--- trunk/lib/Biblio/Isis.pm	2006/07/09 12:18:44	58
+++ trunk/lib/Biblio/Isis.pm	2006/08/25 16:35:47	67
@@ -7,7 +7,7 @@
 BEGIN {
 	use Exporter ();
 	use vars qw ($VERSION @ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
-	$VERSION     = 0.21;
+	$VERSION     = 0.23;
 	@ISA         = qw (Exporter);
 	#Give a hoot don't pollute, do not export more than needed by default
 	@EXPORT      = qw ();
@@ -84,7 +84,7 @@
 	read_fdt => 1,
 	include_deleted => 1,
 	hash_filter => sub {
-		my $v = shift;
+		my ($v,$field_number) = @_;
 		$v =~ s#foo#bar#g;
 	},
 	debug => 1,
@@ -114,7 +114,9 @@
 
 =item hash_filter
 
-Filter code ref which will be used before data is converted to hash.
+Filter code ref which will be used before data is converted to hash. It will
+receive two arguments, whole line from current field (in C<< $_[0] >>) and
+field number (in C<< $_[1] >>).
 
 =item debug
 
@@ -546,6 +548,10 @@
 Define delimiter which will be used to join repeatable subfields. You can
 specify option here instead in L</new> if you want to have per-record control.
 
+=item hash_filter
+
+You can override C<hash_filter> defined in L</new> using this option.
+
 =back
 
 =cut
@@ -557,9 +563,12 @@
 	my $mfn = shift || confess "need mfn!";
 	my $arg;
 
+	my $hash_filter = $self->{hash_filter};
+
 	if (ref($mfn) eq 'HASH') {
 		$arg = $mfn;
 		$mfn = $arg->{mfn} || confess "need mfn in arguments";
+		$hash_filter = $arg->{hash_filter} if ($arg->{hash_filter});
 	}
 
 	# init record to include MFN as field 000
@@ -575,10 +584,8 @@
 		foreach my $l (@{$row->{$f_nr}}) {
 
 			# filter output
-			if ($self->{'hash_filter'}) {
-				$l = $self->{'hash_filter'}->($l);
-				next unless defined($l);
-			}
+			$l = $hash_filter->($l, $f_nr) if ($hash_filter);
+			next unless defined($l);
 
 			my $val;
 			my $r_sf;	# repeatable subfields in this record
@@ -592,7 +599,7 @@
 					next if (! $t);
 					my ($sf,$v) = (substr($t,0,1), substr($t,1));
 					# XXX this might be option, but why?
-					next unless ($v);
+					next unless (defined($v) && $v ne '');
 #					warn "### $f_nr^$sf:$v",$/ if ($self->{debug} > 1);
 
 					if (ref( $val->{$sf} ) eq 'ARRAY') {
@@ -744,13 +751,21 @@
 As this is young module, new features are added in subsequent version. It's
 a good idea to specify version when using this module like this:
 
-  use Biblio::Isis 0.21
+  use Biblio::Isis 0.23
 
 Below is list of changes in specific version of module (so you can target
 older versions if you really have to):
 
 =over 8 
 
+=item 0.23
+
+Added C<hash_filter> to L</to_hash>
+
+=item 0.22
+
+Added field number when calling C<hash_filter>
+
 =item 0.21
 
 Added C<join_subfields_with> to L</new> and L</to_hash>.
@@ -785,6 +800,8 @@
 
 =head1 SEE ALSO
 
+L<Biblio::Isis::Manual> for CDS/ISIS manual appendix F, G and H which describe file format
+
 OpenIsis web site L<http://www.openisis.org>
 
 perl4lib site L<http://perl4lib.perl.org>