root/main/trunk/greenstone2/perllib/plugins/MetadataXMLPlugin.pm @ 30600

Revision 30600, 12.9 KB (checked in by ak19, 4 years ago)

An empty metadata.xml was unrecognised by MetadataXMLPlugin because the self-closing root tag in the XML file was not matched in the regex.

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1###########################################################################
2#
3# MetadataXMLPlugin.pm --
4# A component of the Greenstone digital library software
5# from the New Zealand Digital Library Project at the
6# University of Waikato, New Zealand.
7#
8# Copyright (C) 2006 New Zealand Digital Library Project
9#
10# This program is free software; you can redistribute it and/or modify
11# it under the terms of the GNU General Public License as published by
12# the Free Software Foundation; either version 2 of the License, or
13# (at your option) any later version.
14#
15# This program is distributed in the hope that it will be useful,
16# but WITHOUT ANY WARRANTY; without even the implied warranty of
17# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18# GNU General Public License for more details.
19#
20# You should have received a copy of the GNU General Public License
21# along with this program; if not, write to the Free Software
22# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23#
24###########################################################################
25
26# MetadataXMLPlugin process metadata.xml files in a collection
27
28# Here's an example of a metadata file that uses three FileSet structures
29# (ignore the # characters):
30
31#<?xml version="1.0" encoding="UTF-8" standalone="no"?>
32#<!DOCTYPE DirectoryMetadata SYSTEM "http://greenstone.org/dtd/DirectoryMetadata/1.0/DirectoryMetadata.dtd">
33#<DirectoryMetadata>
34#  <FileSet>
35#    <FileName>nugget.*</FileName>
36#    <Description>
37#      <Metadata name="Title">Nugget Point, The Catlins</Metadata>
38#      <Metadata name="Place" mode="accumulate">Nugget Point</Metadata>
39#    </Description>
40#  </FileSet>
41#  <FileSet>
42#    <FileName>nugget-point-1.jpg</FileName>
43#    <Description>
44#      <Metadata name="Title">Nugget Point Lighthouse, The Catlins</Metadata>
45#      <Metadata name="Subject">Lighthouse</Metadata>
46#    </Description>
47#  </FileSet>
48#  <FileSet>
49#    <FileName>kaka-point-dir</FileName>
50#    <Description>
51#      <Metadata name="Title">Kaka Point, The Catlins</Metadata>
52#    </Description>
53#  </FileSet>
54#</DirectoryMetadata>
55
56# Metadata elements are read and applied to files in the order they appear
57# in the file.
58#
59# The FileName element describes the subfiles in the directory that the
60# metadata applies to as a perl regular expression (a FileSet group may
61# contain multiple FileName elements). So, <FileName>nugget.*</FileName>
62# indicates that the metadata records in the following Description block
63# apply to every subfile that starts with "nugget".  For these files, a
64# Title metadata element is set, overriding any old value that the Title
65# might have had.
66#
67# Occasionally, we want to have multiple metadata values applied to a
68# document; in this case we use the "mode=accumulate" attribute of the
69# particular Metadata element.  In the second metadata element of the first
70# FileSet above, the "Place" metadata is accumulating, and may therefore be
71# given several values.  If we wanted to override these values and use a
72# single metadata element again, we could set the mode attribute to
73# "override" instead.  Remember: every element is assumed to be in override
74# mode unless you specify otherwise, so if you want to accumulate metadata
75# for some field, every occurance must have "mode=accumulate" specified.
76#
77# The second FileSet element above applies to a specific file, called
78# nugget-point-1.jpg.  This element overrides the Title metadata set in the
79# first FileSet, and adds a "Subject" metadata field.
80#
81# The third and final FileSet sets metadata for a subdirectory rather than
82# a file.  The metadata specified (a Title) will be passed into the
83# subdirectory and applied to every file that occurs in the subdirectory
84# (and to every subsubdirectory and its contents, and so on) unless the
85# metadata is explictly overridden later in the import.
86
87package MetadataXMLPlugin;
88
89use strict;
90no strict 'refs';
91
92use Encode;
93
94use BasePlugin;
95use extrametautil;
96use util;
97use FileUtils;
98use metadatautil;
99
100sub BEGIN {
101    @MetadataXMLPlugin::ISA = ('BasePlugin');
102    unshift (@INC, "$ENV{'GSDLHOME'}/perllib/cpan");
103}
104
105use XMLParser;
106
107my $arguments = [
108      { 'name' => "process_exp",
109    'desc' => "{BasePlugin.process_exp}",
110    'type' => "regexp",
111    'reqd' => "no",
112    'deft' => &get_default_process_exp() }
113
114];
115
116my $options = { 'name'     => "MetadataXMLPlugin",
117        'desc'     => "{MetadataXMLPlugin.desc}",
118        'abstract' => "no",
119        'inherits' => "yes",
120        'args'     => $arguments };
121
122sub new {
123    my ($class) = shift (@_);
124    my ($pluginlist,$inputargs,$hashArgOptLists) = @_;
125    push(@$pluginlist, $class);
126
127    push(@{$hashArgOptLists->{"ArgList"}},@{$arguments});
128    push(@{$hashArgOptLists->{"OptList"}},$options);
129
130    my $self = new BasePlugin($pluginlist, $inputargs, $hashArgOptLists);
131
132    if ($self->{'info_only'}) {
133    # don't worry about any options or initialisations etc
134    return bless $self, $class;
135    }
136   
137    # The following used to be passed in as a parameter to XML::Parser,
138    # if the version of perl was greater than or equal to 5.8.
139    # The svn commit comment explaining the reason for adding this was
140    # not very clear and also said that it was quick fix and hadn't
141    # been tested under windows.
142    # More recent work has been to make strings in Perl "Unicode-aware"
143    # and so this line might actually be potentially harmful, however
144    # it is not the case that we encountered an actual error leading to
145    # its removal, rather it has been eliminated in an attempt to tighten
146    # up the code. For example, this protocol encoding is not used in
147    # ReadXMLFile.
148    # 'ProtocolEncoding' => 'ISO-8859-1',
149
150    # create XML::Parser object for parsing metadata.xml files
151    my $parser = new XML::Parser('Style' => 'Stream',                             
152                                  'Pkg' => 'MetadataXMLPlugin',
153                                  'PluginObj' => $self,
154                    'Handlers' => {'Char' => \&Char,
155                         'Doctype' => \&Doctype
156                         });
157
158    $self->{'parser'} = $parser;
159    $self->{'in_filename'} = 0;
160   
161    return bless $self, $class;
162}
163
164
165sub get_default_process_exp
166{
167    return q^metadata\.xml$^;
168}
169
170sub get_doctype {
171    my $self = shift(@_);
172   
173    return "(Greenstone)?DirectoryMetadata"
174}
175
176sub can_process_this_file {
177    my $self = shift(@_);
178    my ($filename) = @_;
179
180    if (-f $filename && $self->SUPER::can_process_this_file($filename) && $self->check_doctype($filename)) {
181    return 1; # its a file for us
182    }
183
184    return 0;
185}
186
187sub check_doctype {
188    my $self = shift (@_);
189   
190    my ($filename) = @_;
191
192    if (open(XMLIN,"<$filename")) {
193    my $doctype = $self->get_doctype();
194    ## check whether the doctype has the same name as the root element tag
195    while (defined (my $line = <XMLIN>)) {
196        ## find the root element
197        if ($line =~ /<([\w\d:]+)[\s\/>]/){
198        my $root = $1;
199        if ($root !~ $doctype){
200            close(XMLIN);
201            return 0;
202        }
203        else {
204            close(XMLIN);
205            return 1;
206        }
207        }
208    }
209    close(XMLIN);
210    }
211   
212    return undef; # haven't found a valid line
213   
214}
215
216sub file_block_read {
217    my $self = shift (@_);
218    my ($pluginfo, $base_dir, $file, $block_hash, $metadata, $gli) = @_;
219   
220    my $filename_full_path = &FileUtils::filenameConcatenate($base_dir, $file);
221    return undef unless $self->can_process_this_file($filename_full_path);   
222
223    if (($ENV{'GSDLOS'} =~ m/^windows$/) && ($^O ne "cygwin")) {
224   
225    my $lower_drive = $filename_full_path;
226    $lower_drive =~ s/^([A-Z]):/\l$1:/i;
227   
228    my $upper_drive = $filename_full_path;
229    $upper_drive =~ s/^([A-Z]):/\u$1:/i;
230   
231    $block_hash->{'metadata_files'}->{$lower_drive} = 1;
232    $block_hash->{'metadata_files'}->{$upper_drive} = 1;       
233    }
234    else {
235    $block_hash->{'metadata_files'}->{$filename_full_path} = 1;
236    }
237
238    return 1;
239}
240
241sub metadata_read
242{
243    my $self = shift (@_);
244    my ($pluginfo, $base_dir, $file, $block_hash,
245    $extrametakeys, $extrametadata,$extrametafile,
246    $processor, $gli, $aux) = @_;
247
248    my $filename = &FileUtils::filenameConcatenate($base_dir, $file);
249    return undef unless $self->can_process_this_file($filename);   
250   
251    $self->{'metadata-file'} = $file;
252    $self->{'metadata-filename'} = $filename;
253   
254    my $outhandle = $self->{'outhandle'};
255   
256    print STDERR "\n<Processing n='$file' p='MetadataXMLPlugin'>\n" if ($gli);
257    print $outhandle "MetadataXMLPlugin: processing $file\n" if ($self->{'verbosity'})> 1;
258    # add the file to the block list so that it won't be processed in read, as we will do all we can with it here
259    &util::block_filename($block_hash,$filename);
260
261    $self->{'metadataref'} = $extrametadata;
262    $self->{'metafileref'} = $extrametafile;
263    $self->{'metakeysref'} = $extrametakeys;
264   
265    eval {
266    $self->{'parser'}->parsefile($filename);
267    };
268
269    if ($@) {
270    print STDERR "**** Error is: $@\n";
271    my $plugin_name = ref ($self);
272    my $failhandle = $self->{'failhandle'};
273    print $outhandle "$plugin_name failed to process $file ($@)\n";
274    print $failhandle "$plugin_name failed to process $file ($@)\n";
275    print STDERR "<ProcessingError n='$file'>\n" if ($gli);
276    return -1; #error
277    }
278
279    return 1;
280
281}
282
283
284# Updated by Jeffrey 2010/04/16 @ DL Consulting Ltd.
285# Get rid off the global $self as it cause problems when there are 2+ MetadataXMLPlugin in your collect.cfg...
286# For example when you have an OAIMetadataXMLPlugin that is a child of MetadataXMLPlugin
287sub Doctype {$_[0]->{'PluginObj'}->xml_doctype(@_);}
288sub StartTag {$_[0]->{'PluginObj'}->xml_start_tag(@_);}
289sub EndTag {$_[0]->{'PluginObj'}->xml_end_tag(@_);}
290sub Text {$_[0]->{'PluginObj'}->xml_text(@_);}
291
292
293sub xml_doctype {
294    my $self = shift(@_);
295    my ($expat, $name, $sysid, $pubid, $internal) = @_;
296
297    # allow the short-lived and badly named "GreenstoneDirectoryMetadata" files
298    # to be processed as well as the "DirectoryMetadata" files which should now
299    # be created by import.pl
300    die if ($name !~ /^(Greenstone)?DirectoryMetadata$/);
301}
302
303sub xml_start_tag {
304    my $self = shift(@_);
305    my ($expat, $element) = @_;
306   
307    if ($element eq "FileSet") {
308    $self->{'saved_targets'} = [];
309    $self->{'saved_metadata'} = {};
310    }
311    elsif ($element eq "FileName") {
312    $self->{'in_filename'} = 1;
313    }
314    elsif ($element eq "Metadata") {
315    $self->{'metadata_name'} = $_{'name'};
316    $self->{'metadata_value'} = "";
317    if ((defined $_{'mode'}) && ($_{'mode'} eq "accumulate")) {
318        $self->{'metadata_accumulate'} = 1;
319    } else {
320        $self->{'metadata_accumulate'} = 0;
321    }
322    }
323}
324
325sub xml_end_tag {
326    my $self = shift(@_);
327    my ($expat, $element) = @_;
328
329    if ($element eq "FileSet") {
330    foreach my $target (@{$self->{'saved_targets'}}) {
331   
332        # FileNames must be regex, but we allow \\ for path separator on windows. convert to /
333        $target = &util::filepath_regex_to_url_format($target);
334
335        # we want proper unicode for the regex, so convert url-encoded chars
336        if (&unicode::is_url_encoded($target)) {
337        $target = &unicode::url_decode($target);
338        }
339
340        my $file_metadata = &extrametautil::getmetadata($self->{'metadataref'}, $target);
341        my $saved_metadata = $self->{'saved_metadata'};
342
343        if (!defined $file_metadata) {
344        &extrametautil::setmetadata($self->{'metadataref'}, $target, $saved_metadata);
345
346        # not had target before
347        &extrametautil::addmetakey($self->{'metakeysref'}, $target);
348        }
349        else {
350        &metadatautil::combine_metadata_structures($file_metadata,$saved_metadata);
351        }
352
353       
354        # now record which metadata.xml file it came from
355
356        my $file = $self->{'metadata-file'};
357        my $filename = $self->{'metadata-filename'};
358
359        if (!defined &extrametautil::getmetafile($self->{'metafileref'}, $target)) {
360            &extrametautil::setmetafile($self->{'metafileref'}, $target, {});
361        }
362
363        &extrametautil::setmetafile_for_named_file($self->{'metafileref'}, $target, $file, $filename);
364    }
365    }
366    elsif ($element eq "FileName") {
367    $self->{'in_filename'} = 0;
368    }
369    elsif ($element eq "Metadata") {
370    # text read in by XML::Parser is in Perl's binary byte value
371    # form ... need to explicitly make it UTF-8
372   
373    my $metadata_name = $self->{'metadata_name'};
374    my $metadata_value = $self->{'metadata_value'};
375    #my $metadata_name = decode("utf-8",$self->{'metadata_name'});
376    #my $metadata_value = decode("utf-8",$self->{'metadata_value'});
377   
378    &metadatautil::store_saved_metadata($self,
379                        $metadata_name, $metadata_value,
380                        $self->{'metadata_accumulate'});
381    $self->{'metadata_name'} = "";
382    }
383
384}
385
386sub xml_text {
387    my $self = shift(@_);
388
389    if ($self->{'in_filename'}) {
390    # $_ == FileName content
391    push (@{$self->{'saved_targets'}}, $_);
392    }
393    elsif (defined ($self->{'metadata_name'}) && $self->{'metadata_name'} ne "") {
394    # $_ == Metadata content
395    $self->{'metadata_value'} = $_;
396    }
397}
398
399# This Char function overrides the one in XML::Parser::Stream to overcome a
400# problem where $expat->{Text} is treated as the return value, slowing
401# things down significantly in some cases.
402sub Char {
403#    use bytes;  # Necessary to prevent encoding issues with XML::Parser 2.31+
404
405#    if ($]<5.008) {
406#   use bytes;  # Necessary to prevent encoding issues with XML::Parser 2.31+ and Perl 5.6
407#    }
408    $_[0]->{'Text'} .= $_[1];
409    return undef;
410}
411
412
413
4141;
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