On setting, if the
valueAsNumber<http://www.whatwg.org/specs/web-apps/current-work/multipage/common-input-element-attributes.html#dom-input-valueasnumber>
attribute
does not apply, as defined for the
input<http://www.whatwg.org/specs/web-apps/current-work/multipage/the-input-element.html#the-input-element>
element's
type<http://www.whatwg.org/specs/web-apps/current-work/multipage/the-input-element.html#attr-input-type>
attribute's
current state, then throw
anINVALID_STATE_ERR<http://www.whatwg.org/specs/web-apps/current-work/multipage/urls.html#invalid_state_err>
exception.
Otherwise, if the
valueAsDate<http://www.whatwg.org/specs/web-apps/current-work/multipage/common-input-element-attributes.html#dom-input-valueasdate>
attribute
applies, run the algorithm to convert a Date object to a
string<http://www.whatwg.org/specs/web-apps/current-work/multipage/the-input-element.html#concept-input-value-date-string>
defined
for that state, passing it a Date object whose time value is the new
value, and set the
value<http://www.whatwg.org/specs/web-apps/current-work/multipage/association-of-controls-and-forms.html#concept-fe-value>
of
the element to resulting string. Otherwise, run the algorithm to convert a
number to a
string<http://www.whatwg.org/specs/web-apps/current-work/multipage/the-input-element.html#concept-input-value-number-string>,
as defined for that state, on the new value, and set the
value<http://www.whatwg.org/specs/web-apps/current-work/multipage/association-of-controls-and-forms.html#concept-fe-value>
of
the element to resulting string.
It seems the current spec doesn't define behavior in a case of setting NaN
or Infinitiy to HTMLInputElement::valueAsNumber.
Because 'input.valueAsDate = null' makes the value empty, I think
'input.valueAsNumber = Number.NaN' also makes the value empty.
--
TAMURA Kent
Software Engineer, Google
