Ruby on rails 坎坎、继承资源和STI

如何将cancan、继承的_资源和单表继承一起使用？ 我有类似于此示例的代码：

class Contact < ActiveRecord::Base; end
class Person < Contact; end
class Company < Contact; end

class Ability
  include CanCan::Ability
  def initialize(user)
    user ||= User.new # in case of guest
    can :read, Contact # User can read People and Companies
    can :create, Person # User can create Person only
    can :manage, :all if user.has_role? :admin
  end
end

class ContactsController <  InheritedResources::Base
  load_and_authorize_resource
  def new
   @contact = contact_sti.new
  end

  private
  def clazz
     self.params[:contact_type].nil? ? "contact" : self.params[:contact_type]
  end
  def contact_sti
    clazz.camelize.constantize
  end
end

class联系人

当我尝试以用户身份创建Person时，我得到CanCan:：AccessDenied。这是因为InheritedResources将Contact用作：resource\u class。

我找到了以下解决方案：

class ContactsController <  InheritedResources::Base
  alias :resource_class :contact_sti
end

class ContactsController