- From: Rich Schwerdtfeger <richschwer@gmail.com>
- Date: Fri, 30 Jun 2017 12:04:16 -0400
- To: Aaron Leventhal <aleventhal@google.com>
- Cc: Joanmarie Diggs <jdiggs@igalia.com>, ARIA Working Group <public-aria@w3.org>
- Message-Id: <AD4CB4B4-C9B2-4073-83A8-E87DFB32EAE1@gmail.com>
Yes. The reason for undefined was that we could not assume that something was false by default - especially when in the case of a checkbox it could be “mixed”. If a property is required for a role it could be undefined. … You might be waiting for a server to tell you what the value is such as for preferences for a given user. I am a little confused about where you think the core-aam is unclear. Here is the current core-aam. The spec. clear states what the default values must be for states and properties and we have mappings associated with each value (which indicates the default): http://rawgit.com/w3c/aria/master/core-aam/core-aam.html <http://rawgit.com/w3c/aria/master/core-aam/core-aam.html> see aria-disabled. It indicates the default. The core-aam reflects the spec. Rich Rich Schwerdtfeger > On Jun 30, 2017, at 10:13 AM, Aaron Leventhal <aleventhal@google.com> wrote: > > To be clear, I've never seen the "undefined" literal used in the real world, but it's good to get this right anyway. > Are these correct: > > - The author can explicitly set the "undefined" literal unless the property is required for the role. > > - Setting "undefined" is equivalent to using the default value > > - The default value itself may be "undefined" (like in aria-checked) or not (e.g. "false" for aria-disabled). Therefore, using "undefined"/undefined may result in undefined or a specific value depending on the property. > > IMO the CORE-AAM could use more clarification. I don't find it covers these cases -- at least it's not clear to me. > > Aaron > > > > > On Fri, Jun 30, 2017 at 9:09 AM Joanmarie Diggs <jdiggs@igalia.com <mailto:jdiggs@igalia.com>> wrote: > This does have interesting implications for (at least) aria-current. > According to the ARIA spec: > > The aria-current attribute is an enumerated type. Any value not > included in the list of allowed values should be treated by > assistive technologies as if the value true had been provided. If > the attribute is not present or its value is an empty string, the > default value of false applies and the aria-current state must not > be exposed by user agents or assistive technologies. > > Thus the language is consistent with what Rich said, which means: If the > value of aria-current is undefined (in the sense of a value having not > been provided), the default of false applies, the element is not > current, and the aria-current state must not be exposed. BUT, if the > value of aria-current is "undefined" (a string literal), then we have a > value not included in the list of allowed values, which should be > treated as if aria-current were set to true (which means the > aria-current state must be exposed by user agents). > > The fact that the results of undefined and "undefined" are expected to > be the complete opposite gives me a headache. > > Also, looking at the Core AAM, aria-current is undefined is "not > mapped": > https://rawgit.com/w3c/aria/master/core-aam/core-aam.html#ariaCurrentUndefined <https://rawgit.com/w3c/aria/master/core-aam/core-aam.html#ariaCurrentUndefined>. > I guess Joseph thinks undefined means not defined? (To be honest, that's > how my brain works too.) And I guess we need to add both flavors of > undefined to Core AAM? > > --joanie > > On 06/29/2017 01:47 PM, Rich Schwerdtfeger wrote: > > Aaron, > > > > The spec. clearly states that (see aria-checked) that “undefined” is the > > (default). If nothing is specified that is what is assumed the value is. > > If the author has not set aria-checked on the role that supports the > > aria-checked states then the default is undefined. When it says default > > it is very clear. Had default not been indicated then I agree there > > would be confusion. > > > > So, “undefined” is a valid value. … so is leaving the attribute off > > altogether. > > > > In aria 1.0 here is a test example for aria-grabbed being set to > > “undefined” from the Candidate Recommendation test harness: > > > > https://dvcs.w3.org/hg/pfwg/raw-file/default/ARIA/1.0/tests/test-files/roles-properties-global/roles-properties-global-main-aria-grabbed-undefined.html <https://dvcs.w3.org/hg/pfwg/raw-file/default/ARIA/1.0/tests/test-files/roles-properties-global/roles-properties-global-main-aria-grabbed-undefined.html> > > > > This passed candidate recommendation and therefor we had working > > implementations. > > > > The important thing to remember is the default value. So, programmers > > can leave it off altogether. > > > > Rich > > > > > > Rich Schwerdtfeger > > > > > > > > > >> On Jun 29, 2017, at 1:32 PM, Aaron Leventhal <aleventhal@google.com <mailto:aleventhal@google.com> > >> <mailto:aleventhal@google.com <mailto:aleventhal@google.com>>> wrote: > >> > >> As I understand ARIA, a possible value of "undefined" means the > >> attribute is not present. If undefined is also the default, then a > >> value of "" is equivalent. However, I would not expect a user agent to > >> process the literal string "undefined" as undefined. > >> > >> Was there an expectation somewhere that the literal string "undefined" > >> should be treated as attribute not present? > >> > >> I feel that the ARIA 1.1 spec could be more clear here: > >> > >> 'The "undefined" value, when allowed on a state or property, is an > >> explicit indication that the state or property is not set. The value > >> is used on states and properties that support tokens, and the > >> "undefined" value is a string that is one of the allowed tokens. It is > >> also used on some states and properties that accept true/false values, > >> when "undefined" has a different meaning than "false".' > >> > >> Perhaps when undefined is discussed it should not be put in quotes -- > >> to programmers this means literal string. Mostly, CORE-AAM does this, > >> but it does have one place under disallowed values that discusses > >> "undefined" as a literal string. It does not, however, discuss the > >> "undefined" literal as an allowed value. > >> > >> Can someone provide more clarity for our implementation? I'd like to > >> see more clarity in both specs. > >> > >> Thank you, > >> > >> - Aaron > >> > >> > >> > > >
Received on Friday, 30 June 2017 16:04:52 UTC