RespondsToParent ================ Adds responds_to_parent to your controller to respond to the parent document of your page. Make Ajaxy file uploads by posting the form to a hidden iframe, and respond with RJS to the parent window. Example ======= Controller: class Test < ActionController::Base def main end def form_action # Do stuff with params[:uploaded_file] responds_to_parent do render :update do |page| page << "alert($('stuff').innerHTML)" end end end end main.rhtml: