Rails Routes Namespaces and form_for - ruby-on-rails

Question

I have namespace in my routes.rb
namespace :businesses do
resources :registration
end
My controller is in a subdirectory businesses/registration_controller.
def new
#business = Business.new
end
In my view, I want to do this form_for #business do |f| ... but I am getting the following error:
No route matches {:controller=>"businesses", :action=>"create"}
Restarted the server and I'm also getting this:
undefined methodbusinesses_path' for #<#:0x10339bb20>`
Here are my rake routes:
home_index GET /home/index(.:format) {:action=>"index", :controller=>"home"}
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 GET /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"}
user_password 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"}
user_registration PUT /users(.:format) {:action=>"update", :controller=>"devise/registrations"}
user_registration DELETE /users(.:format) {:action=>"destroy", :controller=>"devise/registrations"}
users GET /users(.:format) {:action=>"index", :controller=>"users"}
users POST /users(.:format) {:action=>"create", :controller=>"users"}
new_user GET /users/new(.:format) {:action=>"new", :controller=>"users"}
edit_user GET /users/:id/edit(.:format) {:action=>"edit", :controller=>"users"}
user GET /users/:id(.:format) {:action=>"show", :controller=>"users"}
user PUT /users/:id(.:format) {:action=>"update", :controller=>"users"}
user DELETE /users/:id(.:format) {:action=>"destroy", :controller=>"users"}
full_tree_admin_categories GET /admin/categories/full_tree(.:format) {:action=>"full_tree", :controller=>"admin/categories"}
admin_categories GET /admin/categories(.:format) {:action=>"index", :controller=>"admin/categories"}
admin_categories POST /admin/categories(.:format) {:action=>"create", :controller=>"admin/categories"}
new_admin_category GET /admin/categories/new(.:format) {:action=>"new", :controller=>"admin/categories"}
edit_admin_category GET /admin/categories/:id/edit(.:format) {:action=>"edit", :controller=>"admin/categories"}
admin_category GET /admin/categories/:id(.:format) {:action=>"show", :controller=>"admin/categories"}
admin_category PUT /admin/categories/:id(.:format) {:action=>"update", :controller=>"admin/categories"}
admin_category DELETE /admin/categories/:id(.:format) {:action=>"destroy", :controller=>"admin/categories"}
businesses_registration_index GET /businesses/registration(.:format) {:action=>"index", :controller=>"businesses/registration"}
businesses_registration_index POST /businesses/registration(.:format) {:action=>"create", :controller=>"businesses/registration"}
new_businesses_registration GET /businesses/registration/new(.:format) {:action=>"new", :controller=>"businesses/registration"}
edit_businesses_registration GET /businesses/registration/:id/edit(.:format) {:action=>"edit", :controller=>"businesses/registration"}
businesses_registration GET /businesses/registration/:id(.:format) {:action=>"show", :controller=>"businesses/registration"}
businesses_registration PUT /businesses/registration/:id(.:format) {:action=>"update", :controller=>"businesses/registration"}
businesses_registration DELETE /businesses/registration/:id(.:format) {:action=>"destroy", :controller=>"businesses/registration"}
root /(.:format) {:action=>"index", :controller=>"home"}

Answer 1

If you have namespaced routes the best way is:
class Admin::BusinessesController < ApplicationController
def new
#business = Business.new
end
end
in routes.rb:
namespace :admin do
resources :businesses
end
In view:
form_for [:admin, #business] do |f|...
The Docs: http://guides.rubyonrails.org/form_helpers.html section 2.3.1 Dealing with Namespaces
Regarding your case:
In routes.rb everything is o'k. In the view you should write url explicitly because you have variable in controller other than controller name:
form_for #business, :url => business_registration_path do |f|...
I suppose that in businesses/registration_controller you have something like this:
class Businesses::RegistrationController < ApplicationController
def new
#business = Business.new
end
end
And one remark: I wouldn't create registration_controller for registering a new business. I think that keeping business related actions in business_controller is much clearer.

Answer 2

Actually, I think there is a better solution.
form_for [:admin, #business]
the issue with giving a url is that if you abstract the form out as a partial view, you'll need to deal with "create" and "update" situations. They points to different urls, and ends up with providing the #url in controller.