securitycontextproviderattribute.cs

精通SQL Server2005项目开发

#region Copyright & License
//
// Copyright 2001-2005 The Apache Software Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#endregion

// .NET Compact Framework 1.0 has no support for reading assembly attributes
#if !NETCF

using System;
using System.Reflection;

using log4net.Util;
using log4net.Repository;
using log4net.Core;

namespace log4net.Config
{
	/// <summary>
	/// Assembly level attribute to configure the <see cref="SecurityContextProvider"/>.
	/// </summary>
	/// <remarks>
	/// <para>
	/// This attribute may only be used at the assembly scope and can only
	/// be used once per assembly.
	/// </para>
	/// <para>
	/// Use this attribute to configure the <see cref="XmlConfigurator"/>
	/// without calling one of the <see cref="XmlConfigurator.Configure()"/>
	/// methods.
	/// </para>
	/// </remarks>
	/// <author>Nicko Cadell</author>
	[AttributeUsage(AttributeTargets.Assembly)]
	[Serializable]
	public sealed class SecurityContextProviderAttribute : ConfiguratorAttribute
	{
		#region Constructor

		/// <summary>
		/// Construct provider attribute with type specified
		/// </summary>
		/// <param name="providerType">the type of the provider to use</param>
		/// <remarks>
		/// <para>
		/// The provider specified must subclass the <see cref="SecurityContextProvider"/>
		/// class.
		/// </para>
		/// </remarks>
		public SecurityContextProviderAttribute(Type providerType) : base(100) /* configurator priority 100 to execute before the XmlConfigurator */
		{
			m_providerType = providerType;
		}

		#endregion

		#region Public Instance Properties

		/// <summary>
		/// Gets or sets the type of the provider to use.
		/// </summary>
		/// <value>
		/// the type of the provider to use.
		/// </value>
		/// <remarks>
		/// <para>
		/// The provider specified must subclass the <see cref="SecurityContextProvider"/>
		/// class.
		/// </para>
		/// </remarks>
		public Type ProviderType
		{
			get { return m_providerType; }
			set { m_providerType = value; }
		}

		#endregion Public Instance Properties

		#region Override ConfiguratorAttribute

		/// <summary>
		/// Configures the SecurityContextProvider
		/// </summary>
		/// <param name="sourceAssembly">The assembly that this attribute was defined on.</param>
		/// <param name="targetRepository">The repository to configure.</param>
		/// <remarks>
		/// <para>
		/// Creates a provider instance from the <see cref="ProviderType"/> specified.
		/// Sets this as the default security context provider <see cref="SecurityContextProvider.DefaultProvider"/>.
		/// </para>
		/// </remarks>
		override public void Configure(Assembly sourceAssembly, ILoggerRepository targetRepository)
		{
			if (m_providerType == null)
			{
				LogLog.Error("SecurityContextProviderAttribute: Attribute specified on assembly ["+sourceAssembly.FullName+"] with null ProviderType.");
			}
			else
			{
				LogLog.Debug("SecurityContextProviderAttribute: Creating provider of type ["+ m_providerType.FullName +"]");

				SecurityContextProvider provider = Activator.CreateInstance(m_providerType) as SecurityContextProvider;

				if (provider == null)
				{
					LogLog.Error("SecurityContextProviderAttribute: Failed to create SecurityContextProvider instance of type ["+m_providerType.Name+"].");
				}
				else
				{
					SecurityContextProvider.DefaultProvider = provider;
				}
			}
		}

		#endregion

		#region Private Instance Fields

		private Type m_providerType = null;

		#endregion Private Instance Fields
	}
}

#endif // !NETCF