Comments on: Keep session alive with Javascript

By: A. C. Grace

A. C. Grace — Thu, 28 Apr 2011 16:16:02 +0000

Thank you Michal, This is a very unique solution to a nagging problem we have – long form timing out. Thank you for the code and the instructions. I’m going to get my techs right on this and start testing conversions, this should greatly improve them. Thanks again!

By: Neil

Neil — Fri, 12 Nov 2010 17:20:44 +0000

You need to be sure that accessing the image does in fact register as a request with the session provider (and not just serving as a dumb image through Apache or IIS or whatever), by doing something like Mato says to get the PHP/.net/whatever involved – otherwise you’ll be fetching images on a timer up until your session dies, with no ‘keepalive’ effect.

By: Balaji

Balaji — Thu, 30 Sep 2010 04:09:22 +0000

Hi,
I have tried this script in my web application, which is running on Websphere server. when i test the upload functionality, whcih is taking more than 60mins, session time out is still happening though i have followed the keepmealive script.
Kindly help me out.

By: Daniel

Daniel — Thu, 08 Jul 2010 14:40:33 +0000

Great little snippet just what I was looking for

By: Mato

Mato — Tue, 01 Dec 2009 10:33:45 +0000

Here’s a piece of PHP code, that I use to generate 1x1px jpeg image. You can use it with this Michal’s JS to keep sessions alive in PHP environment.

$img = imagecreate( 1, 1 );
header( “Content-type: image/jpeg” );
imagejpeg($img);
imagedestroy($img);

By: Davin Studer

Davin Studer — Wed, 21 Oct 2009 15:08:15 +0000

@Jee Withmosty platforms you cannot just access an image to reset the session. You need to access a page that will cause the server side scripting engine to reset the service. So, you need to access a JSP file. A way you could do it would be to swap the src of an image element with a JSP file that has a date/time stamp query string (to prevent caching). That JSP file would binary read an image file and write it back to the browser with an image content type header. If you are accessing the server side scripting engine that should reset your session.

By: Jee

Jee — Wed, 21 Oct 2009 11:59:33 +0000

How does this work with JSP/J2EE type application?
In my case i need to set the session alive after every 20mins(it is default session out), I tried to use the above mentioned logic and end up with fail.

I have the same scenario like user enters data into the form and take rest for a while(may be more than 20min), and when come back and enter more data try to save the doc, it shows the error saying timeout/some session out issue.

How to make it work without form submit(i.e., without reload) to server.

Thanks,
-Jee

By: troy

troy — Thu, 20 Aug 2009 09:11:44 +0000

Hi, I have used your code it works in IE 8 ie : reload the image every time

it works in local , in IE 8 and Mozilla , but not working in IE 7 .. and also

if the project is moved to IIS – wwwroot Directory , you code has not work .. ???

By: Davin Studer

Davin Studer — Mon, 03 Aug 2009 16:45:51 +0000

Session state is a function of the server side scripting engine, not the web server. So, requesting just an image file will not work. The request has to be passed to the server side scripting engine (i.e. ASP, PHP, ASP.Net, Python, etc.).

By: cocowool

cocowool — Sat, 01 Aug 2009 15:36:17 +0000

i also failed with PHP on apache, i tried a .php file and it works
so i think request a static img file won’t work, is that true?