= 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


There is a generator for quickly creating the context file and the directory if need be

  ./script/generate not_only_but_also Post validations

Adding the context to the model to have it loaded is left for as an exercise for the developer.

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