ruby-on-rails - 如何在事件记录 to_json 中包含嵌套和同级关联？

Question

我有一个类(class)模型，与另一个模型树有 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"

我读到this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}}}} )  

但是我无法同时获得同级和多重嵌套包括:

@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

我也尝试过这个:

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

这里正确的语法是什么？

Answer 1

你们真的很接近。只需使用哈希符号而不是数组即可。

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