Question

想要创建一个轮询应用程序，允许您创建一个包含5种不同答案（多项选择）的问题。

用户可以通过question_form.html.erb创建一个问题，然后是可能的答案，但它只显示一个框，而不是五个。

question_form.html.erb

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

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


  <div class="form-group">
    <%= f.label :title %>
    <%= f.text_field :title, class: "form-control" %>
  </div>

<div class="form-group">
    <%= f.label :kind %><br>
    <% @kind_options.each do |option| %>
      <label>
        <%= f.radio_button :kind, option[1] %>
        <%= option[0] %>
      </label>
  <% end %>


  <p>Specify some choices:</p>
   <%= f.fields_for :possible_answers do |c| %>
  <p>
  <%= c.text_field :title, placeholder: "Type your choice", class: "form-control" %>
  </p>
 <% end %>
</div>

在我的问题控制器中我添加了第5行{@ question.possible_answers.build} 但是当我运行该程序时，它给了我一个盒子来输入答案而不是5？

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


class QuestionsController < ApplicationController
  before_action :set_question, only: [:show, :edit, :update, :destroy]
  before_action :set_poll
  before_action :set_kind_questions
  # GET /questions
  # GET /questions.json
  def index
    @questions = Question.all
  end

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

  **# GET /questions/new
  def new
    @question = @poll.questions.build
    5.times { @question.possible_answers.build }
  end**

  # GET /questions/1/edit
  def edit
  end

  # POST /questions
  # POST /questions.json
  def create
    @question = @poll.questions.build(question_params)

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

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

  # DELETE /questions/1
  # DELETE /questions/1.json
  def destroy
    @question.destroy
    respond_to do |format|
      format.html { redirect_to questions_url, notice: 'Question was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

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

    # Never trust parameters from the scary internet, only allow the white list through.
    def question_params
      params.require(:question).permit(:title, :kind, :poll_id)
    end

    **def set_kind_questions
      @kind_options = [
        [ "Open Answer", "open" ],
        [ "Multiple Choice", "choice" ],
      ]
    end**

    def set_poll
      @poll = Poll.find params[:poll_id] #/polls/1/questions
    end
end

Answer 1

如果您正在使用Build a Polling Application with Rails，那么您最有可能使用的问题模型（您没有列出）是不完整的，因此Rails会在possible_answers上窒息在控制器Questions#new迭代构建方法之前。您需要将accepts_nested_attributes_for :possible_answers添加到模型中。然后5.times { @question.possible_answers.build }就可以了。

应用/模型/ question.rb

class Question < ActiveRecord::Base belongs_to :poll has_many :possible_answers accepts_nested_attributes_for :possible_answers end

我遇到了一些障碍，作者编辑的代码与他的截屏不同步。你必须仔细查看他的啧啧repo上的差异。

Rails 4.1：无法在表单中创建多个答案

1 个答案: