class Task
  include Mongoid::Document

  # @return [TaskValue] target start and end dates of the activity

  # case 1) create works, update fails
  #references_one :target, class_name: "TaskValue", as: :timeable, autosave: true

  # case 2) create and update works
  #references_one :target, class_name: "TaskValue", inverse_of: :task, autosave: true

  # case 3) create works, update fails
  #embeds_one :target, class_name: "TaskValue", as: :timeable
  
  # case 4) create and update works
  embeds_one :target, class_name: "TaskValue", inverse_of: :task
  
  accepts_nested_attributes_for :target
  attr_accessible :target_attributes

end

class TaskValue
  include Mongoid::Document

  # @return [Time] start date and time
  field :start, :type => Time
  # @return [Time] end date and time
  field :end, :type => Time


  # case 1)
  #referenced_in :timeable, polymorphic: true

  # case 2)
  #referenced_in :task, inverse_of: :target

  # case 3)
  #embedded_in :timeable, polymorphic: true

  # case 4)
  embedded_in :task, inverse_of: :target
end