- From: Maciej Stachowiak <mjs@apple.com>
- Date: Thu, 08 Oct 2009 11:39:02 -0700
- To: Brendan Eich <brendan@mozilla.org>
- Cc: Anne van Kesteren <annevk@opera.com>, Cameron McCormack <cam@mcc.id.au>, public-script-coord@w3.org
On Oct 8, 2009, at 11:26 AM, Brendan Eich wrote:
> On Oct 8, 2009, at 10:43 AM, Maciej Stachowiak wrote:
>
>> At first glance, I'm not keen on the idea of making DOM API
>> behavior depend on ES5 strict mode. Strict and non-strict code can
>> mix freely, so to do the mode switching you have to know what kind
>> of code is calling you - that seems yucky to implement and goes
>> beyond the intent of strict mode that nearly all of its effects can
>> happen at compile time.
>
> For our "detecting context" that makes document.all not appear to be
> present when tested by if, ?:, &&, etc., as opposed to your always-
> present but falsy object, compile-time is the right time. Just
> noting this difference.
When testing in Firefox 3.5, I also noticed that document.all returns
undefined in a variable assignment or an object initializer, e.g.
var x = document.all;
var y = {all: document.all};
document.write(document.all);
document.write(x);
document.write(y.all);
You get one all collection and two undefineds.
>
>
>> Also, affecting DOM APIs seems like major scope creep for strict
>> mode. Right now, WebKit's DOM APIs have no idea what kind of code
>> is calling them and I don't relish adding that functionality.
>
> Ok, good feedback. Thanks.
>
>
>> By contrast, document-level quirks mode vs. standards mode is a
>> single global switch for the whole document. So it's much easier to
>> implement the switching and verify that its correct. If we need to
>> have switchable DOM API behavior, I'd rather base it on HTML
>> standards vs. quirks rather than ES strict vs. non-strict.
>
> Are you open to making undetected-document.all emulation depend on
> an HTML standards vs. quirks mode switch?
I think that would be a reasonable option, if that's enough to get the
bulk of the compatibility benefit and if other implementors are on
board.
> Probably we should move now to public-html, if there is no WebIDL
> angle to any of this.
Sounds good to me.
Regards,
Maciej
Received on Thursday, 8 October 2009 18:39:38 UTC