Condition in value in NLog.config

Question

I create my own layout in NLog.config file:

<variable name="MyLayout" value="${message}: ${exception:format=tostring}"/>

But when there is no exception I still see : after message and nothing after it in my log file.

How could I add : only if there is an exception? Maybe something like this (not working code) :

<variable name="MyLayout" value="${message}${exception != null ? ': ' : ''}${exception:format=tostring}"/>

Answer 1

You can do this with ${message}

${message:exceptionSeparator= \: :withException=true}

Or you can use ${onexception}

${message}${onexception: \: }${exception:format=tostring}

Notice : is used as option-delimiter for NLog LayoutRenderer, so it has to be escaped .