From: Josh Cheek <josh.cheek@...>
Date: 2010-02-01T16:53:27+09:00
Subject: Re: manufacturing methods

--001636b2ae2cb2ab56047e8547d4
Content-Type: text/plain; charset=ISO-8859-1

On Mon, Feb 1, 2010 at 1:05 AM, Matthew Pounsett <matt@conundrum.com> wrote:

> Hi there.
>
> Apologies if this is covered somewhere... all the googling I've done on the
> subject has wound up with info on class-factories and and using variables in
> methods.  Not exactly what I'm looking for.
>
> The question I've got is related to manufacturing methods.  In my
> particular case, I'm using a module that relies heavily on callback methods.
>  I need to define a couple dozen callbacks which I'd like to all behave in
> basically the same way.  In order to keep my code simple, I thought I'd try
> manufacturing them all from the same basic code.. but haven't found a syntax
> that works.
>
> Though this syntax clearly doesn't work, an example of the sort of thing
> I'm looking for might look like this, assuming I want to create the methods
> "on_foo", "on_bar", and "on_baz":
>
> %w( foo bar baz ).each do |callback|
>   def on_#{callback}
>      # callback work here
>   end
> end
>
> Is what I'm attempting to do even possible?
>
> Thanks,
>  Matt
>
>
>
>
If you are in a class, you should can do:

class Test
  %w( foo bar baz ).each do |callback|
    define_method "on_#{callback}" do |param|
      puts "This is method #{callback}"
      puts "I have received the parameter: #{param}"
      puts
    end
  end
end


test = Test.new
(test.methods - Object.methods).each_with_index do |method,index|
  test.send method , index
end



Here is a list of useful methods like this
http://weare.buildingsky.net/2009/08/25/rubys-metaprogramming-toolbox

They are a bit cumbersome to use, though. For example, I don't know how to
set it up to receive a block, and you can't use them certain places.

--001636b2ae2cb2ab56047e8547d4--