Custom NLog Json formatter driven by Exception.Data

EventIdLayoutRenderer.cs

[LayoutRenderer("event-id-json-data")]
public class EventIdLayoutRenderer : LayoutRenderer
{
	private const string _eventIdKey = "EventId";

	private static JsonSerializerSettings _jsonSettings = new JsonSerializerSettings
	{
		NullValueHandling = NullValueHandling.Ignore
	};

	protected override void Append(StringBuilder builder, LogEventInfo logEvent)
	{
		if (logEvent.Properties == null)
		{
			return;
		}

		if (!logEvent.Properties.ContainsKey(_eventIdKey))
		{
			return;
		}

		var eventId = (EventId)logEvent.Properties[_eventIdKey];
		var result = new
		{
			Id = eventId.Id,
			Name = eventId.Name
		};

		var resultString = JsonConvert.SerializeObject(result, _jsonSettings);

		builder.Append(resultString);
	}
}

example.json

{
    "time": "2016-06-01T18:54:04.834Z",
    "level": "ERROR",
    "message": "Home page view exception!",
    "event": {
        "Id": 101,
        "Name": "Page View"
    },
    "exceptionMessage": "This is a not implemented exception",
    "exceptionStackTrace": "System.NotImplementedException: This is a not implemented exception ---> System.ArgumentNullException: Value cannot be null.\r\nParameter name: This is an arg null exception\r\n   --- End of inner exception stack trace ---",
    "exceptionData": {
        "userId": 5
    }
}

ExceptionDataLayoutRenderer.cs

[LayoutRenderer("exception-json-data")]
public class ExceptionDataLayoutRenderer : LayoutRenderer
{
	protected override void Append(StringBuilder builder, LogEventInfo logEvent)
	{
		var exception = logEvent.Exception;

		if (exception == null)
		{
			return;
		}

		var data = getExceptionData(exception);

		var result = JsonConvert.SerializeObject(data);

		builder.Append(result);
	}

	private IDictionary<string, object> getExceptionData(Exception ex)
	{
		if (ex == null)
		{
			return new Dictionary<string, object>();
		}

		var innerData = getExceptionData(ex.InnerException);
		var data = ex.Data.Cast<DictionaryEntry>()
			.Where(x => x.Key is string)
			.ToDictionary(x => x.Key as string, x => x.Value);

		return data.Extend(innerData);
	}
}

nlog.config.xml

<?xml version="1.0" encoding="utf-8" ?>
<nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
      xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
      xsi:schemaLocation="http://www.nlog-project.org/schemas/NLog.xsd NLog.xsd"
      autoReload="true"
      throwExceptions="false"
      internalLogLevel="Off" internalLogFile="c:\temp\nlog-internal.log" >
  <variable name="myvar" value="myvalue"/>
  <time xsi:type="FastUTC" />
  <extensions>
    <add assembly="CoreDemo" />
  </extensions>
  <targets async="true">
    <!-- Write events to a file with the date in the filename. -->
    <target xsi:type="File"
      name="f"
      fileName="${basedir}/logs/${shortdate}.log"
      keepFileOpen="true">
      <layout xsi:type="JsonLayout">
        <attribute name="time" layout="${date:format=yyyy-MM-ddTHH\:mm\:ss.fffK}" />
        <attribute name="level" layout="${level:upperCase=true}"/>
        <attribute name="message" layout="${message}" />
        <attribute name='event' layout='${event-id-json-data}' encode='false' />
        <attribute name='exceptionMessage' layout='${exception}' />
        <attribute name='exceptionStackTrace' layout='${exception:format=ToString}' />
        <attribute name='exceptionData' layout='${exception-json-data}' encode='false' />
      </layout>
    </target>
  </targets>
  <rules>
    <logger name="*" minlevel="Debug" writeTo="f" />
  </rules>
</nlog>