PPR and the Back Button

Question

Hi all,
I posted recently about a workaround Oracle showed me for helping manage back button problems more efficiently, but now I'm having a separate back button problem.
Changes that were made to a page via PPR disappear after coming back to the page by clicking the browser back button--for example, if I added a row to an <af:table> using PPR, navigate off the page, and click the back button, the row will disappear again--although it will reappear as soon as any event re-refreshes the table. I've tried turning off browser chaching, and it makes no difference, which makes me suspect this is not a browser caching issue.
Does anyone know if there's a way to make sure a component is always refreshed when the page is loaded, even if it was loaded via the browser back button?
Thanks much,
Avrom

Answer 1

Hi Frank,
Great idea, thanks! I haven't tried it out in all my cases, but it looks like it's going to work!
For the use of others, here's what you do:
1) Make sure your model layer is capable of supporting the back button here, of course.
2) Create a method, String refresh(), in a backing bean. This method can be a no-op (just return null) if you don't need to do any work to re-set the page. But if, for example, you calculated values referred to in the page, you should re-calculate them here. If you had code that calculated them when the page was originally loaded (*not* for PPR), you can take that out, because this will always get called on a new load/back button load/reload.
3) Add a CommandLink like this one to your page (needs to be in a form, but otherwise it doesn't really matter where):
<af:commandLink id="refresh" partialSubmit="true"
  action="#{yourBean.refresh}"/>4) Add a call to a javascript function like the following in your <afh:body>'s "onload" tag:
function refreshPage() {
    var refreshComp;
    if (document.getElementById)
        refreshComp = document.getElementById("refresh");
    else if (document.all)
        refreshComp = document.all["refresh"];
    else if (document.layers)
        refreshComp = document.layers["refresh"];
    if (refreshComp) {
      refreshComp.click();
}(All of that rigmarole is to support different browsers, which have different ways of retrieving a DOM element by its id.)
5) For each component you need refreshed on a back button, set (or add) "refresh" to its partialTriggers property.
6) Sit back and watch the Back button work.