- From: Travis Leithead <Travis.Leithead@microsoft.com>
- Date: Sun, 25 Sep 2011 03:00:41 +0000
- To: Brendan Eich <brendan@mozilla.org>, David Bruant <david.bruant@labri.fr>
- CC: "public-script-coord@w3.org" <public-script-coord@w3.org>
+IE9 (another example using configurable properties--as accessor properties on the prototypes). We did work around the performance issue using caches, as most sites don't mess with the configurability of the properties. We [Microsoft] are strong supporters of the "configurable" DOM type-system. While you can "destroy-the-world" you can also use that power for good (with great power comes great responsibility :). Thanks to configurable properties, we were able to build a very useful tool to help all web developers identify potential compatibility problems on their web sites. http://blogs.msdn.com/b/ie/archive/2011/04/27/ie9-compat-inspector.aspx The tool is simple and replaces built-in DOM APIs with an inspection layer before funneling the calls through to the actual APIs. If the various accessor properties weren't configurable this tool would not be possible. >-----Original Message----- >From: public-script-coord-request@w3.org [mailto:public-script-coord- >request@w3.org] On Behalf Of Brendan Eich >Sent: Friday, September 23, 2011 5:53 PM >To: David Bruant >Cc: public-script-coord@w3.org >Subject: Re: All ECMAScript attributes should be non-configurable > >On Sep 23, 2011, at 3:53 PM, David Bruant wrote: > >> Currently, on Chrome and Opera (12), event attributes are configurable >> own properties (data in the former, accessor in the latter). >> Consequently, the freedom to prevent all events to have a "type" or >> "target" attribute doesn't exist by design. >> Do anyone miss that freedom? In other words, are there use cases of >> wanting this freedom at all or is it just a side-effect of putting >> properties on the prototype and defaulting to configurable=true >> because a choice has to be made? > >The "own" vs. prototype design is intentional. The non-configurable is too. >The combination does make a destroy-the-world button. But is it really a >problem? Same thing can happen with Object.prototype.toString. > >/be
Received on Sunday, 25 September 2011 03:01:22 UTC