Are deeply nested polymorphic resources worth the effort?

Question

I am at the point in my development that I am thinking that deeply (>1) nested resources are not worth the effort.

I have something like this:

  resources :first-level do
    resources :comments
    resources :second-level do
      resources :comments      
      resources :first-child do
        resources :comments
      end
      resources :second-child do
        resources :comments
      end
      resources :third-child do
        resources :comments
      end
    end
  end

The kicker is that the comments are polymorphic to the other resources. My intent was to have clean looking URLs like ~/first-level/34/comments, ~/first-level/34/second-level/56/third-level/comments etc.

The problem so far is the polymorphic routes when nested cause nothing but grief. I am following a couple of Ryan Bates Railscasts as an example. For example if I try to use polymorphic_path on the first level it works fine and I get:

polymorphic_path([@commentable, comments]) => ~/first-level/34/comments

but the same code on ~/first-level/34/second-level/23 fails with:

undefined method 'second-level_comment_path' for #<#<Class:0x007fcc4acfbe58>:0x007fcc4ae73d08> but when I look at my routes the actual named route is first-level_second-level_comment. I tried to manually create that second-level_comment_path to basically alias to first-level_second-level_comment but I could not seem to make that work either.

Unless someone can point out an obvious error here I am leaning towards this approach (http://weblog.jamisbuck.org/2007/2/5/nesting-resources) and just un-nesting these. I have a breadcrumb style navigation to show the hiearchy so that should suffice and the more I look at it the urls do get a bit unwieldily.

Answer 1

With nested resources, you will need to specify all the parent levels when you want to access a child level. Otherwise Rails will not know how to get to your child level. So, you will need to use first-level_second-level_comment and supply first-level and second-level values like this:

first-level_second-level_comments_path(@my_first_level, @my_second_level)

will render:

~/first-level/34/second-level/23/comments

EDIT:

I don't see why you will need to build path incrementally.

You can always build first_level comments path:

first-level_comments_path(@my_first_level)

will render

~/first-level/34/comments

Or listing of all second levels within the first level: (second-level's index action for a given first-level)

first-level_second-levels_path(@my_first_level)

will render

~/first-level/34/second-levels