Re: Mutation events replacement

[Boris Zbarsky]

On 7/6/11 10:23 AM, John J. Barton wrote:
This is another advantage of onModelChanging or 'before' events. All of
the previous values are available for listeners and the task of
selecting which ones to process is left to the listener.

Yes, I realize this is useful.  This is why Gecko internally has an 
AttributeWillChange notification....

Again, the problem is preventing malicious onModelChanging listeners 
from screwing everyone else over.

-Boris