List events of an element wired up with addEventListener

[mebemikeyc@gmail.com]

With Element.addEven tListener, you can easily wire-up several
different event handlers on the fly. This works great, but debugging
can be difficult if I don't know what exactly is reacting to an event.

Is there a way to list event listeners that have been wired-up to an
element's event?

[Thomas 'PointedEars' Lahn]

Re: List events of an element wired up with addEventListene r

mebemikeyc@gmai l.com wrote:

With Element.addEven tListener, you can easily wire-up several
different event handlers on the fly. This works great, but debugging
can be difficult if I don't know what exactly is reacting to an event.
>
Is there a way to list event listeners that have been wired-up to an
element's event?

AFAIK only if you use a wrapper object, and use only its event
listener-registering methods to add event listeners to the wrapped
target object. For example:

function _EventListener( fListener, bCapture)
{
this.listener = fListener || null;
this.capture = !!bCapture;
}

function _EventRegistry( )
{
this.data = {};
}

_EventRegistry. prototype.add = function(sEvent , fListener, bCapture) {
var d = this.data;

if (typeof d[sEvent] == "undefined" )
{
d[sEvent] = [];
}

d[sEvent].push(new _EventListener( fListener, bCapture));
};

_EventRegistry. prototype.get = function(sEvent ) {
return this.data[sEvent];
};

function _Element(oTarge t)
{
this.target = oTarget;
this.events = new _EventRegistry( );
}

_Element.protot ype.addEventLis tener =
function(sEvent , fListener, bCapture) {
// add feature test here

this.target.add EventListener(s Event, fListener, bCapture);
this.events.add (sEvent, fListener, bCapture);
};

// add feature test here

var o = new _Element(docume nt.getElementBy Id("foo"));
o.addEventListe ner("click", function() { window.alert(42 ); }, false);
window.alert(o. events.get("cli ck")[0].listener);

BTW: `Element::addEv entListener' is more like it. We are talking
*interfaces* here.


HTH

PointedEars
--
realism: HTML 4.01 Strict
evangelism: XHTML 1.0 Strict
madness: XHTML 1.1 as application/xhtml+xml
-- Bjoern Hoehrmann