Rails API从嵌套值返回嵌套值

Question

我有一个应用程序，您可以在其中下载测验。每个测验都有多个问题。每个问题有五个可能的答案。这是我的模型：

首先测验型号：

class Quiz < ApplicationRecord 

    has_many :questions 
    has_many :games 

    validates_presence_of :title 
    validates_presence_of :abstract 
    validates_presence_of :category_id 

    validates_uniqueness_of :title 

end 

的问题型号：（每题属于竞猜对象）

class Question < ApplicationRecord 

    belongs_to :quiz 

    has_many :answers 
    has_many :game_questions 

    validates_presence_of :quiz_id 
    validates_presence_of :question 

end 

最后是回答型号：（每个答案都属于一个问题）

class Answer < ApplicationRecord 

    belongs_to :question 

    has_many :game_questions 

    validates_presence_of :question_id 
    validates_presence_of :answer 
    validates_inclusion_of :correct_answer, :in => [true, false] 
    validates_presence_of :order 

end 

我想通过这条路线做一个GET请求我QuizzesController /quiz_content /：ID，然后成为测验与相应的ID和所有问题，并为每个问题所有连接的答案

我已经设法返回它的所有的答案了白卷：

def quiz_content 
    quiz_records = Quiz.where('id = ?', params[:id]).includes(:questions) 
    @quiz_records_with_associations = quiz_records.map do |record| 
     record.attributes.merge('questions' => record.questions) 
    end 
    render json: @quiz_records_with_associations 
    end 

调用此控制器返回以下JSON网络le：

[ 
    { 
    "id": 1, 
    "title": "Testquiz", 
    "abstract": "Questions for dummies", 
    "category_id": 1, 
    "download": 0, 
    "created_at": "2017-05-20T17:16:42.511Z", 
    "updated_at": "2017-05-20T17:16:42.511Z", 
    "questions": [ 
     { 
     "id": 1, 
     "quiz_id": 1, 
     "question": "What is 5 + 5?", 
     "created_at": "2017-05-20T17:16:42.561Z", 
     "updated_at": "2017-05-20T17:16:42.561Z" 
     }, 
     { 
     "id": 2, 
     "quiz_id": 1, 
     "question": "What's the color of the sky?", 
     "created_at": "2017-05-20T17:16:42.588Z", 
     "updated_at": "2017-05-20T17:16:42.588Z" 
     }, 
     { 
     "id": 3, 
     "quiz_id": 1, 
     "question": "How fast can a cheetah run?", 
     "created_at": "2017-05-20T17:16:42.602Z", 
     "updated_at": "2017-05-20T17:16:42.602Z" 
     }, 
     { 
     "id": 4, 
     "quiz_id": 1, 
     "question": "How many eyes does a pig have?", 
     "created_at": "2017-05-20T17:16:42.620Z", 
     "updated_at": "2017-05-20T17:16:42.620Z" 
     },  
     { 
     "id": 5, 
     "quiz_id": 1, 
     "question": "How would you rate this quiz?", 
     "created_at": "2017-05-20T17:16:42.611Z", 
     "updated_at": "2017-05-20T17:16:42.611Z" 
     } 
    ] 
    } 
] 

我现在的问题是，我无法弄清楚如何返回每个问题的所有五个答案。我希望你能帮助我。 :)

Answer 1

在Quizz.rb

def as_json 
    super(include: { questions: { include: :answers } }) 
end 

而且

def quiz_content 
    @quiz = Quiz.includes(questions: :answers).find(params[:id]) 

    render json: @quiz.as_json 
end 

Answer 2

好吧添加这个，我找到了自己的解决方案：

def quiz_content 
    @quiz = Quiz.where('id = ?', params[:id]) 
    render json: @quiz, include: ['questions', 'questions.answers'] 
    end 

我不得不加入协会向串行：

class AnswerSerializer < ActiveModel::Serializer 

    attributes(:id, :question_id, :answer, :correct_answer, :order) 

    belongs_to :question 

end 


class QuestionSerializer < ActiveModel::Serializer 

    attributes(:id, :quiz_id, :question) 

    belongs_to :quiz 
    has_many :answers 
    has_many :game_questions 

end 


class QuizSerializer < ActiveModel::Serializer 

    attributes(:id, :title, :abstract, :category_id, :download) 

    has_many :questions 

end