[whatwg] Form validation against invisible controls

[Tab Atkins Jr.]

On Thu, Jun 3, 2010 at 8:42 AM, João Eiras <joaoe at opera.com> wrote:
> On Thu, 03 Jun 2010 16:16:00 +0100, TAMURA, Kent <tkent at chromium.org> wrote:
>
>>
>>
>>> > An element is a "candidate for constraint validation" if
>>> > 1. it is a validatable type,
>>> >    e.g. true if <input type=number>, false if <input type=reset>
>>> > 2. has no "disabled" attribute,
>>> > 3. has no "readonly" attribute,
>>> > 4. inside of a <form> element,
>>> > 5. has non-empty "name" attribute, and
>>> > 6. not inside of a <datalist> element.
>>> >
>>> > I hope ValidityState and the pseudo classes ignores 2-6.
>>
>>> The pseudo-classes do not ignore 2, 3, and 6. (4 and 5 are now removed.)
>>
>>
>> I'd like to propose to add another condition:
>>  7. it is visible (computed 'display' property of CSS isn't 'none' and no
>> 'hidden' content attribute)
>>
>
> You'd need to check the visibility or display also of all ancestors, that
> opacity is not 0, that the bounding box has enough size to render the form
> to the user and etc.
> That's quite complicated to specify.
>
> Would be easier to tell that user agents might chose to ignore form controls
> that they do not *paint* if that is possible for the UA to implement.

That's even worse - that defeats the time-honored trick to hide
something visually without hiding it in any other way of absolutely
positioning it off the screen.  It might even mean that elements
currently off the screen (but that can be scrolled to) wouldn't
validate.

~TJ