UIX Controller - using the browser back button

Question

I'd like to understand more about the controller and what is going on behind the scenes when I hit the back button. It would appear that some form of page caching is taking place and I want to know if I can effectively get a refreshed version of a page (although in some cases it might be just some elements of a page). My application scenario is this:-
Having done a search, I select a row from a results table and add it to a short list (similar to shopping cart) which is then displayed. My search results page i.e. the previous page has a link to the shortlist with its text attribute databound to a string generated when items are added to the shortlist '3 items shortlisted'. When I hit the back button I get the state of the page before I added my item to the shortlist so the description is wrong. Hitting the browser refresh button displays the correct link text. Anyway I can force this behaviour? Is this what I should be trying to do or is there some best practice technique that I can use? There are several instances where I want to do this sort of thing.
Hope that makes sense
Thanks
Ian

Answer 1

Hi,
In the Struts Framework, I have found code in the controller servlet, like this:
* Render the HTTP headers to defeat browser caching if requested.
* @param response The servlet response we are creating
* @exception IOException if an input/output error occurs
* @exception ServletException if a servlet exception occurs
protected void processNoCache(HttpServletResponse response)
          throws IOException, ServletException
          if (!nocache)
          return;
          response.setHeader("Pragma", "No-cache");
          response.setHeader("Cache-Control", "no-cache");
          response.setDateHeader("Expires", 1);
nocache is a boolean that gets initialized from a parameter specified in the web.xml!
multiple header fields for all different web browsers.
(how to set these header fields in JSP, over to someone else)
I can not remember if, when the user uses the Back button to return to a page with these header fields, he gets a 'Page Expires' message, or if the browser will automagically refresh the page.
(It might even be so that for example IE5 will refresh, and that IE6 will give the message)
Luc