Javascript How to call a function when we choose Stay on Page in Chrome

Question

Please check my code in Chrome Browser, if you hit refresh you will be prompted with 2 options.

1. Leave This Page and
2. Stay on This Page

Answer 1

You can use a combination of the onbeforeunload and onunload events, setting a timer in the former and clearing it in the latter:

var showMsgTimer;

window.onbeforeunload = function(evt) {
    var message = 'Please Stay on this page and we will show you a secret text.';
    showMsgTimer = window.setTimeout(showMessage, 500);

    evt = evt || window.evt;
    evt.returnValue = message;

    return message;
}

window.onunload = function () {
    clearTimeout(showMsgTimer);
}

function showMessage() {
    alert("You've been trolled!");
}

This works because the onunload event never fires when the user chooses to stay on the page.