ruby-on-rails - 通过关联在 has_many 中的 json 中嵌套模型

Question

使用 Rails 3.2。我有以下代码：

# month.rb                        
class Month < ActiveRecord::Base
  has_many :days

  def map_markers
    days.as_json(
      :only => :position,
      :include => {
        :day_shops => { 
          :only => :position, 
          :include => {
            :shops => {
              :only => [ :name ]
            }
          }
        }
      }
    )
  end
end

# day.rb
class Day < ActiveRecord::Base
  belongs_to :month
  has_many :day_shops
  has_many :shops, :through => :day_shops
end

# day_shop.rb
class DayShop < ActiveRecord::Base
  belongs_to :day
  belongs_to :shop
end

# shop.rb
class Shop < ActiveRecord::Base
end

我想要实现的是将模型包装在shop模型day_shop（这是一个through表）中，但是当我将它包装在上面的 JSON 中时，我得到：

undefined method 'shops' for #<DayShop id: 87, day_id: 26, shop_id: 1, position: 1>

我预期的 JSON 将是：

- position: 1
  :day_shops:
  - position: 1
    :shops:
    - name: Company A
  - position: 2
    :shops:
    - name: Company B
- position: 2
  :day_shops:
  - position: 1
    :shops:
    - name: Company A
  - position: 2
    :shops:
    - name: Company C

我怎样才能改变我的方法？谢谢。

Answer 1

DayShop belongs to a Shop当您在方法中包含shopsa时。修改为：day_shopmap_markermap_marker

def map_markers
  days.as_json(
    :only => :position,
    :include => {
      :day_shops => { 
        :only => :position, 
        :include => {
          :shop => {
            :only => [ :name ]
          }
        }
      }
    }
  )
end