```ruby
class Edition
  include Mongoid::Document
  
  embedded_in :guide
  
  embeds_many :parts
  embeds_many :actions
  
  field :version_number, :type => Integer, :default => 1
  field :title, :type => String
  field :created_at, :type => DateTime, :default => lambda { Time.now }

  accepts_nested_attributes_for :parts

  def build_clone
    new_edition = self.guide.build_edition(self.title)
    new_edition.parts = self.parts.map {|p| p.dup }
    new_edition
  end
  
  def order_parts
    parts.each_with_index do |obj, i|
      obj.order = i + 1
    end
  end
  
  def can_request_review?
    latest_action &&  
    latest_action.request_type != Action::REVIEW_REQUESTED && 
    latest_action.request_type != Action::PUBLISHED
  end
  
  def can_review?
    latest_action && Action::REVIEW_REQUESTED == latest_action.request_type
  end
  
  def can_publish?
    latest_action && Action::OKAYED == latest_action.request_type
  end
  
  def can_okay?
    latest_action && Action::REVIEW_REQUESTED == latest_action.request_type
  end
  
  def new_action(user,type,comment)
    self.actions << Action.new(:requester_id=>user.id,:request_type=>type,:comment=>comment)
    self.guide.calculate_statuses
  end

  def latest_action
    self.actions.sort_by(&:created_at).last
  end

end
```

Update accepting of nested attributes to allow us to remove parts
user
```ruby
class Edition
  include Mongoid::Document
  
  embedded_in :guide
  
  embeds_many :parts
  embeds_many :actions
  
  field :version_number, :type => Integer, :default => 1
  field :title, :type => String
  field :created_at, :type => DateTime, :default => lambda { Time.now }

  accepts_nested_attributes_for :parts, :allow_destroy => true, :reject_if => :all_blank

  def build_clone
    new_edition = self.guide.build_edition(self.title)
    new_edition.parts = self.parts.map {|p| p.dup }
    new_edition
  end
  
  def order_parts
    parts.each_with_index do |obj, i|
      obj.order = i + 1
    end
  end
  
  def can_request_review?
    latest_action &&  
    latest_action.request_type != Action::REVIEW_REQUESTED && 
    latest_action.request_type != Action::PUBLISHED
  end
  
  def can_review?
    latest_action && Action::REVIEW_REQUESTED == latest_action.request_type
  end
  
  def can_publish?
    latest_action && Action::OKAYED == latest_action.request_type
  end
  
  def can_okay?
    latest_action && Action::REVIEW_REQUESTED == latest_action.request_type
  end
  
  def new_action(user,type,comment)
    self.actions << Action.new(:requester_id=>user.id,:request_type=>type,:comment=>comment)
    self.guide.calculate_statuses
  end

  def latest_action
    self.actions.sort_by(&:created_at).last
  end

end
```
assistant