On Sep 27, 2009, at 12:37 PM, Boris Zbarsky wrote:
On 9/27/09 2:28 AM, Maciej Stachowiak wrote:
This is not an issue for DOM methods. It's an issue for interfaces
such
as HTMLCollection and HTMLFormElement that support indexing by
function
call syntax, for legacy compatibility reasons.
Huh. Gecko hasn't supported this, and we haven't had problems with
it. Is it really for legacy compat reasons, of just because more
than one vendor happens to support it without really knowing why,
like tags() on HTMLCollection? Did Webkit and Opera have particular
compat issues without implementing this stuff?
For what it's worth, I just tested and it looks like Opera and
Webkit support () on HTMLCollection; the former doesn't support it
on the return value of getElementsByTagName while the latter does.
Gecko does not support either. The spec also has the () thing going
on for HTMLFormControlsCollection; again we've never had any serious
compat problems with this in Gecko.
As for HTMLFormElement, while the spec says what it says, it's not
exactly for "compatibility reasons" other than "IE must be willing
to implement this spec and nothing outside this spec", I assume.
Both Opera and Webkit throw in this testcase:
<!DOCTYPE html>
<body>
<form name="foo">
<input name="bar">
<script>try {
alert(document.foo("bar"));
} catch(e) { alert(e); }
</script>
whereas they should return the input, per spec.
I hadn't realizes the spec required this syntax, and I would be
somewhat interested in understanding why it does and whether it's
actually required "for compatibility reasons" (in the sense that a
new UA on the market would have to implement it to be compatible
with existing sites).
I wouldn't be against dropping things that we really think are
useless. Keep in mind though, there is still old content (yes, often
on Intranets, but sometimes publicly accessible) that just assumes IE,
but more or less works if you implement enough IE-isms. That's the
rationale behind undetectable document.all. Callable collections are
based on the same kind of reasoning. Historically, Opera and Safari
(and Konqueror/KHTML before us) have been somewhat more willing to
implement weird IE-isms than Mozilla.
Regards,
Maciej
