From: Todd Benson <caduceass@...>
Date: 2008-03-14T13:23:41+09:00
Subject: Re: Naming ruby class attribute and methods

On Thu, Mar 13, 2008 at 10:39 PM, Demonic Software
<demonic.software@gmail.com> wrote:
> Thanks David.
>  Is there any way to get the methods on an object that is already
>  instantiated?
>
>  Thanks again
>
>
>
>  On Thu, Mar 13, 2008 at 10:27 PM, David A. Black <dblack@rubypal.com> wrote:
>
>  > Hi --
>  >
>  > On Fri, 14 Mar 2008, Demonic Software wrote:
>  >
>  > > Hello,
>  > >
>  > > Is there a way to name all the methods and attributes/ class
>  > instantiated
>  > > variables that have been created?  For example, from the class below, I
>  > > would like to get all the variables instantiated from the initialize and
>  > > example methods, and then I would also like to be able to get the method
>  > > names.
>  > >
>  > >
>  > > #pseudo code, not sure if it really runs
>  > > class Foo
>  > >  def initialize()
>  > >     @thestring = ''
>  > >     @haha = "HA HA HAA!"
>  > >     @var = "I am a variable"
>  > >  end
>  > >  def example(arg)
>  > >     @arg = arg
>  > >     @thestring = "#{@haha} #{@var}: #{arg}"
>  > >  end
>  > >  def thestring
>  > >     @thestring
>  > >  end
>  > > end
>  > >
>  > >
>  > > So is there a way to extract ["thestring", "var", "haha", "arg"] for the
>  > > variable names and then  ["initialize", "example", "thestring"] for the
>  > > method names.  I can see how I would do it with regular expressions and
>  > > ruby2ruby, but I was wondering if there was another way of extracting
>  > the
>  > > information.  Thanks in advance.
>  >
>  > You can get method and instance variable names. An "attribute" is
>  > really a kind of virtual construct, composed of methods and (usually)
>  > instance variables, so it doesn't appear as a separate thing when you
>  > do introspective stuff on the object. The main time "attribute" exists
>  > is when you create them; after that, they're just methods (though one
>  > is of course free to continue to call them attributes).
>  >
>  > Foo.instance_methods(false) will give you all the instance methods
>  > defined in Foo. (The rather cryptic "false" means: don't include
>  > methods created higher in the ancestry.) To get the instance variables
>  > you have to instantiate the class, run the methods that create them,
>  > and then call the #instance_variables method. (Just defining methods
>  > with i. vars inside them doesn't create the i. vars.)
>  >
>  >
>  > David
>  >
>  > --
>  > Upcoming Rails training from David A. Black and Ruby Power and Light:
>  >   ADVANCING WITH RAILS, April 14-17 2008, New York City
>  >   CORE RAILS, June 24-27 2008, London (Skills Matter)
>  > See http://www.rubypal.com for details. Berlin dates coming soon!
>  >
>  >
>

f = Foo.new
f.public_methods(false)

... works for the instance f

Todd