W3C home > Mailing lists > Public > w3c-wai-ua@w3.org > April to June 1998

tables, object, maps, frames, refresh, etc...

From: Nir Dagan <nir.dagan@econ.upf.es>
Date: Sat, 06 Jun 1998 00:07:05 GMT
Message-Id: <199806051511.RAA02132@darwin.upf.es>
To: w3c-wai-ua@w3.org
CC: dagan@upf.es
I have some comments on the following topics in the UA guidelines:

0. tables
1. objects and longdesc
2. image maps
3. frames
4. meta refresh
5. etc...


Make it optional to render table summary. 

It seems to me somewhat important to allow users to 
read about the organization of a table, if they so wish. 

1. objects

I find the following highly confusing:

...The innermost text of the OBJECT is considered its
alternative text. If the author has not supplied alternative content the
browser should display "Image"."

In my understanding of the spec. the content of the object, and not
the innermost text is the "alterantive text" of an object. The above guideline 
contradicts the specs. 

Consider <OBJECT>text1 <OBJECT>text2</OBJECT></OBJECT> 
if both types of objects are turned off /unsupported, text1 text2 should be rendered, 
not only text2. If only the outmost object is not rendered then 
text1 followed by the second object should be rendered.

Moreover the guideline leads to the following pardox:
the markup <OBJECT data="foo.png"><IMG src="bar.gif" alt=""></OBJECT>
should be rendered as nothing when png and gif are turned off. but:
<OBJECT data="foo.png"></OBJECT> should be rendered as "Image".

In my view it should be assumed that an author wants nothing 
to appear in the second case too, when png is turned off.

Empty OBJECT is valid HTML, and the browser shouldn't assume authors 
make mistakes if the document is valid. Browsers don't fix spelling mistakes
or rude words, and shouldn't "fix" empty OBJECTS.  

With IMG it is a different strory. alt is _required_ by the spec. 
So the guidelines suggest how to recover from  the 
author's _syntax error_.

When an IMG element has a value for the "longdesc" attribute 
and the user has turned off the display of images, render a D-link inline 
to give access to the long description."

I think that users should have the option to turn off the 
presentation of longdesc as D-link. 99% of people who turn 
images off don't want to be bothered with images. Not making 
it optional, will discourage authors (e.g., me) from writing longdesc.
( I don't write d-links since they reduce usability; I will write longdesc 
only if I know that they don't reduce usability and are hidden unless 
explicetily set by the user to show them). 

2. image maps. 

Guidelines may mention supporting alt text to AREA elements. 
All browsers that I know of support only the alt of the IMG used as 
a map, which is good for nothing.
This is priority 1. You can't navigate a site without a navigation bar.

3. frames.

Somethings to add:

Allow to turn off frames.

When frames are turned off:
  1. render the NOFRAMES element(s)
  2. Make it an option to render the FRAME elements as a list of links.
   When doing so use the value of the title attribute of the FRAME 
   as the link description, if not available, use the value of name, 
   if not available use the value of src.

With frames on:  
  Allow users to override author's setting of scrolling=no, and noresize. 

4. Meta refresh

UA who support autoloading of documents 
with <META http-equiv=Refresh ...> should allow turning 
this feature off, possibly with presenting the url of the new 
page as a regular link. ("possibly", as UAs are not required by HTML to
support this in any way)

5. etc.

Among the usability improving things (inspired from Opera):

5.1 allow user to define different text decoration for visited and 
unvisited link (e.g. underline unvisited, do not underline/strike 
through visited). This is good for color blind people or monochrome 
screens. Distinction by color is not sufficient.

5.2 allow users to set "always show image border when used as link"
(override border=0) as well as "always show active frame border".


Nir Dagan                            
Assistant Professor of Economics      
Universitat Pompeu Fabra
Barcelona (Spain)

email: dagan@upf.es
Website: http://www.econ.upf.es/%7Edagan/
Received on Friday, 5 June 1998 11:04:41 UTC

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