Since upgrading my site to Rails 4, the client-side-validations gem has stopped working for me. I have had a look at the various alternatives such as jquery-validation-rails
I was able to use a fork of the original client_side_vlaidations that is very active at the moment. I am using the latest version of simple_form, rails 4.1.8, and this client_side_validations. Simple setup with basic config.