W3C home > Mailing lists > Public > whatwg@whatwg.org > July 2009

[whatwg] scripts, defer, document.write and DOMContentLoaded

From: Ian Hickson <ian@hixie.ch>
Date: Tue, 21 Jul 2009 06:01:21 +0000 (UTC)
Message-ID: <Pine.LNX.4.62.0907210557240.12284@hixie.dreamhostps.com>
On Mon, 20 Jul 2009, Boris Zbarsky wrote:
> Ian Hickson wrote:
> > Actually what's going on is more subtle than that. When you set 
> > innerHTML, it's actually triggering the deferred scripts right there, 
> > if it has them loaded (e.g. inline scripts or cached scripts). If it 
> > doesn't have them loaded yet, it drops them on the floor and doesn't 
> > ever run them.
> > 
> > I've specced this, except that the spec requires that not-yet-loaded 
> > scripts be loaded then run, rather than dropped, before innerHTML 
> > continues, so there's no race conditions.
> 
> Er... wait.  So innerHTML has to block on network access?  And possibly 
> spin the event loop as it does so?
> 
> This doesn't seem desirable to me.... Why do we want this behavior?

Jonas describes why what the spec said before was a compatibility problem 
in his e-mail:

   http://lists.whatwg.org/htdig.cgi/whatwg-whatwg.org/2009-July/020843.html

He cites the following bugs:

   https://bugzilla.mozilla.org/show_bug.cgi?id=28293
   https://bugzilla.mozilla.org/show_bug.cgi?id=461555
   https://bugzilla.mozilla.org/show_bug.cgi?id=461724
   https://bugzilla.mozilla.org/show_bug.cgi?id=469751
   https://bugzilla.mozilla.org/show_bug.cgi?id=474392

The change I have checked in makes us more compatible with what IE 
actually does here, which pages are apparently relying on. We could also 
make the spec introduce a whole new kind of behaviour, such as the one 
Jonas described, but that seems just as likely to have compatibility 
problems as what the spec said before, and also has some weird 
side-effects, like making it possible for the parser to go through the EOF 
point more than once, or having odd behaviour around document.close().

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'
Received on Monday, 20 July 2009 23:01:21 UTC

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