I've looked into this and it might be related to my javascript configs but not sure what I'm missing here:
Views
<%= button_to("Delete Collection", @collection, :confirm => "Really delete bundle and all its examples?", :method => :delete) %>
javascripts/application.js
//= require jquery
//= require jquery_ujs
//= require_tree .
layouts/application.html.erb
<head>
<title>Portfolio</title>
<%= stylesheet_link_tag "application", :media => "all" %>
<%= javascript_include_tag "application" %>
<%= javascript_include_tag :defaults %>
<%= csrf_meta_tags %>
</head>