Nested routes and proper place for a function?

Question

I have a Rails app and in it I have two models, widget and votes. Votes are used to keep track of the desirability of a widget.

In my models I have:

class Vote < ActiveRecord::Base
    belongs_to :widget
end

class Widget < ActiveRecord::Base
    has_many :votes
end

I am trying to figure out the best way to route votes up and votes down. At the moment I am leaning towards this:

resources :widgets do
  member do
      put :vote_up
      put :vote_down
  end
end

Where the respective functions reside in the widgets' controller and it creates and saves votes in that controller. However, I realize that this doesn't really fit correctly with the MVC idea (votes should be created and built in their own controller). Is this acceptable or should I be doing something more like:

resources :widgets do
  resources :votes do
    member do
        put :vote_up
        put :vote_down
    end
  end
end

Answer 1

I would not create custom controller actions. up and down are attributes of a Vote, so I would do the following:

resources :widgets do
  resources :votes, only: [:new, :create]
end

And then send a POST to VotesController#create with params[direction: 'up'] and have an attribute on Vote called direction.

Then validate Vote#direction can only be up or down:

class Vote < ActionController:Base
  validates_inclusion_of :direction, in: %w(up down)
end 

Your check for this kind of routing decision is to run rake routes and make sure the route aliases make sense, in this case we are really creating widget_votes, which looks like:

         Prefix Verb   URI Pattern                             Controller#Action
   widget_votes POST   /widgets/:widget_id/votes(.:format)     votes#create
new_widget_vote GET    /widgets/:widget_id/votes/new(.:format) votes#new