+package Net::Z3950::GRS1;
+
+use strict;
+use IO::Handle;
+use Carp;
+
+
+sub new {
+ my $class = shift;
+ my $self = {};
+
+ $self->{ELEMENTS} = [];
+ $self->{FH} = *STDOUT; ## Default output handle is STDOUT
+ bless $self, $class;
+
+ return $self;
+}
+
+
+sub GetElementList {
+ my $self = shift;
+
+ return $self->{ELEMENTS};
+}
+
+
+sub CreateTaggedElement {
+ my ($self, $type, $value, $element_data) = @_;
+ my $tagged = {};
+
+ $tagged->{TYPE} = $type;
+ $tagged->{VALUE} = $value;
+ $tagged->{OCCURANCE} = undef;
+ $tagged->{META} = undef;
+ $tagged->{VARIANT} = undef;
+ $tagged->{ELEMENTDATA} = $element_data;
+
+ return $tagged;
+}
+
+
+sub GetTypeValue {
+ my ($self, $TaggedElement) = @_;
+
+ return ($TaggedElement->{TYPE}, $TaggedElement->{VALUE});
+}
+
+
+sub GetElementData {
+ my ($self, $TaggedElement) = @_;
+
+ return $TaggedElement->{ELEMENTDATA};
+}
+
+
+sub CheckTypes {
+ my ($self, $which, $content) = @_;
+
+ if ($which == &Net::Z3950::GRS1::ElementData::String) {
+ if (ref($content) eq '') {
+ return 1;
+ } else {
+ croak "Wrong content type, expected a scalar";
+ }
+ } elsif ($which == &Net::Z3950::GRS1::ElementData::Subtree) {
+ if (ref($content) eq __PACKAGE__) {
+ return 1;
+ } else {
+ croak "Wrong content type, expected a blessed reference";
+ }
+ } else {
+ croak "Content type currently not supported";
+ }
+}
+
+
+sub CreateElementData {
+ my ($self, $which, $content) = @_;
+ my $ElementData = {};
+
+ $self->CheckTypes($which, $content);
+ $ElementData->{WHICH} = $which;
+ $ElementData->{CONTENT} = $content;
+
+ return $ElementData;
+}
+
+
+sub AddElement {
+ my ($self, $type, $value, $which, $content) = @_;
+ my $Elements = $self->GetElementList;
+ my $ElmData = $self->CreateElementData($which, $content);
+ my $TaggedElm = $self->CreateTaggedElement($type, $value, $ElmData);
+
+ push(@$Elements, $TaggedElm);
+}
+
+
+sub _Indent {
+ my ($self, $level) = @_;
+ my $space = "";
+
+ foreach (1..$level - 1) {
+ $space .= " ";
+ }
+
+ return $space;
+}
+
+
+sub _RecordLine {
+ my ($self, $level, $pool, @args) = @_;
+ my $fh = $self->{FH};
+ my $str = sprintf($self->_Indent($level) . shift(@args), @args);
+
+ print $fh $str;
+ if (defined($pool)) {
+ $$pool .= $str;
+ }
+}
+
+
+sub Render {
+ my $self = shift;
+ my %args = (
+ FORMAT => &Net::Z3950::GRS1::Render::Plain,
+ FILE => '/dev/null',
+ LEVEL => 0,
+ HANDLE => undef,
+ POOL => undef,
+ @_ );
+ my @Elements = @{$self->GetElementList};
+ my $TaggedElement;
+ my $fh = $args{HANDLE};
+ my $level = ++$args{LEVEL};
+ my $ref = $args{POOL};
+
+ if (!defined($fh) && defined($args{FILE})) {
+ open(FH, '> ' . $args{FILE}) or croak "Render: Unable to open file '$args{FILE}' for writing: $!";
+ FH->autoflush(1);
+ $fh = *FH;
+ }
+ $self->{FH} = defined($fh) ? $fh : $self->{FH};
+ $args{HANDLE} = $fh;
+ foreach $TaggedElement (@Elements) {
+ my ($type, $value) = $self->GetTypeValue($TaggedElement);
+ if ($self->GetElementData($TaggedElement)->{WHICH} == &Net::Z3950::GRS1::ElementData::String) {
+ $self->_RecordLine($level, $ref, "(%s,%s) %s\n", $type, $value, $self->GetElementData($TaggedElement)->{CONTENT});
+ } elsif ($self->GetElementData($TaggedElement)->{WHICH} == &Net::Z3950::GRS1::ElementData::Subtree) {
+ $self->_RecordLine($level, $ref, "(%s,%s) {\n", $type, $value);
+ $self->GetElementData($TaggedElement)->{CONTENT}->Render(%args);
+ $self->_RecordLine($level, $ref, "}\n");
+ }
+ }
+ if ($level == 1) {
+ $self->_RecordLine($level, $ref, "(0,0)\n");
+ }
+}
+
+
+package Net::Z3950::GRS1::ElementData;
+
+## Define some constants according to the GRS-1 specification
+
+sub Octets { 1 }
+sub Numeric { 2 }
+sub Date { 3 }
+sub Ext { 4 }
+sub String { 5 }
+sub TrueOrFalse { 6 }
+sub OID { 7 }
+sub IntUnit { 8 }
+sub ElementNotThere { 9 }
+sub ElementEmpty { 10 }
+sub NoDataRequested { 11 }
+sub Diagnostic { 12 }
+sub Subtree { 13 }
+
+
+package Net::Z3950::GRS1::Render;
+
+## Define various types of rendering formats
+
+sub Plain { 1 }
+sub XML { 2 }
+sub Raw { 3 }
+
+
+1;
+
+__END__
+
+
+=head1 NAME
+
+Net::Z3950::Record::GRS1 - Perl package used to encode GRS-1 records.
+
+=head1 SYNOPSIS
+
+ use Net::Z3950::Record::GRS1;
+
+ my $a_grs1_record = new Net::Z3950::Record::GRS1;
+ my $another_grs1_record = new Net::Z3950::Record::GRS1;
+
+ $a_grs1_record->AddElement($type, $value, $content);
+ $a_grs1_record->render();
+
+=head1 DESCRIPTION
+
+Here goes the documentation. I guess, you'll have to wait for it!
+
+=head1 AUTHOR
+
+Anders Sønderberg Mortensen <sondberg@indexdata.dk>
+Index Data ApS, Copenhagen, Denmark.
+2001/03/09
+
+=head1 SEE ALSO
+
+Specification of the GRS-1 standard, for instance in the Z39.50 protocol specification.
+
+=cut
+
+#$Log: GRS1.pm,v $
+#Revision 1.1 2001-03-13 14:17:15 sondberg
+#Added support for GRS-1.
+#
+