Guardian protects web forms from spam. By adding a hidden input field that counts up, guardian will reject submissions with a duration less than any threshold we deem appropriate (defualt is 2 seconds).

$ gem install guardian-forms

$ git clone http://github.com/forrestgrant/guardian
$ cd guardian
$ rake build
$ rake install

gem 'guardian-forms', require: 'guardian'

Set a before filter in your controller

before_filter :guard

Or

before_filter { |c| c.guard({:threshold => 5})} # 5 seconds

Add guardian to application.js

//= require jquery.guardian

Set Guard specific forms in views

$('form').guard();