nameerror 未定义的局部变量或方法 `log_out' 你的意思是？ logout_url ruby​​ on rails

Posted 2023-02-25

【中文标题】nameerror 未定义的局部变量或方法 `log_out\' 你的意思是？ logout_url ruby​​ on rails

【英文标题】：nameerror undefined local variable or method `log_out' Did you mean? logout_url ruby on railsnameerror 未定义的局部变量或方法 `log_out' 你的意思是？ logout_url ruby​​ on rails

【发布时间】：2017-12-08 02:47:06

【问题描述】：

所以我正在关注 Michael Hartl 的 tutorial，当我尝试注销时，我得到了这个 "NameError in SessionsController#destroy"undefined local variable or method "log_out" for #<SessionsController:0x0000000275f290> Did you mean? logout_url

我的测试和此错误仅在我在测试中添加最后一位后才弹出，但是，我在网站上的注销功能也不起作用。

这是我的 session_helper.rb：

module SessionsHelper

    # Logs in the given user.
  def log_in(user)
    session[:user_id] = user.id
  end

   # Returns the current logged-in user (if any).
  def current_user
    @current_user ||= User.find_by(id: session[:user_id])
  end

   # Returns true if the user is logged in, false otherwise.
  def logged_in?
    !current_user.nil?
  end

# Logs out the current user.
  def destroy
    session.delete(:user_id)
    @current_user = nil
  end
end

这是我的 session_controller：

class SessionsController < ApplicationController
  def new
  end

  def create
    #Gets user from database in lowercase & determines if user is valid
    user = User.find_by(email: params[:session][:email].downcase)
    if user && user.authenticate(params[:session][:password])
      # Log the user in and redirect to the user's show page.
      log_in user
      redirect_to user
    else
      # Create an error message.
      flash.now[:danger] = 'Invalid email/password combination' 
      render 'new'
    end
  end

  # Logs out the current user.
  def destroy
    log_out # undefined variable Name error
    redirect_to root_url
  end
end

我的应用程序控制器：

  class ApplicationController < ActionController::Base
    protect_from_forgery with: :exception
    include SessionsHelper #temporary session cookie, expires automatically upon browser close
  end

我的视图/layouts/_header.html.erb（用于注销链接所在的导航栏）：

<header class="navbar navbar-fixed-top navbar-inverse">
  <div class="container">
    <%= link_to image_tag("logo2.png", alt: "CourseBuddies logo"), root_path, id: "logo" %>
    <%- # link_to "sample app", '#', id: "logo" %>
    <nav>
      <ul class="nav navbar-nav navbar-right">
        <li><%= link_to "Home", root_path   %></li>
        <li><%= link_to "Reviews",   '#' %></li>
        <li><%= link_to "About us",   about_path %></li>

         <%- # LOGIN & SCROLL DOWN BAR %>
        <% if logged_in? %>
          **<li><%= link_to "Users", users_path %></li>
          <li class="dropdown">**
            <a href="#" class="dropdown-toggle" data-toggle="dropdown">
              Account <b class="caret"></b>
            </a>
            <ul class="dropdown-menu">
              **<li><%= link_to "Profile", current_user %></li>
              <li><%= link_to "Settings", '#' %></li>**
              <li class="divider"></li>
              <li>
                **<%= link_to "Log out", logout_path, method: :delete %>**
              </li>
            </ul>
          </li>
        **<% else %>
          <li><%= link_to "Log in", login_path %></li>
        <% end %>**
      </ul>
    </nav>
  </div>
</header>

我的用户模型：

class User < ApplicationRecord
    #before saving, make sure the email is in downcase
    before_save  self.email = email.downcase 

    validates :name,  presence: true, length:  maximum: 50 
    VALID_EMAIL_REGEX = /\A[\w+\-.]+@[a-z\d\-.]+\.[a-z]+\z/i
    validates :email, presence: true, length:  maximum: 255 ,
                    format:  with: VALID_EMAIL_REGEX ,
                    uniqueness: case_sensitive: false


    # Let's you safely store a hashed password_digest to DB,
    # gives you password & password_confirmation attributes, 
    # an authenticate method that returns the user when pw is correct,
    # otherwise false. 
    has_secure_password(validations:false)
    validates :password, presence:true, length:  minimum: 6 

     # Returns the hash digest of the given string.
    def User.digest(string)
        cost = ActiveModel::SecurePassword.min_cost ? BCrypt::Engine::MIN_COST :
                                                  BCrypt::Engine.cost
        BCrypt::Password.create(string, cost: cost)
    end
end

我的用户控制器中的创建方法： 定义创建 @user = User.new(user_params) #params[:user])#user_params)

if @user.save
  log_in @user
  flash[:success] = "Welcome to CourseBuddies!"
  redirect_to @user

else
  render 'new'
end

结束

我的测试/test_helper：

ENV['RAILS_ENV'] ||= 'test'
require File.expand_path('../../config/environment', __FILE__)
require 'rails/test_help'
require "minitest/reporters"
Minitest::Reporters.use!

class ActiveSupport::TestCase
  # Setup all fixtures in test/fixtures/*.yml for all tests in alphabetical order.
  fixtures :all

  # Returns true if a test user is logged in.
  def is_logged_in?
    !session[:user_id].nil?
  end
end

还有我的 user_login_test：

require 'test_helper'

class UsersLoginTest < ActionDispatch::IntegrationTest

  def setup
    @user = users(:michael)
  end

   # Visit the login path.
# Verify that the new sessions form renders properly.
# Post to the sessions path with an invalid params hash.
# Verify that the new sessions form gets re-rendered and that a flash message appears.
# Visit another page (such as the Home page).
# Verify that the flash message doesn’t appear on the new page.  
  test "login with valid information followed by logout" do
    get login_path
    post login_path, params:  session:  email:    @user.email,
                                      password: 'password'  
    assert is_logged_in?
    assert_redirected_to @user
    follow_redirect!
    assert_template 'users/show'
    assert_select "a[href=?]", login_path, count: 0
    assert_select "a[href=?]", logout_path
    assert_select "a[href=?]", user_path(@user)

    #AFTER ADDING THIS MY TEST FAILED

    #after logging in, we use delete to issue a DELETE request to the logout path
    #(Table 8.1) and verify that the user is logged out and redirected to the root URL
    delete logout_path
    assert_not is_logged_in?
    assert_redirected_to root_url
    follow_redirect!
    assert_select "a[href=?]", login_path
    assert_select "a[href=?]", logout_path,      count: 0
    assert_select "a[href=?]", user_path(@user), count: 0
  end
end

最后是我的路线：

Rails.application.routes.draw do

  get 'sessions/new'

  #ROOT, first page to show
  root 'pages#home'

  # maps requests for the URL/pages/home to the about us action in the Pages controller.
  # By using GET we arrange for the route to respond to a GET request.
  # With this we generate a about us action inside the Pages controller, automatically
  # get a page at the address /pages/about us
  get '/about', to: 'pages#about'
  get '/signup', to: 'users#new'
  post '/signup',  to: 'users#create' #signup route that responds to POST requests.
  get    '/login',   to: 'sessions#new'
  post   '/login',   to: 'sessions#create'
  delete '/logout',  to: 'sessions#destroy'

  #resources :sessions
  resources :users
  # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html              

end

对不起，代码太多了！在教程中，它说测试 users_login_test 在添加新代码后应该变成绿色，但它失败了。此外，注销不起作用并给我这个错误： image of error

如果有任何帮助，我将不胜感激！

【参考方案1】：

NameError in SessionsController#destroy"undefined local variable or SessionsController 的方法“log_out”：0x0000000275f290 你有没有 意思是？注销网址

在tutorial(参考8.3)中，sessions_helper中的方法名是log_out，而你把它命名为destroy，但是调用它在sessions_controller 中为log_out。你应该把它改成log_out

def log_out
  session.delete(:user_id)
  @current_user = nil
end

【讨论】：

感谢您注意到我的愚蠢错误并再次教育我，Pavan！你是最棒的！