//
// Copyright (c) 2004-2006 Jaroslaw Kowalski <jaak@jkowalski.net>
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
//
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
//
// * Neither the name of Jaroslaw Kowalski nor the names of its
// contributors may be used to endorse or promote products derived from this
// software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
// THE POSSIBILITY OF SUCH DAMAGE.
//
using System;
using System.Text;
using System.Collections;
using System.Reflection;
using System.Globalization;
using NLog.Internal;
namespace NLog
{
/// <summary>
/// A factory of logging targets. Creates new targets based on their names.
/// </summary>
public sealed class TargetFactory
{
private static TypeDictionary _targets = new TypeDictionary();
static TargetFactory()
{
foreach (Assembly a in ExtensionUtils.GetExtensionAssemblies())
{
AddTargetsFromAssembly(a, "");
}
}
private TargetFactory(){}
/// <summary>
/// Removes all target information from the factory.
/// </summary>
public static void Clear()
{
_targets.Clear();
}
/// <summary>
/// Removes all targets and reloads them from NLog assembly and default extension assemblies.
/// </summary>
public static void Reset()
{
Clear();
AddDefaultTargets();
}
/// <summary>
/// Scans the specified assembly for types marked with <see cref="TargetAttribute" /> and adds
/// them to the factory. Optionally it prepends the specified text to the target names to avoid
/// naming collisions.
/// </summary>
/// <param name="theAssembly">The assembly to be scanned for targets.</param>
/// <param name="prefix">The prefix to be prepended to target names.</param>
public static void AddTargetsFromAssembly(Assembly theAssembly, string prefix)
{
try
{
InternalLogger.Debug("AddTargetsFromAssembly('{0}')", theAssembly.FullName);
foreach (Type t in theAssembly.GetTypes())
{
TargetAttribute[]attributes = (TargetAttribute[])t.GetCustomAttributes(typeof(TargetAttribute), false);
if (attributes != null)
{
foreach (TargetAttribute attr in attributes)
{
AddTarget(prefix + attr.Name, t);
}
}
}
}
catch (Exception ex)
{
InternalLogger.Error("Failed to add targets from '" + theAssembly.FullName + "': {0}", ex);
}
}
/// <summary>
/// Adds default targets from the NLog.dll assembly.
/// </summary>
private static void AddDefaultTargets()
{
AddTargetsFromAssembly(typeof(TargetFactory).Assembly, String.Empty);
}
/// <summary>
/// Registers the specified target type to the factory under a specified name.
/// </summary>
/// <param name="targetName">The name of the target (e.g. <code>File</code> or <code>Console</code>)</param>
/// <param name="targetType">The type of the new target</param>
/// <remarks>
/// The name specified in the targetName parameter can then be used
/// to create target.
/// </remarks>
public static void AddTarget(string targetName, Type targetType)
{
string hashKey = targetName.ToLower(CultureInfo.InvariantCulture);
InternalLogger.Debug("AddTarget('{0}','{1}')", targetName, targetType.FullName);
_targets[hashKey] = targetType;
}
/// <summary>
/// Creates the target object based on its target name.
/// </summary>
/// <param name="name">The name of the target (e.g. <code>File</code> or <code>Console</code>)</param>
/// <returns>A new instance of the Target object.</returns>
public static Target CreateTarget(string name)
{
Type t = _targets[name.ToLower(CultureInfo.InvariantCulture)];
if (t != null)
{
Target la = FactoryHelper.CreateInstance(t) as Target;
if (la != null)
return la;
}
throw new ArgumentException("Target " + name + " not found.");
}
}
}