Other than regularly polling for changes, is there any (standard) way to register an event or callback that will be triggered any time a new property is added to a specific object?
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Might be related: http://stackoverflow.com/questions/4169524/javascript-property-change-event – Shadow The GPT Wizard Mar 17 '11 at 14:01
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@Shadow - detecting a change to an existing property is easy, the question is about detecting addition of _new_ properties. – Alnitak Mar 17 '11 at 14:15
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Simply put, the answer is no.
Mozilla's JavaScript implementation has an overload for unresolvable methods, but it doesn't work for standard properties, see __noSuchMethod__. Of course, you asked for a standard method and no other implementations support this as far as I'm aware.
Andy E
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I rather suspected as much, but figured a decent set of answers and/or workarounds in one place would be of benefit. – Alnitak Mar 17 '11 at 14:00
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@Alnitak: I went looking for an answer to the same question a long time ago. Perhaps we'll see something like this standardized in a future revision of the specification. – Andy E Mar 17 '11 at 14:01
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Once upon a time, ActionScript supported the __resolve property. As far as I know, JS has no similar crossbrowser construct, but maybe you could simulate it with some simple (but still bloaty) accessor function, like this:
http://bytes.com/topic/javascript/answers/789987-does-javascript-support-some-kind-__resolve-method
