column_timestamps

ActiveRecord manages your updated_at columns for you, updating the timestamp when your records change. This gem provides similar, but more granular functionality: in addition to a table-wide updated_at column, you can have additional timestamp columns that track when specific columns change.

Hompage

github.com/myronmarston/column_timestamps

Installation

gem install column_timestamps

Usage

Load the gem using Rails’ 2.1+ gem support. In environment.rb:

config.gem 'column_timestamps'

Usage is pretty simple:

Create a new datetime column using the naming convention <column>_updated_at.
Include ColumnTimestamps in your model.

Example:

# in a migration...
create_table :users, :force => true do |t|
  t.string    :email_address
  t.string    :name
  t.string    :state
  t.datetime  :state_updated_at
  t.timestamps
end

# Model...
class User < ActiveRecord::Base
  include ColumnTimestamps
end

Anytime the state attribute of a user record is changed, the state_updated_at timestamp will be updated to reflect that.

Version Compatibility

column_timestamps relies upon the dirty attributes functionality introduced to ActiveRecord in version 2.1. It works on any version since 2.1, including 3.0.0.beta. It works on ruby 1.8.6], 1.8.7 and 1.9.1.

Note on Patches/Pull Requests