jquery - How to keep alive a user's session while they are posting on a forum? -

i have site session timeout of 15 minutes. on pages user spends longer 15 minutes filling in reply. best solution keep alive session in case?

i use jquery on these pages, possibly pinging server, on events?

the backend struts on tomcat.

given don't want change site's session timeout..

set timeout/interval (< 15min) event in javascript , decide when event triggers. if want session active long page open, fine, keep pinging every < 15 min. that's not want user leaving public computer should logged out @ point.

you maintain variable lastactivity, updated on each document mousemove or document keydown. if there's been activity since last ping, ping again.

to more sophisticated, count events , ping server if number of events > threshold @ timeout.

the basic example:

setinterval(function(){    $.get('/imstillalive.action'); }, 840000); // 14 mins * 60 * 1000 

with basic check typing activity:

$(function(){     var lastupdate = 0;     var checkinterval = setinterval(function(){        if(new date().gettime() - lastupdate > 840000){            clearinterval(checkinterval);        }else{                $.get('/imstillalive.action');        }     }, 840000); // 14 mins * 60 * 1000      $(document).keydown(function(){          lastupdate = new date().gettime();     }); });