问使用accepts_nested_attributes_for和构建方法更新Rails中记录的正确方法是什么？

EN

# question.rb
class Question < ActiveRecord::Base
  has_many :alternativas, dependent: :destroy
  validates_presence_of :text
  accepts_nested_attributes_for :alternativas, reject_if: proc {|attributes| attributes[:texto].blank? }
end

# alternativa.rb
class Alternativa < ActiveRecord::Base
  belongs_to :question
end

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

  def index
    @questions = Question.all
  end

  def show
  end

  def new
    @question = Question.new
    @question.alternativas.build # I also tried 5.times { @question.alternativas.build } for 5 answers text fields
  end

  def edit 
  end

  def create
    @question = Question.new(question_params)

    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
    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

  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
  def set_question
    @question = Question.find(params[:id])
  end

  def question_params
    params.require(:question).permit(:text, { alternativas_attributes: [:texto, :question_id] })
  end
end