Mongoid::AuditLog

Frustrated with the other options for this, I wrote this gem to handle most basic audit logging for Mongoid. It is intended to be stupidly simple, and offers no fancy functionality.

Installation

Add this line to your application's Gemfile:

gem 'mongoid-audit_log'

And then execute:

$ bundle

Or install it yourself as:

$ gem install mongoid-audit_log

Usage

Recording Activity

Include the Mongoid::AuditLog module into your model.

class Model
  include Mongoid::Document
  include Mongoid::AuditLog
  field :name
end

This will not enable logging by itself, only changes made within the block passed to the record method will be saved.

Mongoid::AuditLog.record do
  Model.create!
end

If you want to log the user who made the change, pass that user to the record method:

Mongoid::AuditLog.record(current_user) do
  Model.create!
end

# or

Mongoid::AuditLog.current_modifier = current_user
Mongoid::AuditLog.enable

A basic implementation in a Rails app might look something like:

class ApplicationController < ActionController::Base
  around_filter :audit_log

  def current_user
    @current_user ||= User.find(session[:user_id])
  end

  private

  def audit_log
    Mongoid::AuditLog.record(current_user) do
      yield
    end
  end
end

Viewing Activity

When an audited model is changed, it will create a record of the Mongoid::AuditLog::Entry class. Each class responds to some query methods:

Mongoid::AuditLog.record do
  model = Model.create!
  module.update_attributes(:name => 'model')
end

model.audit_log_entries.length == 2 # => true

model.audit_log_entries.first.create? # => true
model.audit_log_entries.first.update? # => false
model.audit_log_entries.first.destroy? # => false

model.audit_log_entries.second.create? # => false
model.audit_log_entries.second.update? # => true
model.audit_log_entries.second.destroy? # => false

# And on update you have the tracked changes
model.audit_log_entries.second.tracked_changes.should == { 'name' => [nil, 'model'] }

There are also some built-in scopes (examples from the tests):

  create = Entry.create!(:action => :create, :created_at => 10.minutes.ago)
  update = Entry.create!(:action => :update, :created_at => 5.minutes.ago)
  destroy = Entry.create!(:action => :destroy, :created_at => 1.minutes.ago)

  Entry.creates.to_a.should == [create]
  Entry.updates.to_a.should == [update]
  Entry.destroys.to_a.should == [destroy]
  Entry.newest.to_a.should == [destroy, update, create]
end

Additional saved data

You can access the attributes of the model saved on the Mongoid::AuditLog::Entry. They are saved on the document in the #model_attributes, and include any changes in the #tracked_changes hash.

Examples:

Mongoid::AuditLog.record do
  model = Model.create!(:name => 'foo bar')
end

model.audit_log_entries.length == 1 # => true

model.audit_log_entries.first.create? # => true
model.audit_log_entries.first.model_attributes # => {"name"=>"foo bar"}

Restoring

You can restore models for Mongoid::AuditLog::Entry instances for deletions. This works for both root and embedded documents.

Examples:

model = Model.create!(:name => 'foo bar')
Mongoid::AuditLog.record { model.destroy }

entry = Mongoid::AuditLog::Entry.first
entry.restore!

model == Model.find_by(name: 'foo bar') # => true

It's possible to end up in a situation where a destroy entry cannot be restored, e.g. an entry deleting an embedded document for a root document that's already been deleted. In these scenarios, Mongoid::AuditLog::Restore::InvalidRestore will be raised.

Disabling

The AuditLog module provides methods to included classes to allow explicit disabling or enabling of logging. This can be useful if a model includes the mixin indirectly through another mixin or inheritance.

class Parent
  include Mongoid::Document
  include Mongoid::AuditLog
end

class Child < Parent
  disable_audit_log
end

class Grandchild < Child
  enable_audit_log
end

Parent.audit_log_enabled? # => true
Child.audit_log_enabled? # => false
Grandchild.audit_log_enabled? # => true

Contributing

Fork it
Create your feature branch (git checkout -b my-new-feature)
Commit your changes (git commit -am 'Add some feature')
Push to the branch (git push origin my-new-feature)
Create new Pull Request