- From: <hallvord@opera.com>
- Date: Tue, 13 Oct 2009 22:08:50 +0000
- To: Brendan Eich <brendan@mozilla.org>
- Cc: Anne van Kesteren <annevk@opera.com>, Maciej Stachowiak <mjs@apple.com>, HTML WG <public-html@w3.org>
>> I didn't quite understand the comment about "treating assignment as
>> 'detecting'" because we do no such thing.
>
> The jaron is odd, but you do. A "detecting" use of document.all would be
> if (document.all) { IE-only content here }
> We found (see the links in
> https://bugzilla.mozilla.org/show_bug.cgi?id=259935#c0 ) that content
> also did
> d=document;
> this.ie=(d.all);
> and so assignment is "detecting" too, and does *not* detect the
> document.all collection.
Isn't the situation here that the variable d just references the real
document object, so that d.all in turn references the real all
collection, which this.ie again is going to be a reference too. So
when this.ie later is used in a boolean context, it refers to the
same, old doc.all object with its magic "pretend to be false in
boolean contexts" behaviour.
> wondering if using undefined instead of false as the masquerade value
> would not be even better, since undefined is falsy but also compares
> == itself and null.
Quite possibly.
-Hallvord R.
Received on Tuesday, 13 October 2009 22:09:29 UTC