38889 - Click on label sends two onclicks to parent

Status: RESOLVED INVALID

(Core :: DOM: UI Events & Focus Handling, defect, P3)

Description

[Jesse Ruderman]

Steps to reproduce:
1. Load attachment
2 [details] [diff] [review]. Click on label

Expected result: one onclick for parent is recorded
Actual result: two onclicks for parent are recorded

note that the checkbox itself gets one onclick, but its container gets two.

Comment 1

[Jesse Ruderman]

Attachment: html test case

Comment 2

[John Morrison]

This is XP -- mac/linux/win32 builds from today.

See also bug #37262, where keypress events are begin generated twice.

Comment 3

[Nisheeth Ranjan]

I clicked on label and only one onclick was recorded using today's win32 build.  
Can somebody else please test this using 5-11-2000 builds or later.?  I'll leave 
this open for some time...

Comment 4

[John Morrison]

Using this morning's comm. builds on win2k, redhat 6.1 and macos 9, when I click
on the label, _two_ "onclick"s are written into the <textarea>. 

Are you using a debug build (vs. optimized)?

Comment 5

[joki (gone)]

Okay, this shouldn't be too tough.  The problem is that the label frame, which 
needs to redispatch the event to it child, is first allowing its normal 
processing to happen.  So we end up bubbling up, then dispatching to the child, 
then bubbling up again.

I'm not sure if there was a requirement for why events on the label object need 
to first be dispatched normally but I'll let pollmann figure that one out, its 
looks like he owns this code.

Comment 6

[Eric Pollmann]

I think this is actually the correct behaviour, unless there is a way to

Tom, I'm not sure if I'm answering your question, but we need to do default 
processing because the label could have an onclick handler of it's own, per the 
HTML 4 spec:

http://www.w3.org/TR/REC-html40/interact/forms.html#edef-LABEL

And we have to bubble up an event for the form element that the label is FOR 
because that form element may have an onclick handler of it's own (bug I fixed, 
can't remember the number).

So really, it is as if two events have happened in the parent, one on the label, 
and one on the element it is for.  I wish there was a way to say "this is the 
same event", so they would be coalesced on the way up, but I'm not aware of any.

Think of this case:

<form>
<p onclick="document.form.stuff.value='onclick paragraph 1\n' +             
document.form.stuff.value;">
<label for=checkboxFoo>label</label>
</p>

<p onclick="document.form.stuff.value='onclick paragraph 2\n' +             
            document.form.stuff.value;">
<input id="checkboxFoo" type="checkbox">
</p>

<textarea name=stuff></textarea>
</form>

I'm sure someone would complain if either "onclick paragraph 1" or "onclick 
paragraph 2" didn't appear.  Since this seems like the right thing to me, I'm 
going to close this out.  Please reopen if I'm wrong (tell me how it should be 
handled and also satisfy the above testcase), or if there is a way to coalesce 
separate events on the way up (same event, multiple targets).  Thanks!

Comment 7

[ckritzer (gone)]

Mass update:  changing qacontact to [e-mail]

Comment 8

[Loco]

Updating QA Contact.

Comment 9

[Hixie (not reading bugmail)]

Reassigning QA Contact for all open and unverified bugs previously under Lorca's
care to Gerardo as per phone conversation this morning.

Comment 10

[Madhur Bhatia]

QA contact updated