Javascript snippet freezes Firefox3.6

Question

This code is freezing Firefox 3.6.

 // Google Code for Converted Users Remarketing List
    function converted_remarketing() {
        window.google_conversion_id = 1018522404;
        window.google_conversion_language = 'en';
        window.google_conversion_format = '3';
        window.google_conversion_color = '666666';
        window.google_conversion_label = 'e9x2CKzhXXXXpNbV5QM';
        window.google_conversion_value = 0;
        var a = document.createElement('script');
        a.type = 'text/javascript';
        a.async = true;
        a.src = 'https://www.googleadservices.com/pagead/conversion.js';
        var b = document.getElementsByTagName('script')[0];
        b.parentNode.insertBefore(a, b);
    }

converted_remarketing();

Example page: http://jsfiddle.net/LLSu4/11/show/

Looks like it has something to do with the script insertion. The funny thing is that I copied the insertion snippet from Google Analytics code that works flawlessly.

So the question is, why is it freezing Firefox 3.6 and why it doesn't freeze Firefox3.6 when a very similar code is ran to load Google Analytics script ga.js?

What parameter are you supposed to be passing into the method? — My Head Hurts, Dec 08 '11 at 00:42
@MyHeadHurts It doesn;t matter. I removed it to make it easier. Still freezes. — Eduardo, Dec 08 '11 at 01:13
@ThiefMaster: For example, some people use Ubuntu 10.04 LTS or other [distributions with non-rolling releases](http://en.wikipedia.org/wiki/Rolling_release#Counter-examples:_non-rolling_releases). — user123444555621, Dec 10 '11 at 11:59

score 4 · Accepted Answer · answered Dec 10 '11 at 11:43

4

This is apparently related to a document.write() in conversion.js.

See http://jsfiddle.net/LLSu4/19/

ga.js does not use document.write, hence no problem there.

Using document.write in an inserted script is never a good idea. This will confuse the HTML engine. You'll find that bugzilla has several bugs concerning appendChild and document.write, e.g. https://bugzilla.mozilla.org/show_bug.cgi?id=607222

answered Dec 10 '11 at 11:43

user123444555621

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So a possible solution would be to overwrite document.write with something else, like you did in that fiddle? – Eduardo Dec 11 '11 at 02:06
Yes. That img is typical tracking pixel, so you might as well insert it using DOM methods without losing functionality. However, a general solution is pretty tricky. You'd either have to parse markup in JS or use the browser's parser via documentFragment or a hidden iFrame or such. The latter is not guaranteed to work: A colleague of mine had issues with IE and Flash content. – user123444555621 Dec 11 '11 at 08:00

Javascript snippet freezes Firefox3.6

1 Answers1