Rails - Jul 2006 - respond_to and redirect_to

Hi,

I have two controller actions like:

def foo
   do_something
   respond_to :html, :js
end

def bar
   do_something_else
   redirect_to :action => "foo"
end

How can I get foo to return JS, when bar is called via AJAX? What I''d  
like to get is:

bar is called via AJAX
do_something_else is executed
do_something is executed
foo.rjs is rendered


The ideal solution should also work when foo and bar are in different  
controllers.

Thanks for your help,

Timo