C# - ASP.net MVC Keeping Session Alive

 

-- Create an asp.net mvc app; add the following to the home controller:

[HttpPost]
       public JsonResult KeepSessionAlive()
       {

           return new JsonResult { Data = "Postback " + on " + DateTime.Now};
       }

----Add the following to index.cshtml:

<div id="myDiv"></div>
    @section scripts{
<script src="~/SessionUpdater.js"></script>
<script type="text/javascript">
SessionUpdater.Setup('@Url.Action("KeepSessionAlive","Home")');
</script>

} -- reference the following js file [in addition to referencing jquery]

SessionUpdater = (function () {
var clientMovedSinceLastTimeout = false;
var keepSessionAliveUrl = null;
//var timeout = 5 * 1000 * 60; // 5 minutes
var timeout = 15000; // 15 seconds for testing

function setupSessionUpdater(actionUrl) {
       // store local value
       keepSessionAliveUrl = actionUrl;
//    alert(actionUrl);
       // setup handlers
       listenForChanges();
       // start timeout - it'll run after n minutes
       checkToKeepSessionAlive();
}

function listenForChanges() {
       $("body").on("mousemove keydown", function () {
           clientMovedSinceLastTimeout = true;
       });
}


// fires every n minutes - if there's been movement ping server and restart timer
function checkToKeepSessionAlive() {
       setTimeout(function () { keepSessionAlive(); }, timeout);
}

function keepSessionAlive() {
       // if we've had any movement since last run, ping the server


      if (!clientMovedSinceLastTimeout && keepSessionAliveUrl != null) {
           $.ajax({
               type: "POST",
               url: keepSessionAliveUrl,
               success: function (data) {
                   $('#span').text(data);
                   $('#myDiv').append('<br/>' + data);
                   // reset movement flag
                   clientMovedSinceLastTimeout = false;
                   // start listening for changes again
                   listenForChanges();
                   // restart timeout to check again in n minutes
                    checkToKeepSessionAlive();
               },
               error: function (data) {
                   alert("ERROR");
                   console.log("Error posting to " & keepSessionAliveUrl);
               }
           });
      }
      else {
          clientMovedSinceLastTimeout = false;
          listenForChanges();
          checkToKeepSessionAlive();
      }

}

// export setup method
return {
       Setup: setupSessionUpdater
};

    })();