[previous] [next] WebDot Tutorial: Clickable edges

Dot supports a "\N" substitution so that the URLs of the nodes can be based on the node name. Edges can also have URLs, and \E, \H, \T can be used to substitute the edgename, head_node name, tail_node name respectively. Because of the limited abilities of image maps, a label must exist and the URL is attached to it.
digraph G {
        graph [URL="default.html"]
        node [URL="\N.html"]
        a -> b -> c
        a -> c [URL="\E.html", label="\E"]
}

The box around the clickable image can be suppressed with "border=0"
<a href="/cgi-bin/webdot/webdot/hedges.dot.dot.map">
<img src="/cgi-bin/webdot/webdot/hedges.dot.dot.png" border="0" ismap>
</a>