模型属性包含对象的集合 [英] Model attribute contains collection of object

问题描述

我有主模型页面，它是容器.该页面可以有一些待办事项列表、笔记、文件和讨论.这个想法是让它们按特殊顺序排列.

Page.last.container # [Todolist_obj, Note_obj, File_obj, Note_obj, Discussion_obj, File_obj, File_obj] 

• 所以我开始接触使用Mongodb

  • So I came to approach to use Mongodb

    或者我也想过在hstore上使用Postgres，但不知道它会不会有帮助

    Or I also thought about using Postgres with hstore, but don't know will it help or not

    或者可能只是任何数据库并在获取页面时反序列化所有对象，并在保存时序列化对象

    Or maybe just any database and deserialize all objects when getting page, and serialize objects when saving

    或者我可以创建超类 Item 并使用 MTI 从中继承所有包含对象，并使 Page 有很多关系.

    Or I can make superclass Item and inherit all containing objects from it using MTI and make Page has many relationship.

    所以我不知道哪种方式最好?

    或者也许有更好的方法?

    推荐答案

    我已经使用 acts_as_list 来实现可排序的对象非常成功.此外，我会将页面元素抽象为一个单独的模型，这里称为 PageElement.

    I have used acts_as_list for implementing sortable objects very successfully. Additionally, i would abstract the elements of a page into a separate model, here called PageElement.

    我认为没有必要切换到 NoSQL 数据库(尽管我不反对这种方法).这是我的想法的粗略草图:

    I think there is no need to switch to a NoSQL database (although i have nothing against this approach). Here is a rough sketch of what i'm thinking:

    class Page < ActiveRecord::Base
      has_many :page_elements, :order => 'position'
      has_many :todo_lists,  :through => :page_elements, :source => :element, :source_type => 'TodoList'
      has_many :notes,       :through => :page_elements, :source => :element, :source_type => 'Note'
      has_many :files,       :through => :page_elements, :source => :element, :source_type => 'File'
      has_many :discussions, :through => :page_elements, :source => :element, :source_type => 'Discussion'
    end
    
    class PageElement < ActiveRecord::Base
      belongs_to :page
      belongs_to :element, :polymorphic => true
      acts_as_list :scope => :page
    end
    
    class TodoList < ActiveRecord::Base
      has_one :page_element, :as => :element
      has_one :page, :through => :page_elements 
    end
    
    class Note < ActiveRecord::Base
      has_one :page_element, :as => :element
      has_one :page, :through => :page_elements 
    end
    
    class File < ActiveRecord::Base
      has_one :page_element, :as => :element
      has_one :page, :through => :page_elements 
    end
    
    class Discussion < ActiveRecord::Base
      has_one :page_element, :as => :element
      has_one :page, :through => :page_elements 
    end
    

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