//
// 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 NLog;
using NLog.Config;
using NLog.Conditions;
namespace NLog.Filters
{
/// <summary>
/// Matches when the specified condition is met.
/// </summary>
/// <remarks>
/// Conditions are expressed using a simple language
/// described <a href="conditions.html">here</a>.
/// </remarks>
[Filter("when")]
public class ConditionBasedFilter: Filter
{
private ConditionExpression _condition = null;
/// <summary>
/// Initializes a new instance of the filter object.
/// </summary>
public ConditionBasedFilter(){}
/// <summary>
/// The condition expression.
/// </summary>
public string Condition
{
get { return _condition.ToString(); }
set { _condition = ConditionParser.ParseExpression(value); }
}
/// <summary>
/// Checks whether log event should be logged or not.
/// </summary>
/// <param name="logEvent">Log event.</param>
/// <returns>
/// <see cref="FilterResult.Ignore"/> - if the log event should be ignored<br/>
/// <see cref="FilterResult.Neutral"/> - if the filter doesn't want to decide<br/>
/// <see cref="FilterResult.Log"/> - if the log event should be logged<br/>
/// </returns>
protected internal override FilterResult Check(LogEventInfo logEvent)
{
if (_condition == null)
return FilterResult.Neutral;
object val = _condition.Evaluate(logEvent);
if (val != null && val is bool && ((bool)val))
return Result;
else
return FilterResult.Neutral;
}
}
}