graphviz: Support wikilinks embedded in the graph.

(Sponsored by The TOVA Company.)

IkiWiki/Plugin/graphviz.pm

@@ -11,7 +11,7 @@ use IPC::Open2;
 sub import {
 	hook(type => "getsetup", id => "graphviz", call => \&getsetup);
 	hook(type => "needsbuild", id => "version", call => \&needsbuild);
-	hook(type => "preprocess", id => "graph", call => \&graph);
+	hook(type => "preprocess", id => "graph", call => \&graph, scan => 1);
 }
 
 sub getsetup () {
@@ -94,7 +94,42 @@ sub render_graph (\%) {
 
 sub graph (@) {
 	my %params=@_;
-	$params{src} = "" unless defined $params{src};
+
+	# Support wikilinks in the graph source.
+	my $src=$params{src};
+	$src="" unless defined $src;
+	$src=IkiWiki::linkify($params{page}, $params{destpage}, $params{src});
+	return unless defined wantarray; # scan mode short-circuit
+	if ($src ne $params{src}) {
+		# linkify makes html links, but graphviz wants plain
+		# urls. This is, frankly a hack: Process source as html,
+		# throw out everything inside tags that is not a href.
+		my $s;
+		my $nested=0;
+		use HTML::Parser;
+		error $@ if $@;
+		my $p=HTML::Parser->new(api_version => 3);
+		$p->handler(start => sub {
+			my %attrs=%{shift()};
+			if (exists $attrs{href}) {
+				$s.="\"$attrs{href}\"";
+			}
+			$nested++;
+		}, "attr");
+		$p->handler(end => sub {
+			$nested--;
+		});
+		$p->handler(default => sub {
+			$s.=join("", @_) unless $nested;
+		}, "text");
+		$p->parse($src);
+		$p->eof;
+		$params{src}=$s;
+	}
+	else {
+		$params{src}=$src;
+	}
+
 	$params{type} = "digraph" unless defined $params{type};
 	$params{prog} = "dot" unless defined $params{prog};
 	error gettext("prog not a valid graphviz program") unless $graphviz_programs{$params{prog}};

debian/changelog

@@ -8,6 +8,8 @@ ikiwiki (3.20111107) UNRELEASED; urgency=low
     difficult in yaml setup files. (smcv)
   * graphviz: Support urls embedded in the graph, by having graphviz
     generate an imagemap.
+  * graphviz: Support wikilinks embedded in the graph.
+    (Sponsored by The TOVA Company.)
 
  -- Joey Hess <joeyh@debian.org>  Thu, 17 Nov 2011 18:52:23 -0400
 

doc/ikiwiki/directive/graph.mdwn

@@ -5,6 +5,19 @@ graphs in a page.  Example usage:
 
 	\[[!graph src="a -> b -> c; a -> c;"]]
 
+Nodes on the graph can link to external urls using regular graphviz syntax,
+and a clickable imagemap will be created. As a special extension for
+ikiwiki, [[WikiLinks|ikiwiki/wikilink]] can also be used. For example:
+
+	\[[!graph src=""""
+	google [ href="http://google.com/" ]
+	sandbox [ href=[[SandBox]] ]
+	help [ href=[[ikiwiki/formatting]] ]
+	newpage [ href=[[NewPage]] ]
+	
+	google -> sandbox -> help -> newpage -> help -> google;
+	""""]]
+
 The `graph` directive supports the following parameters:
 
 - `src` - The graphviz source to render.