From: Yossef Mendelssohn <ymendel@...>
Date: 2009-08-15T00:24:27+09:00
Subject: Re: Class method aliased in superclass bypasses subclass overrides

On Aug 14, 9:35 am, Marcos <markjr...@gmail.com> wrote:
> So what is it about "alias" that bypasses the override?   Do I have to
> replace my aliases with extra wrapper methods to get the behavior I'm
> looking for?

As far as I can tell (or explain), alias and alias_method work by
creating a new copy of the method. One way to think about it is if you
had the block stored in a variable because you created the first
method like so

    class Blah
      meth = Proc.new { puts 'hi' }
      define_method :first, &meth
    end

Then aliasing the method like `alias :copy :first` is the same as
`define_method :copy, &meth`.

I ran into problems with the same sort of behavior when I was trying
to test-drive an addition of a simple alias for a complicated method,
and I assumed that I could simply test that calling the alias called
the original method with the same arguments. Nope! Calling the alias
went through the same complicated steps as the original. So I changed
the alias_method line to a wrapper function and went on my merry way.

--
-yossef