Rails 4 - 带有accepts_nested_attributes_for控制器设置的嵌套表单？

Question

我正在尝试使用form_for和制作嵌套表单fields_for.经过大量的研究和成功,不再在我的项目上工作了.我只是想重新创建一个railscast,看看我做错了什么.

我正在尝试重新创建在http://railscasts.com/episodes/196-nested-model-form-part-1上找到的示例,因为代码存在,所以不应该那么难,但我可以'设法从调查中创建问题.这是我的代码,直到现在:

rails new surveysays
rails g scaffold survey name:string
rake db:migrate
rails g scaffold question survey_id:integer content:text
rake db:migrate

我正在尝试以完全相同的视频序列进行操作.我的问题模型:

class Question < ActiveRecord::Base
  belongs_to :survey
end

我的调查模型:

class Survey < ActiveRecord::Base
  has_many :questions, dependent: :destroy
  accepts_nested_attributes_for :questions
end

我的调查表格带有嵌套问题字段:

<%= form_for(@survey) do |f| %>
      ...
      <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, :row => 3 %>
        </p>
      <% end %>
      <div class="actions">
        <%= f.submit %>
      </div>
   <% end %>

我的调查显示:

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

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

<ol>
  <% for question in @survey.questions %>
   <li><%=h question.content%></li>
  <% end %>
</ol>

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

而我的SurveysController:

class SurveysController < ApplicationController
 ...

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

  ...

  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(:name)
    end
end

直到分钟5:34并且当它不像视频中所示那样工作并且没有创建问题时,表单显示3个问题,我填写表格,但是当按下create它时不会创建问题:

加载开发环境(Rails 4.1.6)2.1.3:001> s = Survey.all Survey Load(3.0ms)SELECT"survey".*FROM"surveys"=>#]> 2.1.3:002> q = s [0] .questions问题加载(0.6ms)SELECT"questions".*FROM"questions"WHERE"questions"."survey_id"=？[["survey_id",2]] =>#

我看不出我的代码和示例之间有什么区别.我甚至试图在SurveysController没有任何成功的情况下进行一些改动:

在方法survey_params或插入@ survey.questions.create(survey_params [:questions_attributes])之后插入question_attributes:[:id,:content]如果在create方法上调查.这会创建问题,但内容为:nill

此时我被困住了.我不知道该怎么做,我在控制器中缺少什么？谁能给我一些帮助,谢谢.

Answer 1

在survey_params控制器中的方法,你错过了问题参数,它应该看起来像:

def survey_params
 params.require(:survey).permit(:name, :questions_attributes => [:question, :answer ... or whatever attribute for the question model])
end

让我知道事情的后续!