Hi,
Would it be possible for DOM4 to define a way for user objects to be able to
extend EventTarget (as in Object.create(EventTarget))?
The use case: give the ability to create objects that can dispatch events using
native means… instead of hacking around it like so:
var obj = Object.create(null);
var dispatcher = document.createElement("x-EventDispatcher");
//implement EventTarget interface on obj
Object.defineProperty(obj, "addEventListener", {
value: function(type, callback, capture){
dispatcher.addEventListener(type, callback, capture);
}
});
Object.defineProperty(obj, "removeEventListener", {
value: function(type, callback, capture){
dispatcher.removeEventListener(type, callback, capture);
}
});
Object.defineProperty(obj, "dispatchEvent", {
value: function(e){
dispatcher.dispatchEvent(e);
}
});
var e = document.createEvent('CustomEvent');
e.initEvent("myEvent", false, false, null);
dispatcher.dispatchEvent(e);
Also, AFAIK, all JS frameworks have implemented custom ways of handling events
and how they are dispatched, so clearly its a desired part of the platform. For
example:
http://developer.yahoo.com/yui/docs/YAHOO.util.CustomEvent.html
http://api.jquery.com/category/events/event-object/
http://dojotoolkit.org/reference-guide/quickstart/events.html
Developers have also built their own:
http://www.nczonline.net/blog/2010/03/09/custom-events-in-javascript/
Other solutions fire at the document, which means registering listeners on an
object that is not the one that needs to receive the event:
http://tiffanybbrown.com/2011/10/12/dispatching-custom-dom-events/
So, together with CustomEvents provided by the platform, it would be nice to
have a custom EventTarget to fire those things at :)
Kind regards,
Marcos
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Marcos Caceres
