I have a UsersController and RegistrationsController to handle user signups with Devise in rails.
I am adding code for affiliate sign ups, in order to map users to affiliates using a custom HTTP GET parameter called "a".
So for example, I want my sign up to respond like this: www.app.com/users/sign_up?a=affiliate_code
However, Rails doesn't respond to params[:a] in the controller. In my routing file, all I have is resources :users
What is the easiest and most rails way to implement this?