In jQuery, how can I create a custom event with a default? - events

Question

The Event object in jQuery has this helpful preventDefault() method that prevents the default behaviour, obviously.
This is usually used to prevent click events from performing the browser default behaviour.
It seems like it would also be useful for custom events as well.
The task I'd like to achieve with this behaviour is a separate concern but I will explain it as an example for the behaviour I'm looking for:
I have a simple plugin that creates a popup out of a div. I found it on the internet.
$(selector).pop();
I have hacked it to close when you click on anything but a child of the popup, and to prevent default click behaviour on the clicked element.
function closeInactivePop() {
var foundAny = false;
jQ.each(function (i) {
var $this = $(this);
if ($this.hasClass('active') && ! $this.data('activePop')) {
$this.removeClass('active');
foundAny = true;
}
});
return foundAny;
}
$('body').click(function(){
// If we closed any, cancel the propagation. Otherwise let it be.
if (closeInactivePop()) {
$(document).trigger('jQuery.pop.menuClosed');
return false;
}
});
(Now that I paste it I realise I could have done this a bit better, but that notwithstanding).
Now I have added a new plugin that draws a colour picker inside the popup. Except the DOM that this colour picker creates is not inside the popup; it is only inside it visually. The DOM structure is separate.
In the aforementioned hack I would prefer to in fact fire another event, one whose default behaviour is to close the popup.
function closeInactivePop() {
var foundAny = false;
jQ.each(function (i) {
var $this = $(this);
if ($this.hasClass('active') && ! $this.data('activePop')) {
$(document).trigger('jQuery.pop.menuClosed');
$this.removeClass('active');
foundAny = true;
}
});
return foundAny;
}
$('*').click(function(e) {
var $this = $(this);
// This bit is pseudocode, where the Function is the default behaviour
// for this event.
// It is helpful that $this is actually the clicked element and not the body.
$this.trigger('jQuery.pop.menuBeforeClose', function() {
// if we run default behaviour, try to close the popup, or re-trigger the click.
if (!closeInactivePop()) {
$this.trigger(e);
}
});
});
Then I could later do
$('#colour-picker').bind('jQuery.pop.menuBeforeClose', function(e) {
e.preventDefault();
});
And this would prevent the closeInactivePopup default behaviour running when the target of the original click event was the colour picker or something inside it.
Can I do this somehow, even hackily?

Answer 1

I doubt that there is a native way to do that. However, you can either use "triggerHandler()" instead of "trigger()", which provides the ability to return values from the event handlers. Another relatively simple solution is to pass a custom "event" object that can be used to cancel the planned action:
function Action() {
var status = true;
this.cancel = function() { status = false; };
this.status = function() { return status; };
}
$('button').click(function() {
var action = new Action();
$(this).trigger('foo', [action]);
if (action.status()) {
// ... perform default action
}
});​
In the event handler:
$('*').bind('foo', function(event, action) {
action.cancel();
});