Railsfields_for参数为空

Question

I'm trying to build a nested form for a survey and having problems with my params hash missing values from within the fields_for block.

I have the following models. The way the app works is that an admin creates a MiniPost and its MiniPostQuestions . Then a client creates a new MiniPostSurvey using one of the MiniPosts . The client then emails out SurveyInvites to users. When a user responds, a new SurveyResponse is created, along with a new QuestionAnswer for each MiniPostQuestion in the survey.

class MiniPost < ActiveRecord::Base
    has_many :mini_post_questions
    has_many :question_answers, through: :mini_post_questions
    has_many :mini_post_surveys

    belongs_to :employer

    def questions
        mini_post_questions
    end

    def surveys
        mini_post_surveys
    end
end

class MiniPostQuestion < ActiveRecord::Base
    has_many :question_answers

    belongs_to :mini_post
    belongs_to :employer

    def answers
        question_answers
    end
end

class MiniPostSurvey < ActiveRecord::Base
    belongs_to :mini_post
    belongs_to :employer
    belongs_to :company
    has_many :survey_invites
    has_many :survey_responses, through: :survey_invites

    def questions
        mini_post.questions
    end
end

class SurveyInvite < ActiveRecord::Base
    belongs_to :mini_post_survey
    has_many :survey_responses

    def responses
        survey_responses
    end
end

class SurveyResponse < ActiveRecord::Base
    belongs_to :survey_invite
    has_many :question_answers
    has_many :mini_post_questions, through: :question_answers
end

class QuestionAnswer < ActiveRecord::Base
    belongs_to :survey_response
    belongs_to :mini_post_question
    validates :answer, presence: true
end

Here is my response form.

<div class="form-box">
    <%= form_for @response, url: "/survey?key=#{@invite.key}", method: :post, html: { role: 'form' } do |f| %>
        <% @questions.each do |question| %>
            <div class="form-group">
                <%= f.fields_for :mini_post_questions, question do |q| %>
                    <%= q.fields_for :question_answers, question.question_answers.build do |a| %>
                        <%= f.label question.question %>
                        <%= a.text_area :answer, class: 'form-control' %>
                        <%= a.hidden_field :survey_response_id, value: @survey.id %>
                    <% end %>
                <% end %>
            </div>
        <% end %>

        <div><%= f.submit "Submit", :class => "btn btn-primary" %></div>
    <% end %>
</div>

My form renders correctly, however when I submit it, my params hash looks like this:

{"utf8"=>"✓",
 "authenticity_token"=>"p8Tky2So10TH4FUUvLKhIh7j2vjNN39b3HDsF0cYE14=",
 "survey_response"=>{"mini_post_questions"=>{"question_answers"=>{"answer"=>"", "survey_response_id"=>"11"}}},
 "commit"=>"Submit",
 "key"=>"e4fab42244db2286d471082696",
 "controller"=>"surveys",
 "action"=>"create"}

I would expect a mini_post_question key for each question, but I'm not sure how to get to that point.

Answer 1

I think you are on the right track, but you need to have your models accept nested attributes for the objects that you want in your form.

So I think in your SurveyResponse model, you would have

class SurveyResponse < ActiveRecord::Base
  belongs_to :survey_invite
  has_many :question_answers
  accepts_nested_attributes_for :question_answers
  has_many :mini_post_questions, through: :question_answers
end

Also, since it looks like you are not modifying the mini question here, I would say that you don't need to accept nested attributes for the questions, but just have a hidden field that assigns the mini_question_id to the question_answer

So your form should be something like this

<div class="form-box">
  <%= form_for @response, url: "/survey?key=#{@invite.key}", method: :post, html: { role: 'form' } do |f| %>
      <% @questions.each do |question| %>
          <div class="form-group">
              <%= f.fields_for :question_answers, @survey.question_answers.build do |q| %>
                  <%= q.label question.question %>
                  <%= q.text_area :answer, class: 'form-control' %>
                  <%= q.hidden_field :mini_post_question_id, value: question.id %>
              <% end %>
          </div>
      <% end %>

      <div><%= f.submit "Submit", :class => "btn btn-primary" %></div>
  <% end %>
</div>

Since your form is accepting nested attributes for question_answers, you won't need to supply the survey_id.

This should get you closer to what you would need in your form.