Ruby on Rails to_json问题：include

I have the following code

我有以下代码

@asset = Asset.first(
  :include => [
    :asset_statuses => [
      :asset_status_name, 
      {:asset_location => [
        {:asset_floor => :asset_building}
      ]}
    ],
    :asset_type => [
      :asset_category => :asset_department
    ]
  ],

(probably not the best DB table desing but that's what I have to use)

（可能不是最好的数据库表设计，但这就是我必须使用的）

The Asset.first works correctly and it brings back the data correctly but when I try to use the same :include in the to_json method it fails with the followings error:

Asset.first正常工作，它正确地返回数据但是当我尝试使用相同的东西时：在to_json方法中包含它失败并出现以下错误：

@asset.to_json( 
  :include => [
    :asset_statuses => [
      :asset_status_name,
      {:asset_location => [
        {:asset_floor => :asset_building}
      ]}
    ],
    :asset_type => [
      :asset_category => :asset_department]
    ] 
)

NoMethodError (undefined method `macro' for nil:NilClass):

The to_json method has the same :include syntax as find; I don't understand why it is not working.

to_json方法具有相同的：include语法作为find;我不明白为什么它不起作用。

4 个解决方案

#1

In case anyone else runs into a bizarre related issue that I did...to_json will also return this error when you try to include an association that is not defined on the model.

如果其他人遇到了我所做的一个奇怪的相关问题...当你试图包含一个未在模型上定义的关联时，to_json也会返回此错误。

#2

I think the to_json :include syntax is a little different.

我认为to_json：include语法有点不同。

I usually do

我通常这样做

@asset.to_json(:include => { :asset_statuses => {
                             :include => :asset_status_name}})

(and start with a small one then add all of the other stuff. annoying schema!)

（从一个小的开始然后添加所有其他东西。烦人的架构！）

#3

I got this error when trying to mix 1st and 2nd order relationships in a single to_json call. Here is what I originally had:

尝试在单个to_json调用中混合第一和第二顺序关系时出现此错误。这是我原来的：

render :json => @reports.to_json(:include => 
   [:report_type, :organisation, :analysis => {:include => :upload}]

which throws the "undefined method `macro' for nil:NilClass" exception above.

它抛出了“未定义的方法`宏'为nil：NilClass”异常。

Here's how I fixed it:

以下是我修复它的方法：

render :json => @reports.to_json(:include => 
   {:report_type => {}, :organisation => {}, 
    :analysis => {:include => {:upload => {}}}})

The Array will work for single-order relationships, but for second order relationships, the containing object needs to be a Hash.

Array适用于单阶关系，但对于二阶关系，包含对象需要是Hash。

#4

I had this problem when i overrided the as_json function

当我重写as_json函数时，我遇到了这个问题

def as_json(options={})
  if options[:admin] 
    super(:methods => [:url_thumb] )
  else
    super(options.merge( :only => :id ))
  end
end

for some reason when you call the as_json or to_json on an array with no arguments the options became nil.

出于某种原因，当你在没有参数的数组上调用as_json或to_json时，选项变为nil。

The fix is:

修复是：

def as_json(options={})
  options = {} if options.nil?
  if options[:admin] 
    super(:methods => [:url_thumb] )
  else
    super(options.merge( :only => :id ))
  end
end

#1