ISSUE-31: "undefined", instead of absent, value for "expanded" and similar states

undefined value

"undefined", instead of absent, value for "expanded" and similar states

ARIA 1.0
Raised by:
Michael Cooper
Opened on:
Raised during June 2007 Face to Face

Some states and properties state that if the attribute is not provided, a particular behavior is assumed. However, the vagaries of DTD validation mean it's a little unpredictable as to whether an attribute will end up in the DOM, regardless of whether it was defined in the source code. Therefore, it is preferable to provide a value of "undefined" for such states and properties, and make it the default, as well as state that it is equivalent to the attribute not being present. This provides for the case in which the attribute ends up in the DOM unexpectedly, and also allows scripts to set the value to "undefined" if needed.

This wasn't an instant "yes" at the face to face meeting, so it was put on the agenda but never completed.
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Discussed 17 September 2007

implement proposal from except make “main” default for “channel” instead of add undefined

Michael Cooper, 17 Sep 2007, 00:00:00

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