Session End in ASP.net MVC

Question

I am placing user data in the session then passing it to viewdata to view on a page. Now when my user walks away from his computer for a while, the session ends and the data he entered is lost.(that is ok) The problem is that when he returns he refreshes the screen my page is still showing but all the data is gone. So,

How can I redirect the user to a login screen when the session expires (so he doesnt see a blank page) or I would like to redirect him to a page that states "You have been logged out due to inactivity".

Thanks

Answer 1

I use some Javascript in my MasterPage to redirect the user (after a prompt to renew the session) to the logout action. It uses an AJAX request back to the Home page of the app to refresh the server side session window when the user clicks the button in the dialog to extend the session. Relies on jQuery and jQuery UI for the dialog.

 <% if (this.Request.IsAuthenticated)
    {
        int sessionDialogWait = 2 * 60 * 1000 - 60 * 500; // ms = 1.5 minutes
        int sessionTimeout = 28 * 60 * 1000; // ms = 28 minutes
        if (ViewData["sessionTimeout"] != null)
        {
            sessionTimeout = ((int)ViewData["sessionTimeout"] * 60 - 120) * 1000;
        }
%>  
<script type="text/javascript">
    var logoutTimer = null;
    var sessionTimer = null;
    var sessionTimeout = Number('<%= sessionTimeout %>');
    var sessionDialogWait = Number('<%= sessionDialogWait %>');

    $(document).ready( function() {
        $('#sessionEndDialog').dialog( {
            autoOpen: false,
            bgiframe: true,
            modal: true,
            buttons: {
                OK: function() {
                    $(this).dialog('close');
                    $.get( '<%= Url.Action( "About", "Home" ) %>', scheduleSessionPrompt, 'html' );
                },
                Logout: logoutOnSessionExpires
            }
        }).ajaxStart( function() { scheduleSessionPrompt(); } );
        scheduleSessionPrompt();
    });

    function scheduleSessionPrompt()
    {
        if (logoutTimer) clearTimeout(logoutTimer);
        if (sessionTimer) clearTimeout(sessionTimer);

        sessionTimer = setTimeout( sessionExpiring, sessionTimeout  );
    }

    function sessionExpiring()
    {
         logoutTimer = setTimeout( logoutOnSessionExpires, sessionDialogWait );
         $('#sessionEndDialog').dialog('open');
    }

    function logoutOnSessionExpires()
    {
        window.location.href = '<%= Url.Action( "Logout", "Account" ) %>';
    }       

    </script>
<% } %>

<div id="sessionEndDialog" title="Session Expiring" style="display: none;">
    <p>Your session is about to expire.  Click OK to renew your session or Logout to logout of the application.</p>
</div>