From: Bryan Zarnett <bryan_zarnett@...>
Date: 2001-02-20T02:10:09+09:00
Subject: [ruby-talk:11121] Re: Auto-magically determine your class/method in Ruby

Thats great. I would write a long reply but I gotta
play with that and change some code. Thanxs. Cool.

Bryan

--- Dave Thomas <Dave@PragmaticProgrammer.com> wrote:
> Bryan Zarnett <bryan_zarnett@yahoo.ca> writes:
> 
> > Is their a way to auto-magically determine the
> class
> > and method that called an operation in another
> class.
> > For example, I have a logger class that would like
> to
> > embed in the output line the Class and operation
> that
> > logged a message. I don't want to have to pass
> this
> > information as an argument if I have to.
> 
> This is Ruby. Of _course_ there is... :)
> 
> Here's the logging stuff. I made a global function
> called log, and
> encapsulated the actual logging within a class
> Logger. The global
> function picks up the value of 'self', and passes
> it, along with the
> args, to the real logger function. There, we get the
> name of self's
> class, and use the caller function to get the file
> name, line number
> and method name of the invocation of 'log'.
> 
>      def log(*args)
>        Logger.log(self, *args)
>      end
> 
>      class Logger
>        def Logger.log(fromObject, *args)
>          fromClass = fromObject.class.to_s
>          fileEtc = caller(2)[0]
>          txt = args.shift
>          printf "Class
> #{fromClass}[#{fromObject.id}] (#{fileEtc}):
> #{txt}\n", *args
>        end
>      end
> 
>      # Let's test this
> 
>      class Dave
>        def doSomething
>          log("Fortran code is %s", "A")
>        end
>      end
> 
>      log("Toplevel")
> 
>      Dave.new.doSomething
> 
> #=>
>      Class Object[537712200] (t.rb:23): Toplevel
>      Class Dave[537684200] (t.rb:19:in
> `doSomething'): Fortran code is A
> 
> 
> 
> Regards
> 
> 
> Dave
> 
> 
> 


_______________________________________________________
Do You Yahoo!?
Get your free @yahoo.ca address at http://mail.yahoo.ca