From: Andrea Fazzi <andrea.fazzi@...>
Date: 2008-06-26T17:53:09+09:00
Subject: Re: Is it ellegant to use a global variable to store a Logger object?

Chuck Remes ha scritto:
>
> On Jun 25, 2008, at 11:04 AM, Andrea Fazzi wrote:
>
>> Robert Dober ha scritto:
>>> each class would need to have an adapted initialize method, well that
>>>
>>
>> Yes, and indeed this is very annoying. When the system grows up you 
>> have to do with long constructor signatures:
>>
>> Foo.new(logger, service, another_service ... )
>>
>> But I wonder if there is a better method to keep things decoupled..
>
> I typically provide a setter on my classes for configuring the log 
> object. Hardly perfect, but it keeps the constructor signatures short. 
> I am liking this suggestion to use a global variable though. I think 
> I'll experiment.

Ok, you're using setter injection instead of constructor injection.

>
> On a related note, I'm curious how people solve the problem of turning 
> logging on and off during runtime.
>
> I hate code like:
>
> logger.log(:debug, "some msg") unless logger.nil?
>
> I usually provide a null class for my loggers which silently swallow 
> any messages sent to them if the logging function is disabled. It 
> cleans up the code considerably.

Of course you can do that because you're setting a logger instance for 
each object with logging capability. But what to do if you are using a 
global logger instance and you wish to turn off logging selectively?

Andrea