additional global ajax listener

[Sven Meier]

Hi all,

I think I'm in need of a additional global ajax listener:
Up till now I utilized a subscriber to "/ajax/call/before", to show a 
veil on *all* button clicks.

But now I realized, that under certain circumstances the veil is shown 
too late:
If an Ajax request is already running (e.g. an 
AjaxFormComponentUpdatingBehavior which does *not* show the veil), a 
following double click on a button will schedule two ajax requests.
The first one will trigger the veil, but this is too late since the 
second request is already scheduled :/.

A new ajax topic will allow to solve this quite easily:
The event will be published before any throttling and/or scheduling, 
right when the triggering event occurs.

I will name the new topic "/ajax/call/init":

            Topic: {
                ...
                AJAX_CALL_INIT          : '/ajax/call/init',
                AJAX_CALL_BEFORE       : '/ajax/call/before',
                AJAX_CALL_PRECONDITION : '/ajax/call/precondition',
                ...
            }

In Wicket 7/8 we could add IAjaxCallListener#onInitHandler(Component) too.
Any suggestions for a better name?

Regards
Sven