Ember-data和MongoDB，如何处理_id [英] Ember-data and MongoDB, how to handle _id

问题描述

我正在使用带有rails和MongoDB的ember数据，并且在_id字段中存在MongoDB中的ID存在问题。

Ember-data将使用ID作为ID的默认字段，所以我试图重写它：

  App.User = DS.Model。扩展
 primaryKey：_id
名称：DS.attrstring
 image：DS.attrstring
  

这似乎大部分时间都可以工作，但在某些情况下，我收到了ember的异常说：

未捕获错误：断言失败：您的服务器使用
键_id返回散列，但您没有映射

我怀疑这可能是垃圾数据中的一个错误，因为它仍然在很大的开发中，但是我试图找到一种方法来在服务器端映射_id到id？我正在使用mongoid来做mongo映射。

解决方案

如果你在这里使用Mongoid是一个使你这样做的解决方案不必添加方法 def id; object._id.to_s;结束到每个序列化程序

添加以下Rails初始化程序

Mongoid 3.x

 模块Moped 
模块BSON 
类ObjectId 
别名：to_json：to_s 
别名：as_json：to_s 
 end 
 end 
 end 
  

Mongoid 4

 模块BSON 
 class ObjectId 
别名：to_json：to_s 
别名：as_json：to_s 
 end 
 end 
  

活动模型序列化器为构建

  class BuildingSerializer< ; ActiveModel :: Serializer 
属性：id，：name 
 end 
  

产生的JSON

  {
buildings：[
 {id：5338f70741727450f8000000，name ：City Hall}，
 {id：5338f70741727450f8010000，name：Firestation} 
] 
} 
  / pre> 
 
 
这是由 brentkirby ，并通过 arthurnn  
 
I'm using ember-data with rails and MongoDB and am having problem with the way IDs are stored in MongoDB - in a _id field.

Ember-data will use id as the default field for ID so I tried to override it like this:
App.User = DS.Model.extend
    primaryKey: "_id"
    name: DS.attr "string"
    image: DS.attr "string"
This seems to work most of the time but in some instances I get exceptions from ember saying:

  
Uncaught Error: assertion failed: Your server returned a hash with the
  key _id but you have no mappings
I suspect this might be a bug in ember-data because it's still heavily under development, but I was trying to find a way to get to map _id to id on the server side in rails? I'm using mongoid to do the mongo mapping.
解决方案
If you are using Mongoid here is a solution that makes it so you don't have to add a method def id; object._id.to_s; end to every serializer

Add the following Rails initializer

Mongoid 3.x
module Moped
  module BSON
    class ObjectId
      alias :to_json :to_s
      alias :as_json :to_s
    end
  end
end
Mongoid 4
module BSON
  class ObjectId
    alias :to_json :to_s
    alias :as_json :to_s
  end
end
Active Model Serializer for Building
class BuildingSerializer < ActiveModel::Serializer
  attributes :id, :name
end
Resulting JSON
{
  "buildings": [
    {"id":"5338f70741727450f8000000","name":"City Hall"},    
    {"id":"5338f70741727450f8010000","name":"Firestation"}
  ]
}
This is a monkey patch suggested by brentkirby and updated for Mongoid 4 by arthurnn

                        
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