source: trunk/gsdl/perllib/plugins/ReferPlug.pm@ 1991

###########################################################################
#
# ReferPlug.pm - a plugin for bibliography records in Refer format
#
# A component of the Greenstone digital library software
# from the New Zealand Digital Library Project at the 
# University of Waikato, New Zealand.
#
# Copyright 2000 Gordon W. Paynter
# Copyright 1999-2000 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.
#
###########################################################################


# ReferPlug reads bibliography files in Refer format.
#
# by Gordon W. Paynter ([email protected]), November 2000
#
# Loosely based on hcibib2Plug by Steve Jones ([email protected]).
# Which was based on EMAILPlug by Gordon Paynter ([email protected]).
# Which was based on old versions of HTMLplug and HCIBIBPlugby by Stefan
# Boddie and others -- it's hard to tell what came from where, now.
#
#
# ReferPlug creates a document object for every reference in the file.
# It is a subclass of SplitPlug, so if there are multiple records, all
# are read.
#
# Document text:
#   The document text consists of the reference in Refer format
#
# Metadata:
#   $Creator    %A  Author name
#   $Title      %T  Title of article of book
#   $Journal    %J  Title of Journal
#   $Booktitle  %B  Title of book containing the publication
#   $Report     %R  Type of Report, paper or thesis
#   $Volume     %V  Volume Number of Journal
#   $Number     %N  Number of Journal within Volume
#   $Editor     %E  Editor name
#   $Pages      %P  Page Number of article
#   $Publisher  %I  Name of Publisher
#   $Publisheraddr  %C  Publisher's address
#   $Date       %D  Date of publication
#   $Keywords   %K  Keywords associated with publication 
#   $Abstract   %X  Abstract of publication
#   $Copyright  %*  Copyright information for the article
#


package ReferPlug;

use SplitPlug;


# ReferPlug is a sub-class of BasPlug.
sub BEGIN {
    @ISA = ('SplitPlug');
}

# This plugin processes files with the suffix ".bib"
sub get_default_process_exp {
    return q^(?i)\.bib$^;
}

# This plugin splits the input text at blank lines
sub get_default_split_exp {
    return q^\n\s*\n^;
}


# The process function reads a single bibliogrphic record and stores
# it as a new document.

sub process {
    my $self = shift (@_);
    my ($textref, $pluginfo, $base_dir, $file, $metadata, $doc_obj) = @_;
    my $outhandle = $self->{'outhandle'};

    # Check that we're dealing with a valid Refer file
    return undef unless ($$textref =~ /^\s*%/);

    # Report that we're processing the file
    print $outhandle "ReferPlug: processing $file\n"
    if ($self->{'verbosity'}) > 1;

    my %field = ('H', 'Header',
         'A', 'Creator',
         'T', 'Title',
         'J', 'Journal',
         'B', 'Booktitle',
         'R', 'Report',
         'V', 'Volume',
         'N', 'Number',
         'E', 'Editor',
         'P', 'Pages',
         'I', 'Publisher',
         'C', 'PublisherAddress',
         'D', 'Date',
         'O', 'OtherInformation',
         'K', 'Keywords',
         'X', 'Abstract',
         '*', 'Copyright');

    # Metadata fields 
    my %metadata;
    my ($id, $Creator, $Keywords, $text);
    my @lines = split(/\n+/, $$textref);

    
    # Read and process each line in the bib file.
    # Each file consists of a set of metadata items, one to each line
    # with the Refer key followed by a space then the associated data
    foreach my $line (@lines) {
    
    # Add each line.  Most lines consist of a field identifer and
    # then data, and we simply store them, though we treat some
    # of the fields a bit differently.

    $line =~ s/\s+/ /g;
    $text .= "$line\n";
    $ReferFormat .= "$line\n";
    
    next unless ($line =~ /^%[A-Z\*]/);
    $id = substr($line,1,1);
    $line =~ s/^%. //;
    
    # Add individual authors in "Lastname, Firstname" format.
    # (The full set of authors will be added below as "Creator".)
    if ($id eq "A") {

        # Reformat and add author name
        my @words = split(/ /, $line);
        my $lastname = pop @words;
        my $firstname = join(" ",  @words);
        my $fullname = $lastname . ", " . $firstname;
        
        # Add each name to set of Authors
        if ($fullname =~ /\w/) {
        $fullname = &text_into_html($fullname);
        $doc_obj->add_metadata ($cursection, "Author", $fullname);
        }
    }

    # Add individual keywords.
    # (The full set of authors will be added below as "Keywords".)
    if ($id eq "K") {
        my @keywordlist = split(/,/, $line);
        foreach my $k (@keywordlist) {
        $k = lc($k);
        $k =~ s/\s*$//; 
        $k =~ s/^\s*//; 
        if ($k =~ /\w/) {
            $k = &text_into_html($k);
            $doc_obj->add_metadata ($cursection, "Keyword", $k);
        }
        } 
    }
    
    # Add this line of metadata
    $metadata{$id} .= "$line\n";
    }



    # Add the various field as metadata
    my ($f, $name, $value);
    foreach $f (keys %metadata) {
    
    next unless (defined $field{$f});
    next unless (defined $metadata{$f});    

    $name = $field{$f};
    $value = $metadata{$f};

    # Add the various field as metadata 
    
    # The Creator metadata is found by concatenating authors.
    if ($f eq "A") {

        my @authorlist = split(/\n/, $value);
        my $lastauthor = pop @authorlist;
        my $Creator = "";
        if (scalar @authorlist) {
        $Creator = join(", ", @authorlist) . "and $lastauthor";
        } else {
        $Creator = $lastauthor;
        }

        if ($Creator =~ /\w/) {
        $Creator = &text_into_html($Creator);
        $doc_obj->add_metadata ($cursection, "Creator", $Creator);
        }
    }

    # The rest are added in a standard way
    else {
        $value = &text_into_html($value);
        $doc_obj->add_metadata ($cursection, $name, $value);
    }

    # Books and Journals are additionally marked for display purposes
    if ($f eq "B") {
        $doc_obj->add_metadata($cursection, "BookConfOnly", 1);
    } elsif ($f eq "J") {
        $doc_obj->add_metadata($cursection, "JournalsOnly", 1); 
    }


    }

    # Add the text in refer format(all fields)
    if ($text =~ /\w/) {
    $text = &text_into_html($text);
    $doc_obj->add_text ($cursection, $text);
    }

    return 1; # processed the file
}

1;
#
# Convert a text string into HTML.
#
# The HTML is going to be inserted into a GML file, so 
# we have to be careful not to use symbols like ">",
# which ocurs frequently in email messages (and use
# &gt instead.
#
# This function also turns links and email addresses into hyperlinks,
# and replaces carriage returns with <BR> tags (and multiple carriage
# returns with <P> tags).
#

sub text_into_html {
    my ($text) = @_;


    # Convert problem charaters into HTML symbols
    $text =~ s/&/&amp;/g;
    $text =~ s/</&lt;/g;
    $text =~ s/>/&gt;/g;
    $text =~ s/\"/&quot;/g;
    $text =~ s/\'/ /g;
    $text =~ s/\+/ /g;
    $text =~ s/\(/ /g;
    $text =~ s/\)/ /g;

    # convert email addresses and URLs into links
    $text =~ s/([\w\d\.\-]+@[\w\d\.\-]+)/<a href=\"mailto:$1\">$1<\/a>/g;
    $text =~ s/(http:\/\/[\w\d\.\-]+[\/\w\d\.\-]*)/<a href=\"$1">$1<\/a>/g;

    # Clean up whitespace and convert \n charaters to <BR> or <P>
    $text =~ s/ +/ /g;
    $text =~ s/\s*$//; 
    $text =~ s/^\s*//; 
    $text =~ s/\n/\n<BR>/g;
    $text =~ s/<BR>\s*<BR>/<P>/g;

    return $text;
}