Optimizing Performance in NHibernate: Part 2: A Collection of Enhancements

using System;
using System.Collections.Generic;
using System.Text;

namespace Northwind.Domain.Entities.Errors
{
	/// <summary>
	/// Collection of Validation Failures built when an 
	/// object is validated.
	/// </summary>
	public class ValidationFailureCollection
		: List<ValidationFailure>
	{
		private bool _containsError;

		public ValidationFailureCollection() : base( )
		{
			_containsError = false;
		}

		/// <summary>
		/// Checks the IsError on the validaiton failure being
		/// added and sets _containsError appropiately.
		/// </summary>
		/// <param name="failure"></param>
		public new void Add( ValidationFailure failure )
		{
			base.Add(failure);
			if (failure.IsError)
				_containsError = true;
		}

		/// <summary>
		/// Hides the base class Clear to let us clear the
		/// _containsError flag.
		/// </summary>
		public new void Clear()
		{
			_containsError = false;
			base.Clear();
		}

		public void AddChildFailures(ValidationFailureCollection childCollection, string prefix)
		{
			foreach (ValidationFailure failure in childCollection)
			{
				failure.Prefix = prefix + ":" + failure.Prefix;

				//If the child collection contains an error, we now do too.
				if (failure.IsError)
					_containsError = true;
			}

			AddRange(childCollection);
		}

		/// <summary>
		/// Indicates if the collection contans at least one
		/// validation failure which is an error.
		/// </summary>
		public bool ContainsError
		{
			get { return _containsError; } 
		}
	}
}