Solving the "how do I tell whether I have an HTML element?" (or image element, or whatever) problem

Cameron McCormack cam at
Thu Jan 24 00:16:21 PST 2013

On 18/01/13 9:09 AM, Travis Leithead wrote:
> I think this sounds fine. Most web developers don't expect the
> current spec'd behavior, even though to me it seems more natural.
> IE has the current behavior and I expect we would migrate to the new
> behavior at some point once it was defined and agreed upon.

At one point a long time ago, Web IDL did require [[HasInstance]] to be 
overridden to return true even for objects from different windows.  If 
proxies now support trapping that, I'll just add it back.

(And hey, it was still there just commented out!  I must have known it'd 

I guess this will change to the @hasInstance that Allen mentions, once 
ES6 stabilises and I actually understand what "@hasInstance" means. :)

More information about the es-discuss mailing list