使用Rails + active_model_serializers在EmberJS中使用非标准类名称对象加载对象 [英] Side-loading objects with non-standard class names in EmberJS with Rails+active_model_serializers

问题描述

 类问题< p>我有一些Rails中的几个模型看起来像这样： ActiveRecord :: Base 
 belongs_to：reporter，class_name：'User'
 belongs_to：assignee，class_name：'User'
 has_many：comments 
 end 
 
类用户ActiveRecord :: Base 
 end 
 
 class注释< ActiveRecord :: Base 
 end 
  

与序列化器一样：

  class IssueSerializer< ActiveModel :: Serializer 
属性：id 
 embed：ids，include：true 
 
 has_one：reporter，：embed => ：ids 
 has_one：assignee，：embed => ：ids 
 end 
 
 class UserSerializer< ActiveModel :: Serializer 
属性：id，：name 
 end 
 
 class CommentSerializer< ActiveModel :: Serializer 
属性：id，：body 
 end 
  

JSON看起来像以下内容：

  {
issue：[
 {
id：6，
reporter_id：1，
assignee_id：2，
comment_ids：[
 3 
] 
 }，
]，
评论：[
 {
id：3 
body：好评
} 
 
记者：[
 {
id：1 
name：Ben Burton
} 
] 
assignees：[
 {
id：2 
name：Jono Mallanyk
} 
] 
} 
  

问题是边框加载的记者和受让人的JSON对象不被Ember识别为用户对象，我看到以下错误：

 未捕获错误：断言失败：您的服务器与关键记者返回哈希，但您没有映射
  

我不想删除

  embed：ids，include：true 
  

从我的IssueSerializer，因为这样的意见不会被序列化。

有几种可能的方法来解决这个，我考虑过：

• 如果ActiveModel :: Serializer的embed方法在其include选项中接受了模型列表，则可以将JSON响应过滤到仅包含附加注释。


• Ember数据的型号可以配置为从用户，记者和受让人侧边加载用户...但是据我所知，支持sideloadAs的一个键。


• 以某种方式忽略/禁用未知密钥的侧面加载错误（可能是最不好的方法）。

还有另一个选项我在这里错过吗？我想我可能需要编写一个修复程序，并向rails-api / active_model_serializers，emberjs / data或两者提交一个请求。

编辑：我的临时解决方法是将IssueSerializer更改为仅序列化记者和受让人的ID：

  class IssueSerializer< ; ActiveModel :: Serializer 
属性：id，：reporter_id，：assignee_id 
 embed：ids，include：true 
 
 has_many：comments，：embed => ：ids 
 end 
  

解决方案

我有类似的问题并在 ActiveModel :: Serializers readme 中找到解决方案。您可以使用：root 选项。尝试这样的问题序列化程序：

 类IssueSerializer< ActiveModel :: Serializer 
属性：id 
 embed：ids，include：true 
 
 has_one：reporter，：root => users
 has_one：assignee，：root => users
 has_many：comments 
 end 
  

I have a few models in Rails that look something like this:

class Issue < ActiveRecord::Base
  belongs_to :reporter, class_name: 'User'
  belongs_to :assignee, class_name: 'User'
  has_many :comments
end

class User < ActiveRecord::Base
end

class Comment < ActiveRecord::Base
end

with serializers like so:

class IssueSerializer < ActiveModel::Serializer
  attributes :id
  embed :ids, include: true

  has_one :reporter, :embed => :ids
  has_one :assignee, :embed => :ids
end

class UserSerializer < ActiveModel::Serializer
  attributes :id, :name
end

class CommentSerializer < ActiveModel::Serializer
  attributes :id, :body
end

This produces JSON that looks something like the following:

{
  "issues": [
    {
      "id": 6,
      "reporter_id": 1,
      "assignee_id": 2,
      "comment_ids": [
        3
      ]
    },
  ],
  "comments": [
    {
      "id": 3
      "body": "Great comment"
    }
  ],
  "reporters": [
    {
      "id": 1
      "name": "Ben Burton"
    }
  ],
  "assignees": [
    {
      "id": 2
      "name": "Jono Mallanyk"
    }
  ]
}

The problem is that the side-loaded reporters and assignees JSON objects aren't recognized by Ember as User objects, and I see the following error:

Uncaught Error: assertion failed: Your server returned a hash with the key reporters but you have no mapping for it

I don't want to remove

embed :ids, include: true

from my IssueSerializer, because then the comments wouldn't be serialized.

There are a few potential ways to solve this that I've considered:

• If the embed method for ActiveModel::Serializer accepted a list of models in its include option, this could filter the JSON response to only include side-loaded comments.
• Ember data's model could be configured to side load users from "users", "reporters" and "assignees"... but as far as I can tell from the source it only appears to support one key for sideloadAs.
• Somehow ignore/disable side-loading errors for unknown keys (probably the least sane approach).

Is there another option I'm missing here? I think I may have to write a fix and submit a pull request to either rails-api/active_model_serializers, emberjs/data, or both.

EDIT: My temporary workaround for this is to change the IssueSerializer to only serialize the ids for reporter and assignee:

class IssueSerializer < ActiveModel::Serializer
  attributes :id, :reporter_id, :assignee_id
  embed :ids, include: true

  has_many :comments, :embed => :ids
end

解决方案

I had similar problem and have found solution at ActiveModel::Serializers readme. You can use :root option. Try something like this for issue serializer:

class IssueSerializer < ActiveModel::Serializer
  attributes :id
  embed :ids, include: true

  has_one :reporter, :root => "users"
  has_one :assignee, :root => "users"
  has_many :comments
end

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