[Help-smalltalk] Re: Logging facility for GNU-smalltalk

[Joachim Jaeckel]

> I think for me the OutputHandler is indeed the combination of your 
> LogHandler and a formatter, with the difference that Transcript, file, 
> etc. for me are all realized with the same kind of LogHandler; possibly 
> created with different class methods.

Aha.

>  > logHandler log: (formatter format: logEntry).
>
> The problem with this is that in some cases the LogHandler might need 
> the severity and category, as is the case for syslog (and I expect 
> special handling of date/time in some cases might be desirable, for 
> example to put a limit on the number of messages per second).

Ok, seems reasonable, what about
logHandler log: LogEntry formattedMsg: (formatter format: logEntry).

So you have all the data like category, severity, date and time 
available to the logHandler.

> It could be done entirely with a MultiplexOutputHandler that also takes 
> care about filtering unwanted severities, yes.

filtering unwanted severities is currently done in the logger itself 
(which is the only class with a bit of logic) because the Dictionary for 
the channel holds the output-severity for this channel. The other 
classes (LogHandler and Formatter) are really dumb and plugable to the 
channel.

I thought about moving the channel-handling in a seperate class, that 
makes the responsibility a bit clearer, that the channel-handler is also 
responsable for the output-severity of this channel... but than, I 
decided to keep this little logic also in the logger itself  instead of 
creating an additional step of communication to the log-output.

...maybe I should change that...

And the MultiplexOutputHandler sounds to me like my Logger, with the 
difference, that you format the message only once and redirect it to the 
several available streams.


Regards,
Joachim.