Started as GIST: https://gist.github.com/4173299
Tested against Chromium build with Object.observe and acts EXACTLY the same, though Chromium build is MUCH faster.
Trying to stay as close to the spec as possible, this is a work in progress, feel free to comment/update
http://wiki.ecmascript.org/doku.php?id=harmony:observe
Built using polling in combination with getter&setters. This means that if you do something quick enough it won't get caught.
Example:
var myObject = {};
Object.observe(myObject, console.log);
myObject.foo = "bar";
delete myObject.foo;The observer function would never see the addition of foo since it was deleted so quickly.
For FireFox using Proxies will result in better performance. Will look into this more.
See examples folder
Updated to use getters and setters since these result in more reliable and faster updates for known properties.
Fixed some inconsistancies between Chromium special build and this polyfill:
- Calculated properties don't get watched (https://mail.mozilla.org/pipermail/es-discuss/2012-August/024759.html)
- Moved getNotifier to Object.getNotifier()
- Updated exception messages to match