Rails Devise和current_user

Question

這是我對Devise幫助程序方法current_user的用戶的了解：

1. 它僅適用於控制器和視圖，不適用於建模。

2. 這是當前登錄用戶的User對象。

那么，如果是user_signed_in？ 那么我應該能夠執行current_user.email，current_user.id之類的操作（我在User對象中同時包含了電子郵件和ID）。 問題是我得到了

undefined method '[]' for nil:NilClass

當我使用current_user.email時

我可能會忘記什么？

完整跟蹤：

undefined method '[]' for nil:NilClass

Extracted source (around line #12):

9:           <% if user_signed_in? %>
10:               <li class="right_line"><%= link_to(SIGN_OUT_TITLE, destroy_user_session_path, :method => :delete) %></li>
11:               <li><%= link_to "Update user info", edit_user_path(current_user) %></li>
12:               <% if !user_registered(current_user.email) %>
13:                 <%= link_to "Register", register_path(current_user.id)  %>
14:               <% end %>
15:           <% else %

Trace of template inclusion: app/views/layouts/application.html.erb

Rails.root: /Users/mine/Documents/projects/rails/registrar
Application Trace | Framework Trace | Full Trace

lib/assets/common_lib.rb:355:in 'user_registered'
app/views/layouts/_header.html.erb:12:in '_app_views_layouts__header_html_erb__1686513977508462374_70171327747820'
actionpack (3.2.12) lib/action_view/template.rb:145:in 'block in render'
activesupport (3.2.12) lib/active_support/notifications.rb:125:in 'instrument'
actionpack (3.2.12) lib/action_view/template.rb:143:in 'render'
actionpack (3.2.12) lib/action_view/renderer/partial_renderer.rb:265:in 'render_partial'
actionpack (3.2.12) lib/action_view/renderer/partial_renderer.rb:238:in 'block in render'
actionpack (3.2.12) lib/action_view/renderer/abstract_renderer.rb:38:in 'block in instrument'
activesupport (3.2.12) lib/active_support/notifications.rb:123:in 'block in instrument'
activesupport (3.2.12) lib/active_support/notifications/instrumenter.rb:20:in 'instrument'
activesupport (3.2.12) lib/active_support/notifications.rb:123:in 'instrument'
actionpack (3.2.12) lib/action_view/renderer/abstract_renderer.rb:38:in 'instrument'
actionpack (3.2.12) lib/action_view/renderer/partial_renderer.rb:237:in 'render'
actionpack (3.2.12) lib/action_view/renderer/renderer.rb:41:in 'render_partial'
actionpack (3.2.12) lib/action_view/helpers/rendering_helper.rb:27:in 'render'
app/views/layouts/application.html.erb:18:in '_app_views_layouts_application_html_erb__756280269371614523_70171335312940'
actionpack (3.2.12) lib/action_view/template.rb:145:in 'block in render'
activesupport (3.2.12) lib/active_support/notifications.rb:125:in 'instrument'
actionpack (3.2.12) lib/action_view/template.rb:143:in 'render'
actionpack (3.2.12) lib/action_view/renderer/template_renderer.rb:59:in 'render_with_layout'
actionpack (3.2.12) lib/action_view/renderer/template_renderer.rb:45:in 'render_template'
actionpack (3.2.12) lib/action_view/renderer/template_renderer.rb:18:in 'render'
actionpack (3.2.12) lib/action_view/renderer/renderer.rb:36:in 'render_template'
actionpack (3.2.12) lib/action_view/renderer/renderer.rb:17:in 'render'
actionpack (3.2.12) lib/abstract_controller/rendering.rb:110:in '_render_template'
actionpack (3.2.12) lib/action_controller/metal/streaming.rb:225:in '_render_template'
actionpack (3.2.12) lib/abstract_controller/rendering.rb:103:in 'render_to_body'
actionpack (3.2.12) lib/action_controller/metal/renderers.rb:28:in 'render_to_body'
actionpack (3.2.12) lib/action_controller/metal/compatibility.rb:50:in 'render_to_body'
actionpack (3.2.12) lib/abstract_controller/rendering.rb:88:in 'render'
actionpack (3.2.12) lib/action_controller/metal/rendering.rb:16:in 'render'
actionpack (3.2.12) lib/action_controller/metal/instrumentation.rb:40:in 'block (2 levels) in render'
activesupport (3.2.12) lib/active_support/core_ext/benchmark.rb:5:in 'block in ms'
/Users/mine/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/benchmark.rb:296:in 'realtime'
activesupport (3.2.12) lib/active_support/core_ext/benchmark.rb:5:in 'ms'
actionpack (3.2.12) lib/action_controller/metal/instrumentation.rb:40:in 'block in render'
actionpack (3.2.12) lib/action_controller/metal/instrumentation.rb:83:in 'cleanup_view_runtime'
activerecord (3.2.12) lib/active_record/railties/controller_runtime.rb:24:in 'cleanup_view_runtime'
actionpack (3.2.12) lib/action_controller/metal/instrumentation.rb:39:in 'render'
actionpack (3.2.12) lib/action_controller/metal/implicit_render.rb:10:in 'default_render'
actionpack (3.2.12) lib/action_controller/metal/implicit_render.rb:5:in 'send_action'
actionpack (3.2.12) lib/abstract_controller/base.rb:167:in 'process_action'
actionpack (3.2.12) lib/action_controller/metal/rendering.rb:10:in 'process_action'
actionpack (3.2.12) lib/abstract_controller/callbacks.rb:18:in 'block in process_action'
activesupport (3.2.12) lib/active_support/callbacks.rb:425:in '_run__3746696285815827802__process_action__1047298389812609703__callbacks'
activesupport (3.2.12) lib/active_support/callbacks.rb:405:in '__run_callback'
activesupport (3.2.12) lib/active_support/callbacks.rb:385:in '_run_process_action_callbacks'
activesupport (3.2.12) lib/active_support/callbacks.rb:81:in 'run_callbacks'
actionpack (3.2.12) lib/abstract_controller/callbacks.rb:17:in 'process_action'
actionpack (3.2.12) lib/action_controller/metal/rescue.rb:29:in 'process_action'
actionpack (3.2.12) lib/action_controller/metal/instrumentation.rb:30:in 'block in process_action'
activesupport (3.2.12) lib/active_support/notifications.rb:123:in 'block in instrument'
activesupport (3.2.12) lib/active_support/notifications/instrumenter.rb:20:in 'instrument'
activesupport (3.2.12) lib/active_support/notifications.rb:123:in 'instrument'
actionpack (3.2.12) lib/action_controller/metal/instrumentation.rb:29:in 'process_action'
actionpack (3.2.12) lib/action_controller/metal/params_wrapper.rb:207:in 'process_action'
activerecord (3.2.12) lib/active_record/railties/controller_runtime.rb:18:in 'process_action'
actionpack (3.2.12) lib/abstract_controller/base.rb:121:in 'process'
actionpack (3.2.12) lib/abstract_controller/rendering.rb:45:in 'process'
actionpack (3.2.12) lib/action_controller/metal.rb:203:in 'dispatch'
actionpack (3.2.12) lib/action_controller/metal/rack_delegation.rb:14:in 'dispatch'
actionpack (3.2.12) lib/action_controller/metal.rb:246:in 'block in action'
actionpack (3.2.12) lib/action_dispatch/routing/route_set.rb:73:in 'call'
actionpack (3.2.12) lib/action_dispatch/routing/route_set.rb:73:in 'dispatch'
actionpack (3.2.12) lib/action_dispatch/routing/route_set.rb:36:in 'call'
actionpack (3.2.12) lib/action_dispatch/routing/mapper.rb:42: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 (3.2.12) lib/action_dispatch/routing/route_set.rb:601:in 'call'
warden (1.1.1) lib/warden/manager.rb:35:in 'block in call'
warden (1.1.1) lib/warden/manager.rb:34:in 'catch'
warden (1.1.1) lib/warden/manager.rb:34:in 'call'
actionpack (3.2.12) lib/action_dispatch/middleware/best_standards_support.rb:17:in 'call'
rack (1.4.5) lib/rack/etag.rb:23:in 'call'
rack (1.4.5) lib/rack/conditionalget.rb:25:in 'call'
actionpack (3.2.12) lib/action_dispatch/middleware/head.rb:14:in 'call'
actionpack (3.2.12) lib/action_dispatch/middleware/params_parser.rb:21:in 'call'
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rack (1.4.5) lib/rack/session/abstract/id.rb:210:in 'context'
rack (1.4.5) lib/rack/session/abstract/id.rb:205:in 'call'
actionpack (3.2.12) lib/action_dispatch/middleware/cookies.rb:341:in 'call'
activerecord (3.2.12) lib/active_record/query_cache.rb:64:in 'call'
activerecord (3.2.12) lib/active_record/connection_adapters/abstract/connection_pool.rb:479:in 'call'
actionpack (3.2.12) lib/action_dispatch/middleware/callbacks.rb:28:in 'block in call'
activesupport (3.2.12) lib/active_support/callbacks.rb:405:in '_run__1117890029539977785__call__1540971476762589783__callbacks'
activesupport (3.2.12) lib/active_support/callbacks.rb:405:in '__run_callback'
activesupport (3.2.12) lib/active_support/callbacks.rb:385:in '_run_call_callbacks'
activesupport (3.2.12) lib/active_support/callbacks.rb:81:in 'run_callbacks'
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actionpack (3.2.12) lib/action_dispatch/middleware/reloader.rb:65:in 'call'
actionpack (3.2.12) lib/action_dispatch/middleware/remote_ip.rb:31:in 'call'
actionpack (3.2.12) lib/action_dispatch/middleware/debug_exceptions.rb:16:in 'call'
actionpack (3.2.12) lib/action_dispatch/middleware/show_exceptions.rb:56:in 'call'
railties (3.2.12) lib/rails/rack/logger.rb:32:in 'call_app'
railties (3.2.12) lib/rails/rack/logger.rb:16:in 'block in call'
activesupport (3.2.12) lib/active_support/tagged_logging.rb:22:in 'tagged'
railties (3.2.12) lib/rails/rack/logger.rb:16:in 'call'
actionpack (3.2.12) lib/action_dispatch/middleware/request_id.rb:22:in 'call'
rack (1.4.5) lib/rack/methodoverride.rb:21:in 'call'
rack (1.4.5) lib/rack/runtime.rb:17:in 'call'
activesupport (3.2.12) lib/active_support/cache/strategy/local_cache.rb:72:in 'call'
rack (1.4.5) lib/rack/lock.rb:15:in 'call'
actionpack (3.2.12) lib/action_dispatch/middleware/static.rb:62:in 'call'
railties (3.2.12) lib/rails/engine.rb:479:in 'call'
railties (3.2.12) lib/rails/application.rb:223:in 'call'
rack (1.4.5) lib/rack/content_length.rb:14:in 'call'
railties (3.2.12) lib/rails/rack/log_tailer.rb:17:in 'call'
rack (1.4.5) lib/rack/handler/webrick.rb:59:in 'service'
/Users/mine/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/webrick/httpserver.rb:138:in 'service'
/Users/mine/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/webrick/httpserver.rb:94:in 'run'
/Users/mine/.rvm/rubies/ruby-2.0.0-p0/lib/ruby/2.0.0/webrick/server.rb:295:in 'block in start_thread'

Answer 1

這應該工作，我看到的唯一會導致此錯誤的是您為用戶使用了不同的模型名稱，您的用戶模型類如下所示：

class User < ActiveRecord::Base

  # Include default devise modules. Others available are:
  # :token_authenticatable, :confirmable,
  # :lockable, :timeoutable and :omniauthable
  devise :database_authenticatable, :registerable,
         :recoverable, :rememberable, :trackable, :validatable

  # Setup accessible (or protected) attributes for your model
  attr_accessible :email, :password, :password_confirmation, :remember_me,
                  :cellphone, :address, :name, :lastname, :nit, :phone, 
                  :verified, :level, :utype, :ustores, :image

  validates_presence_of :name

  has_many :products

end