| 1 | ###########################################################################
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| 2 | #
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| 3 | # RecPlug.pm --
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| 4 | # A component of the Greenstone digital library software
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| 5 | # from the New Zealand Digital Library Project at the
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| 6 | # University of Waikato, New Zealand.
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| 7 | #
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| 8 | # Copyright (C) 1999 New Zealand Digital Library Project
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| 9 | #
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| 10 | # This program is free software; you can redistribute it and/or modify
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| 11 | # it under the terms of the GNU General Public License as published by
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| 12 | # the Free Software Foundation; either version 2 of the License, or
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| 13 | # (at your option) any later version.
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| 14 | #
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| 15 | # This program is distributed in the hope that it will be useful,
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| 16 | # but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 17 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 18 | # GNU General Public License for more details.
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| 19 | #
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| 20 | # You should have received a copy of the GNU General Public License
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| 21 | # along with this program; if not, write to the Free Software
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| 22 | # Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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| 23 | #
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| 24 | ###########################################################################
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| 25 |
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| 26 | # RecPlug is a plugin which recurses through directories processing
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| 27 | # each file it finds.
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| 28 |
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| 29 | # RecPlug has one option: use_metadata_files. When this is set, it will
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| 30 | # check each directory for an XML file called "metadata.xml" that specifies
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| 31 | # metadata for the files (and subdirectories) in the directory.
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| 32 | #
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| 33 | # Here's an example of a metadata file that uses three FileSet structures
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| 34 | # (ignore the # characters):
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| 35 |
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| 36 | #<?xml version="1.0" encoding="UTF-8" standalone="no"?>
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| 37 | #<!DOCTYPE GreenstoneDirectoryMetadata SYSTEM "http://greenstone.org/dtd/GreenstoneDirectoryMetadata/1.0/GreenstoneDirectoryMetadata.dtd">
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| 38 | #<DirectoryMetadata>
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| 39 | # <FileSet>
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| 40 | # <FileName>nugget.*</FileName>
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| 41 | # <Description>
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| 42 | # <Metadata name="Title">Nugget Point, The Catlins</Metadata>
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| 43 | # <Metadata name="Place" mode="accumulate">Nugget Point</Metadata>
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| 44 | # </Description>
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| 45 | # </FileSet>
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| 46 | # <FileSet>
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| 47 | # <FileName>nugget-point-1.jpg</FileName>
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| 48 | # <Description>
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| 49 | # <Metadata name="Title">Nugget Point Lighthouse, The Catlins</Metadata>
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| 50 | # <Metadata name="Subject">Lighthouse</Metadata>
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| 51 | # </Description>
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| 52 | # </FileSet>
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| 53 | # <FileSet>
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| 54 | # <FileName>kaka-point-dir</FileName>
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| 55 | # <Description>
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| 56 | # <Metadata name="Title">Kaka Point, The Catlins</Metadata>
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| 57 | # </Description>
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| 58 | # </FileSet>
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| 59 | #</DirectoryMetadata>
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| 60 |
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| 61 | # Metadata elements are read and applied to files in the order they appear
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| 62 | # in the file.
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| 63 | #
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| 64 | # The FileName element describes the subfiles in the directory that the
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| 65 | # metadata applies to as a perl regular expression (a FileSet group may
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| 66 | # contain multiple FileName elements). So, <FileName>nugget.*</FileName>
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| 67 | # indicates that the metadata records in the following Description block
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| 68 | # apply to every subfile that starts with "nugget". For these files, a
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| 69 | # Title metadata element is set, overriding any old value that the Title
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| 70 | # might have had.
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| 71 | #
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| 72 | # Occasionally, we want to have multiple metadata values applied to a
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| 73 | # document; in this case we use the "mode=accumulate" attribute of the
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| 74 | # particular Metadata element. In the second metadata element of the first
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| 75 | # FileSet above, the "Place" metadata is accumulating, and may therefore be
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| 76 | # given several values. If we wanted to override these values and use a
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| 77 | # single metadata element again, we could set the mode attribute to
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| 78 | # "override" instead. Remember: every element is assumed to be in override
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| 79 | # mode unless you specify otherwise, so if you want to accumulate metadata
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| 80 | # for some field, every occurance must have "mode=accumulate" specified.
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| 81 | #
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| 82 | # The second FileSet element above applies to a specific file, called
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| 83 | # nugget-point-1.jpg. This element overrides the Title metadata set in the
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| 84 | # first FileSet, and adds a "Subject" metadata field.
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| 85 | #
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| 86 | # The third and final FileSet sets metadata for a subdirectory rather than
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| 87 | # a file. The metadata specified (a Title) will be passed into the
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| 88 | # subdirectory and applied to every file that occurs in the subdirectory
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| 89 | # (and to every subsubdirectory and its contents, and so on) unless the
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| 90 | # metadata is explictly overridden later in the import.
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| 91 |
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| 92 |
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| 93 |
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| 94 | package RecPlug;
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| 95 |
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| 96 | use BasPlug;
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| 97 | use plugin;
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| 98 | use util;
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| 99 |
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| 100 |
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| 101 | BEGIN {
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| 102 | @ISA = ('BasPlug');
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| 103 | unshift (@INC, "$ENV{'GSDLHOME'}/perllib/cpan");
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| 104 | }
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| 105 |
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| 106 | use XML::Parser;
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| 107 |
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| 108 | sub print_usage {
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| 109 | my ($plugin_name) = @_;
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| 110 |
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| 111 | print STDERR "
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| 112 | usage: plugin RecPlug [options]
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| 113 |
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| 114 | -use_metadata_files Read metadata from metadata XML files.
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| 115 |
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| 116 | "
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| 117 | }
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| 118 |
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| 119 | my ($self);
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| 120 | sub new {
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| 121 | my $class = shift (@_);
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| 122 |
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| 123 | # $self is global for use within subroutines called by XML::Parser
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| 124 | $self = new BasPlug ($class, @_);
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| 125 |
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| 126 | if (!parsargv::parse(\@_,
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| 127 | q^use_metadata_files^, \$self->{'use_metadata_files'},
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| 128 | "allow_extra_options")) {
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| 129 | print STDERR "\nRecPlug uses an incorrect option.\n";
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| 130 | print STDERR "Check your collect.cfg configuration file.\n\n";
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| 131 | &print_usage("RecPlug");
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| 132 | die "\n";
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| 133 | }
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| 134 |
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| 135 | if ($self->{'use_metadata_files'}) {
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| 136 | # create XML::Parser object for parsing metadata.xml files
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| 137 | my $parser = new XML::Parser('Style' => 'Stream',
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| 138 | 'Handlers' => {'Char' => \&Char,
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| 139 | 'Doctype' => \&Doctype
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| 140 | });
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| 141 | $self->{'parser'} = $parser;
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| 142 | $self->{'in_filename'} = 0;
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| 143 |
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| 144 | }
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| 145 |
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| 146 | return bless $self, $class;
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| 147 | }
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| 148 |
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| 149 | # return 1 if this class might recurse using $pluginfo
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| 150 | sub is_recursive {
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| 151 | my $self = shift (@_);
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| 152 |
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| 153 | return 1;
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| 154 | }
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| 155 |
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| 156 | sub get_default_block_exp {
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| 157 | my $self = shift (@_);
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| 158 |
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| 159 | return 'CVS';
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| 160 | }
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| 161 |
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| 162 | # return number of files processed, undef if can't process
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| 163 | # Note that $base_dir might be "" and that $file might
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| 164 | # include directories
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| 165 |
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| 166 | # This function passes around metadata hash structures. Metadata hash
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| 167 | # structures are hashes that map from a (scalar) key (the metadata element
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| 168 | # name) to either a scalar metadata value or a reference to an array of
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| 169 | # such values.
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| 170 |
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| 171 | sub read {
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| 172 | my $self = shift (@_);
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| 173 | my ($pluginfo, $base_dir, $file, $in_metadata, $processor, $maxdocs) = @_;
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| 174 |
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| 175 | my $outhandle = $self->{'outhandle'};
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| 176 | my $verbosity = $self->{'verbosity'};
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| 177 | my $read_metadata_files = $self->{'use_metadata_files'};
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| 178 |
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| 179 | # Calculate the directory name and ensure it is a directory and
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| 180 | # that it is not explicitly blocked.
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| 181 | my $dirname = $file;
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| 182 | $dirname = &util::filename_cat ($base_dir, $file) if $base_dir =~ /\w/;
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| 183 | return undef unless (-d $dirname);
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| 184 | return 0 if ($self->{'block_exp'} ne "" && $dirname =~ /$self->{'block_exp'}/);
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| 185 |
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| 186 | # check to make sure we're not reading the archives or index directory
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| 187 | my $gsdlhome = quotemeta($ENV{'GSDLHOME'});
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| 188 | if ($dirname =~ m/^$gsdlhome\/.*?\/import.*?\/(archives|index)$/) {
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| 189 | print $outhandle "RecPlug: $dirname appears to be a reference to a Greenstone collection, skipping.\n";
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| 190 | return 0;
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| 191 | }
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| 192 |
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| 193 | # check to see we haven't got a cyclic path...
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| 194 | if ($dirname =~ m%(/.*){,41}%) {
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| 195 | print $outhandle "RecPlug: $dirname is 40 directories deep, is this a recursive path? if not increase constant in RecPlug.pm.\n";
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| 196 | return 0;
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| 197 | }
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| 198 |
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| 199 | # check to see we haven't got a cyclic path...
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| 200 | if ($dirname =~ m%.*?import/(.+?)/import/\1.*%) {
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| 201 | print $outhandle "RecPlug: $dirname appears to be in a recursive loop...\n";
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| 202 | return 0;
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| 203 | }
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| 204 |
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| 205 | if (($verbosity > 2) && ((scalar keys %$in_metadata) > 0)) {
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| 206 | print $outhandle "RecPlug: metadata passed in: ",
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| 207 | join(", ", keys %$in_metadata), "\n";
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| 208 | }
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| 209 |
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| 210 | # Recur over directory contents.
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| 211 | my (@dir, $subfile);
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| 212 | my $count = 0;
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| 213 | print $outhandle "RecPlug: getting directory $dirname\n" if ($verbosity);
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| 214 |
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| 215 | # find all the files in the directory
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| 216 | if (!opendir (DIR, $dirname)) {
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| 217 | print $outhandle "RecPlug: WARNING - couldn't read directory $dirname\n";
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| 218 | return undef;
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| 219 | }
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| 220 | @dir = readdir (DIR);
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| 221 | closedir (DIR);
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| 222 |
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| 223 | # read XML metadata files (if supplied)
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| 224 | my $additionalmetadata = 0; # is there extra metadata available?
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| 225 | my %extrametadata; # maps from filespec to extra metadata keys
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| 226 | my @extrametakeys; # keys of %extrametadata in order read
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| 227 |
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| 228 | if ($read_metadata_files) {
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| 229 |
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| 230 | # read the directory "metadata.xml" file
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| 231 | my $metadatafile = &util::filename_cat ($dirname, 'metadata.xml');
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| 232 | if (-e $metadatafile) {
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| 233 | print $outhandle "RecPlug: found metadata in $metadatafile\n"
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| 234 | if ($verbosity);
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| 235 | $self->read_metadata_xml_file($metadatafile, \%extrametadata, \@extrametakeys);
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| 236 | $additionalmetadata = 1;
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| 237 | }
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| 238 | }
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| 239 |
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| 240 | # import each of the files in the directory
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| 241 | my $out_metadata;
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| 242 | foreach $subfile (@dir) {
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| 243 |
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| 244 | last if ($maxdocs != -1 && $count >= $maxdocs);
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| 245 | next if ($subfile =~ /^\.\.?$/);
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| 246 | next if ($read_metadata_files && $subfile =~ /metadata\.xml$/);
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| 247 | print $outhandle "RecPlug: preparing metadata for $subfile\n" if ($verbosity > 2);
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| 248 |
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| 249 | # Make a copy of $in_metadata to pass to $subfile
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| 250 | $out_metadata = {};
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| 251 | &combine_metadata_structures($out_metadata, $in_metadata);
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| 252 |
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| 253 | # Next add metadata read in XML files (if it is supplied)
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| 254 | if ($additionalmetadata == 1) {
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| 255 |
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| 256 | my ($filespec, $mdref);
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| 257 | foreach $filespec (@extrametakeys) {
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| 258 | if ($subfile =~ /^$filespec$/) {
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| 259 | print $outhandle "File \"$subfile\" matches filespec \"$filespec\"\n"
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| 260 | if ($verbosity > 2);
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| 261 | $mdref = $extrametadata{$filespec};
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| 262 | &combine_metadata_structures($out_metadata, $mdref);
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| 263 | }
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| 264 | }
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| 265 | }
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| 266 |
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| 267 | # Recursively read each $subfile
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| 268 | print $outhandle "RecPlug recurring: $subfile\n" if ($verbosity > 2);
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| 269 | $count += &plugin::read ($pluginfo, $base_dir,
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| 270 | &util::filename_cat($file, $subfile),
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| 271 | $out_metadata, $processor, $maxdocs);
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| 272 | }
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| 273 | return $count;
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| 274 |
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| 275 | }
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| 276 |
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| 277 |
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| 278 |
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| 279 | # Read a manually-constructed metadata file and store the data
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| 280 | # it contains in the $metadataref structure.
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| 281 | #
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| 282 | # (metadataref is a reference to a hash whose keys are filenames
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| 283 | # and whose values are metadata hash structures.)
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| 284 |
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| 285 | sub read_metadata_xml_file {
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| 286 | my $self = shift(@_);
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| 287 | my ($filename, $metadataref, $metakeysref) = @_;
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| 288 | $self->{'metadataref'} = $metadataref;
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| 289 | $self->{'metakeysref'} = $metakeysref;
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| 290 |
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| 291 | eval {
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| 292 | $self->{'parser'}->parsefile($filename);
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| 293 | };
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| 294 | if ($@) {
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| 295 | my $outhandle = $self->{'outhandle'};
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| 296 | print $outhandle "RecPlug: Warning: Ignoring $filename because it is not a well formed metadata.xml file\n";
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| 297 | return;
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| 298 | }
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| 299 | }
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| 300 |
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| 301 | sub Doctype {
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| 302 | my ($expat, $name, $sysid, $pubid, $internal) = @_;
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| 303 | die if ($name ne "GreenstoneDirectoryMetadata");
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| 304 | }
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| 305 |
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| 306 | sub StartTag {
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| 307 | my ($expat, $element) = @_;
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| 308 |
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| 309 | if ($element eq "FileSet") {
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| 310 | $self->{'saved_targets'} = [];
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| 311 | $self->{'saved_metadata'} = {};
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| 312 | }
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| 313 | elsif ($element eq "FileName") {
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| 314 | $self->{'in_filename'} = 1;
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| 315 | }
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| 316 | elsif ($element eq "Metadata") {
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| 317 | $self->{'metadata_name'} = $_{'name'};
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| 318 | if ((defined $_{'mode'}) && ($_{'mode'} eq "accumulate")) {
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| 319 | $self->{'metadata_accumulate'} = 1;
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| 320 | } else {
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| 321 | $self->{'metadata_accumulate'} = 0;
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| 322 | }
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| 323 | }
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| 324 | }
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| 325 |
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| 326 | sub EndTag {
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| 327 | my ($expat, $element) = @_;
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| 328 |
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| 329 | if ($element eq "FileSet") {
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| 330 | push (@{$self->{'metakeysref'}}, @{$self->{'saved_targets'}});
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| 331 | foreach my $target (@{$self->{'saved_targets'}}) {
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| 332 | $self->{'metadataref'}->{$target} = $self->{'saved_metadata'};
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| 333 | }
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| 334 | }
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| 335 | elsif ($element eq "FileName") {
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| 336 | $self->{'in_filename'} = 0;
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| 337 | }
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| 338 | elsif ($element eq "Metadata") {
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| 339 | $self->{'metadata_name'} = "";
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| 340 | }
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| 341 |
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| 342 | }
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| 343 |
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| 344 | sub Text {
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| 345 |
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| 346 | if ($self->{'in_filename'}) {
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| 347 | # $_ == FileName content
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| 348 | push (@{$self->{'saved_targets'}}, $_);
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| 349 | }
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| 350 | elsif (defined ($self->{'metadata_name'}) && $self->{'metadata_name'} ne "") {
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| 351 | # $_ == Metadata content
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| 352 | my $mname = $self->{'metadata_name'};
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| 353 | if (defined $self->{'saved_metadata'}->{$mname}) {
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| 354 | if ($self->{'metadata_accumulate'}) {
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| 355 | # accumulate mode - add value to existing value(s)
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| 356 | if (ref ($self->{'saved_metadata'}->{$mname}) eq "ARRAY") {
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| 357 | push (@{$self->{'saved_metadata'}->{$mname}}, $_);
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| 358 | } else {
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| 359 | $self->{'saved_metadata'}->{$mname} =
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| 360 | [$self->{'saved_metadata'}->{$mname}, $_];
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| 361 | }
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| 362 | } else {
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| 363 | # override mode
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| 364 | $self->{'saved_metadata'}->{$mname} = $_;
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| 365 | }
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| 366 | } else {
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| 367 | if ($self->{'metadata_accumulate'}) {
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| 368 | # accumulate mode - add value into (currently empty) array
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| 369 | $self->{'saved_metadata'}->{$mname} = [$_];
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| 370 | } else {
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| 371 | # override mode
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| 372 | $self->{'saved_metadata'}->{$mname} = $_;
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| 373 | }
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| 374 | }
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| 375 | }
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| 376 | }
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| 377 |
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| 378 | # This Char function overrides the one in XML::Parser::Stream to overcome a
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| 379 | # problem where $expat->{Text} is treated as the return value, slowing
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| 380 | # things down significantly in some cases.
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| 381 | sub Char {
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| 382 | $_[0]->{'Text'} .= $_[1];
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| 383 | return undef;
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| 384 | }
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| 385 |
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| 386 | # Combine two metadata structures. Given two references to metadata
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| 387 | # element structures, add every field of the second ($mdref2) to the first
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| 388 | # ($mdref1).
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| 389 | #
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| 390 | # Afterwards $mdref1 will be updated, and $mdref2 will be unchanged.
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| 391 | #
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| 392 | # We have to be acreful about the way we merge metadata when one metadata
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| 393 | # structure is in "override" mode and one is in "merge" mode. In fact, we
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| 394 | # use the mode from the second structure, $mdref2, because it is generally
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| 395 | # defined later (lower in the directory structure) and is therefore more
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| 396 | # "local" to the document concerned.
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| 397 | #
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| 398 | # Another issue is the use of references to pass metadata around. If we
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| 399 | # simply copy one metadata structure reference to another, then we're
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| 400 | # effectively justr copyinga pointer, and changes to the new referene
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| 401 | # will affect the old (copied) one also. This also applies to ARRAY
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| 402 | # references used as metadata element values (hence the "clonedata"
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| 403 | # function below).
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| 404 |
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| 405 | sub combine_metadata_structures {
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| 406 | my ($mdref1, $mdref2) = @_;
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| 407 | my ($key, $value1, $value2);
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| 408 |
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| 409 | foreach $key (keys %$mdref2) {
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| 410 |
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| 411 | $value1 = $mdref1->{$key};
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| 412 | $value2 = $mdref2->{$key};
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| 413 |
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| 414 | # If there is no existing value for this metadata field in
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| 415 | # $mdref1, so we simply copy the value from $mdref2 over.
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| 416 | if (!defined $value1) {
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| 417 | $mdref1->{$key} = &clonedata($value2);
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| 418 | }
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| 419 | # Otherwise we have to add the new values to the existing ones.
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| 420 | # If the second structure is accumulated, then acculate all the
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| 421 | # values into the first structure
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| 422 | elsif ((ref $value2) eq "ARRAY") {
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| 423 | # If the first metadata element is a scalar we have to
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| 424 | # convert it into an array before we add anything more.
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| 425 | if ((ref $value1) ne 'ARRAY') {
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| 426 | $mdref1->{$key} = [$value1];
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| 427 | $value1 = $mdref1->{$key};
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| 428 | }
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| 429 | # Now add the value(s) from the second array to the first
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| 430 | $value2 = &clonedata($value2);
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| 431 | push @$value1, @$value2;
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| 432 | }
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| 433 | # Finally, If the second structure is not an array erference, we
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| 434 | # know it is in override mode, so override the first structure.
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| 435 | else {
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| 436 | $mdref1->{$key} = &clonedata($value2);
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| 437 | }
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| 438 | }
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| 439 | }
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| 440 |
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| 441 |
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| 442 | # Make a "cloned" copy of a metadata value.
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| 443 | # This is trivial for a simple scalar value,
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| 444 | # but not for an array reference.
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| 445 |
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| 446 | sub clonedata {
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| 447 | my ($value) = @_;
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| 448 | my $result;
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| 449 |
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| 450 | if ((ref $value) eq 'ARRAY') {
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| 451 | $result = [];
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|---|
| 452 | foreach my $item (@$value) {
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| 453 | push @$result, $item;
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| 454 | }
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| 455 | } else {
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| 456 | $result = $value;
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| 457 | }
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| 458 | return $result;
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| 459 | }
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| 460 |
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| 461 |
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| 462 | 1;
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