Mongoid - embed multiple documents of different types

embed_many_different.rb

class Article
  include Mongoid::Document

  field :title, type: String

  embeds_many :widgets, as: :widgetable
end

class Widget
  include Mongoid::Document

  embedded_in :widgetable, polymorphic: true
end

class Widget::Banner < Widget
  field :title, type: String
end

class Widget::Place < Widget
  field :name, type: String
end

usage.rb

a = Article.new({title: "Example Article"})

a.widgets.build({title: "Banner One"}, Widget::Banner)
a.widgets.build({name: "New York"}, Widget::Place)

a
# => #<Article _id: 574d89bb618eade4080aa284, title: "Testovaci">
a.widgets
# => [#<Widget::Banner _id: 574d8a2c618eade4080aa286, title: "Example Article">, #<Widget::Banner _id: 574d8a26618eade4080aa285, _type: "Widget::Banner", title: "Banner One">, #<Widget::Place _id: 574d8a4d618eade4080aa287, _type: "Widget::Place", name: "New York">]