Hello,
I thought the UA WG might find this interesting.
- Ian
--
Ian Jacobs (jacobs@w3.org)
Tel/Fax: (212) 684-1814
http://www.w3.org/People/Jacobs
Forwarded message 1
WRT to the follow comment in the HTML4.0 spec:
http://www.w3.org/TR/REC-html40/
> 13.2 Including an image: the IMG element
>
> <!-- To avoid problems with text-only UAs as well as
> to make image content understandable and navigable
> to users of non-visual UAs, you need to provide
> a description with ALT, and avoid server-side image maps -->
This is a common misconception of server-side image maps resulting from
a number of popular, but very poor server-side image map processors.
The original design (speaking as the original designer of ISMAP :) was that if
the client
did not/could not support maps that it would send a request to the server with
NO temporal/spatial information would would then trigger an approriate response
from the server (e.g., a menu of the choices or anything else the designer
could dream
up). This gives the page author a lot of desirable flexibility. For example:
<A HREF="http://webhost/smart-image-mapper"><IMG SRC="imagefile" ALT="see
menu"></A>
On a Visual UA would fetch "imagefile" and send spatial coordinates to
smart-image-mapper
On a non-Visual UA would fetch "smart-image-mapper" with no coordinate
data and display
the result in-line (if it can) otherwise it would present the ALT
text as a link which would
fetch "smart-image-mapper" with no spatial coordinate data (which is
expected to
generate an appropriate page).
It really sucks that so many image-map clients are broken and do not generate
pages for
"null" coordinates. Perhaps we need to amend the spec to include a hint to web
browsers
about what they can expect to find, ISMAP could have an optional value:
<A HREF="xxx"><IMG SRC="..." ISMAP> <!-- unknown, prolly
broken -->
<A HREF="xxx"><IMG SRC="..." ISMAP="link"> <!-- prefer a
link to xxx -->
<A HREF="xxx"><IMG SRC="..." ISMAP="inline"> <!-- prefer to
inline output from xxx -->