On Thu, 15 Mar 2007 02:02:46 +0100, Gareth Hay <[EMAIL PROTECTED]> wrote:
On 15 Mar 2007, at 00:30, Magnus Kristiansen wrote:
Mouseover/out events will trigger when elements contained inside the
EventTarget are hovered, and then bubble up. This is contrary to the
most obvious interpretation, as you are still inside (over) the
targeted element. IE supports two events, mouseenter[1] and
mouseleave[2], which solve this problem by not bubbling.
It is possible to work around the problem by using target/relatedTarget
and walking up the DOM tree. However, this requires extra code for
every event handler. Besides, these events were often not meant to be
generated in the first place, by the intent of the author.
I have no statistics for how often mouseover/out are used with and
without intent of bubbling, but the anecdotal evidence from my own
experience has never found me wanting it.
I suggest these two events be added to the web applications spec.
[1] http://msdn.microsoft.com/workshop/author/dhtml/reference/
events/onmouseenter.asp
[2] http://msdn.microsoft.com/workshop/author/dhtml/reference/
events/onmouseleave.asp
Can't you just return false from an event handler to prevent further
bubbling?
As mentioned there are workarounds, although I don't think attempting to
add anti-bubbling handlers on every descendant element is a reliable one.
This unwanted bubbling puts extra load on the user agent for processing
it, and the script author to work around it, when removing the root cause
is easily possible by making the event non-bubbling to begin with.
--
Magnus Kristiansen
"Don't worry; the Universe IS out to get you."
