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Re: DOM Accessibility Issues and the user agent guidelines

From: mark novak <menovak@facstaff.wisc.edu>
Date: Wed, 22 Sep 1999 17:30:13 -0500
Message-Id: <v01540b15b40eb927f1b2@[128.104.23.196]>
To: Jon Gunderson <jongund@staff.uiuc.edu>, w3c-wai-pf@w3.org
Cc: w3c-wai-cg@w3.org, w3c-wai-ua@w3.org
MN:  I think these are necessary UA checkpoints, and would just like to
comment on where I think some of this technology currently stands.

At 3:53 PM 9/21/99, Jon Gunderson wrote:
>Three issues related to User Agent Accessibility Guidelines and the DOM 2
>specification:
>
>1. Exporting DOM to external applications: Can an external program in a
>standard way have read and write access to the DOM of a user agent.
>Review Guideline 6 in trhe current guidelines:
>http://www.w3.org/WAI/UA/WAI-USERAGENT-19990827/


MN:  I think this is improving quickly.  First, from a programming
language basis,
DOM includes IDL definitions in an Appendix, and also a couple of language
specific bindings as examples in an Appendix.  This gives developers of external
applications, a common starting point for interacting with W3C DOM model.
Second, user
agents, such as internet explorer do expose an "interface" to it's DOM
model, by which
an external application can attach, either in or out-of the same process
space as mandated by the application's needs.  IE's DOM model interface
does allow
an external application read/write access.  From what I've read
at the Mozilla site, I think this is also true (someone please correct me
if I'm wrong about Mozilla).  What is critical yet, is to get the UA's to fully
support the W3C DOM model.




>2. Timing of access by an external program to the DOM: It is critical than an
>external assistive technology have high speed access to the DOM of a user agent
>
>Review Guideline 6 in trhe current guidelines:
>http://www.w3.org/WAI/UA/WAI-USERAGENT-19990827/

MN:  My experience with internet explorer, and also from reading about what
Mozilla will offer, I think "high speed access to the DOM of a user agent"
has greatly improved as the result of more component related software
design and development across the industry as a whole.

In terms of internet explorer, for example, the concept of
the browser helper object (BHO) certainly allows for this.  If people would like
to try (need appropriate M'soft tools, ) or read about this technology, go to :

http://msdn.microsoft.com/library/techart/bho.htm

i've experimented enough to realize that the BHO, which is just a specialized
in process DLL, has very fast access to internet explorer's DOM through COM,
thus I feel that "any" external software technology is capable of high
speed access
to the user agents DOM.





>3. Event Bubbling: With event bubbling it is impossible for a user agent to
>determine which child elements of a element with an event will or will not
>respond to the parent event.  Elements with associated events are considered
>active elements in the user agent guidelines.
>
>References in user agent guidelines:
>
>Checkpoint 1.2 Ensure that the user can interact with all active elements of a
>document in a device independent manner. [Priority 1]
>
>Checkpoint 3.4 Provide time-independent access to time-dependent active
>elements
>or allow the user to control the timing of changes. [Priority 1]
>
>Checkpoints 8.4 Allow the user to navigate just among all active elements
>in the
>document. [Priority 2]
>
>Checkpoint 9.7 Provide a mechanism for highlighting and identifying (through a
>standard interface where available) active elements of a document. [Priority 3]
>
>
>Jon Gunderson, Ph.D., ATP
>Coordinator of Assistive Communication and Information Technology
>Chair, W3C WAI User Agent Working Group
>Division of Rehabilitation - Education Services
>University of Illinois at Urbana/Champaign
>1207 S. Oak Street
>Champaign, IL 61820
>
>Voice: 217-244-5870
>Fax: 217-333-0248
>E-mail: jongund@uiuc.edu
>WWW:    http://www.staff.uiuc.edu/~jongund
>                http://www.w3.org/wai/ua
>                http://www.als.uiuc.edu/InfoTechAccess
><html>
>Three issues related to User Agent Accessibility Guidelines and the DOM 2
>specification:<br>
><br>
>1. Exporting DOM to external applications: Can an external program in a
>standard way have read and write access to the DOM of a user agent.<br>
><br>
>Review Guideline 6 in trhe current guidelines:<br>
><a href="http://www.w3.org/WAI/UA/WAI-USERAGENT-19990827/"
>eudora="autourl">http://www.w3.org/WAI/UA/WAI-USERAGENT-19990827/</a><br>
><br>
>2. Timing of access by an external program to the DOM: It is critical
>than an external assistive technology have high speed access to the DOM
>of a user agent<br>
><br>
>Review Guideline 6 in trhe current guidelines:<br>
><a href="http://www.w3.org/WAI/UA/WAI-USERAGENT-19990827/"
>eudora="autourl">http://www.w3.org/WAI/UA/WAI-USERAGENT-19990827/</a><br>
><br>
><br>
>3. Event Bubbling: With event bubbling it is impossible for a user agent
>to determine which child elements of a element with an event will or will
>not respond to the parent event.&nbsp; Elements with associated events
>are considered active elements in the user agent guidelines.<br>
><br>
>References in user agent guidelines:<br>
><br>
>Checkpoint 1.2 Ensure that the user can interact with all
><font color="#0000FF"><u>active elements</font></u> of a document in a
><font color="#0000FF"><u>device independent</font></u> manner. [Priority
>1] <br>
><br>
>Checkpoint 3.4 Provide time-independent access to time-dependent
><font color="#0000FF"><u>active elements</font></u> or allow the user to
>control the timing of changes. [Priority 1] <br>
><br>
>Checkpoints 8.4 Allow the user to navigate just among all
><font color="#0000FF"><u>active elements</font></u> in the document.
>[Priority 2] <br>
><br>
>Checkpoint 9.7 Provide a mechanism for
><font color="#0000FF"><u>highlighting</font></u> and identifying (through
>a standard interface where available) active elements of a document.
>[Priority 3] <br>
><br>
><div>Jon Gunderson, Ph.D., ATP</div>
><div>Coordinator of Assistive Communication and Information
>Technology</div>
><div>Chair, W3C WAI User Agent Working Group</div>
><div>Division of Rehabilitation - Education Services</div>
><div>University of Illinois at Urbana/Champaign</div>
><div>1207 S. Oak Street</div>
><div>Champaign, IL 61820</div>
><br>
><div>Voice: 217-244-5870</div>
><div>Fax: 217-333-0248</div>
><div>E-mail: jongund@uiuc.edu</div>
><div>WWW:<x-tab>&nbsp;&nbsp;&nbsp;&nbsp;</x-tab><a
>href="http://www.staff.uiuc.edu/~jongund"
>EUDORA=AUTOURL>http://www.staff.uiuc.edu/~jongund</a></div>
><div><x-tab>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</x-tab><x-tab>
>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</x-tab><a
>href="http://www.w3.org/wai/ua"
>EUDORA=AUTOURL>http://www.w3.org/wai/ua</a></div>
><x-tab>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</x-tab><x-tab>&nbsp
>;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</x-tab><a
>href="http://www.als.uiuc.edu/InfoTechAccess"
>EUDORA=AUTOURL>http://www.als.uiuc.edu/InfoTechAccess</a>
></html>
Received on Wednesday, 22 September 1999 18:28:25 UTC

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