From: lasitha <lasitha.ranatunga@...>
Date: 2009-02-22T03:36:28+09:00
Subject: Re: How to call a module method dynamically

On Sat, Feb 21, 2009 at 10:28 PM, Adrian Klingel
<adrian.klingel@illumaware.com> wrote:
> I know about object instantiation and the send method, but the methods I
> want to call are not in a class.  They live in a module.
>
> module Foo
>
>  module Bar
>
>    def mymethod
>      "xyz"
>    end
>
>  end
>
> end
>
>
> I can call it statically, like:
>
> myvar = Foo::Bar::xyz

I'm going to assume you meant Foo::Bar::mymethod, but even that wouldn't work.

The way you've defined mymethod above makes it an instance method.
The only way to access a module instance method is to mix the module
into a class/object.  If you need an instance method to double as a
class method, Module#module_function can help:

$: irb
01> module Foo
02>   def mymethod; "xyz"; end
03> end
--> nil
04> Foo::mymethod
NoMethodError: undefined method `mymethod' for Foo:Module
        from (irb):4
        from /usr/local/ruby1.9/bin/irb:12:in `<main>'
05> module Foo
06>   module_function :mymethod
07> end
--> Foo
08> Foo::mymethod
--> "xyz"

Having said all that, you haven't indicated any reason for these be
instance methods.  If they aren't intended to be mixed into anything
and the Module is essentially just a namespace in which to define your
methods, they might as well be class methods.

If so, then Object#send will work just fine:

09> Foo.send(:mymethod)
--> "xyz"


> I want to use a single rake task to kick off
> any job, so I don't have to have a task for every single job

Reconsider.  One of the nice things about rake tasks is they double as
documentation.  Being able to run 'rake -T' and see a listing of
available commands is really useful, and more durable than having to
remember (or document elsewhere) the names of the available methods.
And since rake tasks are created dynamically, some simple reflection
and loop will ensure the tasks always match the methods available:

namespace :command
  Foo.methods(false).each do |method_name|
    desc "run #{method_name}"
    task method_name do
      Foo.send(:method_name)
    end
  end
end

I'm still not sure i understand your problem (!), but i hope some part
of all the above helps :)

lasitha.