| 1 | ###########################################################################
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| 2 | #
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| 3 | # IncrementalDocument.pm -- An object to encapsulate the Greenstone
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| 4 | # document retrieved from the GDBM database.
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| 5 | #
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| 6 | # A component of the Greenstone digital library software
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| 7 | # from the New Zealand Digital Library Project at the
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| 8 | # University of Waikato, New Zealand.
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| 9 | #
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| 10 | # Copyright (C) 2006 DL Consulting Ltd and New Zealand Digital Library Project
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| 11 | #
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| 12 | # This program is free software; you can redistribute it and/or modify
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| 13 | # it under the terms of the GNU General Public License as published by
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| 14 | # the Free Software Foundation; either version 2 of the License, or
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| 15 | # (at your option) any later version.
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| 16 | #
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| 17 | # This program is distributed in the hope that it will be useful,
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| 18 | # but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 19 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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| 20 | # GNU General Public License for more details.
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| 21 | #
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| 22 | # You should have received a copy of the GNU General Public License
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| 23 | # along with this program; if not, write to the Free Software
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| 24 | # Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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| 25 | #
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| 26 | ###########################################################################
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| 27 | package IncrementalDocument;
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| 28 |
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| 29 | use GDBMUtils;
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| 30 | use strict;
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| 31 |
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| 32 | # /**
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| 33 | # */
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| 34 | sub new()
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| 35 | {
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| 36 | my ($class, $collection, $oid) = @_;
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| 37 | #rint STDERR "IncrementalDocument::new($collection, $oid)\n";
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| 38 | # Test the parameters
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| 39 | die ("Error! Can't create a document that doesn't belong to a collection!") unless $collection;
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| 40 | die ("Error! Can't create a document that doesn't have a unique id (OID)!") unless $oid;
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| 41 | # Store the variables
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| 42 | my $self = {};
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| 43 | # The collection this document object has been loaded from.
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| 44 | $self->{'collection'} = $collection;
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| 45 | # An associative array of information retrieved from the GDBM database
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| 46 | # which maps a key string to a nested associative array listing values.
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| 47 | $self->{'data'} = {};
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| 48 | # The unique identifier of the document loaded
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| 49 | $self->{'oid'} = $oid;
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| 50 | # Stores the order in which metadata keys where discovered/added.
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| 51 | $self->{'order'} = {};
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| 52 | # Bless me father for I have sinned
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| 53 | bless $self, $class;
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| 54 | return $self;
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| 55 | }
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| 56 | # /** new() **/
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| 57 |
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| 58 | # /**
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| 59 | # */
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| 60 | sub addMetadata()
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| 61 | {
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| 62 | my ($self, $key, $value, $internal) = @_;
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| 63 | # Validate the arguments
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| 64 | die ("Error! Can't add a metadata value to a document without a valid key!") unless $key =~ /[\w]+/;
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| 65 | die ("Error! Can't add a metadata key to a document without a valid value!") unless $value =~ /[\w\d]+/;
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| 66 | # Is this a new key that we haven't encountered before? If so ensure an
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| 67 | # array exists for its values, and record the order in which we encountered
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| 68 | # this key.
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| 69 | if (!defined($self->{'data'}->{$key}))
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| 70 | {
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| 71 | # Determine how many data keys we're already storing, so we can add the next
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| 72 | # one at the appropriate index
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| 73 | my $index = scalar(keys %{$self->{'order'}});
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| 74 | $self->{'order'}->{$index} = $key;
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| 75 | $self->{'data'}->{$key} = {};
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| 76 | }
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| 77 | # Set the value of the associative path to 1.
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| 78 | $self->{'data'}->{$key}->{$value} = 1;
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| 79 | }
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| 80 | # /** addMetadata() **/
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| 81 |
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| 82 | # /** Retrieve all the metadata of this document as an array of pairs.
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| 83 | # *
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| 84 | # */
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| 85 | sub getAllMetadata()
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| 86 | {
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| 87 | print STDERR "IncrementalDocument.getAllMetadata()\n";
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| 88 | my ($self) = @_;
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| 89 | my @all_metadata;
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| 90 |
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| 91 | my $key_count = scalar(keys %{$self->{'order'}});
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| 92 | for (my $i = 0; $i < $key_count; $i++)
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| 93 | {
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| 94 | my $key = $self->{'order'}->{$i};
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| 95 | # Check if this key has been set
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| 96 | if ($self->{'data'}->{$key})
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| 97 | {
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| 98 | # Note: there may be zero values left
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| 99 | foreach my $value (sort keys %{$self->{'data'}->{$key}})
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| 100 | {
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| 101 | if ($self->{'data'}->{$key}->{$value})
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| 102 | {
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| 103 | print STDERR "* Storing $key => $value\n";
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| 104 | push(@all_metadata, [$key, $value]);
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| 105 | }
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| 106 | }
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| 107 | }
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| 108 | }
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| 109 | print STDERR "Complete!\n";
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| 110 | return \@all_metadata;
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| 111 | }
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| 112 | # /** getAllMetadata() **/
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| 113 |
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| 114 | # /**
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| 115 | # */
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| 116 | sub getDocNum()
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| 117 | {
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| 118 | my ($self) = @_;
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| 119 | my $docnum = -1;
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| 120 | # Check the docnum path exists in the associated data
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| 121 | if(defined($self->{'data'}->{'docnum'}))
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| 122 | {
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| 123 | # Get the list of keys from that associative path
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| 124 | my @values = keys (%{$self->{'data'}->{'docnum'}});
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| 125 | # And since we know there will only ever be one value for docnum
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| 126 | $docnum = $values[0];
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| 127 | }
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| 128 | return $docnum;
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| 129 | }
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| 130 | # /** getDocNum() **/
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| 131 |
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| 132 | # /**
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| 133 | # */
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| 134 | sub loadDocument()
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| 135 | {
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| 136 | my ($self) = @_;
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| 137 | #rint STDERR "IncrementalDocument::loadDocument()\n";
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| 138 | # Load the raw text for the document object from GDBM
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| 139 | my $text = &GDBMUtils::gdbmGet($self->{'collection'}, $self->{'oid'});
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| 140 | # For each line in the raw text, extract the key (enclosed in angle
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| 141 | # brackets) and the value
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| 142 | $text =~ s/<([\w\d\.]+)>(.+?)\r?\n/&addMetadata($self, $1, $2, 1)/egs;
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| 143 | # Done
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| 144 | }
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| 145 | # /** loadDocument() **/
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| 146 |
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| 147 | # /** Locates and removes the given key/value mappings from this document
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| 148 | # * object.
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| 149 | # *
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| 150 | # * @param $self A reference to this IncrementalDocument object
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| 151 | # * @param $key The metadata key as a string
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| 152 | # * @param $value The obsolete metadata value as a string
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| 153 | # *
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| 154 | # * @author John Thompson, DL Consulting Ltd.
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| 155 | # */
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| 156 | sub removeMetadata()
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| 157 | {
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| 158 | my ($self, $key, $value) = @_;
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| 159 | # Ensure the value doesn't exist by simply setting to 0 the correct
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| 160 | # associative path
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| 161 | $self->{'data'}->{$key}->{$value} = 0;
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| 162 | }
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| 163 | # /*** removeMetadat() **/
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| 164 |
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| 165 | # /**
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| 166 | # */
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| 167 | sub saveDocument()
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| 168 | {
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| 169 | my ($self) = @_;
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| 170 | # Get a textual version of this object
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| 171 | my $text = $self->toString();
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| 172 | # Now store the object in the database using the GDBM utilities
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| 173 | &GDBMUtils::gdbmSet($self->{'collection'}, $self->{'oid'}, $text);
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| 174 | # There is a little bit of extra complexity when saving an incremental
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| 175 | # document in that we should ensure that a reverse lookup-from DocNum or
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| 176 | # nodeID to Greenstone document hash-exists in the database.
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| 177 | my $doc_num = $self->getDocNum();
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| 178 | if($doc_num >= 0)
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| 179 | {
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| 180 | my $text = &GDBMUtils::gdbmGet($self->{'collection'}, $doc_num);
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| 181 | # If there is no reverse lookup, then add one now
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| 182 | if($text !~ /<section>/)
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| 183 | {
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| 184 | &GDBMUtils::gdbmSet($self->{'collection'}, $doc_num, "<section>" . $self->{'oid'});
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| 185 | }
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| 186 | }
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| 187 | # Done
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| 188 | #rint STDERR "Stored document:\n[" . $self->{'oid'} . "]\n$text\n";
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| 189 | }
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| 190 | # /** saveDocument() **/
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| 191 |
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| 192 | # /** Produces a textual representation of this object.
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| 193 | # *
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| 194 | # * @return A string which describes this incremental document object
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| 195 | # *
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| 196 | # * @author John Thompson, DL Consulting Ltd.
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| 197 | # */
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| 198 | sub toString()
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| 199 | {
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| 200 | my ($self) = @_;
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| 201 | my $text = "";
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| 202 |
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| 203 | my $key_count = scalar(keys %{$self->{'order'}});
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| 204 | for (my $i = 0; $i < $key_count; $i++)
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| 205 | {
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| 206 | my $key = $self->{'order'}->{$i};
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| 207 | # Check if this key has been set
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| 208 | if ($self->{'data'}->{$key})
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| 209 | {
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| 210 | # Note: there may be zero values left
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| 211 | foreach my $value (sort keys %{$self->{'data'}->{$key}})
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| 212 | {
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| 213 | if ($self->{'data'}->{$key}->{$value})
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| 214 | {
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| 215 | $text .= "<$key>$value\n";
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| 216 | }
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| 217 | }
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| 218 | }
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| 219 | }
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| 220 | return $text;
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| 221 | }
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| 222 | # /** toString() **/
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| 223 |
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| 224 | 1;
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