The Sepcification says
ISMAP An image map is a graphical map by which users can navigate
transparently from one information resource to another. The
ISMAP attribute identifies an image as an image map. The IMG
element can then be used as part of the label for a hypertext
link (see the anchor element). When the user clicks on the
image the location clicked is sent to the server designated by
the hypertext link.
For example:
<A HREF="http://machine/htbin/imagemap/sample">
<IMG SRC="sample.gif" ISMAP></A>
The DTD is even worse:
<!ATTLIST IMG
...
ismap (ismap) #IMPLIED -- pass clicks to server --
>
<!ATTLIST FIG
...
imagemap (%URI) #IMPLIED -- pass background clicks to server --
>
<!ATTLIST OVERLAY
...
imagemap (%URI) #IMPLIED -- pass background clicks to server --
>
Unfortunately, there is no mention of what this is supposed to mean.
*How* is the location sent? Via GET or POST? As one argument or two?
Measured in pixels or fraction of image? From lower or upper left?
The description of the SHAPE attribute on the <A> tag in the spec
says that
The x coordinate increases to the right, and the y coordinate
increases downwards in the same way as IMG and image maps.
But it then goes on to say that the number may be fractional. Are
browsers allowed to send fractions to ISMAP images, figures, and
overlays? (I think that this would be a good idea, especially if they
are allowed to scale images, but I don't think that this is current
practice, and people should probably be warned that this is legal.)
Or am I missing something (it wouldn't be the first time), and there
is a good reason why this is being left unspecified?
----
Evan Kirshenbaum +------------------------------------
HP Laboratories |Pious Jews have a category of
1500 Page Mill Road, Building 4A |questions that can harmlessly be
Palo Alto, CA 94304 |allowed to go without an answer
|until the Messiah comes. I suspect
kirshenbaum@hpl.hp.com |that this is one of them.
(415)857-7572 | Joeseph C. Fineman