Question

With a standard install of Rails_Admin using Devise for authentication and CanCan for authorization, accessing http://localhost:3000/admin as a non-admin user produces the following server log:

Started GET "/admin" for 127.0.0.1 at 2011-08-09 22:46:10 -0400
  Processing by RailsAdmin::MainController#index as HTML
  User Load (0.2ms)  SELECT "users".* FROM "users" WHERE "users"."id" = 1 LIMIT 1
Completed 404 Not Found in 151ms

ActionController::RoutingError (No route matches {:controller=>"gyms"}):
  app/controllers/application_controller.rb:5:in `block in <class:ApplicationController>'

Everything up until the last part seems ok. As far as I can tell, CanCan rescues the exception properly and attempts to redirect to root_url via the following code:

class ApplicationController < ActionController::Base
  protect_from_forgery

  rescue_from CanCan::AccessDenied do |exception|
    redirect_to root_url, :alert => exception.message
  end
end

TopOut::Application.routes.draw do
  mount RailsAdmin::Engine => '/admin', :as => 'rails_admin'
  devise_for :users

  resources :gyms

  root :to => "gyms#index"
end

But for some reason, in redirecting to root_url, CanCan is only attempting to hit

{:controller=>"gyms"}

rather than

{:controller=>"gyms", :action=>"index"}

Is this possibly an issue with CanCan? Or is there some particular facet of redirect_to or root_url which I missed in the docs?

Note: this is a duplicate of an issue I opened on CanCan’s github page, so I’ll be sure to close one if the other is solved.

Answer 1

Based on feedback from users at Github, it appears that routes are being name_scoped and so this is expected behavior.

Proper fix is to call root_url from main_app as follows:

rescue_from CanCan::AccessDenied do |exception|
  redirect_to main_app.root_url, :alert => exception.message
end

Credit for the solution goes to bbenezech at https://github.com/sferik/rails_admin/issues/658