# Copyright (C) 2000, HELM Team.
# 
# This file is part of HELM, an Hypertextual, Electronic
# Library of Mathematics, developed at the Computer Science
# Department, University of Bologna, Italy.
# 
# HELM 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.
# 
# HELM 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 HELM; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
# 
# For details, see the HELM World-Wide-Web page,
# http://cs.unibo.it/helm/.

use XML::Parser;

use Env;
my $HELM_CONFIGURATION_DIR = $ENV{"HELM_CONFIGURATION_DIR"};
my $DEFAULT_HELM_CONFIGURATION_DIR = "@HELM_ETC_DIR@";
# this should be the only fixed constant
if (defined ($HELM_CONFIGURATION_DIR)) {
   $configuration_file = $HELM_CONFIGURATION_DIR."/configuration.xml";
} else {
   $configuration_file = $DEFAULT_HELM_CONFIGURATION_DIR."/configuration.xml";
}

$parser = new XML::Parser(Handlers => {Start => \&handle_start,
                                       End   => \&handle_end,
                                       Char  => \&handle_char});


$parser->parsefile($configuration_file, ErrorContext => 3);


sub handle_start
{
   if ($_[1] eq "value-of") {
      $$varname .= ${$_[3]};
   } elsif ($_[1] ne "configuration") {
      $varname = $_[1];
   }
}

sub handle_end
{
   if ($_[1] ne "value-of" && $_[1] ne "configuration") {
      # Next line for debugging only:
      # print "OK: #$_[1]# := #$$varname#\n";
      $varname = undef;
   }
}

sub handle_char
{
   $$varname .= $_[1];
}