allow format to use any language supported by highlight

format: Provide a htmlizefallback hook that other plugins can use to
handle formats that are not suitable for general-purpose htmlize hooks.

highlight: Use the hook to allow formatting of any language/extension,
without it needing to be enabled for standalone source files.

highlight: If the highlight perl binding is not available, fallback
safely to a passthrough mode.

1 files changed, 20 insertions, 8 deletions

diff --git a/IkiWiki/Plugin/format.pm b/IkiWiki/Plugin/format.pm
index bbe3aa9fe..1513cbed7 100644
--- a/IkiWiki/Plugin/format.pm
+++ b/IkiWiki/Plugin/format.pm
@@ -10,21 +10,33 @@ sub import {
 }
 
 sub preprocess (@) {
-	my $format=$_[0];
-	shift; shift;
-	my $text=$_[0];
-	shift; shift;
 	my %params=@_;
+	my $format=shift;
+	shift;
+	my $text=IkiWiki::preprocess($params{page}, $params{destpage}, shift);
+	shift;
 
 	if (! defined $format || ! defined $text) {
 		error(gettext("must specify format and text"));
 	}
-	elsif (! exists $IkiWiki::hooks{htmlize}{$format}) {
-		error(sprintf(gettext("unsupported page format %s"), $format));
+	elsif (exists $IkiWiki::hooks{htmlize}{$format}) {
+		return IkiWiki::htmlize($params{page}, $params{destpage},
+		                        $format, $text);
 	}
+	else {
+		# Other plugins can register htmlizefallback
+		# hooks to add support for page types
+		# not suitable for htmlize. Try them until
+		# one succeeds.
+		my $ret;
+		IkiWiki::run_hooks(htmlizefallback => sub {
+			$ret=shift->($format, $text)
+				unless defined $ret;
+		});
+		return $ret if defined $ret;
 
-	return IkiWiki::htmlize($params{page}, $params{destpage}, $format,
-		IkiWiki::preprocess($params{page}, $params{destpage}, $text));
+		error(sprintf(gettext("unsupported page format %s"), $format));
+	}
 }
 
 1