How do I create a resource that is the sub-set of an existing resource

In my "routes.rb" file I have the following line:

resource :users

which gives me a bunch of named routes for accessing my User model in a RESTful manner.

Now, I've made some additions to the User model including creating a special class of user. These are still stored in the User model but there is a "special" flag in the database that identifies them as special.

So, is it possible to create special_users resource? For example, I'd like to have a "special_users_path" as a 开发者_高级运维named route to "/special_users" which will return an index of only the special users when you perform a GET on the URL.

Is there a way to do this?

In Rails routing, a 'resource' refers to the standard 7 routes that are created for RESTful resources: index, show, new, create, edit, update and destroy. Normally that is enough, but sometimes you might want to create another action.

In the model, you want to create a scope that only returns special users:

class User < ActiveRecord::Base
  scope :special, where(:special => true)
end

On the controller side, there are two ways to go about this. What you are suggesting is the creation of an additional action:

match "/users/special" => "users#special"  
resource :users

In the controller, your special action would return the scope you just created:

class UsersController < ApplicationController
  def special
    @users = User.special
  end
end

That will do what you ask, but I would suggest NOT doing it this way. What if you add other flags later that you want to search by? What if you want to search by multiple flags? This solution isn't flexible enough for that. Instead, keep the routes the way they are:

resource :users

and just add an additional line to your controller:

class UsersController < ApplicationController
  def index
    @users = User.all
    @users = @users.special if params[:special]
  end
end

and now, when you want to display special users, simply direct the user to /users?special=true

This approach is much more future-proof, IMO.

(This answer is assuming Rails-3. If you're still using 2.3 let me know)

You could set the special_users as a resource:

resource :special_users

If you need to point it to a special controller, you could specify it with:

resource :special_users, :controller => :users

But I would really suggest you to not creating another controller for retrieving a kind of user, but using a param to get them:

 class UsersController < ApplicationController
   def index
     users = case params[:type].to_s
               when "special"
                 User.special_users # Using named scopes
               else
                 User.all
             end
   end
 end

When you use the users_path to call the special users:

users_path(:type => :special)