Question

我有一个users_manager引擎，它有一个User模型类。

在其他购物引擎中，我在User模型中添加了以下代码中的一些关联，位于shopping/lib/shopping.rb：

module Shopping
  class Engine<Rails::Engine
    initializer :shopping_append_user do
       UsersManager::User.class_eval do
        has_many :products,:class_name=>"Shopping::Product"
        has_many :virtues,:class_name=>"Shopping::Virtue"
        has_many :containers,:class_name=>"Shopping::Container"
        has_many :concerns,:class_name=>"Shopping::Concern"
        has_many :remarks,:class_name=>"Shopping::Remark"
        has_many :praisings,:class_name=>"Shopping::Praising"
        has_one  :cart,:class_name=>"Shopping::Cart"
        has_one  :shop_information,:class_name=>"Shopping::ShopInformation"
        has_many :comments,:class_name=>"Shopping::Comment"
        has_many :created_orders,:class_name=>"Shopping::Order",:foreign_key=>"creator_id"
        has_many :processing_orders,:class_name=>"Shopping::Order",:foreign_key=>"processor_id"
      end
    end

    initializer :shopping_append_file do
      Upload::File.class_eval do
        has_many :image_uuids,:class_name=>"Shopping::ImageUuid"
      end
    end
  end

  def self.table_name_prefix
    "shopping_"
  end
end

运行rails server后，应用程序正常运行。但是，在修改一个控制器文件后，我浏览了网页，它给了我以下消息：

undefined method `products' for #<UsersManager::User:0x00000003022a58>

rails如何在修改文件后重新加载文件？如何让我的引擎正常工作？

我的rails版本是github的3.2.0.pre，Ruby是1.9.0。

Answer 1

每次请求都不会重新加载初始值设定项，这意味着重新加载UsersManager::User类的自定义设置时会丢失。

您可以执行以下操作：

module Shopping
  class Engine < Rails::Engine
    config.to_prepare do
      Shopping.customize_user
      Shopping.customize_file
    end
  end

  def self.customize_user
     UsersManager::User.class_eval do
      has_many :products,:class_name=>"Shopping::Product"
      has_many :virtues,:class_name=>"Shopping::Virtue"
      has_many :containers,:class_name=>"Shopping::Container"
      has_many :concerns,:class_name=>"Shopping::Concern"
      has_many :remarks,:class_name=>"Shopping::Remark"
      has_many :praisings,:class_name=>"Shopping::Praising"
      has_one  :cart,:class_name=>"Shopping::Cart"
      has_one  :shop_information,:class_name=>"Shopping::ShopInformation"
      has_many :comments,:class_name=>"Shopping::Comment"
      has_many :created_orders,:class_name=>"Shopping::Order",:foreign_key=>"creator_id"
      has_many :processing_orders,:class_name=>"Shopping::Order",:foreign_key=>"processor_id"
    end
  end

  def self.customize_file
    Upload::File.class_eval do
      has_many :image_uuids,:class_name=>"Shopping::ImageUuid"
    end
  end

  def self.table_name_prefix
    "shopping_"
  end
end

config.to_prepare块在生产中和开发中的每个请求（source）之前运行一次。

修改控制器文件后加载了哪些文件？

1 个答案: