訪問父對象

Question

我有一個提交模型

belongs_to :report 
has_many :answers 

報表模型

has_many :questions 

問題型號

has_many :answers # answer has submission_id 

現在Rabl的模板，我需要這樣的

輸出

 object @submission 
     attributes :status, :submission_time 

     child :report do 
      attribute :id, :name 
      child :questions do 
       attribute :id, :content 
       node(:answers_count) do |question| 
        question.answers.where("submission_id = ?", @submission.id).count 
       end 
       node(:answers) do |question| 
        question.answers.where("submission_id = ?", @submission.id).collect{ |answer| {:name => answer.name, :id => answer.id}} 
       end 
      end 
     end 

這工作完全正常，但問題是在answers_count和答案節點我使用@submission，因爲該索引操作不起作用。

它很好地顯示操作，但索引操作正在創建問題，因爲@submission在索引操作中不可用。

PS：一旦我解決了這個問題，我會將大查詢從視圖移到模型。我知道，爲了簡單起見，我已經粘貼了內聯。

Answer 1

這是不是最好的解決方案，但它會工作

object @submission 
attributes :status, :submission_time 

child :report do 
    attribute :id, :name 

    submission_id = locals['submission'] ? locals['submission'].id : locals[:object].id 

    child :questions do 
     attribute :id, :content 
     node(:answers_count) do |question| 
      question.answers.where("submission_id = ?", submission_id).count 
     end 
     node(:answers) do |question| 
      question.answers.where("submission_id = ?", submission_id).collect{ |answer| {:name => answer.name, :id => answer.id}} 
     end 

    end 
end 

Answer 2

這應該適合你，雖然這是一個黑客承認。我已經把下面的非工作的解決方案，爲後人：

object @submission 
attributes :status, :submission_time 

child :report do 
    submission_id = root_object.id 
    attribute :id, :name 
    child :questions do 
     attribute :id, :content 
     node(:answers_count) do |question| 
      question.answers.where("submission_id = ?", submission_id).count 
     end 
     node(:answers) do |question| 
      question.answers.where("submission_id = ?", submission_id).collect{ |answer| {:name => answer.name, :id => answer.id}} 
     end 
    end 
end  

不正確的解決方案：

使用root_object此：

node(:answers_count) do |question| 
    question.answers.where("submission_id = ?", root_object.id).count 
end 

或者，把它作爲參數傳遞給child :report block：

object @submission 
    attributes :status, :submission_time 

    child :report do |submission| 
     attribute :id, :name 
     child :questions do 
      attribute :id, :content 
      node(:answers_count) do |question| 
       question.answers.where("submission_id = ?", submission.id).count 
      end 
      node(:answers) do |question| 
       question.answers.where("submission_id = ?", submission.id).collect{ |answer| {:name => answer.name, :id => answer.id}} 
      end 
     end 
    end 

不幸的是，這些方法都沒有奏效。第一個解決方案不起作用，因爲root_object隨塊範圍而變化（它標識包含塊的父項）。第二個解決方案不起作用，因爲與node不同，child傳遞該迭代的子對象。不幸的是，這與the documentation會讓你相信。