Simple ActiveRecord diff functionality.

Example usage:

require 'active_record/diff'

class User < ActiveRecord::Base
include ActiveRecord::Diff
end

alice = User.create(:name => 'alice', :email_address => 'alice@example.org')

bob = User.create(:name => 'bob', :email_address => 'bob@example.org')

alice.diff?(bob) # => true

alice.diff(bob) # => => ['alice', 'bob'], :email_address => ['alice@example.org', 'bob@example.org']

alice.diff(=> 'eve') # => => ['alice', 'eve']


By default, ActiveRecord::Base.content_columns is used to decide which attributes
to compare. You can include or exclude attributes from this as follows:

class User < ActiveRecord::Base
diff :include => [:id], :exclude => [:password_hash]
end


Alternatively, you can specify exactly which columns to compare:

class User < ActiveRecord::Base
diff :id, :name, :email_address
end


This is an updated version of the "riff" rails plugin.


To the extent possible under law, Tim Fletcher has waived all copyright and
related or neighboring rights to activerecord-diff. This work is published
from the United Kingdom. http://creativecommons.org/publicdomain/zero/1.0/