an_intro.textile

If one was inclined to use the acts_as_yaffle pattern, they would probably use the second one, rather than the heavily cargo-culted first one.

first.rb

module Yaffle
  def self.included(base)
    base.send :extend, ClassMethods
  end

  module ClassMethods
    def acts_as_yaffle(options = {})
      cattr_accessor :yaffle_text_field
      self.yaffle_text_field = (options[:yaffle_text_field] || :last_squawk).to_s
      send :include, InstanceMethods
    end
  end

  module InstanceMethods
    def squawk(string)
      write_attribute(self.class.yaffle_text_field, string.to_squawk)
    end
  end
end

ActiveRecord::Base.send :include, Yaffle

second.rb

module Yaffle
  def acts_as_yaffle(options = {})
    cattr_accessor :yaffle_text_field
    self.yaffle_text_field = (options[:yaffle_text_field] || :last_squawk).to_s
    include InstanceMethods
  end

  module InstanceMethods
    def squawk(string)
      write_attribute(self.class.yaffle_text_field, string.to_squawk)
    end
  end
end

ActiveRecord::Base.extend(Yaffle)

the_code_annotated.rb

module Yaffle
  # since this is for internal consumption only, just extend directly;
  # don't rewrite the include method to mean extend
  def self.included(base)
    # extend is a public method
    base.send :extend, ClassMethods
  end

  # if we extended directly, we could get rid of the ClassMethods
  # module and move the methods into the Yaffle module. You onluy
  # ever need one of ClassMethods or InstanceMethods
  module ClassMethods
    def acts_as_yaffle(options = {})
      cattr_accessor :yaffle_text_field
      self.yaffle_text_field = (options[:yaffle_text_field] || :last_squawk).to_s

      # we're inside the class, so we don't need to use send to
      # use a private method
      send :include, InstanceMethods
    end
  end

  module InstanceMethods
    def squawk(string)
      write_attribute(self.class.yaffle_text_field, string.to_squawk)
    end
  end
end

# If we'd used extend, we wouldn't need a send
ActiveRecord::Base.send :include, Yaffle

with my last code, all you do is:

include Yaffle
self.yaffle_text_field = "blah"

If cattr_accessor was changed to allow for sets by parameter on the reader method, then this would read even better:

include Yaffle
yaffle_text_field "blah"

And can be implemented easily.

You seem to be unaware that:

class A; include B, C, D; end

is valid right now.

Actually, your last code will raise a "NoMethodError: undefined method options". I get what you're saying, but in general, whatever initialization included() does might not be easily reversible.

I was unaware that Module#include took *args. Oh, well! I suppose one could check the type of the second arg, since I doubt anybody depends on include raising a TypeError.

meh. two lines of code for users is fine. breaking stuff for the sake of replacing "\n" with ", :([^ ]+) => " is silly IMO

anyone know how to /ignore further comments on a gist?

Wow. It doesn't take a genius to realize that there are many places to ask that question that are more likely to garner an answer than in the comments of a gist that six people have posted to. You did that just to broadcast that you disagreed with and disapproved of me. Presumably, you thought that doing so would either shame me or inform others of your superiority. To me, it communicated your inability to handle dissent.

I read the anguish in your earlier comments as intolerance of whimsy. I take it you'll be celebrating whyday for a reason entirely different from most.

i was only asking because i'm done with this.

oh, i see, you were trying to be "artistic"