Basic rails delegating form object factory

delegating_form_object.rb

class PartialReportForm
  include DelegatingFormObject.new(Report)

  delegate :name, :name=,
    to: :report

  validates :name,
    presence: true
end

module DelegatingFormObject
  def self.new(model_class)
    Module.new do
      extend ActiveSupport::Concern

      included do
        include ActiveModel::Model

        @_model_name = ActiveModel::Name.new(self, nil, model_class.name)
        attr_accessor @_model_name.singular

        delegate :persisted?, to: @_model_name.singular

        def initialize(obj, params = {})
          instance_variable_set("@#{self.class.model_name.singular}".to_sym, obj)
          super params.fetch(self.class.model_name.singular.to_sym, {})
        end
      end

      def save
        return false unless valid?

        public_send(self.class.model_name.singular).save(validate: false)
      end
    end
  end
end