linkmap: Add option to omit disconnected pages from the map.

IkiWiki/Plugin/linkmap.pm

@@ -49,6 +49,7 @@ sub genmap ($) {
 	my $mapnum=shift;
 	return "" unless exists $maps{$mapnum};
 	my %params=%{$maps{$mapnum}};
+	my $connected=IkiWiki::yesno($params{connected});
 
 	# Get all the items to map.
 	my %mapitems = map { $_ => urlto($_, $params{destpage}) }
@@ -79,24 +80,38 @@ sub genmap ($) {
 	print OUT "charset=\"utf-8\";\n";
 	print OUT "ratio=compress;\nsize=\"".($params{width}+0).", ".($params{height}+0)."\";\n"
 		if defined $params{width} and defined $params{height};
+	my %shown;
+	my $show=sub {
+		my $item=shift;
+		if (! $shown{$item}) {
+			print OUT "\"$item\" [shape=box,href=\"$mapitems{$item}\"];\n";
+			$shown{$item}=1;
+		}
+	};
 	foreach my $item (keys %mapitems) {
-		print OUT "\"$item\" [shape=box,href=\"$mapitems{$item}\"];\n";
+		$show->($item) unless $connected;
 		foreach my $link (map { bestlink($item, $_) } @{$links{$item}}) {
-			print OUT "\"$item\" -> \"$link\";\n"
-				if $mapitems{$link};
+			next unless length $link and $mapitems{$link};
+			foreach my $endpoint ($item, $link) {
+				$show->($endpoint);
+			}
+			print OUT "\"$item\" -> \"$link\";\n";
 		}
 	}
 	print OUT "}\n";
-	close OUT;
+	close OUT || error gettext("failed to run dot");
 
 	local $/=undef;
 	my $ret="<object data=\"".urlto($dest, $params{destpage}).
 	       "\" type=\"image/png\" usemap=\"#linkmap$mapnum\">\n".
 	        <IN>.
 	        "</object>";
-	close IN;
+	close IN || error gettext("failed to run dot");
 	
 	waitpid $pid, 0;
+	if ($?) {
+		error gettext("failed to run dot");
+	}
 	$SIG{PIPE}="DEFAULT";
 	error gettext("failed to run dot") if $sigpipe;
 

debian/changelog

@@ -11,6 +11,7 @@ ikiwiki (3.20091219) UNRELEASED; urgency=low
   * comments: Add a checksum to the name of comment pages, to
     avoid merge conflicts when comments are posted to two branches of a
     site.
+  * linkmap: Add option to omit disconnected pages from the map.
 
  -- Joey Hess <joeyh@debian.org>  Fri, 25 Dec 2009 14:31:22 -0500
 

doc/ikiwiki/directive/linkmap.mdwn

@@ -7,9 +7,7 @@ graph showing the links between a set of pages in the wiki. Example usage:
 
 Only links between mapped pages will be shown; links pointing to or from
 unmapped pages will be omitted. If the pages to include are not specified,
-the links between all pages (and other files) in the wiki are mapped. For
-best results, only a small set of pages should be mapped, since otherwise
-the map can become very large, unwieldy, and complicated.
+the links between all pages (and other files) in the wiki are mapped. 
 
 Here are descriptions of all the supported parameters to the `linkmap`
 directive:
@@ -18,5 +16,14 @@ directive:
 * `height`, `width` - Limit the size of the map to a given height and width,
   in inches. Both must be specified for the limiting to take effect, otherwise
   the map's size is not limited.
+* `connected` - Controls whether to include pages on the map that link to
+  no other pages (connected=no, the default), or to only show pages that
+  link to others (connected=yes).
+
+For best results, only a small set of pages should be mapped, since
+otherwise the map can become very large, unwieldy, and complicated.
+If too many pages are included, the map may get so large that graphviz
+cannot render it. Using the `connected` parameter is a good way to prune
+out pages that clutter the map.
 
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