Set the value to the Element

   
 
#region License and Copyright
/*
 * Dotnet Commons Xml
 *
 *
 * This library is free software; you can redistribute it and/or modify it 
 * under the terms of the GNU Lesser General Public License as published by 
 * the Free Software Foundation; either version 2.1 of the License, or 
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but 
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License 
 * for more details. 
 *
 * You should have received a copy of the GNU Lesser General Public License 
 * along with this library; if not, write to the 
 * Free Software Foundation, Inc., 
 * 59 Temple Place, 
 * Suite 330, 
 * Boston, 
 * MA 02111-1307 
 * USA 
 * 
 */
#endregion

using System;
using System.Collections;
using System.Collections.Specialized;
using System.Diagnostics;
using System.IO;
using System.Reflection;
using System.Text;
using System.Text.RegularExpressions;
using System.Xml;
using System.Xml.Xsl;
using System.Xml.Serialization;

//using Dotnet.Commons.Reflection;

namespace Dotnet.Commons.Xml
{
  
  ///  
  /// <summary>
  /// This utility class contains wrapper functions that help to ease the handling and 
    /// manipulation of Xml documents, such as adding an element, adding an attribute
    /// to an element, copying and cloning of nodes, etc.
  ///
  /// </summary>
  /// 
    
  public abstract class XmlUtils
  {
    /// -----------------------------------------------------------
    /// <summary>
    /// Set the value to the Element
    /// </summary>
    /// <param name="node">the node to set the value </param>
    /// <param name="nodeValue">Value to set</param>
    /// <exception cref="XmlException">
    ///    Thrown if XmlNode is not an element or node is 
    ///    not a text node (no child nodes)
    ///  </exception>
    /// -----------------------------------------------------------
    public static void SetNodeValue( XmlNode node, object nodeValue )
    {  
      if (node == null)
        throw new ArgumentNullException("node");

      if (node.NodeType != XmlNodeType.Element)
        throw new XmlException("Node is not an element.");

      if (node.ChildNodes.Count > 0)
        throw new XmlException("Node is not a text node as it has child nodes.");

      node.AppendChild(node.OwnerDocument.CreateTextNode(nodeValue.ToString()));
    }

    /// ------------------------------------------------------------------
    /// <summary>
    /// Set the value to a node
    /// </summary>
    /// <param name="parentNode">parentNode to start search from</param>
    /// <param name="xpath">XPath to the child node</param>
    /// <param name="nodeValue">the new value to set to</param>
    /// <exception cref="ArgumentNullException">Thrown if parentNode is null</exception>
    /// <exception cref="ArgumentException">Thrown if no text node is found at the xpath provided.</exception>
    /// <exception cref="XmlException">Thrown if node to set the value is not a text node (ie. no child nodes)</exception>
    /// ------------------------------------------------------------------
    public static void SetNodeValue(XmlNode parentNode, 
                    string xpath, 
                    object nodeValue)
    {
      if (parentNode == null)
        throw new ArgumentNullException("parentNode");

      XmlNode childNode = parentNode.SelectSingleNode(xpath);
      
      if(childNode == null)
        throw new ArgumentException(String.Format("No node is not found at the path specified &#039;{0}&#039;", xpath), "xpath");
      
      if (childNode.ChildNodes.Count > 0)
        throw new XmlException("Child node is not a text node as it has child nodes.");

      childNode.InnerText = nodeValue.ToString();
      
    }

    /// -----------------------------------------------------------
    /// <summary>
    /// Set a blog of binary data encoded with Base64 to an XML element.
    /// </summary>
    /// <param name="node">the node to set the blog of data</param>
    /// <param name="byteArray">an array of bytes containing the actual data</param>
    /// <exception cref="XmlException">Thrown if XmlNode is not an element or 
    ///    node is not a text node (no child nodes)</exception>
    /// -----------------------------------------------------------
    public static void SetNodeBase64BinaryValue( XmlNode node, byte[] byteArray )
    {
      if (node.NodeType != XmlNodeType.Element)
        throw new XmlException("Node is not an element.");

      if (node.ChildNodes.Count > 0)
        throw new XmlException("Node is not a text node as it has child nodes.");

      // Convet byte array into Base64 string
      string encodedData = Convert.ToBase64String(byteArray);
      
      node.AppendChild(node.OwnerDocument.CreateTextNode(encodedData));
    }


    /// -----------------------------------------------------------
    /// <summary>
    /// Encode a value to Base64 and set it to the node.
    /// </summary>
    /// <param name="node">the node to set the value</param>
    /// <param name="value">value to set to the node</param>
    /// <exception cref="XmlException">Thrown if XmlNode is not an element 
    /// or node is not a text node (no child nodes)</exception>
    /// -----------------------------------------------------------
    public static void SetNodeBase64EncodedValue( XmlNode node, object value)
    {
      if (value is byte[])
        SetNodeBase64BinaryValue(node, (byte[])value);

      if (node.NodeType != XmlNodeType.Element)
        throw new XmlException("Node is not an element.");

      if (node.ChildNodes.Count > 0)
        throw new XmlException("Node is not a text node as it has child nodes.");

      // Convet byte array into Base64 string
      ASCIIEncoding encoding = new ASCIIEncoding();
      byte[] bytes = encoding.GetBytes(value.ToString());

      SetNodeBase64BinaryValue(node, bytes);      
    }
    }
}