LogChanges

log_changes is a simple gem that writes ActiveRecord#changes contents to model-dedicated logfiles.

To log attribute changes for a model simply add include LogChanges::Base to an ActiveRecord model:

class User < ApplicationRecord
  include LogChanges::Base

  def to_s
    "#{first_name} #{last_name}"
  end
end

In this example, if the User record with id = 1 had his name updated you may see an entry like this appear logs/record_changes/2016.12_User.log:

12/29/2016 at 3:48 PM (UTC)
Updated User {id: 1} John Smith
  first_name:
    FROM: Johnny
    TO: John
  last_name:
    FROM: Smithers
    TO: Smith

Logfiles are prefixed with a month stamp (to prevent them from getting too big over time).

If your Rails app runs in a load-balanced distributed environment, you may wish to aggregate logs from multiple servers. log_changes comes with a rake task for this purpose:

rake log_changes:merge['/path/to/logs/directory']

Make sure the path you pass to the task has multiple subfolders (one per server), each with a record_changes directory containing the log files.

Add this line to your application's Gemfile:

gem 'log_changes'

And then execute:

$ bundle install

The gem is available as open source under the terms of the MIT License.