System.Xml.Linq Extensions

I thought I would some extension methods I have been using for a little while now for Linq to Xml. When loading and retrieving the attribute values from XML nodes via Linq there is a bit of code to write to make sure the attribute exists and that the value is a valid data type. Rather than having a bunch of code to do this I simply wrote some extensions that operate on an XElement and are targeted at returning the value of an XAttribute.

Usage:

var element = XElement.Parse("<value x="50.5"/>");var value = element.GetDoubleValue("x");
.csharpcode, .csharpcode pre{ font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/}.csharpcode pre { margin: 0em; }.csharpcode .rem { color: #008000; }.csharpcode .kwrd { color: #0000ff; }.csharpcode .str { color: #006080; }.csharpcode .op { color: #0000c0; }.csharpcode .preproc { color: #cc6633; }.csharpcode .asp { background-color: #ffff00; }.csharpcode .html { color: #800000; }.csharpcode .attr { color: #ff0000; }.csharpcode .alt{ background-color: #f4f4f4; width: 100%; margin: 0em;}.csharpcode .lnum { color: #606060; }.csharpcode, .csharpcode pre{ font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/}.csharpcode pre { margin: 0em; }.csharpcode .rem { color: #008000; }.csharpcode .kwrd { color: #0000ff; }.csharpcode .str { color: #006080; }.csharpcode .op { color: #0000c0; }.csharpcode .preproc { color: #cc6633; }.csharpcode .asp { background-color: #ffff00; }.csharpcode .html { color: #800000; }.csharpcode .attr { color: #ff0000; }.csharpcode .alt{ background-color: #f4f4f4; width: 100%; margin: 0em;}.csharpcode .lnum { color: #606060; }

Anyway, here is the class for the extensions:

   1:  using System;
   2:  using System.Xml.Linq;
   3:   
   4:  namespace System.Xml.Linq
   5:  {
   6:      public static class XLinqEx
   7:      {
   8:          /// <summary>
   9:          /// Gets a short value for the specified attribute.
  10:          /// </summary>
  11:          /// <param name="element">The element to parse.</param>
  12:          /// <param name="attributeName">The XName of the attribute to parse.</param>
  13:          /// <returns>A short value representation of the attribute value.</returns>
  14:          public static short GetInt16Value(this XElement element, XName attributeName)
  15:          {
  16:              var attribute = element.Attribute(attributeName);
  17:              if (attribute == null)
  18:                  return 0;
  19:   
  20:              short result = 0;
  21:              Int16.TryParse(attribute.Value, out result);
  22:              return result;
  23:          }
  24:   
  25:          /// <summary>
  26:          /// Gets an int value for the specified attribute.
  27:          /// </summary>
  28:          /// <param name="element">The element to parse.</param>
  29:          /// <param name="attributeName">The XName of the attribute to parse.</param>
  30:          /// <returns>An int value representation of the attribute value.</returns>
  31:          public static int GetInt32Value(this XElement element, XName attributeName)
  32:          {
  33:              var attribute = element.Attribute(attributeName);
  34:              if (attribute == null)
  35:                  return 0;
  36:   
  37:              int result = 0;
  38:              Int32.TryParse(attribute.Value, out result);
  39:              return result;
  40:          }
  41:   
  42:          /// <summary>
  43:          /// Gets a long value for the specified attribute.
  44:          /// </summary>
  45:          /// <param name="element">The element to parse.</param>
  46:          /// <param name="attributeName">The XName of the attribute to parse.</param>
  47:          /// <returns>A long value representation of the attribute value.</returns>
  48:          public static long GetInt64Value(this XElement element, XName attributeName)
  49:          {
  50:              var attribute = element.Attribute(attributeName);
  51:              if (attribute == null)
  52:                  return 0;
  53:   
  54:              long result = 0;
  55:              Int64.TryParse(attribute.Value, out result);
  56:              return result;
  57:          }
  58:   
  59:          /// <summary>
  60:          /// Gets a double value for the specified attribute.
  61:          /// </summary>
  62:          /// <param name="element">The element to parse.</param>
  63:          /// <param name="attributeName">The XName of the attribute to parse.</param>
  64:          /// <returns>A double value representation of the attribute value.</returns>
  65:          public static double GetDoubleValue(this XElement element, XName attributeName)
  66:          {
  67:              var attribute = element.Attribute(attributeName);
  68:              if (attribute == null)
  69:                  return 0;
  70:   
  71:              double result = 0;
  72:              Double.TryParse(attribute.Value, out result);
  73:              return result;
  74:          }
  75:   
  76:          /// <summary>
  77:          /// Gets a bool value for the specified attribute.
  78:          /// </summary>
  79:          /// <param name="element">The element to parse.</param>
  80:          /// <param name="attributeName">The XName of the attribute to parse.</param>
  81:          /// <returns>A bool value representation of the attribute value.</returns>
  82:          public static bool GetBooleanValue(this XElement element, XName attributeName)
  83:          {
  84:              var attribute = element.Attribute(attributeName);
  85:              if (attribute == null)
  86:                  return false;
  87:   
  88:              bool result = false;
  89:              Boolean.TryParse(attribute.Value, out result);
  90:              return result;
  91:          }
  92:   
  93:          /// <summary>
  94:          /// Gets a string value for the specified attribute.
  95:          /// </summary>
  96:          /// <param name="element">The element to parse.</param>
  97:          /// <param name="attributeName">The XName of the attribute to parse.</param>
  98:          /// <returns>A string value representation of the attribute value.</returns>
  99:          public static string GetStringValue(this XElement element, XName attributeName)
 100:          {
 101:              var attribute = element.Attribute(attributeName);
 102:              if (attribute == null)
 103:                  return String.Empty;
 104:   
 105:              return attribute.Value;
 106:          }
 107:   
 108:          /// <summary>
 109:          /// Gets a byte array from the base 64 encoded value of the current element.
 110:          /// </summary>
 111:          /// <param name="element">The element to parse.</param>
 112:          /// <returns>A byte array of the base 64 encoded element value.</returns>
 113:          public static byte[] GetByteArray(this XElement element)
 114:          {
 115:              var value = element.Value;
 116:              if (!String.IsNullOrEmpty(value))
 117:              {
 118:                  return Convert.FromBase64String(value);
 119:              }
 120:              return null;
 121:          }
 122:      }
 123:  }
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1/19/2010


Silverlight 4 Business Application Development – Beginner’s Guide

For those of you out there wanting to get into Silverlight development but just do not know where to start, Frank LaVigne and I have just about completed our book titled Microsoft Silverlight 4 Business Application Development – Beginner’s Guide(link to pre-order). This book will be ideal for current Windows or ASP.NET developers who want to learn Silverlight and because the book is centered on Business Application Development we will empower you with knowledge so you can recommend Silverlight for the next business project at your company.

Gaining the basics required to develop in Silverlight, make use of data binding, WCF and RIA Services you will be prepared to lead the Silverlight charge at your company. Be warned, once you start developing in Silverlight you will have a hard time going back to normal ASP.NET development.

1/18/2010