CodeProject Article Scraper, Revisited

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Reflection;

namespace CPAMLib
{

	public enum GenericSortOrder { Ascending, Descending };

	//////////////////////////////////////////////////////////////////////////////////////
/*  Derived from the code found here:
	
	    http://www.c-sharpcorner.com/UploadFile/dipenlama22/SortingUsingGeneric07052006081035AM/SortingUsingGeneric.aspx?ArticleID=dafdb8cc-fd02-4a4d-bd17-0c5785b1b91d
		
	Usage:

		myList.Sort(new GenericComparer<listObject>("PropertyName", GenericSortOrder.Ascending));

	Changes made by JSOP:
    I needed to sort by multiple columns so I implemented different code for the Compare method.
*/ 
    /// <summary>
    /// This class is used to compare any type(property) of a class for sorting. This 
	/// class automatically fetches the type of the property and compares.
    /// </summary>
    public sealed class GenericComparer<T> : IComparer<T>
    {
        private GenericSortOrder sortingOrder;
		private string[] propertyArray = null;

		//--------------------------------------------------------------------------------
        /// <summary>
        /// Sorting order.
        /// </summary>
        public GenericSortOrder SortingOrder { get { return sortingOrder; } }

		//--------------------------------------------------------------------------------
        public GenericComparer(string sortColumn, GenericSortOrder sortingOrder)
        {
			if (string.IsNullOrEmpty(sortColumn))
			{
				throw new Exception("The sortColumn parameter is null/empty");
			}
			this.sortingOrder = sortingOrder;
			this.propertyArray = new string[1] {sortColumn};
        }

		//--------------------------------------------------------------------------------
		public GenericComparer(string[] properties, GenericSortOrder order)
		{
			if (properties == null || properties.Length < 1)
			{
				throw new Exception("Properties array cannot be null/empty.");
			}
			this.sortingOrder = order;
			this.propertyArray = properties;
		}

		//--------------------------------------------------------------------------------
        /// <summary>
        /// Compare the two objects. This will compare as many properties as is specified 
		/// in the propertyArray.
        /// </summary>
        /// <param name="x">custom Object</param>
        /// <param name="y">custom Object</param>
        /// <returns>int</returns>
        public int Compare(T x, T y)
        {
			int          index  = 0;
			int          count  = propertyArray.Length;
			int          result = 0;
			PropertyInfo propertyInfo = null;
			IComparable  obj1 = null;
			IComparable  obj2 = null;
			do
			{
				propertyInfo = typeof(T).GetProperty(propertyArray[index]);
				if (propertyInfo != null)
				{
					obj1         = (IComparable)propertyInfo.GetValue(x, null);
					obj2         = (IComparable)propertyInfo.GetValue(y, null);
					if (obj1 != null && obj2 != null)
					{
						result       = obj1.CompareTo(obj2);
						if (this.SortingOrder == GenericSortOrder.Descending)
						{
							result = -result;
						}
					}
				}
				index++;
			} while (result == 0 && index < count);
			return result;
        }

    }

}