2 Replies Latest reply on Sep 20, 2012 3:55 AM by P Alcove

    Datatable empty after function call with redirect?

    P Alcove Newbie



      I´m using a datatable on "example.jsf" with commandlinks in each column:


           <h:commandLink id="bla" action="#{formBean.selectCombination()}">
                <h:graphicImage value="resources/icons/log.png" />


      When clicking the button in my bean-function selectCombination() I do a redirect:





      Everything fine so far but when I use my browsers "back" button or manually go back to example.jsf my datatable is empty.


      In debugger the getter method for my datatable content is called, and the content is there but it is not rendered.


      My bean is session scoped.




      Thanks for any help

        • 1. Re: Datatable empty after function call with redirect?
          Brendan Healey Master

          Is the browser caching the page? try running with a decent browser such as chrome or firefox and see if the page is being served

          from the cache, using the developer tools network tab or firebug.


          The response headers in a .jsf page need to be set so that the page isn't cached which you'd do in a servlet filter:



          response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate"); // HTTP 1.1.

          response.setHeader("Pragma", "no-cache"); // HTTP 1.0.

          response.setDateHeader("Expires", 0); // Already expired


          sharp eyed readers will spot BalusCs original comments! you'd also typically setup response headers to ensure that you do

          cache your static resources such as css and images.


          This is one of those things with JSF that aren't all that immediately obvious and can take a lot of time to get right. I probably spent

          3-4 weeks getting a cache filter exactly right.








          p.s. the other thing I was going to ask is which jsf version are you using? with JSF 2 the action method can just


          return "combinationSelected.jsf?faces-redirect=true"; - this will do a post-redirect-get and the URL will show the

          correct value rather than lagging a step behind.




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          • 2. Re: Datatable empty after function call with redirect?
            P Alcove Newbie

            Hy Brendan,


            thx for your suggestions. I looked into the cache thing but even when I manually emptied the cache before going back to "example.jsf"

            the problem remained.


            Here is how I solved it (maybe someone can explain to me why this is working and how ... would be great!)

            Instead of creating a request by using commandlink I used:


            <a4j:ajax event="click" listener="#{formBean.selectCombination}" />


            So when using ajax instead of a request when I go back now me datatable still has all the content.

            Remember my bean is session scope... so I thought it would not make any difference if I use ajax or request in my special case.

            What do I miss here?