[Netcommon-developer] Runtime error with custom LoggerFactoryAdapter/Logger

[Geoghegan, W. A (Willie) <wil...@in...>]

Hello,

I am currently evaluating Common.Logging.  I have implemented a custom
LoggerFactoryAdapter/Logger to wrap a logger that I wrote that logs via
System.Diagnostics.TraceSource.  Because the underlying logger is based
on TraceSources, my factory does not require any additional
configuration parameters.  I created my logger factory adapter by
subclassing from AbstractCachingLoggerFactoryAdapter and implementing
the constructor which takes the NameValueCollection and also the
CreateLogger method.

When I configure Common.Logging (via the app.config file) to use my
custom logger factory adapter, I get an exception that says:

"Unable to create instance of type <my fully qualified logger factory
adapter class>.  Possible explanation is lack of zero arg and single arg
NameValueCollection constructors."

The inner exception says "No parameterless constructor defined for this
object".

I do have the NameValueCollection constructor, however, I do not have
any configuration parameters in my app.config file (since my factory
does not require any).  I tried adding a zero arg constructor and got a
compile error that the AbstractCachingLoggerFactoryAdapter does not
contain a constructor that takes 0 arguments.

I have worked around this by simply adding a dummy name/value pair to my
factory adapter's configuration.  It seems like it should be ok to have
no configuration properties and that Common.Logging should be tolerant.


Inside of LogManager.cs in BuildLoggerFactoryAdapterFromLogSettings
around line 303, setting.Properties is tested.  If it is not null and if
setting.Properties.Count > 0, then the adapter is created via the
"NameValueCollection" constructor.  Otherwise, it is created via the
zero arg constructor.

Thanks.

Willie Geoghegan.