Question

我是新手编程并在尝试浏览Rails教程的第9章时遇到以下错误。我多次检查代码，但仍然不明白为什么我的局部变量或方法没有被定义。每次我重写代码时都会遇到类似的错误：未定义的局部变量或方法'current_user'。

错误：

ERROR["test_layout_links", SiteLayoutTest, 0.888518]
test_layout_links#SiteLayoutTest (0.89s)
ActionView::Template::Error:         ActionView::Template::Error: undefined local variable or method `current_user' for #<#<Class:0x007fcd97c44cf0>:0x007fcd97c4c4a0>
        app/helpers/sessions_helper.rb:22:in `logged_in?'
        app/views/layouts/_header.html.erb:8:in `_app_views_layouts__header_html_erb__1982327839123609485_70260496954760'
        app/views/layouts/application.html.erb:12:in `_app_views_layouts_application_html_erb___2753884707929057206_70260450931560'
        test/integration/site_layout_test.rb:6:in `block in <class:SiteLayoutTest>'
    app/helpers/sessions_helper.rb:22:in `logged_in?'
    app/views/layouts/_header.html.erb:8:in `_app_views_layouts__header_html_erb__1982327839123609485_70260496954760'
    app/views/layouts/application.html.erb:12:in `_app_views_layouts_application_html_erb___2753884707929057206_70260450931560'
    test/integration/site_layout_test.rb:6:in `block in <class:SiteLayoutTest>'

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])
      log_in user
      params[:session][:remember_me] == '1' ? remember(user) : forget(user)
      redirect_back_or user
    else
      flash.now[:danger] = 'Invalid email/password combination' #Not quite right!
      render 'new'
    end
  end

  def destroy
    log_out if logged_in?
    redirect_to root_url
  end
end

users_controller

class UsersController < ApplicationController

  before_action :logged_in_user, only: [:edit, :update]
  before_action :correct_user,   only: [:edit, :update]

  def show
    @user = User.find(params[:id])
  end

  def new
    @user = User.new
  end

  def create
    @user = User.new(user_params)
    if @user.save
      log_in @user
      flash[:success] = "Welcome to the Sample App!"
      redirect_to @user
    else
      render 'new'
    end
  end

  def edit
  end

  def update
    if @user.update_attributes(user_params)
      flash[:success] = "Profile updated"
      redirect_to @user
    else
      render 'edit'
    end
  end

  private

    def user_params
      params.require(:user).permit(:name, :email, :password,
                               :password_confirmation)
    end

    # Before filters

    # Confirms a logged-in user.
    def logged_in_user
      unless logged_in?
        store_location
        flash[:danger] = "Please log in."
        redirect_to login_url
      end
    end

    # Confirms the correct user.
    def correct_user
      @user = User.find(params[:id])
      redirect_to(root_url) unless current_user?(@user)
    end
end

sessions_helper

module SessionsHelper

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

    #Remembers a user in a persistent session.
    def remember(user)
        user.remember
        cookies.permanent.signed[:user_id] = user.id
        cookies.permanent[:remember_token] = user.remember_token
    end

    #Returns the user corresponding to the remember token cookie.
    def current_user?(user)
    user == current_user
    end

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

    #Forgets a persistent session.
    def forget(user)
        user.forget
        cookies.delete(:user_id)
        cookies.delete(:remember_token)
    end

    #logs out the current user.
    def log_out
        forget(current_user)
        session.delete(:user_id)
        @current_user = nil
    end

    # Redirects to stored location (or to the default).
  def redirect_back_or(default)
    redirect_to(session[:forwarding_url] || default)
    session.delete(:forwarding_url)
  end

  # Stores the URL trying to be accessed.
  def store_location
    session[:forwarding_url] = request.url if request.get?
  end
end

sessions_helper_test

require 'test_helper'

class SessionsHelperTest < ActionView::TestCase

  def setup
    @user = users(:michael)
    remember(@user)
  end

  test "current_user returns right user when session is nil" do
    assert_equal @user, current_user
    assert is_logged_in?
  end

  test "current_user returns nil when remember digest is wrong" do
    @user.update_attribute(:remember_digest, User.digest(User.new_token))
    assert_nil current_user
  end
end

Answer 1

我认为你可能错过了current_user方法。 It's defined here.

虽然名称相似，但current_user与current_user?完全不同。问号是一种约定，通常意味着该方法将返回true或false。

Answer 2

您在current_user中错过了sessions_helper.rb方法。请回来Chapter 8.57

Michael Hartl的Rails教程第9章（第9.2.3节友好转发）测试失败

2 个答案: