Manual and/or guide should have an AJAX example

After looking at the manual and guide it is not clear whether Play! has any actual support for AJAX (aside from building the requests manually or using jQuery). The template docs mention #{jsAction} but without a clear understanding of what the JavaScript functions actually do (do they support JSON, POST, PUT, what does the server-side action look like? should it return a value for GET or still call render()?).

There has to be a section in the docs about AJAX and how Play! helps us by avoiding to write our own requests in XmlHttpRequest or jQuery, via #{jsAction} possibly (if indeed it does the wrapping).