javascript - How to know browser idle time?

Question

How can I track the browser idle time? I am using IE8.

I am not using any session management and don't want to handle it on server side.

Answer 1

Here is pure JavaScript way to track the idle time and when it reach certain limit do some action:

var IDLE_TIMEOUT = 60; //seconds
var _idleSecondsTimer = null;
var _idleSecondsCounter = 0;

document.onclick = function() {
    _idleSecondsCounter = 0;
};

document.onmousemove = function() {
    _idleSecondsCounter = 0;
};

document.onkeypress = function() {
    _idleSecondsCounter = 0;
};

_idleSecondsTimer = window.setInterval(CheckIdleTime, 1000);

function CheckIdleTime() {
     _idleSecondsCounter++;
     var oPanel = document.getElementById("SecondsUntilExpire");
     if (oPanel)
         oPanel.innerHTML = (IDLE_TIMEOUT - _idleSecondsCounter) + "";
    if (_idleSecondsCounter >= IDLE_TIMEOUT) {
        window.clearInterval(_idleSecondsTimer);
        alert("Time expired!");
        document.location.href = "logout.html";
    }
}

#SecondsUntilExpire { background-color: yellow; }

You will be auto logged out in <span id="SecondsUntilExpire"></span> seconds.