Subj : Re: [spidermonkey] JS_CallFunction in Finalize
To   : netscape.public.mozilla.jseng
From : Brendan Eich
Date : Fri Aug 26 2005 03:19 pm

Brendan Eich wrote:
> Brendan Eich wrote:
> 
>> Consider DOM window objects.  If I write <script> 
>> window.open("foo.com") </script>, I shouldn't leak, but the opened 
>> window should be visually closed when the user clicks on its close [x] 
>> box or whatever widget is used by the desktop/window-manager/OS for 
>> closing windows, and at *that* point, "onunload" or a hypothetical 
>> "onclose" event handler should run -- *not* later when the window 
>> object is finalized by the GC.
> 
> 
> Now consider
> 
> <script>
> var w = window.open("http://foo.com");
> w.close();
> alert(w.fooVar);
> </script>

This example was fake, it pretended that window.open is synchronous. 
Here's a real example:

/tmp/foo.html:
<script>
var w = window.open("file:///tmp/bar.html");
alert(w);
w.onload = function () {
     w.close();
     alert(w.barVar);
};
</script>

/tmp/bar.html:
<script>
var barVar = "hello from bar.html!";
</script>

Once you've disabled the Firefox popup blocker appropriatly for file: 
(or the empty host part, eek!), you should see a new window followed by 
two alerts, the first showing "[object Window]", the second "hello from 
bar.html!".

/be

.