From: Philip Mak <pmak@...>
Date: 2002-07-11T02:49:32+09:00
Subject: Thanks (Re: Accessing caller's binding?)

On Wed, Jul 10, 2002 at 10:03:36AM +0900, Ned Konz wrote:
-snip-

Thanks! That code solved the puzzle for me and taught me the
following:

1. Use instance_eval, allowing me to pass 'self' instead of having
   to type 'binding()', or 'eval' a block of returned code (which
   is dangerous now that I think about it, if the variable names
   contain unsafe characters).

2. Even if I can't define a variable inside eval(), I can still
   define a function with the same name that returns the value I want.

The way #2 works seems a bit awkward, but it works.

So, here's what I'm doing now:

class CGI
    def export(target, vars)
        vars.each do |var|
            target.instance_eval("def self.#{var}; $cgi['#{var}'][0]; end")
        end
    end
end

$cgi.export(self, %w(name phone email))

(I was able to remove the _mycgi stuff because in my application,
there's a global variable called $cgi that is initialized to CGI.new
at the beginning of every new HTTP request.)

Thanks again.