173244 - Wrong event type fired on CHECKBOX or RADIO INPUT changing in value of CHECKED attribute

Status: RESOLVED INVALID

(Core :: DOM: Events, defect)

Description

[Leland M. George]

User-Agent:       Mozilla/5.0 (Windows; U; Win 9x 4.90; en-US; rv:1.2b) Gecko/20021007
Build Identifier: Mozilla/5.0 (Windows; U; Win 9x 4.90; en-US; rv:1.2b) Gecko/20021007

When an <INPUT TYPE="CHECKBOX"> or <INPUT TYPE="RADIO"> element is ticked by the
user, an event of type [on]change fires.


Reproducible: Always

Steps to Reproduce:
1. Set up an event listener to fire onchange when a checkbox or radio button is
ticked.
2. Tick the control
3.

Actual Results:  
Event listener onchange fires, incorrectly.

Expected Results:  
Event of type [on]change must not fire, as the value of the element has not
changed, and the element has not lost focus.  See DOM 2 specification at

http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html#Events-eventgroupings-htmlevents

"The change event occurs when a control loses the input focus and its value has
been modified since gaining focus."

The [on]attrmodified event (domAttrModified) must fire instead, as required by
the specification: "DOMAttrModified [must be f]ired after an Attr has been
modified on a node. The target of this event is the Node whose Attr changed."  See

http://www.w3.org/TR/2000/REC-DOM-Level-2-Events-20001113/events.html#Events-eventgroupings-mutationevents

Other browsers:
Both Netscape 4.x and Internet Explorer observe the quoted restrictions on event
type [on]change.  Event type onpropertychange fires in Internet Explorer as
[on]attrmodified should in Mozilla.  Netscape 4.x has no equivalent event type,
as far as I know, but a JavaScript watch could probably be set to create the
desired effect.

Search for duplicates:
Failed using string "input event" (criterion: "contains all words..."), turning
up related but distinct bugs 97058 and 111992.

Attachment is ready; will provide it as soon as Bugzilla permits me to.

Comment 1

[Leland M. George]

Attachment: Shows onchange firing, onattrmodified filing to fire.

Also demonstrates two distinct bugs, which I'll file separately

Comment 2

[Leland M. George]

Attachment: Shows onchange firing, onattrmodified filing to fire.

Also demonstrates two distinct bugs, which I'll file separately.

Please delete/ignore first attachment.	I lost a variable when simplifying the
script.

Comment 3

[Leland M. George]

Comment on attachment 102158 [details]
Shows onchange firing, onattrmodified filing to fire.

See bug 173255 and bug 173270.

Comment 4

[Peter Van der Beken [:peterv]]

> DOMAttrModified [must be f]ired after an Attr has been
> modified on a node. The target of this event is the Node whose Attr changed.

Changing the presentational value of a form control does *not* change the HTML
value attribute. It changes the DOM value attribute on the element, but that is
not an Attr.

Comment 5

[Leland M. George]

Still, onchange shouldn't be firing: "The onchange event occurs when a control
loses the input focus _and _its value has been modified since gaining focus..."
(http://www.w3.org/TR/html401/interact/scripts.html#h-18.2.3)