Question

Hey! I am trying to set up routes in a Rails application so that, depending on the type of parameter passed, Rails sends the request to a different action.

I have courses which have an attribute state which is a string with a two letter state abbreviation. When a user visits /courses/1, I want Rails to display the show action in the courses controller (and pass the parameter as :id). When a user visits /courses/CO though, I want Rails to display the index action and pass the parameter as :state.

So /courses/1 would be equivalent to

:controller => 'courses', :action => 'show', :id => '1'

And /courses/CO would be equivalent to

:controller => 'courses', :action => 'index', :state => 'CO'

I have tried this:

map.resources :courses, :except => { :index, :show }
map.connect 'courses/:state', :controller => 'courses', :action => 'index', :state => /[A-Z]{2}/
map.connect 'courses/:id',    :controller => 'courses', :action => 'show', :id => /[0-9]+/

But it breaks (the rails server wont even start). I don’t usually do things like this with routes, so I am outside of my know-how. Thanks!

Edit: Fixed a typo, thanks JC.

Current solution looks like this:

map.resources :courses, :except => [ :index, :show ]
  map.courses  '/courses',        :controller => 'courses', :action => 'index', :state => 'AL', :method => :get
  map.courses  '/courses/:state', :controller => 'courses', :action => 'index', :requirements => { :state => /[A-Z]{2}/ }, :method => :get
  map.course   '/courses/:id',    :controller => 'courses', :action => 'show',  :requirements => { :id => /[0-9]+/      }, :method => :get

Answer 1

This works, but you will need to go edit all your links to the index to say things like courses_path('AA') and you won’t be able to use some of the nice helpers, like form_for, which assume you are following the convention that #create is simply #index with a POST request. (Get comfortable with form_tag)

ActionController::Routing::Routes.draw do |map|
  map.resources :courses, :except => [ :index, :show ]
  map.courses  '/courses/:state', :controller => 'courses', :action => 'index', :requirements => { :state => /[A-Z]{2}/ } , :method => :get
  map.course   '/courses/:id',    :controller => 'courses', :action => 'show',  :requirements => { :id => /[0-9]+/      } , :method => :get
end

It will keep your routes named the same, though.

(by the way, your /co does not match your regex, which requires upper case chars)

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Fun aside: Do we really need the abstraction of a router? http://blog.peepcode.com/tutorials/2010/rethinking-rails-3-routes