Put chubby models on a diet with concerns by David of 37signals

Hey Women! Welcome to the Ruby on Rails community, where the creator blogs about chubby models needing to go on a diet.

Different models in your Rails application will often share a set of cross-cutting concerns. In Basecamp, we have almost forty such concerns with names like Trashable, Searchable, Visible, Movable, Taggable. These concerns encapsulate both data access and domain logic about a certain slice of responsibility. Here’s a simplified version of the taggable concern: module Taggable extend ActiveSupport::Concern included do has_many :taggings, as: :taggable, dependent: :destroy has_many :tags, through: :taggings end def tag_names tags.map(&:name) end end This concern can then be mixed into all the models that are taggable and you’ll have a single place to update the logic and reason about it. Here’s a similar concern where all we add is a single class method: # current_account.posts.visible_to(current_user) module Visible extend ActiveSupport::Concern module ClassMethods def visi...

Full article: http://37signals.com/svn/posts/3372-put-chubby-models-on-...