Mongoid Top Linked List

A relatively simple module that provides a doubly top linked list for your documents. Every change creates a new document, with a link to the old one. All the documents have a link to the newest document. This setup should provide better performance in applications that usually need the newest version.

An example:

require 'mongoid'
require 'mongoid-tll'

class MyDocument
  include Mongoid::Document
  include Mongoid::TLL
  
  field :data
end

@doc = MyDocument.create(data: "first version")
@doc.data = "second version"
@doc.save

@doc.data
>> "second version"
@doc.prev.data
>> "first version"

A default scope is added to only find the newest versions by default. Use the unscoped method to circumvent this.

Other helper methods have been added:

• newest - Returns the newest version of the document.
• newest? - Is this the newest version?
• oldest? - Is this the oldest (original) version?
• prev - Returns the previous version of the document.