嵌套表单以'has_many到'多对多关系创建许多新的关联对象

Question

I have a many to many relationship between DailyQuestionSets and Questions. I have a one to many relationship between Questions and Answers. What I am having trouble working out is how to build the right kind of nested form that could retrieve a set of Questions with a label showing the question text as well as a form field with the answer which would get posted to the Answer model.

Models:

class Question < ApplicationRecord
  has_many :dailyquestions, foreign_key: 'dailyquestion_id'
  has_many :dailyquestionsets, :through => :dailyquestions
end

class DailyQuestion < ApplicationRecord
  belongs_to :daily_question_set
  belongs_to :question
end

class DailyQuestionSet < ApplicationRecord
  has_many :daily_questions, foreign_key: 'question_id'
  has_many :questions, :through => :daily_questions, :source => :question
end

class Answer < ApplicationRecord
  belongs_to :users
  belongs_to :questions
  belongs_to :dailyquestionset
end

View:

<p id="notice"><%= notice %></p>

<%= form_tag('/answers/answerquestions') do %>
  <% @questions.each do |q| %>
    <%= fields_for '@answers[]', Answer do |a| %>

      <div class="field">
        <%= q.label :content %><br>
        <%= a.text_field :answer_text %>
      </div>

    <% end %>
  <% end %>
  <div class="actions">
    <%= submit_tag %>
  </div>
<% end %>

Controller:

  def answerquestions
    @dailyquestionset = DailyQuestionSet.get_today_dailyquestionset
    @questions = @dailyquestionset.questions
    @answers = []
    @questions.count.times do
      @answers << Answer.new
  end 

The problem is that I'm not able to get a label value out of q (Question) in the view and this is no surprise as I have taken a wild guess as to how to construct this nested form syntax.

undefined method `label' for #<Question:0x00007f54383ce748>
Extracted source (around line #8):
      <div class="field">
        <%= q.label :content %><br>
        <%= a.text_field :answer_text %>
      </div>

Any ideas on how to handle the form correctly most appreciated :)

Answer 1

It seems you are trying to create a text field and a related label with text taken from the Questions 's content property:

<div class="field">
  <%= a.label :answer_text, q.content %><br>
  <%= a.text_field :answer_text %>
</div>

ie label is a method on the FormBuilder and the desired text (here q.content ) is passed as second argument. See documentation .