Rails: I installed ActiveAdmin and my devise link stopped working

Question

I have devise installed.
And I have a link: <%= link_to "Sign up", new_user_registration_path %>

When I installed ActiveAdmin (for existing model User), this link stopped working:

undefined local variable or method `new_user_registration_path'

I used git diff for routes.rb and here it is (added lines are black):

ActiveAdmin.routes(self)
devise_for :users, ActiveAdmin::Devise.config

Also <%= link_to "Sign out", destroy_user_session_path, :method => :delete %> now leads to /admin/logout

How can I solve this problem?

rake routes:

     admin_dashboard            /admin(.:format)                       {:action=>"index", :controller=>"admin/dashboard"}
         admin_codes GET        /admin/codes(.:format)                 {:action=>"index", :controller=>"admin/codes"}
                     POST       /admin/codes(.:format)                 {:action=>"create", :controller=>"admin/codes"}
      new_admin_code GET        /admin/codes/new(.:format)             {:action=>"new", :controller=>"admin/codes"}
     edit_admin_code GET        /admin/codes/:id/edit(.:format)        {:action=>"edit", :controller=>"admin/codes"}
          admin_code GET        /admin/codes/:id(.:format)             {:action=>"show", :controller=>"admin/codes"}
                     PUT        /admin/codes/:id(.:format)             {:action=>"update", :controller=>"admin/codes"}
                     DELETE     /admin/codes/:id(.:format)             {:action=>"destroy", :controller=>"admin/codes"}
         admin_users GET        /admin/users(.:format)                 {:action=>"index", :controller=>"admin/users"}
                     POST       /admin/users(.:format)                 {:action=>"create", :controller=>"admin/users"}
      new_admin_user GET        /admin/users/new(.:format)             {:action=>"new", :controller=>"admin/users"}
     edit_admin_user GET        /admin/users/:id/edit(.:format)        {:action=>"edit", :controller=>"admin/users"}
          admin_user GET        /admin/users/:id(.:format)             {:action=>"show", :controller=>"admin/users"}
                     PUT        /admin/users/:id(.:format)             {:action=>"update", :controller=>"admin/users"}
                     DELETE     /admin/users/:id(.:format)             {:action=>"destroy", :controller=>"admin/users"}
      admin_comments GET        /admin/comments(.:format)              {:action=>"index", :controller=>"admin/comments"}
                     POST       /admin/comments(.:format)              {:action=>"create", :controller=>"admin/comments"}
   new_admin_comment GET        /admin/comments/new(.:format)          {:action=>"new", :controller=>"admin/comments"}
  edit_admin_comment GET        /admin/comments/:id/edit(.:format)     {:action=>"edit", :controller=>"admin/comments"}
       admin_comment GET        /admin/comments/:id(.:format)          {:action=>"show", :controller=>"admin/comments"}
                     PUT        /admin/comments/:id(.:format)          {:action=>"update", :controller=>"admin/comments"}
                     DELETE     /admin/comments/:id(.:format)          {:action=>"destroy", :controller=>"admin/comments"}
    new_user_session GET        /admin/login(.:format)                 {:action=>"new", :controller=>"active_admin/devise/sessions"}
        user_session POST       /admin/login(.:format)                 {:action=>"create", :controller=>"active_admin/devise/sessions"}
destroy_user_session DELETE|GET /admin/logout(.:format)                {:action=>"destroy", :controller=>"active_admin/devise/sessions"}
       user_password POST       /admin/password(.:format)              {:action=>"create", :controller=>"active_admin/devise/passwords"}
   new_user_password GET        /admin/password/new(.:format)          {:action=>"new", :controller=>"active_admin/devise/passwords"}
  edit_user_password GET        /admin/password/edit(.:format)         {:action=>"edit", :controller=>"active_admin/devise/passwords"}
                     PUT        /admin/password(.:format)              {:action=>"update", :controller=>"active_admin/devise/passwords"}
                root            /                                      {:controller=>"codes", :action=>"list"}
                                /:controller(/:action(/:id(.:format)))

I checked out old revision, and routes were:

        new_user_session GET    /users/sign_in(.:format)               {:action=>"new", :controller=>"devise/sessions"}
            user_session POST   /users/sign_in(.:format)               {:action=>"create", :controller=>"devise/sessions"}
    destroy_user_session DELETE /users/sign_out(.:format)              {:action=>"destroy", :controller=>"devise/sessions"}
           user_password POST   /users/password(.:format)              {:action=>"create", :controller=>"devise/passwords"}
       new_user_password GET    /users/password/new(.:format)          {:action=>"new", :controller=>"devise/passwords"}
      edit_user_password GET    /users/password/edit(.:format)         {:action=>"edit", :controller=>"devise/passwords"}
                         PUT    /users/password(.:format)              {:action=>"update", :controller=>"devise/passwords"}
cancel_user_registration GET    /users/cancel(.:format)                {:action=>"cancel", :controller=>"devise/registrations"}
       user_registration POST   /users(.:format)                       {:action=>"create", :controller=>"devise/registrations"}
   new_user_registration GET    /users/sign_up(.:format)               {:action=>"new", :controller=>"devise/registrations"}
  edit_user_registration GET    /users/edit(.:format)                  {:action=>"edit", :controller=>"devise/registrations"}
                         PUT    /users(.:format)                       {:action=>"update", :controller=>"devise/registrations"}
                         DELETE /users(.:format)                       {:action=>"destroy", :controller=>"devise/registrations"}

Answer 1

One thing you might be missing is to declare your User model as 'registerable' to get the signup routes generated by Devise.

You should have something like this:

class User < ActiveRecord::Base
  # Include devise modules
  devise :database_authenticatable, :registerable, ...

I ran into this problem once and this is what solved it.

Answer 2

It seems that you are using the same model for both normal users and admin users. ActiveAdmin requires a separate model for admins. Try reverting the changes made by the generator and then run this:

rails generate active_admin:resource AdminUser
rake db:migrate

This will create an AdminUser model that will have absolutely no link with your site's users.