javascript alert on parent page when child popup closes

Question

I am using javascript window.open method to open lets say http://www.google.com [its always going to be some external url]

I have stored the reference of the window object in a variable, the problem is that variable never gets null on the parent page and I am not able to alert the user that the pop up has been closed.

Here's the code

 
        var winFB;
        var winTWt;
        var counterFB = 0;
        var counterTWT = 0;
        var timerFB;
        function openFB() {

            if (counterFB == 0) {
                winFB = window.open("http://www.google.com");
                counterFB = 1;
            }
            if (counterFB > 0) {
                alert(winFB);
                if (winFB == null) {
                    counterFB = 0;
                    clearTimeout(timerFB);
                    alert("Window Closed");
                }
            }
          timerFB= setTimeout("openFB()", 1000);
        }

    

I can not put any javascript code on the pop up/child window.

Hope someone can help me on this

Answer 1

The window variable doesn't get nulled out when it's closed, however its .closed property is true, so just change your check to be for that property, like this:

var winFB;
var winTWt;
var counterFB = 0;
var counterTWT = 0;
var timerFB;
function openFB() {
    if (counterFB == 0) {
        winFB = window.open("http://www.google.com");
        counterFB = 1;
    }
    if (counterFB > 0) {
        if (winFB.closed) {
            counterFB = 0;
            clearTimeout(timerFB);
            alert("Window Closed");
        }
    }
    timerFB = setTimeout(openFB, 1000);
}

Also note the setTimeout() change, pass a function in whenever possible (almost always) rather than a string, you'll have a lot less problems with scoping.

Answer 2

//in the parent
winFB = window.open("http://www.google.com");

//in the child window you can access
var _parent = window.opener.document;

//also use the onunload event in the child window
onunload="doSomething()"

hope this gives you some direction..