- From: Boris Zbarsky <bzbarsky@MIT.EDU>
- Date: Mon, 31 Oct 2011 21:51:29 -0400
- To: Charles Pritchard <chuck@jumis.com>
- CC: public-webapps@w3.org
On 10/31/11 9:32 PM, Charles Pritchard wrote:
> Structured cloning fails for NodeList, same as postMessage, because of
> circular structure.
What circular structure? Structured clone can handle that.
It fails because it's a host object (based on its [[Class]]) that's not
whitelisted in the structured clone algorithm.
> With .join, you get the .toString of the DOM Nodes.
Yes, as you would for an array of DOM nodes.
A quick skim through the ES spec shows that Array.prototype.concat also
considers the [[Class]] of its arguments, by the way. And indeed, this
testcase:
<script>
var l = document.getElementsByTagName("html");
var a = Array.prototype.slice.call(l);
l.__proto__.__proto__ = Array.prototype;
var test1 = [].concat(l);
var test2 = [].concat(a);
alert(test1[0] instanceof HTMLHtmlElement);
alert(test2[0] instanceof HTMLHtmlElement);
</script>
alerts "false" followed by "true" in UAs.
So we really do need to decide what it means for a return value to "be
an Array". For example, how does it behave with concat()?
-Boris
Received on Tuesday, 1 November 2011 01:52:03 UTC