the Law of Demeter

Please go to http://rails-bestpractices.com/posts/15-the-law-of-demeter

Before:

class Invoice < ActiveRecord::Base
  belongs_to :user
end

<%= @invoice.user.name %>
<%= @invoice.user.address %>
<%= @invoice.user.cellphone %>

After:

class Invoice < ActiveRecord::Base
  belongs_to :user
  delegate :name, :address, :cellphone, :to => :user, :prefix => true
end

<%= @invoice.user_name %>
<%= @invoice.user_address %>
<%= @invoice.user_cellphone %>