render-async
render_async lets you include pages asynchronously with AJAX
...It works with Rails and its tools out of the box. A quick overview of how render_async does its magic. User visits a page, render_async makes an AJAX request on the controller action, controller renders a partial, partial renders in the place where you put render_async view helper. JavaScript is injected straight into <%= content_for :render_async %> so you choose where to put it. Advanced usage includes information on different options. render_async renders an element that gets replaced with the content of your request response. ...