- From: Charles L. Chen <clc@clcworld.net>
- Date: Thu, 26 Jul 2007 21:30:11 -0500
- To: David Poehlman <david.poehlman@handsontechnologeyes.com>
- CC: Jim Allan <jimallan@tsbvi.edu>, wai-xtech@w3.org, pparent@us.ibm.com
Already spoke to Jim on the phone and will attend the UA meeting next Thursday to discuss this. -Charles aka, the author of Fire Vox >The author of firevox might be able to help. > >----- Original Message ----- >From: "Jim Allan" <jimallan@tsbvi.edu> >To: <wai-xtech@w3.org> >Cc: <pparent@us.ibm.com> >Sent: Thursday, July 26, 2007 4:30 PM >Subject: FW: ACTION: PP to Proposal on ways User Agents could use live >regions. > > >Hi, >Live regions were discussed during several User Agent Working Group >meetings. There is a proposal for rewriting a checkpoint. A reality check >is needed on the assumptions and what the expected UA (UA+AT) behavior >should be for live region markup. See the message below. > >Any thoughts appreciated. > >Jim Allan > -----Original Message----- > From: w3c-wai-ua-request@w3.org [mailto:w3c-wai-ua-request@w3.org]On >Behalf Of Peter Parente > Sent: Thursday, July 26, 2007 9:24 AM > To: Jan Richards > Cc: WAU-ua; w3c-wai-ua-request@w3.org > Subject: ACTION: PP to Proposal on ways User Agents could use live >regions. > > > This action item concerns checkpoint 3.5: Toggle automatic content >retrieval and its application to dynamic regions within a page (e.g. AJAX). >I indicated on the wiki that user agents may be able to respect this >guideline for partial page refreshes if the page contains appropriate live >region markup. (wiki checkpoint 3.5 >http://www.w3.org/WAI/UA/wiki/ConfigToNotRender) > > We must answer two questions before we can decide how to rewrite this >guideline. I discuss them in detail below. At the end of the email, I take a >crack at reformulating checkpoint 3.5 under a few assumptions. > > 1) What "part" of the UA should we hold responsible for this guideline? > > So far, it has been implied that the AT is responsible for deciding how >live regions are presented. For instance, if a screen reader is busy reading >the content of a page and an event occurs outside the point of regard in a >"rude" live region, whether that change is announced or not is determined by >the screen reader settings (e.g. "Rude regions interrupt? [yes/no]"). >However, use of live region information is not limited to ATs. For instance, >the browser could conceivably have an inherent setting that controls whether >or not changes to the DOM are allowed. Essentially, this toggle would allow >the user to make parts of the DOM "read-only" on demand. In both cases, the >granularity can range from a single live region, to live regions with >certain properties, to all live regions on a page. > > We need the following information from browser developers before we know >if this technique is feasible or not. > > a) Is it possible to implement a "read-only DOM" setting without breaking >existing Web apps? > b) Is the base browser the right place to implement such a setting? > c) Is it possible to implement in a browser extension? > > 2) Is "retrieval" what we should really be toggling? > > This question is about the intention of the guideline as compared with the >language used. Relying on live region markup to block changes to the DOM is >a technique applied after content has been retrieved. In fact, it can only >be applied after content has been fetched. Beforehand, the browser has no >concept of the purpose of the fetch. For instance, some Javascript code >might send a message to the server and receive a response that is never >rendered for the user. On the other hand, the Javascript code may intend to >write the response into the DOM for the user. But until that code actually >touches the DOM API, the UA has no way of determining where in the page it >will appear (i.e. in what live region, not in a live region, not in a >visible element). > > I think the true intention of this checkpoint is to "toggle automatic >content changes." In some cases, such as a full page refresh, blocking >content retrieval may be the proper technique. In the case of AJAX, however, >it is not, nor should it be implied. > > If we assume that implementing read-only DOM is possible and retrieval is >more of a technique than a requirement, we might rewrite the guideline as >follows: > > 3.5 Toggle automatic content updates > > 1. Allow configuration so that the user agent only replaces existing page >content on explicit user request. > > Normative inclusions and exclusions > > 1. When the user chooses not to update content, the user agent may ignore >that content; buffering is not required for later rendering. > 2. When automatic content updates are disabled, a user agent may choose to >avoid retrieving content that it will ultimately not render. The browser >should take care not to block fetches that will not render in the UI. > 3. This checkpoint only applies when the user agent, not the server, >automatically initiates a content update. > > (I suggest we remove the second part of 3.5 about redirects. Why don't >these count?) > > Notes > > (Can stay the same.) > > Techniques > > (This is where notes about blocking page refreshes, blocking redirects, >and making live regions read-only can go.) > > Peter Parente > pparent@us.ibm.com > Tie: 526-2346 > IBM: 919-486-2346 > Jan Richards <jan.richards@utoronto.ca> > > > Jan Richards <jan.richards@utoronto.ca> > Sent by: w3c-wai-ua-request@w3.org > 07/12/2007 03:44 PM > > > To > WAU-ua <w3c-wai-ua@w3.org> > > > cc > > > > Subject > Re: User Agent Teleconference for July 12 2007 > > > > > Notes from the call: > > http://www.w3.org/2007/07/12-ua-minutes.html > > > Action items: > > ACTION: JR to Expand on idea of blocking functional areas: animation, > low contrast, etc. > > ACTION: PP to Proposal to combine 3.2 and 3.3 > > ACTION: JR to Proposal to limit "background image" to body of document > > ACTION: JA to Get thoughts together about 3.4 "All executable content", > managing configuration > > ACTION: JR to Proposal to have config uration not to have stripped down > user agent windoews > > ACTION: PP to Proposal on ways User Agents could use live regions. > > ACTION: JA to Proposal that if a live region has focus, it shouldn't > update.] > > > Cheers, > Jan > > > Jim Allan wrote: > > W3C User Agent Teleconference for July 12 2007 > > ------------------------------------------------------------- > > Chair: Jim Allan > > Date: Thursday, July 122007 > > Time: 2:00-3:00 pm Boston Local Time, USA (19:00-20:00 UTC/GMT) > > Call-in: Zakim bridge at: +1-617-761-6200, code 8294# > > for UK use 44-117.270-6152 > > IRC: sever: irc.w3.org, port: 6665, channel: #ua. > > ------------------------------------------------------------- > > > > Regrets, agenda requests, or comments to the list > > > > Agenda: > > > > 1. Changing Meeting time (move meeting time ahead 1 hour) > > > > 2. Ideas for topics for Tech Plenary day > > > > 3. Wiki - review edits > > http://www.w3.org/WAI/UA/wiki/UaagDocument > > > > Jim Allan, Webmaster & Statewide Technical Support Specialist > > Texas School for the Blind and Visually Impaired > > 1100 W. 45th St., Austin, Texas 78756 > > voice 512.206.9315 fax: 512.206.9264 http://www.tsbvi.edu/ > > "We shape our tools and thereafter our tools shape us." McLuhan, 1964 > > > > -- > Jan Richards, M.Sc. > User Interface Design Specialist > Adaptive Technology Resource Centre (ATRC) > Faculty of Information Studies > University of Toronto > > Email: jan.richards@utoronto.ca > Web: http://jan.atrc.utoronto.ca > Phone: 416-946-7060 > Fax: 416-971-2896 > > > > > > > > >
Received on Friday, 27 July 2007 02:30:29 UTC