lytol / mongoid-historicals

Mongoid Historicals

Record a snapshot of current values to reference later as historical values.

Installation

Add to your Gemfile

gem 'mongoid-historicals', :require => 'mongoid/historicals'

Usage

Here is an example of how to track the week-to-week score for the players in my fictional MMORPGFPS:

class Player
  include Mongoid::Document
  include Mongoid::Historicals

  field :username, type: String
  field :score,    type: Integer

  historicals :score, :max => 52, :frequency => :weekly
end

In a cron task, I could run the following every Sunday before midnight:

Player.all.each do |player|
  player.record!
end

Then, I could show each player's historical score like this:

<h2>Your Current Score: <%= @player.score %></h2>
<p>Your Score Last Week: <%= @player.historical(:score, 1.week.ago) %> / Difference: <%= @player.historical_difference(:score, 1.week.ago) %></p>