTextElement( doc, elem, "lastwrite", entry.LastWriteTime.ToString() );
            addTextElement( doc, elem, "isfile", ( (entry.Attributes & FileAttributes.Directory) > 0 ) ? "False" : "True" );
            addTextElement( doc, elem, "isdir", ( (entry.Attributes & FileAttributes.Directory) > 0 ) ? "True" : "False" );
            addTextElement( doc, elem, "readonly", ( (entry.Attributes & FileAttributes.ReadOnly) > 0 ) ? "True" : "False" );
         }
               
         return doc;
      } 
       

      /// <summary>
      /// This private method adds a text element to the XML document as the last
      /// child of the current element.
      /// </summary>
      /// <param name="doc">The XML document</param>
      /// <param name="nodeParent">Parent of the node we are adding</param>
      /// <param name="strTag">The tag of the element to add</param>
      /// <param name="strValue">The text value of the new element</param>
      private void
      addTextElement( XmlDocument doc, XmlElement nodeParent, string strTag, string strValue )
      {
          XmlElement nodeElem = doc.CreateElement( strTag );
          XmlText nodeText = doc.CreateTextNode( strValue );
          nodeParent.AppendChild( nodeElem );
          nodeElem.AppendChild( nodeText );
      } 


      /// <summary>
      /// This private method generates a list of files in a directory as XML and
      /// returns the XML as a W3C DOM document using the XmlTextWriter class.
      /// </summary>
      /// <param name="strDirectory">List files in this directory</param>
      /// <returns>A W3C DOM docuemnt with the directory file list</returns>
      private XmlDocument
      getXMLUsingTextWriterClass( string strDirectory )
      {
         StringWriter writerString = new StringWriter();
        
         XmlTextWriter writer = new XmlTextWriter( writerString );
         
         writer.WriteStartDocument(true);
         
         Boolean bFirst = true;
      
         // Process the directory list
         DirectoryInfo dir = new DirectoryInfo( strDirectory );
         foreach ( FileSystemInfo entry in dir.GetFileSystemInfos() ) 
         {
            
            if ( bFirst == true )
            {
               // If we haven't added any elements yet, go ahead and add a text element which
               // contains the full directory path.
               writer.WriteStartElement( "dirlist", "" );

               String strFullName = entry.FullName;
               String strFileName = entry.Name;
               String strDir = strFullName.Substring( 0, strFullName.Length - strFileName.Length );

               writer.WriteAttributeString( "dir", strDir );
               bFirst = false;
            }   

            // Add a new text node with a tag entry.  There will be one added per
            // item encountered in the directory.
            writer.WriteStartElement( "entry", "" );
         
            // Write out the things we are interested in about this entry in the
            // directory.
            writer.WriteElementString( "name", entry.Name );
            writer.WriteElementString( "created", entry.CreationTime.ToString() );
            writer.WriteElementString( "lastaccess", entry.LastAccessTime.ToString() );
            writer.WriteElementString( "lastwrite", entry.LastWriteTime.ToString() );
            writer.WriteElementString( "isfile", ( (entry.Attributes & FileAttributes.Directory) > 0 ) ? "False" : "True" );
            writer.WriteElementString( "isdir", ( (entry.Attributes & FileAttributes.Directory) > 0 ) ? "True" : "False" );
            writer.WriteElementString( "readonly", ( (entry.Attributes & FileAttributes.ReadOnly) > 0 ) ? "True" : "False" );
   
            writer.WriteEndElement();    // entry     
         }

         writer.WriteEndElement();       // dirlist
         writer.WriteEndDocument();

         string strXML = writerString.ToString();
         StringReader reader = new StringReader( strXML );
               
         XmlDocument doc = new XmlDocument();
         doc.Load( reader );
         
         return doc;
      } 
   }



}