Re: Detecting the "type" of a DOM object

• From: Cameron McCormack <cam@mcc.id.au>
• Date: Fri, 22 Jun 2012 11:31:26 +1000
• To: David Bruant <bruant.d@gmail.com>
• CC: Boris Zbarsky <bzbarsky@MIT.EDU>, public-script-coord@w3.org
• Message-ID: <4FE3CAEE.7030104@mcc.id.au>

David Bruant:
> The direct proxy proposal lists the things that can't be faked by the
> handler and instanceof is one of them.

Exactly.  A while ago, Web IDL used to require the [[HasInstance]] 
behaviour that Gecko has for its old-style bindings, where it didn't 
matter which global the RHS constructor object came from.  Once we 
starting considering what is possible for pure JS implementations, we 
dropped that.  Since there's no hasInstance trap on proxies, it would 
not be possible to implement a Web IDL interface object with pure JS.

Received on Friday, 22 June 2012 01:32:06 UTC