Ticket #10563 (closed bug: fixed)
jQuery.Event no longer contains the element that matched the selector in event delegation.
| Reported by: | SlexAxton | Owned by: | |
|---|---|---|---|
| Priority: | blocker | Milestone: | 1.7 |
| Component: | event | Version: | git |
| Keywords: | delegation | Cc: | timmywil |
| Blocking: | Blocked by: |
Description
Perhaps this was a misunderstanding of mine prior to 1.7, but in my backbone apps, I often will do something like this
events: { '.someElement click' : 'myFunc' }
That essentially just delegates the '.someElement' class from whatever your root element is for that view.
$('#myRoot').delegate( '.someElement', 'click', myFunc);
The important part is that, in backbone, you don't use this to refer to the element you clicked like you might in a pure jQuery app. The context is always the view or the model, etc.
So the myFunc function would usually have something like:
myFunc: function( e ) { console.log( e.currentTarget ); }
And _that_ property of the event object has always pointed at the element that matched the selector. Now it points to the most specific element that you clicked on (usually a sub element of the element that you actually care about). It essentially doesn't differ from event.target as far as I can tell.
I thought event.delegateTarget was what I was looking for, but that also seems to be the root element that the event was actually attached to.
Is there a canonical way to reference this element? If not, should there be?
Change History
comment:1 Changed 20 months ago by SlexAxton
- Cc timmywil added
- Keywords delegation added
- Component changed from unfiled to event
- Milestone changed from None to 1.7
comment:2 Changed 20 months ago by SlexAxton
The docs for currentTarget seem to imply that unless you explicitly change the context, the two should be the same: http://api.jquery.com/event.currentTarget/
comment:3 Changed 20 months ago by dmethvin
- Priority changed from undecided to blocker
- Status changed from new to open
Looks like I broke that in the refactor, but I agree it be the same element as this. The new delegateTarget property should always be the element where the event is attached, as you noted.
comment:4 Changed 20 months ago by Dave Methvin
- Status changed from open to closed
- Resolution set to fixed
Fix #10563. Ensure event.currentTarget==this if delegated.
Now, event.delegateTarget is always the element where the event was handled, regardless of whether delegated handlers are attached.
Changeset: 84d2307e0e20e9245523731a4450314cc0de6a95
comment:6 Changed 20 months ago by SlexAxton
- Status changed from closed to reopened
- Resolution fixed deleted
Uh oh, I think this fix might have opened up a new can of worms. Happy to open a separate ticket, but it's still in the same vicinity.
http://jsfiddle.net/SlexAxton/u3NyG/1/
Check your console after clicking on the inner-subcontent.
It logs out for both .inner _and_ .inner-subcontent - where I think it should only log out once (for .inner).
As far as I can tell the .inner-subcontent doesn't match the selector, and therefore should not trigger any callback.
In case it ends up mattering, I've pretty much only tested this in Chrome Dev Channel (16ish) and Canary.
Please follow the bug reporting guidlines and use jsFiddle when providing test cases and demonstrations instead of pasting the code in the ticket.
