Ruby on Rails - Restricting click by IP...

Question

I am new to rails so go easy. I have created a blog with the ability to "vote" on a post by using a feature much like Facebook's "like". I am not using any authentication but would like to restrict voting on a particular post by IP. That is, once someone votes for a post, they cannot vote again (unless they reset their router of course).

I feel like this should be something I affect by modifying the votes or posts Model, but I fear it has to do with Sessions, which...I don't have any experience yet.

Let me know if you need me to post any code. Here is the votes controller.

class VotesController < ApplicationController

  def create
    @post = Post.find(params[:post_id])
    @vote = @post.votes.create!(params[:vote])

       respond_to do |format|
       format.html { redirect_to @post}
       format.js
     end
  end
end

Answer 1

You could add an ip_address attribute to your votes table and validates_uniqueness_of :ip_address to ensure that only one vote can come from an IP.

Answer 2

Two ways of doing it come to mind right away, there are probably others. Both require storing an IP in the database.

1. Block the vote from being created with a uniqueness validation.

   class Vote < ActiveRecord::Base
     validates_uniqueness_of :ip_address
     ...
   end
   

2. Block the vote from being created in the controller

   class VotesConroller < ApplicationController
     ...
     def create
       unless Vote.find_by_post_id_and_ip_address(params[:post_id],request.remote_ip)
          posts.votes.create!(params[:vote].update({:ip_address => request.remote_ip}))
       end
     end
   end
   

Answer 3

I would do both EmFi and bensie said and store the IP address with the vote but you might also want to look into creating a blacklist of IPs which you want to block because the represent popular proxy servers (for example, the many proxies in the http://proxy.org/ list).

As you add to the list it will make it at least a little bit harder for users to cheat.