###########################################################################
#
# AZSectionList.pm --
# A component of the Greenstone digital library software
# from the New Zealand Digital Library Project at the 
# University of Waikato, New Zealand.
#
# Copyright (C) 1999 New Zealand Digital Library Project
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
#
###########################################################################

# classifier plugin for sorting sections alphabetically

# this is very similar to AZList except it sorts by
# section level metadata (excluding the top level)
# instead of just top level metadata

# the only change is to the classify() subroutine which 
# must now iterate through each section, adding each
# to the classification

package AZSectionList;

use AZList;
use sorttools;

sub BEGIN {
    @ISA = ('AZList');
}

sub classify {
    my $self = shift (@_);
    my ($doc_obj) = @_;

    my $doc_OID = $doc_obj->get_OID();
    my $thissection = $doc_obj->get_next_section ($doc_obj->get_top_section());

    while (defined $thissection) {
	$self->classify_section ($thissection, $doc_obj);
	$thissection = $doc_obj->get_next_section ($thissection);
    }
}

sub classify_section {
    my $self = shift (@_);
    my ($section, $doc_obj) = @_;

    my $doc_OID = $doc_obj->get_OID();
    my $metavalue = $doc_obj->get_metadata_element ($section, $self->{'metaname'});

    # if this section doesn't contain the metadata element we're
    # sorting by we won't include it in this classification
    if (defined $metavalue && $metavalue ne "") {
	if ($self->{'metaname'} eq 'Creator') {
	    &sorttools::format_string_name_english (\$metavalue);
	} else {
	    &sorttools::format_string_english (\$metavalue);
	}
	if (defined $self->{'list'}->{"$doc_OID.$section"}) {
	    print STDERR "WARNING: AZSectionList::classify called multiple times " .
		"for $doc_OID.$section\n";
	} 
	$self->{'list'}->{"$doc_OID.$section"} = $metavalue;
    }
}


1;