nested_mass_assignment.rb

module NestedMassAssignment
  extend ActiveSupport::Concern

  included do
    include ActiveAttr::BasicModel
    include ActiveAttr::BlockInitialization
    include ActiveAttr::Logger
    # include ActiveAttr::MassAssignment
    include ActiveAttr::AttributeDefaults
    include ActiveAttr::QueryAttributes
    include ActiveAttr::TypecastedAttributes
    include ActiveAttr::Serialization

    def initialize(attributes=nil, options={})
      assign_attributes attributes, options
      super
    end

    def assign_attributes(new_attributes, options={})
      sanitized_new_attributes = sanitize_for_mass_assignment_if_sanitizer new_attributes, options

      sanitized_new_attributes.each do |name, value|
        if self.class.attributes[name][:class]
          value = self.class.attributes[name][:class].constantize.new(value)
        end
        writer = "#{name}="
        send writer, value if respond_to? writer
      end if sanitized_new_attributes
    end
  end
end

class Whatever
  include NestedMassAssignment

  attribute :member, class: "Whatever::Member"
  attribute :code

  class Member
    include NestedMassAssignment

    attribute :some_id
  end
end