Rails 是否有“未经授权”的例外情况？

我正在编写一个应用程序，它使用普通的旧 Ruby 对象 (PORO) 从控制器中抽象出授权逻辑。

目前，我有一个名为的自定义异常类NotAuthorized that I rescue_from在控制器级别，但我很想知道：Rails 4 是否已经带有异常来指示操作未经授权？我是否通过实现此异常而重新发明轮子？

澄清: The raise AuthorizationException不是发生在控制器内部的任何地方，而是发生在控制器外部完全解耦的 PORO 内部。该对象不了解 HTTP、路由或控制器。

Rails 似乎没有映射异常:unauthorized.

默认映射定义在activerecord/lib/active_record/railtie.rb https://github.com/rails/rails/blob/4-1-stable/activerecord/lib/active_record/railtie.rb#L25:

config.action_dispatch.rescue_responses.merge!(
  'ActiveRecord::RecordNotFound'   => :not_found,
  'ActiveRecord::StaleObjectError' => :conflict,
  'ActiveRecord::RecordInvalid'    => :unprocessable_entity,
  'ActiveRecord::RecordNotSaved'   => :unprocessable_entity
)

and actionpack/lib/action_dispatch/middleware/exception_wrapper.rb https://github.com/rails/rails/blob/4-1-stable/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb#L8:

@@rescue_responses.merge!(
  'ActionController::RoutingError'             => :not_found,
  'AbstractController::ActionNotFound'         => :not_found,
  'ActionController::MethodNotAllowed'         => :method_not_allowed,
  'ActionController::UnknownHttpMethod'        => :method_not_allowed,
  'ActionController::NotImplemented'           => :not_implemented,
  'ActionController::UnknownFormat'            => :not_acceptable,
  'ActionController::InvalidAuthenticityToken' => :unprocessable_entity,
  'ActionDispatch::ParamsParser::ParseError'   => :bad_request,
  'ActionController::BadRequest'               => :bad_request,
  'ActionController::ParameterMissing'         => :bad_request
)

您可以从应用程序的配置中添加自定义异常（或自定义异常）Railtie http://api.rubyonrails.org/classes/Rails/Railtie.html):

Your::Application.configure do

  config.action_dispatch.rescue_responses.merge!(
    'AuthorizationException' => :unauthorized
  )

  # ...

end

或者简单地使用rescue_from.