Rails 嵌套表单构建测验

Question

我正在构建一个测验并使用嵌套表单来提交答案。我想我正在研究如何提交嵌套表单数组？

我有以下设置：

测验

has_many :quiz_answers, dependent: :destroy
accepts_nested_attributes_for :quiz_answers, allow_destroy: true

测验答案

belongs_to :quiz, optional: true

接下来的两个创建由管理员设置的测验问题和选项（即 a、b、c、d）。这允许根据需要即时添加和取出问题。这部分工作正常，我在这里没有问题。

测验问题

has_many :quiz_options, dependent: :destroy
accepts_nested_attributes_for :quiz_options, allow_destroy: true

测验选项

belongs_to :quiz_question, optional: true

我遇到的这个问题是当用户开始测验时，我如何遍历每个问题并让用户提交一个选项，单击下一步并继续下一个问题，直到全部完成？到目前为止，我认为它正在为数据库保存一个答案，但它列出了所有问题：

class QuizzesController < ApplicationController
 def new
    @quiz = Quiz.new
    @quiz_question = QuizQuestion.where(active: true)
    @quiz.quiz_answers.build
  end
 
def create
    @quiz = Quiz.new(quiz_params)
   
    respond_to do |format|
      if @quiz.save
        format.html { redirect_to quiz_url(@quiz), notice: "Quiz was successfully created." }
        format.json { render :show, status: :created, location: @quiz }
      else
        format.html { render :new, status: :unprocessable_entity }
        format.json { render json: @quiz.errors, status: :unprocessable_entity }
      end
    end
  end
end

表格

<%= form_with(model: quiz) do |form| %>
 <%= form.fields_for :quiz_answers do |builder| %>
  <%= render 'quiz_answer', form: builder %>
 <% end %>
 <%= form.submit "Submit", class: 'btn btn-primary' %>
<% end %>

部分

<% @quiz.each do |question| %>
 <h2><%= question.question %></h2>
  <% question.quiz_options.each do |o| %>
   <%= form.radio_button :answer, o.answer %> <%= o.answer %>
  <% end %>
<% end %>

总而言之，我想知道问题 1、用户提交答案、问题 2、用户提交答案等是否可以在嵌套表单环境中全部来自预先确定的问题和答案？

Answer 1

您可以在下面的代码中执行此操作：

我想您的quiz_answers 表中有quiz_option_id 列，如果没有，则必须将其添加到表中

add_reference :quiz_answers, :quiz_option, null: false, 

# controllers/quizzes_controller.rb

class QuizzesController < ApplicationController
  def new
    @quiz = Quiz.new
    @quiz_questions = QuizQuestion.where(active: true)
    @quiz_questions.each.with_index do |question, i|
      @quiz.quiz_answers.build(quiz_question_id: question.id, is_current: i.zero?)
    end
  end

  def create
    @quiz = Quiz.new(quiz_params)

    respond_to do |format|
      if @quiz.valid?
        if @quiz.quiz_answers.all?(&-> (answer) { answer.quiz_option_id.present? })
          @quiz.save
          format.html { redirect_to quiz_url(@quiz), notice: "Quiz was successfully created." }
          format.json { render :show, status: :created, location: @quiz }
        else
          new_current = @quiz.quiz_answers.detect(&-> (answer) { !ActiveModel::Type::Boolean.new.cast(answer.is_current) && answer.quiz_option_id.blank? })
          current_active = @quiz.quiz_answers.detect(&-> (answer) { ActiveModel::Type::Boolean.new.cast(answer.is_current) })
          current_active.is_current = false
          new_current.is_current = true

          format.html { render :new, status: :unprocessable_entity }
          format.json { render json: @quiz.errors, status: :unprocessable_entity }
        end
      else
        format.html { render :new, status: :unprocessable_entity }
        format.json { render json: @quiz.errors, status: :unprocessable_entity }
      end
    end
  end

  private

  def quiz_params
    params.require(:quiz).permit(quiz_answers_attributes: %i[is_current quiz_question_id quiz_option_id])
  end
end

# models/quiz_answer.rb

class QuizAnswer < ApplicationRecord
  attr_accessor :quiz_question_id, :is_current

  belongs_to :quiz, optional: true
  belongs_to :quiz_option, optional: true

  validates :quiz_option_id, presence: true, if: -> { ActiveModel::Type::Boolean.new.cast(is_current) }

  def quiz_question
    @quiz_question ||= QuizQuestion.find_by(id: quiz_question_id)
  end
end

类 d-none 来自 Bootstrap 或者您可以定义自己的

.d-none {
  display: none;
}

# views/quizzes/_quiz_answer.html.erb

<div class="<%= ActiveModel::Type::Boolean.new.cast(form.object.is_current) ? "" : "d-none" %>">
  <h2><%= form.object.quiz_question.question %></h2>
  <%= form.hidden_field :quiz_question_id %>
  <%= form.hidden_field :is_current %>
  <%= form.collection_radio_buttons :quiz_option_id, form.object.quiz_question.quiz_options, :id, :answer %>
  <%= form.object.errors.full_messages.first %>
  <br/>
</div>

另外我想在new.html.erb 你有一些文件：

# views/quizzes/new.html.erb

<%= render "form", quiz: @quiz %>

如果您有任何问题，请随时提出