Report on event listener investigation

As per my assignment some time ago, I started to investigate the proper way
to restart the conversation about getting a standard interface that would
allow the querying of registered listeners for events via the DOM.  Here is
a summary of what I learned.


   1. Apparently, it has been discussed and rejected several times.
   2. The right place to restart the conversation is the www-dom mailing
   list at the w3c.
   3. While the DOM is a 'living standard' to some people, in W3C parlance
   DOM4 is already feature complete.  We would need to suggest this for a
   future version if at all.
   4. As we assumed, and were somewhat aware, each browser has some sort of
   an interface, but it is hard to get to and is obviously not standardized.
   5. There are some tools that use these proprietary interfaces (e.g.,
   AInspector Sidebar and FAE 2.0 - thanks Jon Gunderson!)
   6. The argument against exposing such a standard interface is that it
   can lead to abuse.

My personal belief is that we could probably push for this. I think there
could be an interface, but as James Craig has already mentioned in a
separate thread to the PF, adding an attribute to the EventTarget with a
listeners list would be even simpler.

Since the DOM is part of the HTML activity, it is subject to the extension
specification rules I think.  This means we could produce a simple
extension specification to add this one attribute - even against DOM4.
 Again, if I understand the rules correctly.

Alternately, we could run the proposal through the HTML working group's DOM
team.  There is clearly some opposition to this in the community, and we
might run into that opposition harder there than if we just did it
ourselves.

Anyway, that's what I know so far.  I know this is on the agenda for today,
and I will be on the call, although I will be out of my office.