= Not Only... But Also

The Rails 'fat model' pattern is a good one but can result in very large model classes. It can be
unwieldy to work in such files as they begin to look a bit messy. Assuming you have judiciously 
appraised the model for opportunities to extract out pieces into libraries, it still may leave you with
a lot of code. I find this is particularly the case for validations for models with a large number of columns.

This is where allowing for multiple files to define a class can help and is what NotOnlyButAlso does. It defines a
convention to help organise multiple files as well as avoiding the need for repititive code when using modules as
containers or re-opening the classes.
 
You might recognise this style of solution as used by the concerned_with plugin (http://github.com/jakehow/concerned_with/).
I wrote this a long time ago before I knew of the concerned_with plugin. I have released it because its got a simpler interface
and I love the name.

For interest here are some discussions of this type of solution in regards to concerned_with: 

http://m.onkey.org/2008/9/15/active-record-tips-and-tricks

http://paulbarry.com/articles/2008/08/30/concerned-with-skinny-controller-skinny-model

For extra credit:

http://en.wikipedia.org/wiki/Not_Only..._But_Also

== Install

From Gemcutter:

  gem install not_only_but_also

Or as plugin:

  ./script/install plugin git://github.com/adzap/not_only_but_also.git

== Usage

For example you want to extract out the validations to a separate file:

  class Post
    not_only_but_also :validations
  end

  # in app/models/post/validations.rb

  Post.not_only_but_also do
    validates_presence_of :title
  end

OR the shorthand version:

  class Post
    also_has :validations
  end

  # in app/models/post/validations.rb

  Post.also_has do
    validates_presence_of :title
  end


Copyright (c) 2009 Adam Meehan, released under the MIT license