nil : NilClass에 대한 정의되지 않은 메소드`questions '

NoMethodError가 발생 undefined method `questions' for nil:NilClass합니다. 라인에서 생성 작업을 가리 킵니다.@question = @conversation.questions.build(params[:question])

질문 컨트롤러 :

  respond_to :js, :html

   def index
      @questions = Question.all
      respond_with(@questions)
  end

  def show
    @question = Question.find(params[:id])
    @questions = Question.order("created_at DESC")
    respond_with(@questions)
  end

  def new
    @question = Question.new
    respond_with(@question)
  end

  def create
      @question = @conversation.questions.build(params[:question])
      if @question.save
        @message = current_user.messages.new(:subject => "You have a question from #{@question.sender_id}",
                               :notification_id => @question.sender_id,
                               :receiver_id => @question.recipient_id,
                               :body => @question.question)

        @question.message = @message
        @question.save
        redirect_to questions_path, notice: 'Your question was saved successfully. Thanks!'
      else
        render :new, alert: 'Sorry. There was a problem saving your question.'
      end
    end
  end

대화 컨트롤러 :

       helper_method :mailbox, :conversation
        before_filter :conversation, only: :show

     def index
        @conversations ||= current_user.mailbox.inbox.all
        end

      def reply
        current_user.reply_to_conversation(conversation, *message_params(:body, :subject))
        redirect_to conversation
      end

      def trash_folder
        @trash ||= current_user.mailbox.trash.all 
        end

      def trash
        conversation.move_to_trash(current_user)
        redirect_to :conversations
        end

      def untrash
        conversation.untrash(current_user)
        redirect_to :conversations
        end

        def empty_trash
          current_user.mailbox.trash.each do |conversation|    conversation.receipts_for(current_user).update_all(:deleted => true)
          end
         redirect_to :conversations
        end
      end

  private

  def mailbox
   @mailbox ||= current_user.mailbox
  end

  def conversation
   @conversation ||= mailbox.conversations.find(params[:id])
  end

  def conversation_params(*keys)
   fetch_params(:conversation, *keys)
  end

  def message_params(*keys)
   fetch_params(:message, *keys)
  end

  def fetch_params(key, *subkeys)
   params[key].instance_eval do
     case subkeys.size
     when 0 then self
     when 1 then self[subkeys.first]
     else subkeys.map{|k| self[k] }
     end
   end
  end
end

메시지 컨트롤러 :

 def index
      redirect_to conversations_path(:box => @box)
    end

  # GET /message/new
  def new
    @message = current_user.messages.new
  end

   # POST /message/create
  def create
    @recipient = User.find(params[:user])
    current_user.send_message(@recipient, params[:body], params[:subject])
    flash[:notice] = "Message has been sent!"
    redirect_to :conversations
  end

질문 모델 :

  attr_accessible :answer, :question, :sender_id, :recipient_id
  belongs_to :user

  belongs_to :sender,
    :class_name => 'User',
    :foreign_key => 'sender_id'
    belongs_to :recipient,
    :class_name => 'User',
    :foreign_key => 'recipient_id'

    belongs_to :message

end

사용자 모델 :

 acts_as_messageable
  has_many :notifications
  has_many :questions, foreign_key: :recipient_id
  has_many :sent_questions, class_name: 'Question', foreign_key: :sender_id


    def mailboxer_email(object)
        if self.no_email
          email
        else
            nil
        end
    end
end

개발 로그 :

Started POST "/questions" for 127.0.0.1 at 2014-05-29 12:32:46 -0400
Processing by QuestionsController#create as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"YWtv+TixScaYsXpJ6F47uBHkNvcruyHV7cyOtU6pWnQ=", "question"=>{"question"=>"This question should have an conversation id", "sender_id"=>"2", "recipient_id"=>"1"}, "commit"=>"Add Question"}
  User Load (0.3ms)  SELECT `users`.* FROM `users` WHERE `users`.`auth_token` = 'Mqy5_1kyb4hAsrmB9Q0fug' LIMIT 1
   (0.2ms)  BEGIN
  SQL (0.4ms)  INSERT INTO `questions` (`created_at`, `question`, `recipient_id`, `sender_id`, `updated_at`) VALUES ('2014-05-29 16:32:47', 'This question should have an conversation id', 1, 2, '2014-05-29 16:32:47')
   (0.5ms)  COMMIT
WARNING: Can't mass-assign protected attributes for Message: notification_id, reciver_id
    app/controllers/questions_controller.rb:23:in `create'
    app/controllers/application_controller.rb:13:in `user_time_zone'
   (0.2ms)  BEGIN
  User Load (0.5ms)  SELECT `users`.* FROM `users` WHERE `users`.`id` = 2 ORDER BY `users`.`id` ASC LIMIT 1
  SQL (0.3ms)  INSERT INTO `notifications` (`body`, `created_at`, `sender_id`, `sender_type`, `subject`, `type`, `updated_at`) VALUES ('This question should have an conversation id', '2014-05-29 16:32:47', 2, 'User', 'You have a question from 2', 'Message', '2014-05-29 16:32:47')
  SQL (0.3ms)  UPDATE `questions` SET `message_id` = 164, `updated_at` = '2014-05-29 16:32:47' WHERE `questions`.`id` = 135
   (0.5ms)  COMMIT
Redirected to http://localhost:3000/questions
Completed 302 Found in 308ms (ActiveRecord: 10.2ms)

이 새 코드로 인해 질문 테이블에 질문이 생성되지 않습니다. 데이터베이스에 제출하는 질문이 있었기 때문에 코드를 변경했지만 conversation_idNotifications 테이블 내부에 메일 박스 젬이 생성되지 않았습니다 . 다음은 질문 테이블 내부의 질문을 만들었지 만했다 원래의 코드 NULL에 대해 conversation_id.

def create
    @question = Question.new(params[:question])
    if @question.save
      @message = current_user.messages.new(:subject => "You have a question from #{@question.sender_id}",
                             :notification_id => @question.sender_id,
                             :reciver_id => @question.recipient_id,
                             :body => @question.question)

      @question.message = @message
      @question.save
      redirect_to questions_path, notice: 'Your question was saved successfully. Thanks!'
    else
      render :new, alert: 'Sorry. There was a problem saving your question.'
    end
  end

그래서 정의되지 않은 방법을 수정하고 질문이 conversation_id. conversation_id질문을받는 사람받은 편지함 (사용자가 질문에 대답하는 곳)으로 보낼 수 있도록 설정이 필요합니다 .