From: "FireAphis@..." <FireAphis@...>
Date: 2007-07-25T17:00:04+09:00
Subject: Re: Regarding Constants

On Jul 25, 10:17 am, "FireAp...@gmail.com" <FireAp...@gmail.com>
wrote:
> On Jul 24, 11:21 pm, Harnish Botadra <harnish_...@yahoo.com> wrote:
>
>
>
> > Hi,
>
> > I am having some difficulty in the use of constants in Ruby.  I've a
> > module:
>
> > eg.
> > -------------------
> > Module Constants
>
> > MY_CONST = "hello"
>
> > end
> > -------------------
>
> > I include this module in my model.  Further, the name of the constant
> > (MY_CONST) would be passed in a variable say 'var'.  My question, is how
> > do I access the value of the constant from the constant name in 'var'?
>
> > Something like, :: + "{#var}" or similar?  Any help greatly appreciated.
> > Thanks.
>
> > Regards,
> > Harnish
> > --
> > Posted viahttp://www.ruby-forum.com/.
>
> If I understand you correctly then:
>
> Module Constants
>     MY_CONST = "hello"
> end
>
> def get_constant_value_by_name(var)
>    Constants.const_get(var)
> end
>
> get_constant_value_by_name("MY_CONST")
> => "hello"
>
> Hope this helps,
> FireAphis

Of course, as Skye pointed out Module should be lowercase.
You can see that there's a slight difference between my and Skye's
implementation. That's because 'const_get' can receive either a symbol
or a string. I am personally not familiar with to_sym method. But if I
want to pass a symbol instead of a string I'd use 'var.intern'. That
is
    Constants.const_get(var.intern)
which is exactly the same as
    Constants.const_get(var)

FireAphis