Wipe out all your ActiveRecord methods and expose only the api you need and want to support!

active-record-clear-interface.rb

# (c) Copyright 2012 Elia Schito, released under the MIT license
# 
# = ActiveRecord::ClearInterface
# 
# Wipe out all your AR methods and expose only the api you need 
# and want to support!
# 
# Example:
# 
# 
#     class Message < ActiveRecord::Base
#       include ActiveRecord::ClearInterface
#         
#       attr_accessible :subject, :body
#         
#       def save_to_db
#         save
#       end
#         
#       validates :subject, :body, :user, presence: true
#     end
# 
# And joyfully the new interface is tiny!
# 
#     # BEFORE
#     (Message.new.public_methods - Object.new.public_methods).size # => 250
#     
#     # AFTER
#     (Message.new.public_methods - Object.new.public_methods).size # => 67
#     Message.new.save # => protected method `save' called for #<Message:0x007f9c24b22d80>
# 
module ActiveRecord::ClearInterface
  extend ActiveSupport::Concern
  
  included do
    allowed_methods = 
      Object.public_instance_methods +
      ActiveModel::Naming.public_instance_methods + 
      ActiveModel::Conversion.public_instance_methods + 
      ActiveModel::Validations.public_instance_methods + 
      [:persisted?, :logger]
    
    protected *(ActiveRecord::Base.public_instance_methods - allowed_methods)
  end
end