protected override void FormatXml()

in src/log4net/Layout/XmlLayoutSchemaLog4j.cs [128:243]
85 lines of code
19 McCabe index (conditional complexity)

  protected override void FormatXml(XmlWriter writer, LoggingEvent loggingEvent)
  {
    // Translate logging events for log4j

    // Translate hostname property
    if (loggingEvent.EnsureNotNull().LookupProperty(LoggingEvent.HostNameProperty) is not null
        && loggingEvent.LookupProperty("log4jmachinename") is null)
    {
      loggingEvent.GetProperties()["log4jmachinename"] = loggingEvent.LookupProperty(LoggingEvent.HostNameProperty);
    }

    // translate appdomain name
    if (loggingEvent.LookupProperty("log4japp") is null
        && loggingEvent.Domain?.Length > 0)
    {
      loggingEvent.GetProperties()["log4japp"] = loggingEvent.Domain;
    }

    // translate identity name
    if (loggingEvent.Identity?.Length > 0 &&
      loggingEvent.LookupProperty(LoggingEvent.IdentityProperty) is null)
    {
      loggingEvent.GetProperties()[LoggingEvent.IdentityProperty] = loggingEvent.Identity;
    }

    // translate user name
    if (loggingEvent.UserName.Length > 0 &&
        loggingEvent.LookupProperty(LoggingEvent.UserNameProperty) is null)
    {
      loggingEvent.GetProperties()[LoggingEvent.UserNameProperty] = loggingEvent.UserName;
    }

    // Write the start element
    writer.EnsureNotNull().WriteStartElement("log4j:event", "log4j", "event", "log4net");
    writer.WriteAttributeString("logger", loggingEvent.LoggerName);

    // Calculate the timestamp as the number of milliseconds since january 1970
    // 
    // We must convert the TimeStamp to UTC before performing any mathematical
    // operations. This allows use to take into account discontinuities
    // caused by daylight savings time transitions.
    TimeSpan timeSince1970 = loggingEvent.TimeStampUtc - _sDate1970;

    writer.WriteAttributeString("timestamp", XmlConvert.ToString((long)timeSince1970.TotalMilliseconds));
    if (loggingEvent.Level is not null)
    {
      writer.WriteAttributeString("level", loggingEvent.Level.DisplayName);
    }
    writer.WriteAttributeString("thread", loggingEvent.ThreadName);

    // Append the message text
    if (loggingEvent.RenderedMessage is not null)
    {
      writer.WriteStartElement("log4j:message", "log4j", "message", "log4net");
      Transform.WriteEscapedXmlString(writer, loggingEvent.RenderedMessage, InvalidCharReplacement);
      writer.WriteEndElement();
    }

    if (loggingEvent.LookupProperty("NDC") is object ndcObj)
    {
      string? valueStr = loggingEvent.Repository?.RendererMap.FindAndRender(ndcObj);
      if (!string.IsNullOrEmpty(valueStr))
      {
        // Append the NDC text
        writer.WriteStartElement("log4j:NDC", "log4j", "NDC", "log4net");
        Transform.WriteEscapedXmlString(writer, valueStr!, InvalidCharReplacement);
        writer.WriteEndElement();
      }
    }

    // Append the properties text
    PropertiesDictionary properties = loggingEvent.GetProperties();
    if (properties.Count > 0)
    {
      writer.WriteStartElement("log4j:properties", "log4j", "properties", "log4net");
      foreach (KeyValuePair<string, object?> entry in properties)
      {
        writer.WriteStartElement("log4j:data", "log4j", "data", "log4net");
        writer.WriteAttributeString("name", entry.Key);

        // Use an ObjectRenderer to convert the object to a string
        string? valueStr = loggingEvent.Repository?.RendererMap.FindAndRender(entry.Value);
        if (!string.IsNullOrEmpty(valueStr))
        {
          writer.WriteAttributeString("value", valueStr);
        }

        writer.WriteEndElement();
      }
      writer.WriteEndElement();
    }

    string? exceptionStr = loggingEvent.GetExceptionString();
    if (!string.IsNullOrEmpty(exceptionStr))
    {
      // Append the stack trace line
      writer.WriteStartElement("log4j:throwable", "log4j", "throwable", "log4net");
      Transform.WriteEscapedXmlString(writer, exceptionStr!, InvalidCharReplacement);
      writer.WriteEndElement();
    }

    if (LocationInfo)
    {
      if (loggingEvent.LocationInformation is LocationInfo locationInfo)
      {
        writer.WriteStartElement("log4j:locationInfo", "log4j", "locationInfo", "log4net");
        writer.WriteAttributeString("class", locationInfo.ClassName);
        writer.WriteAttributeString("method", locationInfo.MethodName);
        writer.WriteAttributeString("file", locationInfo.FileName);
        writer.WriteAttributeString("line", locationInfo.LineNumber);
        writer.WriteEndElement();
      }
    }

    writer.WriteEndElement();
  }