A way to refer to this current 'votable' element in an action in Rails (e.g. either #post and #comment)? - ruby-on-rails-3

Question

I have two models, Post and Comment that have a polymorphic association with another model called Vote.
post.rb and comment.rb have has_many :votes, :as => :votable, :dependent => :destroy
vote.rb has belongs_to :votable, :polymorphic => true
This controller has two actions one to add up votes for Post and the other for Comment:
controllers/votes_controller.rb:
class VotesController < ApplicationController
def vote_up
#post = Post.find(params[:id])
if #post.votes.exists?(:user_id => current_user.id)
#notice = 'You already voted'
else
#vote = #post.votes.create(:user_id => current_user.id, :polarity => 1)
end
respond_to do |format|
format.js
end
end
def vote_up2
#comment = Comment.find(params[:id])
if #comment.votes.exists?(:user_id => current_user.id)
#notice2 = 'You already voted'
else
#vote2 = #comment.votes.create(:user_id => current_user.id, :polarity => 1)
end
respond_to do |format|
format.js
end
end
end
I think that's unnecesary. Is there any way of using a single name to refer to the current votable element or either #post and #comment?
Edit
routes.rb:
get 'votes/:id/vote_up' => 'votes#vote_up', as: 'vote_up'
get 'votes/:id/vote_down' => 'votes#vote_down', as: 'vote_down'

Answer 1

The vote_up action should be implemented in your posts and comments controller respectively. Users are voting on posts or comments, they're not voting on a vote.
I would extract the voting logic and place it in a module that your models will include, then call it on a votable object from the controller.
in your lib directory, create votable.rb
module Votable
def up_vote_from(usr)
place_vote(1, usr.id)
end
def down_vote_from(usr)
place_vote(-1, usr.id)
end
private
def place_vote(direction, usr_id)
v = self.votes.find_or_create_by_user_id(usr_id)
v.update_attribute(:polarity, direction)
end
end
(This revised code will alter a user's original vote if they vote again. Vote methods will return true if the vote saves, false otherwise.)
In each votable model, such as post.rb and comment.rb, add this line to mix in your voting methods:
include Votable
Now, this can be done in a controller:
#post.up_vote_from current_user # => true
As far as implementation is concerned, you will end up with some repetition in your controllers/routes.
In each votable controller, set something up like:
def cast_vote
#post = Post.find params[:id]
if #post.call("#{params[:updown]}_vote_from", current_user)
respond_to do |format|
format.js
end
else
head :not_found
end
end
(this expects .../posts/123/vote/up for an upvote, .../posts/123/vote/down for a downvote.)
then append each resource to include your vote method:
resources :posts do
member do
post 'vote/:updown', :to => "posts#cast_vote", :as => :vote_on
end
end
which can be called in your views with:
<%= button_to "Up", :url => vote_on_post_path(#post, "up"), :remote => true %>
<%= button_to "Down", :url => vote_on_post_path(#post, "down"), :remote => true %>
This is a lot less work than it looks. It'll make sense once you put it in place. It'll make even more sense if you code it in by hand vs. cut and paste. :)