Prevent users from voting multiple times in Rails

Question

I've a simple rating system setup in a blog model. I use a custom method to increase rating, which is integer in blog db.

def increase
  @post = Post.find(params[:id]).increment!(:rating)
  if logged_in?
    current_user.increment!(:votes)
  end
  flash[:notice] = "Thanks for rating"
  redirect_to posts_url
end

Right now, I can vote as many times as I want, which is of course a recipe for disaster. Users can vote multiple times and drive the count way way up.

How do I make it so that the vote submit button go away after submitting it once. I thought of making a separate model for rating and use a custom token, but seems needlessly complicated for a simple app.

Any help?

Senthil

Answer 1

One way of doing this would be to have your Post model and a RatedPost model. The RatedPost model could contain info like incremented:boolean, decremented:boolean, changed_by:integer (user_id), post_id:integer.

You can then identify if RatedPost.find_by_post_id_and_changed_by(post.id, user.id) returns any records.

You can also identify if the points were incremented or decremented. Thus you can allow a user to change his vote for a certain period of time (say 24 hours).