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