Re: LYNX-DEV ISMAP/USEMAP alt text

[Foteos Macrides]

"Hiram Lester, Jr." <address@hidden> wrote:
>On Sat, 5 Apr 1997, Al Gilman wrote:
>
>> Can anybody think of a reason to keep the [ISMAP] legend on the
>> screen if a USEMAP has been furnished in the web page?  I would
>> agree with Hiram that it's best it just vanish if there is a 
>> USEMAP that Lynx can use.
>
>The reason that it is kept is that it points to a different URL than the
>USEMAP does.  The USEMAP points to a fragment (theoretically could be an
>external document, but as of Netscape 3.01, external USEMAP references
>don't work), while the ISMAP points to a map file.  If you completely
>remove it, you end up with a link that can't be followed.  99% of the time
>it would be pointless to follow the link anyway...

        The MAP/USEMAP markup started off as a rogue ID from Spyglass,
back when HTML 3.0 was still being seriously discussed in the HTML-WG,
and was shunned by the WG in favor of the far superior FIG markup.
Netscape implemented the MAP/USEMAP markup instead of the FIG markup.
Then, the FIG markup was dropped and the MAP/USEMAP markup was put
in the W3C's so-called HTML 3.2 as one of the cop-outs in the May
1996 "carjacking" of HTML standarization.

        When I implemented MAP/USEMAP handling in Lynx, we had set
up the server-side imagemap "workaround" of sending 0,0 coordinates
so that Lynx-friendly sites could use that point, presumeable as
part of the background "default", for sending a text-suitable
alternative page to Lynx.  The MAP/USEMAP markup does not include
a "default" attribute -- one of its many, frequently criticized,
weaknesses -- and few providers have figured out how to work around
that handicap.  The consequence is that it can be difficult to work
a text-suitable AREA into the MAP without conflicts for GUIs.  I
therefore ignored the provision that an ISMAP attribute, if present,
should be ignored if a USEMAP attribute is present, and set up the
code to use the ALT string, if present, for the client-side MAP
content, but prepend an "[ISMAP]" link followed by a hyphen to
indicate that it is associated with (an alternative to) the
client-side MAP content, and could still be used to send a 0,0
coordinate pair for the text-suitable page at the Lynx-friendly
sites.  If clickable_images is configured or toggled ON, then
another hyphen is appended followed by an "[IMAGE]" link, to
indicate that it is the actual image associated with the map
link(s).


>On Sat, 5 Apr 1997, Klaus Weide wrote:
>
>> I suggest that it should still be shown if
>> 
>> *           IMAGE_TOGGLE  toggle handling of all images as links
>> 
>> is in effect.  (That would mean that '*' toggles on-or-off *two*
>> additional links in this case.)  Just on the principle that if there is
>> some kind of link, it should be accessible with Lynx (even if it's not 
>> wanted in _most_ cases).
>
>I thought of that, but the link is actually to the .map file and not to
>the image itself.  If you use the current behavior, and toggle images on,
>you actually get something like:
>
>    [IMAGE]-[ISMAP]-[USEMAP]
>
>If you allow the ISMAP to be toggled with images, you'd have 2 links to
>toggle on/off...

        If Klaus' patch is used, it needs code to eliminate the
associated Anchor for the server-side imagemap, and not yield a
dangling link when links_are_numbered is ON.  That wasn't needed
for the vanilla code, which creates links for both.

                                Fote

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 Foteos Macrides            Worcester Foundation for Biomedical Research
 address@hidden         222 Maple Avenue, Shrewsbury, MA 01545
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