How can I call an action, pass a value to the action from js and re-render the js on a page in rails 3?

I have a page poweroutput.html.erb whose controller action is as follows:

def poweroutput

   # other stuff here...

   if (request.xhr?)
     @date = :date
     respond_to do |format|
        format.html
     end
   else
      @date = Time.now.getlocal.strftime("%d.%m.%Y")
   end

end

The else clause is executing fine on loading the page. I am expecting the if clause to execute on change of a text field element in my poweroutput.html.erb which is as follows:

<%= text_field_tag(
          'dt', nil,
          {  :id => 'date-field',
             :class => 'dateformat-d-dt-m-dt-Y',
             :value => Time.now.getlocal.strftime("%d.%m.%Y"), 
             :onchange => remote_function(
                 :url => {:controller => 'pages', :action => 'poweroutput'}, :with => "'date=' + $('date-field').value"),

          })
%>

So what I'd like to happen onchange of the text field is: (1) controller action, poweroutput, to be called, (2) for the contents of this text field be assigned to @date instance variable in the controller action and (3) for the javascript (located within script tags in poweroutput.html.erb) to be re-rendered (is re-rendered even the right word?). I'm not even su开发者_如何转开发re I'm on the right path here. Please tell me if there is a better way to do this. The nonfunctional code you see above is just the product of two days of google searching. Any help would be greatly appreciated.

As I noticed in your remote_function you don't specify the element to replace with the answer.

More info is here http://apidock.com/rails/ActionView/Helpers/PrototypeHelper/remote_function