mongoid-history: undefined local variable or method `metadata' for

Question

I am using rails 4, mongoid 4. I want to version my model with mongoid-history gem. This is my historyTracker file:

class HistoryTracker
  include Mongoid::History::Tracker
end

This is initializer:

Mongoid::History.tracker_class_name = :history_tracker

This is my user model.

class User
  include Mongoid::Document
  include Mongoid::Timestamps
  include Mongoid::Paranoia
  include Mongoid::Token
  include SimpleEnum::Mongoid
  include ActiveModel::Validations
  include Mongoid::History::Trackable

  field :email
  field :username


  track_history   :on => [:username, :email], 
                  :modifier_field => :modifier, 
                  :modifier_field_inverse_of => :nil, 
                  :version_field => :version,   
                  :track_create   =>  false,   
                  :track_update   =>  true,     
                  :track_destroy  =>  false 

When I am going to seed database with rake and it give an error. I can not handle it. What is the best way to install this correctly?

Answer 1

I had the same issue and had to look at the source code to figure it out. Since you're using mongoid 4, there is a method in the source gem file that's called isMongoid3? We have to disable that method in our local initializer file. To do that, go to your mongoid-history.rb (in initializers) and add this:

module Mongoid
  module History
    def self.mongoid3?
      false
    end
  end
end

Mongoid::History.tracker_class_name = :history_tracker

Now when you go to your rails console and make a change, you can see the changes in your history_tracks