Nlog: Call another taget within a custom target?

[snowjim]

Hi,

I have wrote my own custom target by inherit from the TargetWithLayout. My custom target will log to database but in some cases this could fail. I still needs to log in some way so the question is if its possible to call a known target like the EventLogTarget from within the custom target and then log there? Or do I have to create the EvenLog code manually within the CustomTarget?

[304NotModified]

What about the fallback target? https://github.com/NLog/NLog/wiki/FallbackGroup-target

or writing to both always? (e.g. <logger ... writeto=myTarget,eventLogger`

[snowjim]

Thanks!

That looks like a good way to do it but how will it know if one failes? From what I have seen there is really not much happening after a exception is thrown from within a custom target. I do not get a carscading exception to the calling code it just dont log anything. Will nlog note the exception in the customTarget and then try the next target in config?

<targets> <target xsi:type="FallbackGroup" name="String" returnToFirstOnSuccess="Boolean"> <target xsi:type="CustomMail" ... /> <target xsi:type="Evenlog" ... /> </target> </targets>

So if the mail is failing in the above with an exception the Evenlog will and only then be used? I dont wnat to log to 2 targets at the same time, it would generate more data then needed.

[snakefoot]

So if the mail is failing in the above with an exception the Evenlog will and only then be used?

NLog attaches a lambda-function to each logevent (AsyncLogEventInfo). This lamba-function is called by the destination target on logevent-write-completion (both on success or on exception).

The fallback-wrapper attaches/chains its own delegate to the logevent-lambda, and when the destination-target calls the logevent-lambda, then the fallback-wrapper is notified whether the logevent-write completed with an exception. On exception then the attached fallback-wrapper-lambda will redirect the logevent to the specified fallback-target.

The short answer is that the fallback-wrapper will only call the fallback-target, when the primary target fails with an exception.

[snowjim]

Thanks!