From: Tim Hunter <Tim.Hunter@...>
Date: 2002-12-10T08:23:31+09:00
Subject: Re: Newbie: invoking class methods

On Mon, 09 Dec 2002 20:55:42 GMT, jd204c@nih.gov (James Davis) wrote:

>(Using Ruby 1.6.6)
>I am writing a game.  A "splash" screen displays four buttons to the
>user.  Each button has an action assigned to it, loaded from a file.
>When a user clicks a button, I want to execute a class method such as
>Game.new.  First, I thought I wanted a Proc for this purpose,  so I
>tried:
>   ba = proc {ba}  # ba = "Game.new"
>...
>   ba.call
>This approach didn't work.  Didn't produce errors.  So I switched to
>  eval(ba)
>which does work, but I was hoping for a better technique.  Eval seems
>crude and unsafe to me, particularly since the button actions are
>loaded from a file.  I am wondering if there might be another approach
>such as something like "instance_method" for class methods, or send,
>or yield.  Any advice appreciated.  Thanks,
>
>- Jim Davis -

It's not clear to me what the "action" can be, however, I'll offer the
following thoughts.

If the "action" is always a the name of a Game class method, convert
the name to a symbol and send it to the Game class:

m = "new"
Game.send m.intern

If the "action" is always the name of a class and the name of a class
method in the class (i.e. "Game" and "new") then you can get the class
id from the class name with Class.get_const.

c = Class.get_const "Game"
m = "new" 
c.send m.intern