如何获取Mongoid文档的所有字段名称？

Question

我正在构建后端系统,如Iain Hecker的教程中所述:http://iain.nl/backends-in-rails-3-1,我尝试使用Mongoid将其调整为MongoDB.

所以当我需要写backend/resourse_helper.rb时

module Backend::ResourceHelper

  def attributes
    resource_class.attribute_names - %w(id created_at updated_at)
  end

end

我收到以下错误:

undefined method `attribute_names' for Backend::User:Class

(我将后端植根到"后端/用户#index").后端::用户继承自用户:

class User
  include Mongoid::Document

  devise_for :users

  field :name
  field :address
end

我只需要该用户的字段列表:类,我猜(即["电子邮件","名称","地址",...]),但我试图找到方法.

Answer 1

Mongoid已经为您提供了对象的属性:

Model.new.attributes

要获取这些属性的名称:

Model.fields.keys

Answer 2

使用内置方法:

Model.attribute_names
# => ["_id", "created_at", "updated_at", "name", "address"]