polymorphic_url generates wrong URL for namespaced nested resources

[miharekar]

I wrote this to heartcombo/simple_form#805 but we figured simple_form just uses polymorphic_url to generate URLs, so the problem must be there. I'm using Rails 4 rc 1.

I have Galleries with nested Photos and both namespaced under Admin

  namespace :admin do
    resources :galleries do
      resources :photos
    end
  end

So when I do
simple_form_for [@admin_gallery, @admin_photo]
I get undefined method 'admin_gallery_admin_photos_path'.

If I do simple_form_for [:admin, @admin_gallery, @admin_photo]
I get undefined method 'admin_admin_gallery_admin_photo_path'.

I got it to work by giving the simple_form the direct url like so: url: admin_gallery_photo_path(@admin_gallery, @admin_photo)
but that isn't pretty, and polymorphic_url should probably handle that better 😃

[josevalim]

If your model is namespaced, the model name will indeed be admin_gallery and the error undefined method 'admin_admin_gallery_admin_photo_path' is actually correct.

There is a disconnection in between how you are naming your routes and the names you are giving to your model. The namespace :admin call in your router doesn't imply the model name should be namespaced. Notice polymorphic_url heuristic is very simple, it simply gets the model names, put them together and attempt to generate a URL.

That said, there are two ways you could solve your problem:

1. Use as: :admin_gallery and as: :admin_photo on your resources call

2. In app/models/admin.rb, add this:

module Admin
  def self.use_relative_model_naming?
    true
  end
end

I haven't tried this approach directly yet but this will tell Rails that you want the model Admin::Gallery to be treated as Gallery. So the generated route won't include the admin_ nor the parameter name (you will use params[:gallery] instead of params[:admin_gallery] in your controller too).

[miharekar]

Thanks a lot. I'll look into that 👍