Question

I regularly use shallow routes on nested resources, so thought I missed something simple, but don’t see why I’m getting a routing error for students#show.

I have a School with two nested resources: Courses and Students. All actions work on Courses. The :index, :new and :create actions work for Students.

Why do I get a routing error for /students/3 instead of being routed to students#show as indicated in rake routes?

exception on /students/3 :

Routing Error
No route matches {:controller=>"students"}

Try running rake routes for more information on available routes.

Here are the relevant bits…

rake routes output:

...
            school_students GET    /schools/:school_id/students(.:format)     students#index
                            POST   /schools/:school_id/students(.:format)     students#create
         new_school_student GET    /schools/:school_id/students/new(.:format) students#new
               edit_student GET    /students/:id/edit(.:format)               students#edit
                    student GET    /students/:id(.:format)                    students#show
                            PUT    /students/:id(.:format)                    students#update
                            DELETE /students/:id(.:format)                    students#destroy
             approve_course GET    /courses/:id/approve(.:format)             courses#approve
             publish_course GET    /courses/:id/publish(.:format)             courses#publish
             school_courses GET    /schools/:school_id/courses(.:format)      courses#index
                            POST   /schools/:school_id/courses(.:format)      courses#create
          new_school_course GET    /schools/:school_id/courses/new(.:format)  courses#new
                edit_course GET    /courses/:id/edit(.:format)                courses#edit
                     course GET    /courses/:id(.:format)                     courses#show
                            PUT    /courses/:id(.:format)                     courses#update
                            DELETE /courses/:id(.:format)                     courses#destroy
                    schools GET    /schools(.:format)                         schools#index
                            POST   /schools(.:format)                         schools#create
                 new_school GET    /schools/new(.:format)                     schools#new
                edit_school GET    /schools/:id/edit(.:format)                schools#edit
                     school GET    /schools/:id(.:format)                     schools#show
                            PUT    /schools/:id(.:format)                     schools#update
                            DELETE /schools/:id(.:format)                     schools#destroy
...

routes.rb

Lms::Application.routes.draw do
...
resources :schools, :shallow => true do
  resources :students
  resources :courses do         # Courses still work if I remove this block.
    member do
      get 'approve'
      get 'publish'
    end
  end
end
...

controllers and views

I inspected, but since this is a routing exception, I don’t think this code is reached. If you tell me otherwise, I can add them.

libraries

I’m using cancan with authlogic, but have never experienced a routing error from these.

Answer 1

Yes, it was something simple. I made a wrong assumption that a routing error means the controller and views aren’t reached….and this “genius” forgot the logs have the full stack trace:

Completed 500 Internal Server Error in 89ms

ActionController::RoutingError (No route matches {:controller=>"students"}):
  app/views/shared/_breadcrumbs.html.erb:27:in `_app_views_shared__breadcrumbs_html_erb___658518109680707361_70357170598800'
  app/views/layouts/application.html.erb:45:in `_app_views_layouts_application_html_erb__2976677320852012228_70357170792580'
  app/controllers/students_controller.rb:19:in `show'

My breadcrumbs was attempting to construct a link to students#index which doesn’t exist. The breadcrumbs try to handle this case (line 25) but the check fails for nested resources:

25: <% elsif controller.class.action_methods.include?('index') %>
26:   <li>
27:     <%= link_to controller_name.titleize, :controller => controller_name, :action => 'index' %>
28:     <span class="divider">/</span>
29:   </li>