An Extension to the Enterprise Library Logging Application Block

//===============================================================================
// Microsoft patterns & practices Enterprise Library
// Logging Application Block
//===============================================================================
// Copyright � Microsoft Corporation.  All rights reserved.
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY
// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT
// LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
// FITNESS FOR A PARTICULAR PURPOSE.
//===============================================================================

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Configuration;
using System.Diagnostics;
using Microsoft.Practices.EnterpriseLibrary.Common.Configuration;

namespace Microsoft.Practices.EnterpriseLibrary.Logging.Configuration
{
	/// <summary>
	/// Represents the configuration for a <see cref="TraceListener"/>.
	/// </summary>
	/// <remarks>
	/// Since trace listeners are not under our control, the building mechanism can't rely 
	/// on annotations to the trace listeners to determine the concrete <see cref="TraceListenerData"/> subtype 
	/// when deserializing. Because of this, the schema for <see cref="TraceListenerData"/> includes the actual 
	/// type of the instance to build.
	/// </remarks>
	public class TraceListenerData : NameTypeConfigurationElement
	{
		/// <summary>
		/// Name of the property that holds the type for a <see cref="TraceListenerData"/>.
		/// </summary>
		/// <remarks>
		/// This property will hold the type of the object it holds it. However, it's used during the 
		/// deserialization process when the actual type of configuration element to create has to be determined.
		/// </remarks>
		protected internal const string listenerDataTypeProperty = "listenerDataType";
		
		/// <summary>
		/// Name of the property that holds the <see cref="TraceOptions"/> of a <see cref="TraceListenerData"/>.
		/// </summary>
		protected internal const string traceOutputOptionsProperty = "traceOutputOptions";

		private static IDictionary<string, string> emptyAttributes = new Dictionary<string, string>(0);

		/// <summary>
		/// Initializes an instance of the <see cref="TraceListenerData"/> class.
		/// </summary>
		public TraceListenerData()
		{
		}

		/// <summary>
		/// Initializes an instance of <see cref="TraceListenerData"/> with a name and <see cref="TraceOptions"/> for 
		/// a TraceListenerType.
		/// </summary>
		/// <param name="name">The name for the instance.</param>
		/// <param name="traceListenerType">The trace listener type.</param>
		/// <param name="traceOutputOptions">The trace options.</param>
		protected TraceListenerData(string name, Type traceListenerType, TraceOptions traceOutputOptions)
			: base(name, traceListenerType)
		{
			this.ListenerDataType = this.GetType();
			this.TraceOutputOptions = traceOutputOptions;
		}

		/// <summary>
		/// Gets or sets the type of the actual <see cref="TraceListenerData"/> type.
		/// </summary>
		/// <remarks>
		/// Should match the this.GetType().
		/// </remarks>
		[ConfigurationProperty(listenerDataTypeProperty, IsRequired= true)]
		[TypeConverter(typeof(AssemblyQualifiedTypeNameConverter))]
		public Type ListenerDataType
		{
			get
			{
				return (Type)this[listenerDataTypeProperty];
			}
			set
			{
				this[listenerDataTypeProperty] = value;
			}
		}

		/// <summary>
		/// Gets or sets the <see cref="TraceOptions"/> for the represented <see cref="TraceListener"/>.
		/// </summary>
		[ConfigurationProperty(traceOutputOptionsProperty, IsRequired= false)]
		public TraceOptions TraceOutputOptions
		{
			get
			{
				return (TraceOptions)this[traceOutputOptionsProperty];
			}
			set
			{
				this[traceOutputOptionsProperty] = value;
			}
		}
	}
}