The basic structure for a HTML page using client side image maps will have the following layout
// Image map specification with name "mapname" <MAP NAME=...> ... specification ... </MAP> // Image tag <img src="..." ISMAP USEMAP="mapname">
This poses an interesting question. Since we normally call the graphing script directly in the <img> tag how do we get hold of the image map (which is available only in the image script) in this "HTML wrapper" script?
In JpGraph there is actually two ways of solving this.
Use the preferred "builtin" way using the modified
StrokeCSIM() instead of
Directly use the
Graph::GetHTMLImageMap() which gives you
fine control at the expense of more complex coding. This is necessary if
several image map graphs are needed on the same page.
The first (and preferred) way modifies the stroke method so that instead of
returning an image (like the standard
StrokeCSIM() actually returns an HTML page containing both the
image map specification and the correct
This means that it is necessary to treat an image map returning image script
differently from a non-CSIM image script, for example it is not posible to use it
directly as the target for the "
src" attribute of the
<IMG> tag since it sends back a HTML page containing both an
image tag together with an image map.