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

From: Ian Jacobs <ij@w3.org>
Date: Wed, 15 Sep 1999 09:11:54 -0400
Message-ID: <37DF9B1A.6F741083@w3.org>
To: Ted Wugofski <Ted.Wugofski@OTMP.com>
CC: "'w3c-html-wg@w3.org'" <w3c-html-wg@w3.org>, "'steven.pemberton@cwi.nl'" <steven.pemberton@cwi.nl>, "'w3t-ui@w3.org'" <w3t-ui@w3.org>, "'dsr@w3.org'" <dsr@w3.org>, "'w3c-wai-gl@w3.org'" <w3c-wai-gl@w3.org>
Ted Wugofski wrote:
> 
> I find this a very interesting proposal, but I am a bit concerned that
> it is making implicit things that ought to be explicit.  For example,
> and I quote:
> 
> %  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.
> 
> This is very loaded.  If a browser wants to assume that a MAP in a
> document is a navigation bar, does that mean that all MAPs in a document
> are navigation bars?  

It would be a misuse of MAP to use it for anything but navigation.
Thus, in a sense, a user agent may suppose that all MAPs are
for navigation (even if they may differ in structure).

> Are there additional hints that a browser should
> use (such as the topmost or bottommost or ....) to narrow down the
> decision. Could there be a style (CSS) property so that navigation bars
> can be rendered differently on different browsers?

I think this is about semantics, not presentation. Therefore, for
HTML one could add an element specifically to create navigation bars
(e.g.,
the BANNER element in HTML 3 as pointed out by Bert Bos). Or, 
one could write a schema that includes vocabulary for navigation
bars. This would provide definitive information to any
user agent that recognized the schema.
 
> As to the specific changes, they both seem reasonable. However, I am
> concerned that the premise behind these changes might be faulty.
> Perhaps we need to enrich the language with something that clearly
> denotes content which is a "navigation bar" from content that is not.
> 
> Ted
> 
> %  -----Original Message-----
> %  From: Ian Jacobs [mailto:ij@w3.org]
> %  Sent: Friday, September 10, 1999 6:50 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
> %
> %

-- 
Ian Jacobs (jacobs@w3.org)   http://www.w3.org/People/Jacobs
Tel/Fax:                     +1 212 684-1814
Cell:                        +1 917 450-8783
Received on Wednesday, 15 September 1999 09:12:11 GMT

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