ruby-on-rails – 未初始化的常量ApplicationRecord

发布时间：2020-12-17 04:31:27 所属栏目：百科来源：网络整理

导读：我正在线上的rails教程书,当我转到 http://localhost:3000/时,我收到以下错误消息 “uninitialized constant ApplicationRecord” 它给了我以下代码突出显示第一行. class User ApplicationRecord attr_accessor :remember_token before_save { self.email =

我正在线上的rails教程书,当我转到 http://localhost:3000/时,我收到以下错误消息

“uninitialized constant ApplicationRecord”

它给了我以下代码突出显示第一行.

class User < ApplicationRecord
  attr_accessor :remember_token
  before_save { self.email = email.downcase }
  validates :name,presence: true,length: { maximum: 50 }
  VALID_EMAIL_REGEX = /A[w+-.]+@[a-zd-.]+.[a-z]+z/i
  validates :email,length: { maximum: 255 },

这是我的application.html.erb文件：

<!DOCTYPE html>
<html>
  <head>
    <title><%= full_title(yield(:title)) %></title>
    <%= stylesheet_link_tag "application",media: "all","data-turbolinks-track" => true %>
    <%= javascript_include_tag "application","data-turbolinks-track" => true %>
    <%= csrf_meta_tags %>
    <%= render 'layouts/shim' %>
  </head>
  <body>
    <%= render 'layouts/header' %>
    <div class="container">
      <% flash.each do |message_type,message| %>
        <div class="alert alert-<%= message_type %>"><%= message %></div>
      <% end %>
      <%= yield %>
      <%= render 'layouts/footer' %>
      <%= debug(params) if Rails.env.development? %>
    </div>
  </body>
</html>

和我的user.rb文件：

class User < ApplicationRecord
  attr_accessor :remember_token
  before_save { self.email = email.downcase }
  validates :name,format: { with: VALID_EMAIL_REGEX },uniqueness: { case_sensitive: false }
  has_secure_password
  validates :password,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

  # Returns a random token.
  def User.new_token
    SecureRandom.urlsafe_base64
  end

  # Remembers a user in the database for use in persistent sessions.
  def remember
    self.remember_token = User.new_token
    update_attribute(:remember_digest,User.digest(remember_token))
  end

  # Returns true if the given token matches the digest.
  def authenticated?(remember_token)
    return false if remember_digest.nil?
    BCrypt::Password.new(remember_digest).is_password?(remember_token)
  end

  # Forgets a user.
  def forget
    update_attribute(:remember_digest,nil)
  end
end

解决方法

看来你正在使用Rails 5教程,但是使用Rails 4.在Rails 5中,所有模型都继承自ApplicationRecord,而来自ActiveRecord :: Base的Rails 4

立即修复：

class User < ActiveRecord::Base
...
end

长期修复,切换到Rails 5并学习Rails 5

（编辑：李大同）

【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容!