Logger for class method from an included module

[Iain Barnett]

Hi,

I want to log what's happening when a class method is called, using a =
Logger instance. The code resembles this:=20

=20
module Helpers
def self.included(klass)
klass.extend ClassMethods
end
=20
module ClassMethods
=20
def my_classy_method( arg1, arg2 )
#I want to log in here
...
end

end#ClassMethods

end#Helpers


class User
=20
include Helpers

#boring stuff...

end


#called as such
User.my_classy_method( "blah", "plop" )


I've no idea where I should send the logger instance to that I've =
already set up in the rest of the app. Would someone be good enough to =
enlighten me? Should I perhaps alter the method signature to send the =
logger in as an argument on the end like this:

def my_classy_method( arg1, arg2, options=3D{} )
options[:logger].debug ...

User.my_classy_method( "blah", "plop", {logger: @logger} )

or would that be bad form?

Any help on the matter is much appreciated.


Regards,
Iain=

 

[Tim Pease]

Hi,
=20
I want to log what's happening when a class method is called, using a =

Logger instance. The code resembles this:=20

I've no idea where I should send the logger instance to that I've =

already set up in the rest of the app. Would someone be good enough to =
enlighten me? Should I perhaps alter the method signature to send the =
logger in as an argument on the end like this:

=20
def my_classy_method( arg1, arg2, options=3D{} )
options[:logger].debug ...
=20
User.my_classy_method( "blah", "plop", {logger: @logger} )
=20
or would that be bad form?
=20
Any help on the matter is much appreciated.
=20

Since you want to reference a single Logger instance globally, perhaps a =
global variable might be useful?

$app_logger =3D Logger.new( ... )

If global variables turn your stomach, you could create an application =
level module that contains your logger and/or other common objects.

module MyApp
extend self

def logger
@logger ||=3D Logger.new( ... )
end
end

And now from anywhere in your code you can get the global logger thus

MyApp.logger

Another option to consider is the "logging" gem =
<https://github.com/TwP/logging>. The advantages of the logging gem are =
the ability to give each class it's own logger and still send all log =
events to the same destination (stdout, file, syslog, or any =
combination). You can then tweak the log level on a class by class =
basis. You can set the log level for one class to "debug" and keep all =
the others at "info" or "warn". This is great when you only need to =
debug a small subset of your application.

Blessings,
TwP

 

[Iain Barnett]

=20
Since you want to reference a single Logger instance globally, perhaps =

a global variable might be useful?

=20
$app_logger =3D Logger.new( ... )
=20
If global variables turn your stomach,

I think the general ire against global vars prevented my head from =
considering this

you could create an application level module that contains your logger = and/or other common objects.
=20
module MyApp
extend self
=20
def logger
@logger ||=3D Logger.new( ... )
end
end
=20
And now from anywhere in your code you can get the global logger thus
=20
MyApp.logger

I can see I start using this in code a lot, not just for loggers, and =
probably inappropriately, but there you go.

=20
Another option to consider is the "logging" gem =

<https://github.com/TwP/logging>. The advantages of the logging gem are =
the ability to give each class it's own logger and still send all log =
events to the same destination (stdout, file, syslog, or any =
combination). You can then tweak the log level on a class by class =
basis. You can set the log level for one class to "debug" and keep all =
the others at "info" or "warn". This is great when you only need to =
debug a small subset of your application.

I've downloaded it and am giving it a whirl now! Thanks.

Regards,
Iain=