Rails 3: Getting the ID of a Namespaced Model - ruby-on-rails

Question

I have a model called Contributor, which also acts as a namespace for several other models, such as Contributor::Alias and Contributor::Reassignment. I want to use a URL that includes the Contributor ID like so:
/contributors/1/reassignments/new
But I get this error:
No route matches [GET] "/contributors/1/reassignments/new"
My routes.rb file includes:
namespace :contributor do
resources :reassignments
end
resources :contributors
I've also tried:
resources :contributors do
resources :reassignments
end
This results in a different error:
uninitialized constant ReassignmentsController
Any idea how to approach this? Perhaps I shouldn't use a namespace that also acts as a model? I haven't seen this done in any tutorials, though it seems like it could be possible.
UPDATE:
How do you handle a deeply nested namespace model, such as:
resources :contributors do
resources :reassignments, :module => "contributor" do
resources :approvals, :module => "reassignment"
end
end
Using this approach, I get the error:
No route matches {:action=>"create", :controller=>"contributor/reassignment/approvals"}
My controller directory does have the following structure:
contributor ->
reassignment ->
approvals_controller.rb
This seems related to the first error, but perhaps it's something new.

Answer 1

It's not clear if you have a Contributor resource or not. If you do, the following in your routes.rb:
resources :contributors do
resources :reassignments, :module => "contributor"
end
If not, try:
resources :reassignments, :module => "contributor", :path => "/contributors/:contributor_id/reassignments"
Just note that in the 2nd case you will need to construct an url and explicitly pass :contributor_id to it in calls to link_to, form_for, and similar places.
If you want to use [#contributor,#reassignment] format there you better stick to the 1st approach where yu do have a Contributor resource.
UPDATE: for three-level nesting if your controllers directories don't also nest in parallel with resources you could specify controllers explicitly, e.g.:
resources :contributors do
resources :reassignments, :controller => "contributor/reassignments" do
resources :approvals, :controller => "reassignment/approvals"
end
end
But, please, don't do that. 3-and-more-level nesting is actively discouraged in Rails. See what is recommended instead here: http://weblog.jamisbuck.org/2007/2/5/nesting-resources