ruby-on-rails - "Unable to autoload constant User"开发中更改代码时出错

Question

我的 Rails 应用程序有问题。从 更新后 rails 3 至 4 .
当我在开发模式下启动服务器后浏览页面时，一切都很好。

但是在单个代码更改(甚至添加空格)之后，每个页面请求都会显示以下错误。

Unable to autoload constant User, expected /path/to/my/rails-app/app/models/user.rb to define it

该文件就在那里并定义了类:

class User < ActiveRecord::Base
  …

我用 config.autoload_paths 尝试了很多东西和 config.eager_load_paths在 application.rb但没有运气。
停用 Spring 也无济于事。

开发应用程序并在每次更改后都必须重新启动服务器似乎是 90 年代。

$ rails -v
Rails 4.2.4
$ ruby -v
ruby 2.1.7p400 (2015-08-18 revision 51632) [x86_64-linux]

一些相关配置:

发展.rb

MyApp::Application.configure do
    # Settings specified here will take precedence over those in config/application.rb

  # In the development environment your application's code is reloaded on
  # every request.  This slows down response time but is perfect for development
  # since you don't have to restart the webserver when you make code changes.
  config.cache_classes = false

  # Do not eager load code on boot. This avoids loading your whole application
  # just for the purpose of running a single test. If you are using a tool that
  # preloads Rails for running tests, you may have to set it to true.
  config.eager_load = false

  # Show full error reports and disable caching
  config.consider_all_requests_local       = true
  config.action_controller.perform_caching = false

  # Don't care if the mailer can't send
  config.action_mailer.raise_delivery_errors = false

  # Print deprecation notices to the Rails logger
  config.active_support.deprecation = :log

  # Only use best-standards-support built into browsers
  config.action_dispatch.best_standards_support = :builtin

  # Do not compress assets
  config.assets.compress = false

  # Expands the lines which load the assets
  config.assets.debug = true

  config.action_mailer.delivery_method = :test
  config.action_mailer.default_url_options = {
    host: 'localhost',
    port: 3000
  }

end

应用程序.rb

module Serviceportal
  class Application < Rails::Application    
    # Enable the asset pipeline
    config.assets.enabled = true

    # Version of your assets, change this if you want to expire all your assets
    config.assets.version = '1.0'

    [… some asset precompile stuff …]

    # Configure the default encoding used in templates for Ruby 1.9.
    config.encoding = 'utf-8'

    # Custom directories with classes and modules you want to be autoloadable.
    config.autoload_paths += Dir["#{config.root}/app/mailers",
        "#{config.root}/app/controllers/concerns",
        "#{config.root}/app/models/concerns",
        "#{config.root}/app/decorators/concerns",
        "#{config.root}/lib",
        "#{config.root}/lib/shared"
    ]
    config.eager_load_paths += Dir["#{config.root}/app/mailers",
        "#{config.root}/app/controllers/concerns",
        "#{config.root}/app/models/concerns",
        "#{config.root}/app/decorators/concerns",
        "#{config.root}/lib",
        "#{config.root}/lib/shared"]

    # Set Time.zone default to the specified zone and make Active Record auto-convert to this zone.
    # Run "rake -D time" for a list of tasks for finding time zone names. Default is UTC.
    config.time_zone = 'Berlin'

    # The default locale is :en and all translations from config/locales/*.rb,yml are auto loaded.
    # config.i18n.load_path += Dir[Rails.root.join('my', 'locales', '*.{rb,yml}').to_s]
    config.i18n.default_locale = :de

    [… some SQL and active support stuff …]

    config.action_controller.include_all_helpers = false

    config.action_controller.action_on_unpermitted_parameters = :raise

    # Do not swallow errors in after_commit/after_rollback callbacks.
    config.active_record.raise_in_transactional_callbacks = true
  end
end

编辑:该错误主要出现在以下函数的 lib/auth/user_proxy.rb 中。也许这有助于缩小可能原因的范围。

def self.usertype_allowed?(type)
  [ User, TempCustomer ].include? type.classify.safe_constantize rescue false
end

编辑 2: Stringify 编辑 1 中的类名有帮助(感谢@Benjamin Sinclare)。但只会导致下一个错误。我也可以避免使用类。但是在 app/controllers/concerns/security.rb 中出现以下错误时，没有什么可以改变的吗？

Unable to autoload constant User, expected /path/to/my/rails-app/app/models/user.rb to define it

代码:

def set_current_user
  User.current = current_user
end

当前用户保存在线程中(代码来自/path/to/my/rails-app/app/models/user.rb

def self.current
  Thread.current['current_user']
end

def self.current=(user)
  Thread.current['current_user'] = user
end

再次澄清一下:它在开发中的服务器重新启动后工作，直到我在某处更改一些代码。

Answer 1

1 查看是否有任何多级类或模块声明在一行中完成，并将它们更改为在多行中声明。

代替

class Parent::Sub::Child
end

做

module Parent
  module Sub
    class Child
    end
  end
end

2 检查您的模型关联定义，并确保您从不使用常量。改用字符串。

代替

belongs_to :manager, class_name: User

做

belongs_to :manager, class_name: 'User'

3 刚看到你的编辑。你可以这样重构吗？

# I assume `type` is a string or such, so we can compare classes
# names instead of constants, and get rid of `safe_constantize`
def self.usertype_allowed?(type)
  ['User', 'TempCustomer'].include? type.classify rescue false
end

4 序列化线程存储中的事件记录对象不是一个好主意。将其更改为存储用户 ID，如下所示:

def set_current_user
  User.current = current_user.id
end

def self.current
  Thread.current['current_user_id']
end

def self.current=(user_id)
  Thread.current['current_user_id'] = user_id
end