Hi John and jQuery team,

Please read at least first and last paragraphs: the effect of this bug
is a permanent page reload and strain on webservers:

The effect of this error can be disastrous to web servers, as it can
reload the page permanently, so as I spent a few hours on this issue,
and want to document/share the solution, and report the issue to
jQuery team too:


Sporadically I had in firefox 3.5.4 the error "document.body is null"


This was exactly reported in IE too here:
http://groups.google.com/group/jquery-en/browse_thread/thread/70e8a050f60f8b08

(that thread being closed, i am opening a new one here)


Interestingly turning cache off with webdeveloper plugin, the error
came systematically, and *worse*, did systematically reload the page
automatically, cycling the like F5 button pressed permanently, putting
load on server. But that also allowed to use firebug to debug.

- When not having any javascript inline code in head, the error went
away. So this worked fine (no page reloads):

        <script type="text/javascript" src="http://www.example.com/
jquery-1.3.1/jquery-1.3.1.js"></script><script type="text/
javascript"><!--
jQuery.noConflict();
--></script>

- But with just having this it was already permanently reloading the
page with cache off and also throwing error "document.body is null" :

        <script type="text/javascript" src="http://www.example.com/
jquery-1.3.1/jquery-1.3.1.js"></script><script type="text/
javascript"><!--
jQuery.noConflict();
--></script>
        <script type="text/javascript"><!--
jQuery(document).ready(function($){
/*
*/
});
--></script>


No other javascript in the page, only CSS files and valid transitional
HTML !


Finally, I saw that in the site template, some CSS files where loaded
after that javascript code, and being jQuery 1.3, it's better to load
them before....


So i have put all CSS files <link> before the javascript code above,
and the error disappeared completely.


As this is a recommendation for jQuery 1.3, well, you could classify
this as a ... template-designer-error, but still:


IMPORTANT CONCLUSION:

*However* : if a site template (e.g. in joomla, where the template
used by the site is not under the control of the extension developer
using jQuery) puts some CSS files after the Javascript headers, then
the issue that *it triggers permanent fast page reloads* is a big
issue for webserver sanity, and imho something should be done in
jQuery to check at least check for the condition "document.body ===
null" before deciding that the document is ready.

So that should be fixed in jQuery imho, not just trusting the dom
ready event, which seems to be fired too on CSS file loads, but to
check that there is really a document.body there before trusting the
event and starting touching the body even before it exists.

Best Regards,
Beat

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