Question

我正在制作一个调查应用程序，我有3个模型：调查，问题和答案。调查has_many个问题，问题has_many答案。

我有两个主要错误：

我的代码应该为每个问题生成4个答案字段，但只生成1个答案字段。

当我在表单上按提交时，我

unknown attribute 'answers' for Survey. 提取的来源（第33行）：

  # POST /surveys.json
  def create
    @survey = Survey.new(survey_params)

    respond_to do |format|
      if @survey.save

我认为第二个问题在某种程度上与答案模型有关，但我不确定如何。这是我的代码：

surveys_controller：

class SurveysController < ApplicationController
  before_action :set_survey, only: [:show, :edit, :update, :destroy]

  # GET /surveys
  # GET /surveys.json
  def index
    @surveys = Survey.all
  end

  # GET /surveys/1
  # GET /surveys/1.json
  def show
  end

  # GET /surveys/new
  def new
    @survey = Survey.new
    3.times do 
     question = @survey.questions.build 
     4.times { question.answers.build }

      end
  end

  # GET /surveys/1/edit
  def edit

  end

  # POST /surveys
  # POST /surveys.json
  def create
    @survey = Survey.new(survey_params)

    respond_to do |format|
      if @survey.save
        format.html { redirect_to @survey, notice: 'Survey was successfully created.' }
        format.json { render :show, status: :created, location: @survey }
      else
        format.html { render :new }
        format.json { render json: @survey.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /surveys/1
  # PATCH/PUT /surveys/1.json
  def update
    respond_to do |format|
      if @survey.update(survey_params)
        format.html { redirect_to @survey, notice: 'Survey was successfully updated.' }
        format.json { render :show, status: :ok, location: @survey }
      else
        format.html { render :edit }
        format.json { render json: @survey.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /surveys/1
  # DELETE /surveys/1.json
  def destroy
    @survey.destroy
    respond_to do |format|
      format.html { redirect_to surveys_url, notice: 'Survey was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_survey
      @survey = Survey.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def survey_params
      params.require(:survey).permit!
    end


end

调查/ _form.html.erb

<%= form_for(@survey) do |f| %>
  <% if @survey.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@survey.errors.count, "error") %> prohibited this survey from being saved:</h2>

      <ul>
      <% @survey.errors.full_messages.each do |message| %>
        <li><%= message %></li>
      <% end %>
      </ul>
    </div>
  <% end %>


  <div class="field">
    <%= f.label :name %><br>
    <%= f.text_field :name %>
  </div>

    <%= f.fields_for :questions do |builder| %>
  <p>
    <%= builder.label :content, "Question" %><br />
    <%= builder.text_area :content, :rows => 3 %>
  </p>

   <%= f.fields_for :answers do |builder| %>
  <p>
    <%= builder.label :content, "Answer" %>
    <%= builder.text_field :content %>
  </p>
  <% end %> 
  <% end %> 



  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

调查/ show.html.erb

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

<p>
  <strong>Name:</strong>
  <%= @survey.name %>
</p>

<ol>
  <% @survey.questions.each do |question| %>
  <li><%= question.content  %>
  <ul>
    <% for answer in question.answers %>
    <li><%= answer.content %></li>
    <% end %>
  </ul>
  </li>
    <% end %>
</ol>


<%= link_to 'Edit', edit_survey_path(@survey) %> |
<%= link_to 'Back', surveys_path %>

survey.rb：

class Survey < ActiveRecord::Base
    has_many :questions, :dependent => :destroy
    accepts_nested_attributes_for :questions, :reject_if => -> (a) {a[:content].blank? }, :allow_destroy => true
end

question.rb：

class Question < ActiveRecord::Base
    belongs_to :survey
    has_many :answers, :dependent => :destroy
    accepts_nested_attributes_for :answers, :reject_if => -> (a) {a[:content].blank? }, :allow_destroy => true
end

answer.rb

class Answer < ActiveRecord::Base
    belongs_to :question
end

任何帮助都会受到赞赏，我已经被困在这几个小时了！

Answer 1

我不知道错误是否与fields_for相关，当你这样做时会发生什么：

 <%= f.fields_for :questions do |question_attribute| %>
  <p>
    <%= question_attribute.label :content, "Question" %><br />
    <%= question_attribute.text_area :content, :rows => 3 %>
  </p>

   <%= question_attribute.fields_for :answers do |answer_attribute| %>
    <p>
      <%= answer_attribute.label :content, "Answer" %>
      <%= answer_attribute.text_field :content %>
    </p>
   <% end %> 
 <% end %>

让我知道结果是什么。

嵌套表单，遇到奇怪的错误

1 个答案: