javascript - using onbeforeunload event, url change on selecting stay on this page

Question

Rewriting the question -

I am trying to make a page on which if user leave the page (either to other link/website or closing window/tab) I want to show the onbeforeunload handeler saying we have a great offer for you? and if user choose to leave the page it should do the normal propogation but if he choose to stay on the page I need him to redirect it to offer page redirection is important, no compromise. For testing lets redirect to google.com

I made a program as follows -

var stayonthis = true;
  var a;
  function load() {
   window.onbeforeunload = function(e) {
        if(stayonthis){
         a = setTimeout('window.location.href="http://google.com";',100);
         stayonthis = false;    
         return "Do you really want to leave now?";
        }
        else {
            clearTimeout(a);
        }

    };
    window.onunload = function(e) {
         clearTimeout(a);
    };
  }
  window.onload = load;

but the problem is that if he click on the link to yahoo.com and choose to leave the page he is not going to yahoo but to google instead :(

Help Me !! Thanks in Advance

here is the fiddle code

here how you can test because onbeforeunload does not work on iframe well

Answer 1

This solution works in all cases, using back browser button, setting new url in address bar or use links. What i have found is that triggering onbeforeunload handler doesn't show the dialog attached to onbeforeunload handler. In this case (when triggering is needed), use a confirm box to show the user message. This workaround is tested in chrome/firefox and IE (7 to 10)

http://jsfiddle.net/W3vUB/4/show

http://jsfiddle.net/W3vUB/4/

EDIT: set DEMO on codepen, apparently jsFiddle doesn't like this snippet(?!) BTW, using bing.com due to google not allowing no more content being displayed inside iframe.

http://codepen.io/anon/pen/dYKKbZ

var a, b = false,
    c = "http://bing.com";

function triggerEvent(el, type) {
    if ((el[type] || false) && typeof el[type] == 'function') {
        el[type](el);
    }
}

$(function () {
    $('a:not([href^=#])').on('click', function (e) {
        e.preventDefault();
        if (confirm("Do you really want to leave now?")) c = this.href;


        triggerEvent(window, 'onbeforeunload');

    });
});

window.onbeforeunload = function (e) {
    if (b) return;
    a = setTimeout(function () {
        b = true;
        window.location.href = c;
        c = "http://bing.com";
        console.log(c);
    }, 500);
    return "Do you really want to leave now?";
}
window.onunload = function () {
    clearTimeout(a);
}