- From: John M Slatin <john_slatin@austin.utexas.edu>
- Date: Sat, 23 Apr 2005 15:12:42 -0500
- To: "Loretta Guarino Reid" <lguarino@adobe.com>, <w3c-wai-gl@w3.org>
Responses inline, preceded by "js:" UAAG 1.0 Guideline 6 can be boiled down to, "Implement interoperable interfaces to communicate with other software (e.g., assistive technologies, the operating environment, and plug-ins)." Therefore, WCAG boils down to what the author provides so that the appropriate information is communicated via the APIs. This includes everything from the alt attribute on the img element to using structural elements properly (to fill the DOM in a meaningful way) to role and state information of scripted/non-standard/non-default widgets/elements. @@question about the API related to the DHTML roadmap *UAAG 1.0: 6.1 Programmatic access to HTML/XML infoset (P1)* This checkpoint refers to the XML infoset [1]. Seems to me as long as an author uses any XML-based language according to spec, they will have provided all info according to the infoset and therefore the UA will have the info needed to satisfy provisions 1 and 2. Provision 3 says, " If the user can modify the state or value of a piece of HTML or XML content through the user interface (e.g., by checking a box or editing a text area), allow programmatic read access to the current state or value, and allow the same degree of write access programmatically as is available through the user interface."Here, the author needs to provide state or value information if the user agent is unable to determine state or value. It seems that the DHTML roadmap is helping ensure, "allow the same degree of write access programmatically as is available through the user interface" but I'm not sure what that means for the author. Js: This seems like an issue for screen readers (for example) that walk the DOM when they load a page but don't look at it again to catch any changes made through scripting. So maybe this would involve some client-side scripting techniques for the two baselines where scripting is enabled? [1] <<http://www.w3.org/TR/xml-infoset/>http://www.w3.org/TR/xml-infoset/> (UAAG 1.0 references the Oct 2001 draft. The most current is Feb 2004) *UAAG 1.0: 6.2 DOM access to HTML/XML content (P1) *Specific to HTML. Only DOM Level 2 Core. "Note: This checkpoint stands apart from checkpoint 6.1 to emphasize the distinction between what information is required and how to provide access to that information." - seems to say that as long as we've provided all the info needed for Guideline 6.1, the UA will have all of the information needed to communicate with other software. *UAAG 1.0: 6.3 Programmatic access to non-HTML/XML content (P1) *"Note: This checkpoint addresses content not covered by checkpoints 6.1 and 6.2."* *If providing a custom widget ensure UA has state and value info (ala UAAG 6.1). If we write a general enough requirement for 6.1, then is there anything additional required for this Checkpoint? *UAAG 1.0: 6.4 Programmatic access to information about rendered content (P1) *Even if the delivery unit causes creation of a new viewport, it is the UA that is rendering the perceivable unit and will therefore know the coordinates and provide access to content via points 6.2 and 6.3. i.e., if scripting causes a pop-up window, the UA actual creates the window and knows about its contents. if java or flash cause a pop-up, their VMs should provide programmatic access to them. Therefore, nothing additional for the author to do. *UAAG 1.0: 6.5 Programmatic operation of user agent user interface (P1) *If we distinguish between the viewport and the "user agent user interface controls, selection, content focus, and user interface focus," then the author has nothing additional to do for this UAAG checkpoint. Js: agree Event handlers provided in the delivery unit and instantiated by the user agent do not render focus and selection - the handlers will provide instructions for when and how to change focus and selection but the UA will actually do the work. Although, see the next checkpoint. *UAAG 1.0: 6.6 Programmatic notification of changes (P1) *"The user agent is not required to provide notification of changes in the rendering of content (e.g., due to an animation effect or an effect caused by a style sheet) unless the document object is modified as part of those changes." Therefore, the requirement is for the author to ensure that the document object is modified. If the author does something in such a way that it is updated appropriately by default, then they don't have anything more to do. If the document object is not modified appropriately, the author needs to update it. @@techniques-o-rama - related to baseline. Js: agree-- my comment about 6.1 probably makes more sense here. *UAAG 1.0: 6.7 Conventional keyboard APIs (P1) *No requirements for authors. Js: agree *UAAG 1.0: 6.8 API character encodings (P1) *Assumes authors are providing proper character encoding information. Js: Hmmm. Nothing in WCAG seems really to cover this. It's related in some ways to 3.1 L1 SC1 (identifying natural language of the delivery unit), in the sense that identifying the text-processing language (as discussed by I18N) may affect the rendering of characters (e.g., glyphs shared among Chinese, Japanese, Korean but having a somewhat different apperance in each language). But this seems to have something to do with Principle 1 as well-- we have lots of stuff aimed at making *non-text content* perceivable, but we take it for granted that *text* is perceivable by default. The following sections seems relevant and interesting, although I can't quite figure out how: Normative inclusion: For content, user agent features, or both <<http://www.w3.org/TR/UAAG10/conformance.html#content-or-ua>http://www. w3.org/TR/UAAG10/conformance.html#content-or-ua>js: hmmm. If I read the UAAG material right, does this mean there are notations throughout UAAG that identify checkpoints where the content is responsible for doing something so that the UA can render it? If so, do we need to review UAAG looking for those notations? John
Received on Saturday, 23 April 2005 20:12:45 UTC