Why is location.href not executed immediately?

gnubie · May 24, 2003

I have a

Code:

top.location.href

statement followed by an

Code:

alert

. The

Code:

alert

should never be executed because the

Code:

top.location.href

statement should update the all the frames, so the alert should not be seen. Right? After I click OK on the alert, the frames ARE all updated. (I only tried this on IE 6).

Code:

html>
<head>
  <title>top.location.href test</title>
</head>
<body>
<script type=&quot;text/javascript&quot;>
top.location.href=&quot;[URL unfurl="true"]http://www.collectiblesbycarole.com/&quot;;[/URL]
// Why isn't the location.href statement above executed immediately?
// The alert below should not be executed, but is.
alert(&quot;Why is this executed?&quot;);
</script>
</body>
</html>

xutopia · May 24, 2003

I'm stumped!! It shouldn't do that. Normally after it changes url the javascript engine should be turned off.

Gary

http://www.xutopia.com

Haran
==========================

gnubie · May 25, 2003

Additional info:

Same behavior on Netscape 7.02.

I too, am embaffleated.

G.

jemminger · May 25, 2003

Moz does the same thing...i'm stumpified.

=========================================================
try { succeed(); } catch(E) { tryAgain(); }
-jeff

http://www.jeffemminger.com

gnubie · May 26, 2003

Well, I still don't know why the behavior occurs, but I do know how to workaround the problem: terminate the JavaScript segment and begin a new one. The new example below works as desired.

Code:

<html>
<head>
  <title>top.location.href test</title>
</head>
<body>

<script type=&quot;text/javascript&quot;>
top.location.href=&quot;[URL unfurl="true"]http://www.collectiblesbycarole.com/&quot;;[/URL]
</script>

<script type=&quot;text/javascript&quot;>
alert(&quot;No longer executed?&quot;);
</script>

</body>
</html>

keteracel · May 26, 2003

The reason why it works in the second example is due to the fact that modern browsers use a Document Object Model (DOM) type internal structure. They can only process a certain html tag when they have received all the data for it -- i.e when it has received all the markup up to and including the close tag. If an entire page is nested within an element, say a

Code:

<div>

for arguements sake, then the whole page will only display when the entire markup has been received.

So, in the second example the top.location.href = www.keteracel.com will be processed on it's own.

As for the first example, the javascript processor does not stop when the top.location.href line is reached. It sends the request to the browser (and the browser to the operating system) and then continues. I guess that it is all just a matter of timing -- if you look at the status bar in internet explorer you can see that the page has started loading but has been suspended by the alert, suggesting that the browser has simply not had enough time to complete the request before the alert has popped up.

Hope you find this useful,

keteracel

[sub]( keywords: DOM document object model top.location.href location.href alert javascript keteracel browser )

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Why is location.href not executed immediately?

gnubie

Programmer

xutopia

Programmer

gnubie

Programmer

jemminger

Programmer

gnubie

Programmer

keteracel

Programmer

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