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Re: PROPOSAL FOR HTML 4.01: MAP used for navigation mechanisms.

From: <thatch@us.ibm.com>
Date: Sat, 11 Sep 1999 22:01:47 -0500
To: Ian Jacobs <ij@w3.org>
cc: w3c-html-wg@w3.org, w3t-ui@w3.org, w3c-wai-gl@w3.org
Message-ID: <852567EA.0020405C.00@d54mta02.raleigh.ibm.com>


Reworded/corrected statement below about HPR and MAPs!

Ian said quote Thus, an author could use MAP with a
list of links as content and no associated image to
create a navigation bar endquote. I want to support this
wonderfully simple construction to address a pervasive
problem. Most commercial sites (and some non-commercial)
have extensive navigation across the top and down the left.
A blind user must listen to all of that - often on every page -
or conceive of strategies to skip over it. IBM Home Page
Reader, skips MAP content by default. Other speciality
browsers could relatively quickly adopt that strategy.

Jim Thatcher
IBM Special Needs Systems
www.ibm.com/sns
thatch@us.ibm.com
(512)838-0432


Ian Jacobs <ij@w3.org> on 09/10/99 06:50:08 PM

To:   w3c-html-wg@w3.org, steven.pemberton@cwi.nl
cc:   w3t-ui@w3.org, dsr@w3.org, w3c-wai-gl@w3.org
Subject:  PROPOSAL FOR HTML 4.01:  MAP used for navigation mechanisms.





Steven,

The HTML 4.01 Proposed Recommendation [1] includes
some changes to the content model of the MAP element [2]
to allow mixing of block content and AREA elements:

<!ELEMENT MAP - - ((%block;) | AREA)+ -- client-side image map -->

This change was incorporated into HTML 4.0 [3] to allow authors
to create richer non-graphical alternatives to image maps.
The HTML 4.0 Recommendation used the wrong content model,
however, but HTML 4.01 corrects that mistake.

In HTML 4.01, the following text describes the role of
the block content:

<BLOCKQUOTE>
   2. Block-level content. This content should include
      A elements that specify the geometric regions of the
      image map and the link associated with each region.
      Note that the user agent may render block-level
      content of a MAP element. Authors should use this
      method to create more accessible documents.
</BLOCKQUOTE>

I am proposing two changes to the description of MAP,
again to promote accessibility. The goal of the proposal
is to make it easier for users of speech
synthesizers and users with motor impairments
to bypass navigation bars (groups of links).
These groups of links often appear first on a page
and are often repeated on many pages of a site. Often,
the users cited must wade through numerous links
before getting to important content on the page.

If user agents can suppose that MAP may be used
to identify navigation bars (or other navigation
mechanisms), they can offer navigation bar
hide/display functionality. The HTML 4.01 specification
does not prohibit the use of MAP for general navigation
mechanisms, but this proposal will make it more obvious
that this is possible.

The proposal involves two changes:

Change 1) Change the second sentence of the above
          quoted text to "User agents should
          render block-level content of the MAP element." The
          change is from "may render" to "should render".

          In a number of current browsers tested, block-level
          content is rendered, so this change conforms to
          current practice and will not break pages.

Change 2) Change the first sentence of section 13.6.1's
          description of the MAP element from:

           <BLOCKQUOTE>
            The MAP element specifies a client-side
            image map that may be associated with one or more
            elements (IMG, OBJECT, or INPUT).
           </BLOCKQUOTE>

           to:

            "The MAP element specifies a client-side
            image map (or other navigation mechanism)
            that may be associated with one or more
            elements (IMG, OBJECT, or INPUT)."

          Note that HTML 4.01 does not require that a MAP
          be associated with an image (IMG, OBJECT, or
          INPUT elements). Thus, an author could use
          MAP with a list of links as content and no
          associated image to create a navigation bar.

I realize that this proposal comes during the Proposed
Recommendation review period, but the changes would cost
little and would help the WAI Guidelines Working Groups
(Web Content, User Agent, Authoring Tool) who have been
wrestling with this issue for quite some time. It would
be a timely boon for the UA and AT Working Groups
in particular as they have documents nearing Proposed
Recommendation.

Thank you for considering this proposal,

  - Ian


[1] http://www.w3.org/TR/1999/PR-html40-19990824
[2] http://www.w3.org/TR/html40/struct/objects.html#h-13.6.1
[3] http://www.w3.org/TR/REC-html40/struct/objects.html#h-13.6.1

--
Ian Jacobs (jacobs@w3.org)   http://www.w3.org/People/Jacobs
Tel/Fax:                     +1 212 684-1814
Cell:                        +1 917 450-8783
Received on Sunday, 12 September 1999 01:52:36 GMT

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