如何在活动记录 to_json 中包含嵌套和兄弟关联？

Question

我有一门课程 model 与另一个 model，树有 2 个关联：

belongs_to  :interaction_outline, :class_name => "Tree", 
                                  :foreign_key => "interaction_outline_id"
belongs_to  :token_outline, :class_name => "Tree", 
                                  :foreign_key => "token_outline_id"

我阅读了这篇文章，并且能够在我的 controller 中包含兄弟关联。

@course.to_json(:include=> [:interaction_outline, :token_outline]

我还能够获得多重嵌套关联：

@course.to_json(:include=>{:interaction_outline=> 
                              {:include=> {:tree_node=> 
                                     {:include=> :definition}}}} )  

但我不能同时获得兄弟和多重嵌套包括：

@course.to_json (:include=> [{:interaction_outline=> 
                               {:include=> {:tree_node=> 
                                    {:include=> :definition}}}}, 
                            {:token_outline=> 
                               {:include=> {:tree_node=> 
                                   {:include=> :definition}}}} ] ) 
#NoMethodError (undefined method `macro' for nil:NilClass)
#the error you get when the syntax or the association is wrong

我也试过这个：

@course.to_json (:include=> [:interaction_outline=> 
                               {:include=> {:tree_node=> 
                                   {:include=> :definition}}}, 
                          :token_outline=> 
                             {:include=> {:tree_node=> 
                                    {:include=> :definition}}} ] ) 
#same error

这里的正确语法是什么？

Answer 1

你真的很亲近。 只需使用 hash 表示法而不是数组。

@course.to_json (:include=> {:interaction_outline=> 
                               {:include=> {:tree_node=> 
                                    {:include=> :definition}}}, 
                             :token_outline=> 
                               {:include=> {:tree_node=> 
                                   {:include=> :definition}}}} )