To provide alternate text for a hotspot in an image map, assign the text to the destination of the hotspot link. For example:
[GraphALT]
; destination or GraphicID#dest or URL dest = desired alt text
; a URL destination is the last part of the URL without extension
; ch01f853#RFstage = Tuner first stage
; IFstage = Intermediate Frequency stage
The text you assign becomes the content of the alt attribute of the hotspot <area> tag, unless you tell DITA2Go to use the title attribute instead; see §32.9.1.2 Using the title attribute for alternate text for a hotspot.
The destination ID must be one of the following, depending on the type of link:
Suppose you use a HyperLink PI marker for an image-map link, with the following marker content:
<?dthtm HyperLink="http://www.chezmoi.com/mylife.htm"
?>
You would assign alternate text for the hotspot to destination identifier mylife, which is the target file name (without path or extension):
[GraphALT
mylife = alternate text for hotspot
However, if the HyperLink PI marker content looks like this:
<?dthtm HyperLink="http://www.chezmoi.com/mylife.htm#siblings"
?>
You would assign alternate text as follows:
[GraphALT
mylife#siblings = alternate text for hotspot
Suppose your image-map link is a HyperJump PI marker, with a destination in the same document; for example:
<?dthtm HyperJump="awards.dita:firstplace"
?>
You would assign alternate text for the hotspot to destination identifier firstplace, which is the target HyperAnchor PI marker content:
[GraphALT
firstplace = alternate text for hotspot
If you have several graphics with image-map links that all point to the same destination, and you want different alternate text for one of them, prefix the destination identifier with the file name of the graphic (no extension) and a #. For example:
[GraphALT
ab34e651#firstplace = different alternate text for hotspot