Question

我通过＆＃39; railstutorial＆＃39;来学习。对于第9章，当用户注销浏览器时显示错误undefined method update_attribute for nil:NilClass（仅当用户未经过身份验证时出现此错误），当用户通过身份验证时，它才能正常运行。

有我的sessions_controller

class SessionsController < ApplicationController

  def new
  end

  def create
    user = User.find_by(email: params[:session][:email].downcase)
    if user && user.authenticate(params[:session][:password])
        sign_in user
      redirect_to user
    else
      render 'new'
    end
  end

  def destroy
    sign_out
    redirect_to signin_path
  end
end

有我的sessions_helper

module SessionsHelper
  def sign_in(user)
    remember_token = User.new_remember_token
    cookies.permanent[:remember_token] = remember_token
    user.update_attribute(:remember_token, User.encrypt(remember_token))
    self.current_user = user
  end

  def current_user
    remember_token = User.encrypt(cookies[:remember_token])
    @current_user ||= User.find_by(remember_token: remember_token)
  end

    def signed_in?
    !current_user.nil?
  end

    def sign_out
    current_user.update_attribute(:remember_token,
                                  User.encrypt(User.new_remember_token))
    cookies.delete(:remember_token)
    self.current_user = nil
  end


    def current_user=(user)
    @current_user = user
  end
end

抱歉我的英文不好

Answer 1

当他未登录时，您无法注销用户。

因此，请将destroy中的SessionsController操作更改为：

  def destroy
    sign_out if !signed_in?
    redirect_to signin_path
  end

nil的未定义方法`update_attribute'：NilClass.Railstutorial

1 个答案: