From: Nilesh Trivedi <nilesh.tr@...>
Date: 2009-09-10T21:52:05+09:00
Subject: Re: defining a singleton method dynamically

--00151747921cbfa09c047338881e
Content-Type: text/plain; charset=ISO-8859-1

On Thu, Sep 10, 2009 at 6:05 PM, Nilesh Trivedi <nilesh.tr@gmail.com> wrote:

> How do I define a singleton method dynamically?
>
> I have code similar to this:
>
> def foo(obj,label)
>   def obj.name; label; end #we want to define a singleton method called
> "name" on obj which returns the value in label
>   puts obj.name #this is an example. Actually I have some code here which
> expects this singleton method in obj
> end
>
> When I try to run this as foo(Object.new,"xyz"), it throws a "NameError:
> undefined local variable or method `label' for #<Object:0xb7b02018>" whereas
> I want it to print "xyz" to screen.
>
> Of course, line 2 in method foo is not correct. But what is the correct
> way?
>

Replacing line 2 by:

obj.instance_eval "def name; '#{label}'; end"

does get the behaviour that I want. Is this the best way to do this or is
there a better, cleaner way?

cheers
nilesh

--00151747921cbfa09c047338881e--