I'm leaving for Rails 5 and I can not find a replacement for link_to_remote
that has been discontinued.
In my old code, I have a "Cadastro" link, which when clicked, makes a request to the "register" action and renders the return in the above form "div".
Here are the basics of my view:
<%= javascript_include_tag :defaults %>
<div id="form">
</div>
<%= link_to_remote "Cadastro", :update => "form",
:url => { :action => "register" } %>