[Netcommon-developer] Bridging System.Diagnostics.Trace to NLog (bug fix)

[Israel E. <hs....@gm...>]

I have finally managed to set up a logging bridge from
System.Diagnostics.Trace to NLog. In my scenario, I am specifically
concerned with the Trace output from the System.Net namespace. I hope
this helps anyone else who is trying to bridge Bridging
System.Diagnostics.Trace to NLog. The code should fix should also
allow someone to bridge to log4net.

There were a couple issues I had to work around. First, the
documentation on configuration is slightly wrong. Second, there is a
bug in Common.Logging.Factory.AbstractLogger.

For my configuration, I have the following 2 files: app.config and NLog.config

My app.config looks like this:

        <configuration>
          <configSections>
            <sectionGroup name="common">
              <section name="logging"
type="Common.Logging.ConfigurationSectionHandler, Common.Logging" />
            </sectionGroup>
          </configSections>
          <common>
            <logging>
              <factoryAdapter
type="Common.Logging.NLog.NLogLoggerFactoryAdapter,
Common.Logging.NLog">
                <arg key="configType" value="FILE" />
                <arg key="configFile" value="~/NLog.config" />
              </factoryAdapter>
            </logging>
          </common>
          <system.diagnostics>
            <sharedListeners>
              <add name="Diagnostics"

type="Common.Logging.Simple.CommonLoggingTraceListener,
Common.Logging"
                   initializeData="DefaultTraceEventType=Verbose;
LoggerNameFormat=System.Net.All">
                <filter type="System.Diagnostics.EventTypeFilter"
initializeData="Verbose"/>
              </add>
            </sharedListeners>
            <sources>
              <source name="System.Net">
                <listeners>
                  <add name="Diagnostics" />
                </listeners>
              </source>
            </sources>
            <switches>
              <add name="System.Net" value="Verbose"/>
            </switches>
            <trace>
              <listeners>
                <add name="Diagnostics" />
              </listeners>
            </trace>
          </system.diagnostics>
        </configuration>


and my NLog.config (in the same directory) looks like this:

        <nlog>
          <targets>
            <target name="trace" xsi:type="File"
fileName="${nlogdir}/System.Net.log"

layout="${date:format=HH\:mm\:ss}|${level}|${stacktrace}|${message}"/>
          </targets>
          <rules>
            <logger name="System.Net.*" minlevel="Trace" writeTo="trace" />
          </rules>
        </nlog>


Finally, I had to make a small bug fix in
Common.Logging.Factory.AbstractLogger by modifying the ToString()
method. (There are constructors invocations that supply null for the
IFormatProvider, but ToString() does not guard on that.)

            public override string ToString()
            {
                if (cachedMessage == null)
                {
                    if (FormatProvider != null)
                    {
                        cachedMessage = string.Format(FormatProvider,
Message, Args);
                    }
                    else
                    {
                        cachedMessage = Message;
                    }
                }
                return cachedMessage;
            }




Regards,
Iz