Ruby on Rails - 未定义的方法 - 控制器无法访问模型
Ruby on Rails - undefined method - Model can't be accessed by Controller
已解决 - 我在显示个人资料头像之前在 HTML.erb 中添加了一个 if 语句，它现在出现了。感谢 Mark 和 Holger 的帮助。
我试图让我的用户出现在联盟中 table 但我收到一条错误消息，指出我的 LeaguesController 文件中有一个未定义的方法。我已经为我的控制器文件尝试了以下 class 名称 - LeaguesController < Application Controller 和 LeaguesController < UsersController （我知道该方法已在此 class 中定义，将 post 都在下面） . 'index' 匹配 html.erb 文件名。
LeaguesController（我已经尝试 User.includes(:profile).order(etc) 但仍然没有获取用户字段）
class LeaguesController < ApplicationController
def index
@LMSusers = User.order('last_sign_in_at DESC')
@MVPusers = User.order('sign_in_count DESC')
@LMSuser_position = User.order('last_sign_in_at DESC').find_index(current_user)
@MVPuser_position = User.order('sign_in_count DESC').find_index(current_user)
end
end
用户模型文件
class User < ApplicationRecord
# Include default devise modules. Others available are:
# :confirmable, :lockable, :timeoutable and :omniauthable
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :trackable, :validatable
# Association - Ruby Documentation
belongs_to :plan
has_one :profile
end
用户控制器
class UsersController < ApplicationController
before_action :authenticate_user!
def index
@users = User.includes(:profile)
end
# Use rails routes in console to find what URL path should be used and
# what dynamic ids need to be included. Use params in relevant controller file
# to include the paramater.
# GET to /users/:id
def show
# "User" is refering to model with same name -> user.rb
@user = User.find( params[:id] )
end
end
真正奇怪的是这段代码过去工作正常。在它停止工作之前，我将它与之前的提交进行了比较，它们似乎完美匹配。当我克隆提交时，它也工作正常，所以我真的不知道从哪里开始寻找这个错误。我没有联赛的模型文件，但我从来没有做过，而且它曾经工作得很好。我从未将联赛纳入任何 belongs_to/has_many 协会，但同样，它曾经工作得很好......
这里也是路由文件。
Routes.rb
Rails.application.routes.draw do
root to: 'pages#home'
devise_for :users, controllers: { registrations: 'users/registrations' }
resources :users do
# Singular resource and profile because requiring only one resource and profile per user
resource :profile
end
resources :leagues
get 'about', to: 'pages#about'
resources :contacts, only: :create
get 'contact-us', to: 'contacts#new', as: 'new_contact'
# Nested Resources Documentation
end
HTML.erb 文件
<div>
<h1 class="text-center">The Leaderboard</h1></br>
<p class="text-center">Check how you compare to the top 5 in the community.</p></br>
</div>
<div class="container">
<div class="row">
<div class="col-md-6">
<div>
<table class="table">
<tr>
<th class="league-header" colspan="6">Last Man Standing</th>
</tr>
<tr class="row-header">
<th>Position</th>
<th>Name</th>
<th class="left-column">Job Title</th>
<th class="left-column">Last Logged In</th>
</tr>
<% @LMSusers.each_with_index do |user, index| %>
<% if index < 5 %>
<tr class="tr">
<td style="padding-top: 20px;"><%= index+1 %></td>
<td class="left-column"><%= link_to user do %><%= image_tag user.profile.avatar.url, class: 'sml-avatar-show-img' %><% end %> <%= link_to user do %><%= user.profile.first_name %> <%= user.profile.last_name %><% end %></td>
<td style="padding-top: 20px;" class="left-column"><%= user.profile.job_title %></td>
<td style="padding-top: 20px;" class="left-column"><%= user.last_sign_in_at.strftime("%d/%m/%Y") %></td>
</tr>
<% end %>
<% end %>
<% if user_signed_in? %>
<% if current_user.profile %>
<tr class="tr user-tr">
<td style="padding-top: 20px;" ><%= @LMSuser_position + 1 %></td>
<td class="left-column"><%= link_to user_path(current_user.id) do %><%= image_tag current_user.profile.avatar.url, class: 'sml-avatar-show-img' %><% end %> <%= link_to user_path(current_user.id) do %><%= current_user.profile.first_name %> <%= current_user.profile.last_name %><% end %></td>
<td style="padding-top: 20px;" class="left-column"><%= current_user.profile.job_title %></td>
<td style="padding-top: 20px;" class="left-column"><%= current_user.last_sign_in_at.strftime("%d/%m/%Y") %></td>
</tr>
<% end %>
<% end %>
</table>
</div>
</div>
<div class="col-md-6">
<div>
<table class="table">
<tr>
<th class="league-header" colspan="6">MVP</th>
</tr>
<tr class="row-header">
<th>Position</th>
<th>Name</th>
<th class="left-column">Job Title</th>
<th class="left-column">Number of Logins</th>
</tr>
<% @MVPusers.each_with_index do |user, index| %>
<% if index < 5 %>
<tr class="tr">
<td style="padding-top: 20px;"><%= index + 1 %></td>
<td class="left-column"><%= link_to user do %><%= image_tag user.profile.avatar.url, class: 'sml-avatar-show-img' %><% end %> <%= link_to user do %><%= user.profile.first_name %> <%= user.profile.last_name %><% end %></td>
<td style="padding-top: 20px;" class="left-column"><%= user.profile.job_title %></td>
<td style="padding-top: 20px;" class="left-column"><%= user.sign_in_count %></td>
</tr>
<% end %>
<% end %>
<% if user_signed_in? %>
<% if current_user.profile %>
<tr class="tr user-tr">
<td style="padding-top: 20px;" ><%= @MVPuser_position + 1 %></td>
<td class="left-column"><%= link_to user_path(current_user.id) do %><%= image_tag current_user.profile.avatar.url, class: 'sml-avatar-show-img' %><% end %> <%= link_to user_path(current_user.id) do %><%= current_user.profile.first_name %> <%= current_user.profile.last_name %><% end %></td>
<td style="padding-top: 20px;" class="left-column"><%= current_user.profile.job_title %></td>
<td style="padding-top: 20px;" class="left-column"><%= current_user.sign_in_count %></td>
</tr>
<% end %>
<% end %>
</table>
</div>
</div>
</div>
</div>
错误日志
Started GET "/leagues" for xx.xxx.xx.xxx at 2017-03-28 14:23:54 +0000
Cannot render console from xx.xxx.xx.xxx! Allowed networks: xxx.x.x.x, ::1, xxx.x.x.x/xxx.xxx.xxx.xxx
Processing by LeaguesController#index as HTML
User Load (0.3ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? ORDER BY "users"."id" ASC LIMIT ? [["id", 3], ["LIMIT", 1]]
User Load (0.3ms) SELECT "users".* FROM "users" ORDER BY last_sign_in_at DESC
Profile Load (0.2ms) SELECT "profiles".* FROM "profiles" WHERE "profiles"."user_id" IN (9, 3, 8, 7, 6, 5, 2, 4, 1)
User Load (0.3ms) SELECT "users".* FROM "users" ORDER BY sign_in_count DESC
Profile Load (0.2ms) SELECT "profiles".* FROM "profiles" WHERE "profiles"."user_id" IN (3, 1, 2, 5, 7, 4, 6, 8, 9)
Rendering leagues/index.html.erb within layouts/application
CACHE (0.0ms) SELECT "users".* FROM "users" ORDER BY last_sign_in_at DESC
CACHE (0.0ms) SELECT "profiles".* FROM "profiles" WHERE "profiles"."user_id" IN (9, 3, 8, 7, 6, 5, 2, 4, 1)
Rendered leagues/index.html.erb within layouts/application (76.6ms)
Completed 500 Internal Server Error in 88ms (ActiveRecord: 1.5ms)
ActionView::Template::Error (undefined method `avatar' for nil:NilClass):
21: <% if index < 5 %>
22: <tr class="tr">
23: <td style="padding-top: 20px;"><%= index+1 %></td>
24: <td class="left-column"><%= link_to user do %><%= image_tag user.profile.avatar.url, class: 'sml-avatar-show-img' %><% end %> <%= link_to user do %><%= user.profile.first_name %> <%= user.profile.last_name %><% end %></td>
25: <td style="padding-top: 20px;" class="left-column"><%= user.profile.job_title %></td>
26: <td style="padding-top: 20px;" class="left-column"><%= user.last_sign_in_at.strftime("%d/%m/%Y") %></td>
27: </tr>
app/views/leagues/index.html.erb:24:in `block (2 levels) in _app_views_leagues_index_html_erb___1987220472087352031_70206048257300'
app/views/leagues/index.html.erb:24:in `block in _app_views_leagues_index_html_erb___1987220472087352031_70206048257300'
app/views/leagues/index.html.erb:20:in `each_with_index'
app/views/leagues/index.html.erb:20:in `_app_views_leagues_index_html_erb___1987220472087352031_70206048257300'
Rendering /usr/local/rvm/gems/ruby-2.3.0@saasapp/gems/actionpack-5.0.0/lib/action_dispatch/middleware/templates/rescues/template_error.html.erb within rescues/layout
Rendering /usr/local/rvm/gems/ruby-2.3.0@saasapp/gems/actionpack-5.0.0/lib/action_dispatch/middleware/templates/rescues/_source.html.erb
Rendered /usr/local/rvm/gems/ruby-2.3.0@saasapp/gems/actionpack-5.0.0/lib/action_dispatch/middleware/templates/rescues/_source.html.erb (7.2ms)
Rendering /usr/local/rvm/gems/ruby-2.3.0@saasapp/gems/actionpack-5.0.0/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb
Rendered /usr/local/rvm/gems/ruby-2.3.0@saasapp/gems/actionpack-5.0.0/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb (2.7ms)
Rendering /usr/local/rvm/gems/ruby-2.3.0@saasapp/gems/actionpack-5.0.0/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb
Rendered /usr/local/rvm/gems/ruby-2.3.0@saasapp/gems/actionpack-5.0.0/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb (1.4ms)
Rendered /usr/local/rvm/gems/ruby-2.3.0@saasapp/gems/actionpack-5.0.0/lib/action_dispatch/middleware/templates/rescues/template_error.html.erb within rescues/layout (38.7ms)
如果您想查看任何其他文件，请在评论中告诉我。对此表示感谢 help/advice。谢谢你的时间。
您收到了常见的 for nil:NilClass 错误。您在索引视图中有一个列表，您尝试在其中显示记录的属性。
您可以通过在记录上调用它们的 getter 方法来访问这些属性。这里唯一的问题是，您的记录值是 nil。暂无记录
具体来说：您使用了 user.profile.avatar user 记录在那里，但是当您在此 user 上调用 .profile 时，您收到 nil。
在调用方法之前，您可以确保检查记录是否可用。
中给出了如何做的想法
Can you see any issue with my controller/model which might explain why these records aren't available?
您的 LeaguesController 加载了 User 条记录。但是您可以在您的视图中访问 users 的个人资料。在访问它们之前，您需要确保您的 User 具有关联的 profile。
我看不到你的视图文件，但我假设你在每个用户或他们的个人资料上调用 .avatar？
如果您将 user.avatar 或 user.profile.avatar 更改为：
user.avatar if user.avatar
或
user.profile.avatar if user.profile && user.profile.avatar
那么你应该清除你的错误，只收到一个空白区域，他们的头像应该在这个地方。
编辑：查看视图文件后，这两行之一：
<%= image_tag user.profile.avatar.url, class: 'sml-avatar-show-img' %>
<%= image_tag current_user.profile.avatar.url, class: 'sml-avatar-show-img' %>
显然是在抛出错误。将它们更改为：
<%= (image_tag user.profile.avatar.url, class: 'sml-avatar-show-img') if user.profile && user.profile.avatar %>
<%= (image_tag current_user.profile.avatar.url, class: 'sml-avatar-show-img') if current_user && current_user.profile && current_user.profile.avatar %>
已解决 - 我在显示个人资料头像之前在 HTML.erb 中添加了一个 if 语句，它现在出现了。感谢 Mark 和 Holger 的帮助。
我试图让我的用户出现在联盟中 table 但我收到一条错误消息，指出我的 LeaguesController 文件中有一个未定义的方法。我已经为我的控制器文件尝试了以下 class 名称 - LeaguesController < Application Controller 和 LeaguesController < UsersController （我知道该方法已在此 class 中定义，将 post 都在下面） . 'index' 匹配 html.erb 文件名。
LeaguesController（我已经尝试 User.includes(:profile).order(etc) 但仍然没有获取用户字段）
class LeaguesController < ApplicationController
def index
@LMSusers = User.order('last_sign_in_at DESC')
@MVPusers = User.order('sign_in_count DESC')
@LMSuser_position = User.order('last_sign_in_at DESC').find_index(current_user)
@MVPuser_position = User.order('sign_in_count DESC').find_index(current_user)
end
end
用户模型文件
class User < ApplicationRecord
# Include default devise modules. Others available are:
# :confirmable, :lockable, :timeoutable and :omniauthable
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :trackable, :validatable
# Association - Ruby Documentation
belongs_to :plan
has_one :profile
end
用户控制器
class UsersController < ApplicationController
before_action :authenticate_user!
def index
@users = User.includes(:profile)
end
# Use rails routes in console to find what URL path should be used and
# what dynamic ids need to be included. Use params in relevant controller file
# to include the paramater.
# GET to /users/:id
def show
# "User" is refering to model with same name -> user.rb
@user = User.find( params[:id] )
end
end
真正奇怪的是这段代码过去工作正常。在它停止工作之前，我将它与之前的提交进行了比较，它们似乎完美匹配。当我克隆提交时，它也工作正常，所以我真的不知道从哪里开始寻找这个错误。我没有联赛的模型文件，但我从来没有做过，而且它曾经工作得很好。我从未将联赛纳入任何 belongs_to/has_many 协会，但同样，它曾经工作得很好......
这里也是路由文件。
Routes.rb
Rails.application.routes.draw do
root to: 'pages#home'
devise_for :users, controllers: { registrations: 'users/registrations' }
resources :users do
# Singular resource and profile because requiring only one resource and profile per user
resource :profile
end
resources :leagues
get 'about', to: 'pages#about'
resources :contacts, only: :create
get 'contact-us', to: 'contacts#new', as: 'new_contact'
# Nested Resources Documentation
end
HTML.erb 文件
<div>
<h1 class="text-center">The Leaderboard</h1></br>
<p class="text-center">Check how you compare to the top 5 in the community.</p></br>
</div>
<div class="container">
<div class="row">
<div class="col-md-6">
<div>
<table class="table">
<tr>
<th class="league-header" colspan="6">Last Man Standing</th>
</tr>
<tr class="row-header">
<th>Position</th>
<th>Name</th>
<th class="left-column">Job Title</th>
<th class="left-column">Last Logged In</th>
</tr>
<% @LMSusers.each_with_index do |user, index| %>
<% if index < 5 %>
<tr class="tr">
<td style="padding-top: 20px;"><%= index+1 %></td>
<td class="left-column"><%= link_to user do %><%= image_tag user.profile.avatar.url, class: 'sml-avatar-show-img' %><% end %> <%= link_to user do %><%= user.profile.first_name %> <%= user.profile.last_name %><% end %></td>
<td style="padding-top: 20px;" class="left-column"><%= user.profile.job_title %></td>
<td style="padding-top: 20px;" class="left-column"><%= user.last_sign_in_at.strftime("%d/%m/%Y") %></td>
</tr>
<% end %>
<% end %>
<% if user_signed_in? %>
<% if current_user.profile %>
<tr class="tr user-tr">
<td style="padding-top: 20px;" ><%= @LMSuser_position + 1 %></td>
<td class="left-column"><%= link_to user_path(current_user.id) do %><%= image_tag current_user.profile.avatar.url, class: 'sml-avatar-show-img' %><% end %> <%= link_to user_path(current_user.id) do %><%= current_user.profile.first_name %> <%= current_user.profile.last_name %><% end %></td>
<td style="padding-top: 20px;" class="left-column"><%= current_user.profile.job_title %></td>
<td style="padding-top: 20px;" class="left-column"><%= current_user.last_sign_in_at.strftime("%d/%m/%Y") %></td>
</tr>
<% end %>
<% end %>
</table>
</div>
</div>
<div class="col-md-6">
<div>
<table class="table">
<tr>
<th class="league-header" colspan="6">MVP</th>
</tr>
<tr class="row-header">
<th>Position</th>
<th>Name</th>
<th class="left-column">Job Title</th>
<th class="left-column">Number of Logins</th>
</tr>
<% @MVPusers.each_with_index do |user, index| %>
<% if index < 5 %>
<tr class="tr">
<td style="padding-top: 20px;"><%= index + 1 %></td>
<td class="left-column"><%= link_to user do %><%= image_tag user.profile.avatar.url, class: 'sml-avatar-show-img' %><% end %> <%= link_to user do %><%= user.profile.first_name %> <%= user.profile.last_name %><% end %></td>
<td style="padding-top: 20px;" class="left-column"><%= user.profile.job_title %></td>
<td style="padding-top: 20px;" class="left-column"><%= user.sign_in_count %></td>
</tr>
<% end %>
<% end %>
<% if user_signed_in? %>
<% if current_user.profile %>
<tr class="tr user-tr">
<td style="padding-top: 20px;" ><%= @MVPuser_position + 1 %></td>
<td class="left-column"><%= link_to user_path(current_user.id) do %><%= image_tag current_user.profile.avatar.url, class: 'sml-avatar-show-img' %><% end %> <%= link_to user_path(current_user.id) do %><%= current_user.profile.first_name %> <%= current_user.profile.last_name %><% end %></td>
<td style="padding-top: 20px;" class="left-column"><%= current_user.profile.job_title %></td>
<td style="padding-top: 20px;" class="left-column"><%= current_user.sign_in_count %></td>
</tr>
<% end %>
<% end %>
</table>
</div>
</div>
</div>
</div>
错误日志
Started GET "/leagues" for xx.xxx.xx.xxx at 2017-03-28 14:23:54 +0000
Cannot render console from xx.xxx.xx.xxx! Allowed networks: xxx.x.x.x, ::1, xxx.x.x.x/xxx.xxx.xxx.xxx
Processing by LeaguesController#index as HTML
User Load (0.3ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? ORDER BY "users"."id" ASC LIMIT ? [["id", 3], ["LIMIT", 1]]
User Load (0.3ms) SELECT "users".* FROM "users" ORDER BY last_sign_in_at DESC
Profile Load (0.2ms) SELECT "profiles".* FROM "profiles" WHERE "profiles"."user_id" IN (9, 3, 8, 7, 6, 5, 2, 4, 1)
User Load (0.3ms) SELECT "users".* FROM "users" ORDER BY sign_in_count DESC
Profile Load (0.2ms) SELECT "profiles".* FROM "profiles" WHERE "profiles"."user_id" IN (3, 1, 2, 5, 7, 4, 6, 8, 9)
Rendering leagues/index.html.erb within layouts/application
CACHE (0.0ms) SELECT "users".* FROM "users" ORDER BY last_sign_in_at DESC
CACHE (0.0ms) SELECT "profiles".* FROM "profiles" WHERE "profiles"."user_id" IN (9, 3, 8, 7, 6, 5, 2, 4, 1)
Rendered leagues/index.html.erb within layouts/application (76.6ms)
Completed 500 Internal Server Error in 88ms (ActiveRecord: 1.5ms)
ActionView::Template::Error (undefined method `avatar' for nil:NilClass):
21: <% if index < 5 %>
22: <tr class="tr">
23: <td style="padding-top: 20px;"><%= index+1 %></td>
24: <td class="left-column"><%= link_to user do %><%= image_tag user.profile.avatar.url, class: 'sml-avatar-show-img' %><% end %> <%= link_to user do %><%= user.profile.first_name %> <%= user.profile.last_name %><% end %></td>
25: <td style="padding-top: 20px;" class="left-column"><%= user.profile.job_title %></td>
26: <td style="padding-top: 20px;" class="left-column"><%= user.last_sign_in_at.strftime("%d/%m/%Y") %></td>
27: </tr>
app/views/leagues/index.html.erb:24:in `block (2 levels) in _app_views_leagues_index_html_erb___1987220472087352031_70206048257300'
app/views/leagues/index.html.erb:24:in `block in _app_views_leagues_index_html_erb___1987220472087352031_70206048257300'
app/views/leagues/index.html.erb:20:in `each_with_index'
app/views/leagues/index.html.erb:20:in `_app_views_leagues_index_html_erb___1987220472087352031_70206048257300'
Rendering /usr/local/rvm/gems/ruby-2.3.0@saasapp/gems/actionpack-5.0.0/lib/action_dispatch/middleware/templates/rescues/template_error.html.erb within rescues/layout
Rendering /usr/local/rvm/gems/ruby-2.3.0@saasapp/gems/actionpack-5.0.0/lib/action_dispatch/middleware/templates/rescues/_source.html.erb
Rendered /usr/local/rvm/gems/ruby-2.3.0@saasapp/gems/actionpack-5.0.0/lib/action_dispatch/middleware/templates/rescues/_source.html.erb (7.2ms)
Rendering /usr/local/rvm/gems/ruby-2.3.0@saasapp/gems/actionpack-5.0.0/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb
Rendered /usr/local/rvm/gems/ruby-2.3.0@saasapp/gems/actionpack-5.0.0/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb (2.7ms)
Rendering /usr/local/rvm/gems/ruby-2.3.0@saasapp/gems/actionpack-5.0.0/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb
Rendered /usr/local/rvm/gems/ruby-2.3.0@saasapp/gems/actionpack-5.0.0/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb (1.4ms)
Rendered /usr/local/rvm/gems/ruby-2.3.0@saasapp/gems/actionpack-5.0.0/lib/action_dispatch/middleware/templates/rescues/template_error.html.erb within rescues/layout (38.7ms)
如果您想查看任何其他文件，请在评论中告诉我。对此表示感谢 help/advice。谢谢你的时间。
您收到了常见的 for nil:NilClass 错误。您在索引视图中有一个列表，您尝试在其中显示记录的属性。
您可以通过在记录上调用它们的 getter 方法来访问这些属性。这里唯一的问题是，您的记录值是 nil。暂无记录
具体来说：您使用了 user.profile.avatar user 记录在那里，但是当您在此 user 上调用 .profile 时，您收到 nil。
在调用方法之前，您可以确保检查记录是否可用。
Can you see any issue with my controller/model which might explain why these records aren't available?
您的 LeaguesController 加载了 User 条记录。但是您可以在您的视图中访问 users 的个人资料。在访问它们之前，您需要确保您的 User 具有关联的 profile。
我看不到你的视图文件，但我假设你在每个用户或他们的个人资料上调用 .avatar？
如果您将 user.avatar 或 user.profile.avatar 更改为：
user.avatar if user.avatar
或
user.profile.avatar if user.profile && user.profile.avatar
那么你应该清除你的错误，只收到一个空白区域，他们的头像应该在这个地方。
编辑：查看视图文件后，这两行之一：
<%= image_tag user.profile.avatar.url, class: 'sml-avatar-show-img' %>
<%= image_tag current_user.profile.avatar.url, class: 'sml-avatar-show-img' %>
显然是在抛出错误。将它们更改为：
<%= (image_tag user.profile.avatar.url, class: 'sml-avatar-show-img') if user.profile && user.profile.avatar %>
<%= (image_tag current_user.profile.avatar.url, class: 'sml-avatar-show-img') if current_user && current_user.profile && current_user.profile.avatar %>