Applied Use of LinFu/Cecil and Aspect-Oriented Programming Concepts - A Library

using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Security.Permissions;
using System.Text;
using System.Threading;
using System.Web;
using BrainTechLLC.ThreadSafeObjects;

namespace BrainTechLLC
{
	/// <summary>
	/// A collection of sequential changes to a single property on a uniquely identified business object / class
	/// </summary>
	public class PropertyChangeCollection<T> where T : new()
	{
		/// <summary>
		/// Stores the original property value.  Used when CancelUpdate is called to revert properties (quickly) back to their original values.
		/// </summary>
		public object _originalValue;

		public string _propertyName;
		public ThreadSafeList<PropertyChangeNotificationArgs> _propertyChanges = new ThreadSafeList<PropertyChangeNotificationArgs>();
		public PropertyDescriptor _propertyDescriptor = null;

		public object FinalValue { get { return _propertyChanges.GetLastItemInList(); } }

		public void Reset()
		{
			_propertyChanges.Clear();
			_originalValue = null;
		}

		/// <summary>
		/// Records a property change
		/// </summary>		
		public void RecordChange(PropertyChangeNotificationArgs changeArgs)
		{
			if (_originalValue == null)
			{
				Interlocked.CompareExchange<object>(ref _originalValue, changeArgs._previousValue, null);
				_propertyDescriptor = TypeDescriptor.GetProperties(typeof(T))[changeArgs.PropertyName];
				_propertyName = changeArgs.PropertyName;
			}

			_propertyChanges.Add(changeArgs);
		}
	}
}