ruby-on-rails - 如何防止在使用嵌套表单和 rails 4 时创建空白？

Question

我有一个嵌套表单 question.erb，它显示预先写好的问题 (:poll)，然后有用于答案的 text_fields (:response)。我遇到的问题是在数据库中创建了空白问题。我对这个问题做了相当多的研究，看来答案是添加

accepts_nested_attributes_for :questions, reject_if: proc { |attributes| attributes['poll'].blank? }

事件模型。这个问题当然是现在我正在阻止所有内容被写入。我将如何只将答案写入数据库并忽略(或根本不创建)空白问题？如果解决方案可能需要任何其他文件，请告诉我。

谢谢!

问题.erb

<%= simple_form_for(@event) do |f| %>
     <%= f.error_notification %>
     <%= f.object.name %>
     <%= f.simple_fields_for :questions, @event.questions do |q| %>
        <%= q.object.poll%>
        <%= q.simple_fields_for :answers, q.object.answers.build do |a|%>
           <%= a.text_field :response %>
        <% end %>
     <% end %>
     <%= f.button :submit%>
<% end %>

事件.rb

class Event < ActiveRecord::Base
    has_many :questions
    accepts_nested_attributes_for :questions
end

events_controller.rb(部分)

 def question
  @event = Event.find(params[:id])
 end 

def update
    @event = Event.find(params[:id])
    if @event.update(event_params)
        redirect_to events_path, notice: "Answers saved"
     else
        redirect_to events_question_path, notice: "Answers not saved"
    end
end 

  def event_params
    params.require(:event).permit(
        questions_attributes: [:poll, answers_attributes: [:response]])
  end

问题.rb

 class Question < ActiveRecord::Base

 belongs_to :user
 belongs_to :event

 has_many :answers


 accepts_nested_attributes_for :answers
 end

问题 Controller .rb

class QuestionsController < ApplicationController
    before_action :set_question, only: [:show, :edit, :update, :destroy]

    def index
       @questions = Question.all
    end

    def show
    end

    def new
       @question = Question.new

    end


    def edit
    end

    def create
        @question = Question.new(question_params)

        @question.user = current_user

        respond_to do |format|
            if @question.save
                format.html { redirect_to @question, 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

   def update
        @question.user = current_user.id
        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 }
              format.json { head :no_content }
          end
       end

   private

   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(:poll, :event_id, answer_attributes: [:response, :question, :event, :user, :event_id, :question_id, :user_id])
    end
 end

Answer 1

试试这个:

class Event < ActiveRecord::Base
    has_many :questions
    accepts_nested_attributes_for :questions, reject_if: :all_blank
end

您可以在 the official docs 上阅读更多相关信息，但简而言之，这将阻止保存任何完全空白的问题，并让任何填充的问题通过。