On 6/6/12 7:47 PM, Ian Hickson wrote:
On Fri, 27 Jan 2012, Boris Zbarsky wrote:
On 1/27/12 1:30 AM, Ian Hickson wrote:
On Wed, 5 Oct 2011, Henri Sivonen wrote:
On Tue, Oct 4, 2011 at 9:54 PM, Boris Zbarsky<bzbar...@mit.edu> wrote:
What Firefox does do is block execution of<script> tags (but not
timeouts, callbacks, etc!) if there are pending non-altenate
parser-inserted stylesheet loads. This is necessary to make sure
that scripts getting layout properties see the effect of those
stylesheets. A side-effect is that a<script> coming after a<link>
will never see the link in an unloaded state... unless there's a
network error for the<link> or whatever.
One exception: If an inline script comes from document.write(), it
doesn't block on pending sheets. It runs right away. If it blocked
on pending sheets, the point at which document.write() returns would
depend on network performance, which I think would be worse than
having document.written inline scripts that poke at styles fail
depending on network performance.
Note that this is not conforming. The spec does not currently define
any such behaviour.
Which part is not conforming? The exception for alternate sheets, the
inline script inside document.write thing, or something else?
Unless I'm mistaken, nothing in the HTML spec does anything differently
based on whether a script comes from document.write() or not. The
information about whether a character in the tokeniser came from the
network, document.write() during a network parse, or document.write() on a
completely script-written document, is not stored along with the character
in the tokeniser's input stream.
Oh, I see. The problem with that is situations like this script:
var x = 0;
document.write("<link rel=stylesheet href=something>" +
"<script>x = 1;</" + "script>");
alert(x);
This interoperably alerts "1" in Trident, Gecko, Presto, and WebKit.
That means that either the write() call can't return until the sheet is
done loading or the script from write() needs to be able to run before
the sheet is done loading.
A bit of further experimentation indicates that in all of the above
browsers its the latter: the script that sets x=1 runs before the <link>
is loaded.
If the spec says something different, the spec probably needs to change
to match implementations here...
-Boris
