Working Solution

rails3_example/app/controllers/home_controller.rb

@@ -1,5 +1,30 @@
 class HomeController < ApplicationController
+
   def index
+
+  end
+
+  def savesort
+    neworder = JSON.parse(params[:set])
+    prev_item = nil
+    neworder.each do |item|
+      dbitem = Category.find(item['id'])
+      prev_item.nil? ? dbitem.move_to_root : dbitem.move_to_right_of(prev_item)
+      sort_children(item, dbitem) unless item['children'].nil?
+      prev_item = dbitem
+    end
+    Category.rebuild!
+    render :nothing => true
+  end
+
+  def sort_children(element,dbitem)
+    prevchild = nil
+    element['children'].each do |child|
+      childitem = Category.find(child['id'])
+      prevchild.nil? ? childitem.move_to_child_of(dbitem) : childitem.move_to_right_of(prevchild)
+      sort_children(child, childitem) unless child['children'].nil?
+      prevchild = childitem
+    end
   end
 
 end

rails3_example/app/views/home/index.html.erb

@@ -1,3 +1,43 @@
 <% content_for :head do -%>
   <%= javascript_include_tag 'nestedsortables.min' %>
+  <style type="text/css" media="screen">
+    #sortable{width:300px;}
+    ul{margin-bottom:0px;}
+    .highlight{background-color:#d6d88e;}
+  </style>
+  <script type="text/javascript" charset="utf-8">
+    $(function() {
+      $("#sortable").nestedSortable({
+        listType: 'ul',
+        items: 'li',
+        placeholder: "highlight",
+        forcePlaceholderSize: true,
+        handle: 'span',
+        helper: 'clone',
+        opacity: .6,
+        revert: 250,
+        tabSize: 25,
+        tolerance: 'pointer',
+        toleranceElement: '> span'
+      });
+      $("#sortable").disableSelection(); // make links not clickable
+      $('#serialize').click(function (){
+        var c = {set : JSON.stringify($('#sortable').nestedSortable('toHierarchy', {startDepthCount: 0}))};
+        $.post("savesort", c, $('#output').html('<p id="flash_notice">Saved Successfully</p>'));
+        return false;
+      });
+    });
+  </script>
 <% end -%>
+
+<h1>Category Sorting Example</h1>
+<p>Drag and drop the categories into a nested set then hit save</p>
+<h3><a href='#' id='serialize'>Save Sorted Elements</a></h3>
+<ul id='sortable'>
+  <% for cat in Category.roots %>
+    <li id='category_<%= cat.id %>'>
+      <span><%= cat.name %></span>
+      <%= render 'shared/children', :item => cat unless cat.leaf? %>
+    </li>
+  <% end -%>
+</ul>

rails3_example/app/views/shared/_children.html.erb

@@ -0,0 +1,8 @@
+<ul>
+  <% item.children.each do |child| %>
+    <li id='category_<%=child.id %>'>
+      <span><%= child.name %></span>
+      <%= render 'shared/children', :item => child unless child.leaf? %>
+    </li>
+  <% end -%>
+</ul>

rails3_example/public/stylesheets/application.css

@@ -1,3 +1,6 @@
+body {
+  color:#444;
+}
 a img {
   border: none;
 }