0

通过在我的控制器中查询不存在的帖子时

@post = Post.find_by_id(params[:id])

我得到 ActiveRecord::RecordNotFound。但是当我在 Rails 控制台中做同样的事情时，我得到了 nil 返回。

我也尝试过find_by_id!（注意感叹号）应该触发 404，但它仍然只给我 ActiveRecord::RecordNotFound。

我发现 gem 可能会导致这种问题（请参阅问题：Rails Find_by_id raises exception），所以我的问题是如何确定我使用的哪个 gem 会导致同样的问题？

这是我的宝石文件

source 'https://rubygems.org'

gem 'rails', '3.2.7'
gem 'pg'
gem 'jquery-rails'
gem 'fancybox-rails', :git => 'https://github.com/sverigemeny/fancybox-rails'
gem 'bcrypt-ruby', '~> 3.0.0'
gem 'omniauth-twitter'
gem 'omniauth-facebook'
gem 'omniauth-google-oauth2'
gem 'validates_email_format_of', :git => 'git://github.com/alexdunae/validates_email_format_of.git'
gem 'cancan'
gem 'thin'
gem 'chronic'
gem 'simple_form'
gem 'twitter'
gem 'kaminari'

group :assets do
  gem 'sass-rails'
  gem 'compass-rails'
  gem 'coffee-rails'
  gem 'uglifier', '>= 1.0.3'
end

group :development do
  gem 'quiet_assets'
  gem 'faker'
end

在找到可能导致此问题的 Gem 之前，我不知道如何才能一一禁用，因为由于过程中的 Gem 依赖关系，我很可能会触发许多其他错误。

有人知道我应该怎么做吗？

更新 这是完整的堆栈跟踪：

ActiveRecord::RecordNotFound in PostsController#edit

Couldn't find Post with id=123202

activerecord (3.2.7) lib/active_record/relation/finder_methods.rb:341:in `find_one'
activerecord (3.2.7) lib/active_record/relation/finder_methods.rb:312:in `find_with_ids'
activerecord (3.2.7) lib/active_record/relation/finder_methods.rb:107:in `find'
activerecord (3.2.7) lib/active_record/querying.rb:5:in `find'
cancan (1.6.8) lib/cancan/model_adapters/abstract_adapter.rb:20:in `find'
cancan (1.6.8) lib/cancan/controller_resource.rb:114:in `find_resource'
cancan (1.6.8) lib/cancan/controller_resource.rb:68:in `load_resource_instance'
cancan (1.6.8) lib/cancan/controller_resource.rb:32:in `load_resource'
cancan (1.6.8) lib/cancan/controller_resource.rb:25:in `load_and_authorize_resource'
cancan (1.6.8) lib/cancan/controller_resource.rb:10:in `block in add_before_filter'
activesupport (3.2.7) lib/active_support/callbacks.rb:418:in `_run__4208450199150212965__process_action__1027836660135587880__callbacks'
activesupport (3.2.7) lib/active_support/callbacks.rb:405:in `__run_callback'
activesupport (3.2.7) lib/active_support/callbacks.rb:385:in `_run_process_action_callbacks'
activesupport (3.2.7) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (3.2.7) lib/abstract_controller/callbacks.rb:17:in `process_action'
actionpack (3.2.7) lib/action_controller/metal/rescue.rb:29:in `process_action'
actionpack (3.2.7) lib/action_controller/metal/instrumentation.rb:30:in `block in process_action'
activesupport (3.2.7) lib/active_support/notifications.rb:123:in `block in instrument'
activesupport (3.2.7) lib/active_support/notifications/instrumenter.rb:20:in `instrument'
activesupport (3.2.7) lib/active_support/notifications.rb:123:in `instrument'
actionpack (3.2.7) lib/action_controller/metal/instrumentation.rb:29:in `process_action'
actionpack (3.2.7) lib/action_controller/metal/params_wrapper.rb:207:in `process_action'
activerecord (3.2.7) lib/active_record/railties/controller_runtime.rb:18:in `process_action'
actionpack (3.2.7) lib/abstract_controller/base.rb:121:in `process'
actionpack (3.2.7) lib/abstract_controller/rendering.rb:45:in `process'
actionpack (3.2.7) lib/action_controller/metal.rb:203:in `dispatch'
actionpack (3.2.7) lib/action_controller/metal/rack_delegation.rb:14:in `dispatch'
actionpack (3.2.7) lib/action_controller/metal.rb:246:in `block in action'
actionpack (3.2.7) lib/action_dispatch/routing/route_set.rb:73:in `call'
actionpack (3.2.7) lib/action_dispatch/routing/route_set.rb:73:in `dispatch'
actionpack (3.2.7) lib/action_dispatch/routing/route_set.rb:36:in `call'
journey (1.0.4) lib/journey/router.rb:68:in `block in call'
journey (1.0.4) lib/journey/router.rb:56:in `each'
journey (1.0.4) lib/journey/router.rb:56:in `call'
actionpack (3.2.7) lib/action_dispatch/routing/route_set.rb:600:in `call'
omniauth (1.1.1) lib/omniauth/strategy.rb:177:in `call!'
omniauth (1.1.1) lib/omniauth/strategy.rb:157:in `call'
omniauth (1.1.1) lib/omniauth/strategy.rb:177:in `call!'
omniauth (1.1.1) lib/omniauth/strategy.rb:157:in `call'
omniauth (1.1.1) lib/omniauth/strategy.rb:177:in `call!'
omniauth (1.1.1) lib/omniauth/strategy.rb:157:in `call'
omniauth (1.1.1) lib/omniauth/builder.rb:48:in `call'
actionpack (3.2.7) lib/action_dispatch/middleware/best_standards_support.rb:17:in `call'
rack (1.4.3) lib/rack/etag.rb:23:in `call'
rack (1.4.3) lib/rack/conditionalget.rb:25:in `call'
actionpack (3.2.7) lib/action_dispatch/middleware/head.rb:14:in `call'
actionpack (3.2.7) lib/action_dispatch/middleware/params_parser.rb:21:in `call'
actionpack (3.2.7) lib/action_dispatch/middleware/flash.rb:242:in `call'
rack (1.4.3) lib/rack/session/abstract/id.rb:210:in `context'
rack (1.4.3) lib/rack/session/abstract/id.rb:205:in `call'
actionpack (3.2.7) lib/action_dispatch/middleware/cookies.rb:338:in `call'
activerecord (3.2.7) lib/active_record/query_cache.rb:64:in `call'
activerecord (3.2.7) lib/active_record/connection_adapters/abstract/connection_pool.rb:473:in `call'
actionpack (3.2.7) lib/action_dispatch/middleware/callbacks.rb:28:in `block in call'
activesupport (3.2.7) lib/active_support/callbacks.rb:405:in `_run__503554315877740465__call__403817388267166975__callbacks'
activesupport (3.2.7) lib/active_support/callbacks.rb:405:in `__run_callback'
activesupport (3.2.7) lib/active_support/callbacks.rb:385:in `_run_call_callbacks'
activesupport (3.2.7) lib/active_support/callbacks.rb:81:in `run_callbacks'
actionpack (3.2.7) lib/action_dispatch/middleware/callbacks.rb:27:in `call'
actionpack (3.2.7) lib/action_dispatch/middleware/reloader.rb:65:in `call'
actionpack (3.2.7) lib/action_dispatch/middleware/remote_ip.rb:31:in `call'
actionpack (3.2.7) lib/action_dispatch/middleware/debug_exceptions.rb:16:in `call'
actionpack (3.2.7) lib/action_dispatch/middleware/show_exceptions.rb:56:in `call'
railties (3.2.7) lib/rails/rack/logger.rb:26:in `call_app'
railties (3.2.7) lib/rails/rack/logger.rb:16:in `call'
quiet_assets (1.0.1) lib/quiet_assets.rb:20:in `call_with_quiet_assets'
actionpack (3.2.7) lib/action_dispatch/middleware/request_id.rb:22:in `call'
rack (1.4.3) lib/rack/methodoverride.rb:21:in `call'
rack (1.4.3) lib/rack/runtime.rb:17:in `call'
activesupport (3.2.7) lib/active_support/cache/strategy/local_cache.rb:72:in `call'
rack (1.4.3) lib/rack/lock.rb:15:in `call'
actionpack (3.2.7) lib/action_dispatch/middleware/static.rb:62:in `call'
railties (3.2.7) lib/rails/engine.rb:479:in `call'
railties (3.2.7) lib/rails/application.rb:220:in `call'
rack (1.4.3) lib/rack/content_length.rb:14:in `call'
railties (3.2.7) lib/rails/rack/log_tailer.rb:17:in `call'
thin (1.5.0) lib/thin/connection.rb:81:in `block in pre_process'
thin (1.5.0) lib/thin/connection.rb:79:in `catch'
thin (1.5.0) lib/thin/connection.rb:79:in `pre_process'
thin (1.5.0) lib/thin/connection.rb:54:in `process'
thin (1.5.0) lib/thin/connection.rb:39:in `receive_data'
eventmachine (1.0.0) lib/eventmachine.rb:187:in `run_machine'
eventmachine (1.0.0) lib/eventmachine.rb:187:in `run'
thin (1.5.0) lib/thin/backends/base.rb:63:in `start'
thin (1.5.0) lib/thin/server.rb:159:in `start'
rack (1.4.3) lib/rack/handler/thin.rb:13:in `run'
rack (1.4.3) lib/rack/server.rb:268:in `start'
railties (3.2.7) lib/rails/commands/server.rb:70:in `start'
railties (3.2.7) lib/rails/commands.rb:55:in `block in <top (required)>'
railties (3.2.7) lib/rails/commands.rb:50:in `tap'
railties (3.2.7) lib/rails/commands.rb:50:in `<top (required)>'
script/rails:6:in `require'
script/rails:6:in `<main>'
4

2 回答 2

2

正如drawinglis指出的那样，这是由cancan引起的。

Cancan 加载帖子以确定用户是否有权对其执行任何操作。如果未找到该帖子，它将返回 404，ActiveRecord::RecordNotFound。

在这里，Ryan 稍微介绍了这背后的原因：https ://github.com/ryanb/cancan/issues/43如果这不是您需要的行为，他还建议从 404 中拯救出来。

于 2013-01-16T07:17:23.667 回答
0

drwesinglis 和 cheeseweasel 是正确的，这是由 CanCan 引起的。我无法从帖子https://github.com/ryanb/cancan/issues/43中获得解决方案来工作，所以我load_and_authorize_resource从我的控制器中删除了，我现在手动检查用户是否有权完成操作.

我的控制器现在看起来像这样：

@post = Post.find_by_id(params[:id])
if @post
  if can? :update, @post
    ...
  else
    flash[:error] = 'You are not authorized to access this post.'
    redirect_to root_url
  end
else
  flash[:error] = 'This post doesn\'t exist.'
  redirect_to root_url
end

我将在开发周期的后期更新我的代码以重定向到更好的 404 页面，但现在我只显示消息。

于 2013-01-16T17:06:31.010 回答