How Can I Keep My ASP.NET Session Alive Using Unobtrusive AJAX?

Prolonging ASP.NET Sessions with Subtle AJAX Calls

Extended browser sessions often lead to server-side session timeouts. This article presents a non-intrusive method using timed AJAX requests to a dummy handler to address this issue, ensuring continuous session activity.

AJAX Implementation Details

The following jQuery code initiates a recurring AJAX call to SessionHeartbeat.ashx every five minutes. This simple ping refreshes the session's timeout counter.

<code class="language-javascript">function setHeartbeat() {
    setTimeout("heartbeat()", 5*60*1000); // 5-minute interval
}

function heartbeat() {
    $.get("/SessionHeartbeat.ashx", function(data) {
        // Session refresh confirmation
        setHeartbeat();
    }, "json");
}</code>

Session Handler: SessionHeartbeat.ashx

This HTTP handler manages session lifespan. Implementing IRequiresSessionState guarantees Session object access.

<code class="language-csharp">public class SessionHeartbeatHttpHandler : IHttpHandler, IRequiresSessionState
{
    public void ProcessRequest(HttpContext context)
    {
        context.Session["Heartbeat"] = DateTime.Now;
    }
}</code>

Web.config Configuration

The handler is registered in web.config:

<code class="language-xml"><httphandlers>
  <add path="SessionHeartbeat.ashx" type="SessionHeartbeatHttpHandler" validate="false" verb="GET,HEAD" />
</httphandlers></code>

Enhancing User Experience with Visual Feedback

A simple heartbeat animation provides visual confirmation of session maintenance. The following CSS and JavaScript create this effect.

<code class="language-javascript">function beatHeart(times) {
    var interval = setInterval(function () {
        $(".heartbeat").fadeIn(500).fadeOut(500);
    }, 1000); // 1-second beat

    setTimeout(function () { clearInterval(interval); }, (1000 * times) + 100);
}</code>

<code class="language-css">.heartbeat {
    position: absolute;
    display: none;
    margin: 5px;
    color: red;
    right: 0;
    top: 0;
}</code>

This solution effectively extends ASP.NET sessions for the duration of the browser window, maintaining form and application functionality.

The above is the detailed content of How Can I Keep My ASP.NET Session Alive Using Unobtrusive AJAX?. For more information, please follow other related articles on the PHP Chinese website!