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.Diagnostics;
using System.IO;
using Microsoft.Practices.EnterpriseLibrary.Common.Configuration;
using Microsoft.Practices.EnterpriseLibrary.Logging.Configuration;
using Microsoft.Practices.EnterpriseLibrary.Logging.Formatters;

namespace Microsoft.Practices.EnterpriseLibrary.Logging.TraceListeners
{
	/// <summary>
	/// A <see cref="TraceListener"/> that writes an email message, formatting the output with an <see cref="ILogFormatter"/>.
	/// </summary>
	[ConfigurationElementType(typeof(EmailTraceListenerData))]
	public class EmailTraceListener : FormattedTraceListenerBase
	{
		string toAddress = String.Empty;
		string fromAddress = String.Empty;
		string subjectLineStarter = String.Empty;
		string subjectLineEnder = String.Empty;
		string smtpServer = String.Empty;
		int smtpPort = 25;

		/// <summary>
		/// Initializes a new instance of <see cref="EmailTraceListener"/>.
		/// </summary>
		public EmailTraceListener()
			: base()
		{
		}

		/// <summary>
		/// Initializes a new instance of <see cref="EmailTraceListener"/> with a <see cref="ILogFormatter"/>.
		/// </summary>
		/// <param name="formatter">The formatter.</param>
		public EmailTraceListener(ILogFormatter formatter)
			: base(formatter)
		{
		}

		/// <summary>
		/// Initializes a new instance of <see cref="EmailTraceListener"/> with a toaddress, fromaddress, 
		/// subjectlinestarter, subjectlinender, smtpserver, and a formatter
		/// a <see cref="ILogFormatter"/>.
		/// </summary>
		/// <param name="toAddress">A semicolon delimited string the represents to whom the email should be sent.</param>
		/// <param name="fromAddress">Represents from whom the email is sent.</param>
		/// <param name="subjectLineStarter">Starting text for the subject line.</param>
		/// <param name="subjectLineEnder">Ending text for the subject line.</param>
		/// <param name="smtpServer">The name of the SMTP server.</param>
		/// <param name="formatter">The Formatter <see cref="ILogFormatter"/> which determines how the 
		/// email message should be formatted</param>
		public EmailTraceListener(string toAddress, string fromAddress, string subjectLineStarter, string subjectLineEnder, string smtpServer, ILogFormatter formatter)
			: this(toAddress, fromAddress, subjectLineStarter, subjectLineEnder, smtpServer, 25, formatter)
		{
		}

		/// <summary>
		/// Initializes a new instance of <see cref="EmailTraceListener"/> with a toaddress, fromaddress, 
		/// subjectlinestarter, subjectlinender, smtpserver, smtpport, and a formatter
		/// a <see cref="ILogFormatter"/>.
		/// </summary>
		/// <param name="toAddress">A semicolon delimited string the represents to whom the email should be sent.</param>
		/// <param name="fromAddress">Represents from whom the email is sent.</param>
		/// <param name="subjectLineStarter">Starting text for the subject line.</param>
		/// <param name="subjectLineEnder">Ending text for the subject line.</param>
		/// <param name="smtpServer">The name of the SMTP server.</param>
		/// <param name="smtpPort">The port on the SMTP server to use for sending the email.</param>
		/// <param name="formatter">The Formatter <see cref="ILogFormatter"/> which determines how the 
		/// email message should be formatted</param>
		public EmailTraceListener(
			string toAddress,
			string fromAddress,
			string subjectLineStarter,
			string subjectLineEnder,
			string smtpServer,
			int smtpPort,
			ILogFormatter formatter
		)
			: base(formatter)
		{
			this.toAddress = toAddress;
			this.fromAddress = fromAddress;
			this.subjectLineStarter = subjectLineStarter;
			this.subjectLineEnder = subjectLineEnder;
			this.smtpServer = smtpServer;
			this.smtpPort = smtpPort;
		}


		/// <summary>
		/// Initializes a new instance of <see cref="EmailTraceListener"/> with a toaddress, fromaddress, 
		/// subjectlinestarter, subjectlinender, smtpserver, smtpport, and a formatter
		/// a <see cref="ILogFormatter"/>.
		/// </summary>
		/// <param name="toAddress">A semicolon delimited string the represents to whom the email should be sent.</param>
		/// <param name="fromAddress">Represents from whom the email is sent.</param>
		/// <param name="subjectLineStarter">Starting text for the subject line.</param>
		/// <param name="subjectLineEnder">Ending text for the subject line.</param>
		/// <param name="smtpServer">The name of the SMTP server.</param>
		public EmailTraceListener(string toAddress, string fromAddress, string subjectLineStarter, string subjectLineEnder, string smtpServer)
			: this(toAddress, fromAddress, subjectLineStarter, subjectLineEnder, smtpServer, 25)
		{
		}

		/// <summary>
		/// Initializes a new instance of <see cref="EmailTraceListener"/> with a toaddress, fromaddress, 
		/// subjectlinestarter, subjectlinender, smtpserver, smtpport, and a formatter
		/// a <see cref="ILogFormatter"/>.
		/// </summary>
		/// <param name="toAddress">A semicolon delimited string the represents to whom the email should be sent.</param>
		/// <param name="fromAddress">Represents from whom the email is sent.</param>
		/// <param name="subjectLineStarter">Starting text for the subject line.</param>
		/// <param name="subjectLineEnder">Ending text for the subject line.</param>
		/// <param name="smtpServer">The name of the SMTP server.</param>
		/// <param name="smtpPort">The port on the SMTP server to use for sending the email.</param>
		public EmailTraceListener(string toAddress, string fromAddress, string subjectLineStarter, string subjectLineEnder, string smtpServer, int smtpPort)
			: base()
		{
			this.toAddress = toAddress;
			this.fromAddress = fromAddress;
			this.subjectLineStarter = subjectLineStarter;
			this.subjectLineEnder = subjectLineEnder;
			this.smtpServer = smtpServer;
			this.smtpPort = smtpPort;
		}

		/// <summary>
		/// Sends an email message given a predefined string
		/// </summary>
		/// <param name="message">The string to write as the email message</param>
		public override void Write(string message)
		{
			EmailMessage mailMessage = new EmailMessage(toAddress, fromAddress, subjectLineStarter, subjectLineEnder, smtpServer, smtpPort, message, this.Formatter);
			mailMessage.Send();
		}

		/// <summary>
		/// Sends an email message given a predefined string
		/// </summary>
		/// <param name="message">The string to write as the email message</param>
		public override void WriteLine(string message)
		{
			Write(message);
		}


		/// <summary>
		/// Delivers the trace data as an email message.
		/// </summary>
		/// <param name="eventCache">The context information provided by <see cref="System.Diagnostics"/>.</param>
		/// <param name="source">The name of the trace source that delivered the trace data.</param>
		/// <param name="eventType">The type of event.</param>
		/// <param name="id">The id of the event.</param>
		/// <param name="data">The data to trace.</param>
		public override void TraceData(TraceEventCache eventCache, string source, TraceEventType eventType, int id, object data)
		{
			if (data is LogEntry)
			{
				EmailMessage message = new EmailMessage(toAddress, fromAddress, subjectLineStarter, subjectLineEnder, smtpServer, smtpPort, data as LogEntry, this.Formatter);
				message.Send();
				InstrumentationProvider.FireTraceListenerEntryWrittenEvent();
			}
			else if (data is string)
			{
				Write(data);
			}
			else
			{
				base.TraceData(eventCache, source, eventType, id, data);
			}
		}

		/// <summary>
		/// Declare the supported attributes for <see cref="EmailTraceListener"/>
		/// </summary>
		protected override string[] GetSupportedAttributes()
		{
			return new string[7] { "formatter", "toAddress", "fromAddress", "subjectLineStarter", "subjectLineEnder", "smtpServer", "smtpPort" };
		}

	}
}