如何使用to_json访问':has_many:虽然'连接表数据？

Question

我有三个模型(这里简化):

class Child < ActiveRecord::Base
  has_many    :childviews, :dependent => :nullify
  has_many    :observations, :through => :childviews  
end
class Childview < ActiveRecord::Base
  belongs_to  :observation
  belongs_to  :child
end
class Observation < ActiveRecord::Base
  has_many    :childviews, :dependent => :nullify
  has_many    :children, :through => :childviews
end

我正在使用Rails的to_json方法将此发送给一些JavaScript,如下所示:

render :layout => false , :json => @child.to_json(
  :include => {
    :observations => {
      :include => :photos, 
      :methods => [:key, :title, :subtitle]
    }
  },
  :except => [:password]
)

这非常有效.通过连接表(子视图)可以很好地检索观察结果.

但是,我还想获取位于childviews连接表中的数据; 特别是'needs_edit'的值.

我无法弄清楚如何在to_json调用中获取此数据.

谁能帮我？提前谢谢了.

qryss

Answer 1

不确定,但不应该这样吗？

@child.to_json(
  :include => {
    :observations => {
      :include => :photos, 
      :methods => [:key, :title, :subtitle]
    },
    :childviews => { :only => :needs_edit }
  }, 
  :except => [:password]
)

编辑:这可能也有效,因为childviews属于overvation:

@child.to_json(
  :include => {
    :observations => {
      :include => { :photos, :childviews => { :only => :needs_edit } } 
      :methods => [:key, :title, :subtitle]
    }
  }, 
  :except => [:password]
)