root/main/trunk/greenstone2/perllib/plugins/MetadataXMLPlugin.pm @ 23895

Revision 23895, 12.0 KB (checked in by sjm84, 9 years ago)

Modified several Perl files to merge the locations where XML::Parser checked for the current version of perl into one location. Also tidied up several locations where a difference was specified between 5.6 and 5.8+ to do with ProtocolEncoding? being used to initialise an XML::Parser. Given the recent "

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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 util;
96use metadatautil;
97
98sub BEGIN {
99    @MetadataXMLPlugin::ISA = ('BasePlugin');
100    unshift (@INC, "$ENV{'GSDLHOME'}/perllib/cpan");
101}
102
103use XMLParser;
104
105my $arguments = [
106      { 'name' => "process_exp",
107    'desc' => "{BasePlugin.process_exp}",
108    'type' => "regexp",
109    'reqd' => "no",
110    'deft' => &get_default_process_exp() }
111
112];
113
114my $options = { 'name'     => "MetadataXMLPlugin",
115        'desc'     => "{MetadataXMLPlugin.desc}",
116        'abstract' => "no",
117        'inherits' => "yes",
118        'args'     => $arguments };
119
120sub new {
121    my ($class) = shift (@_);
122    my ($pluginlist,$inputargs,$hashArgOptLists) = @_;
123    push(@$pluginlist, $class);
124
125    push(@{$hashArgOptLists->{"ArgList"}},@{$arguments});
126    push(@{$hashArgOptLists->{"OptList"}},$options);
127
128    my $self = new BasePlugin($pluginlist, $inputargs, $hashArgOptLists);
129
130    if ($self->{'info_only'}) {
131    # don't worry about any options or initialisations etc
132    return bless $self, $class;
133    }
134   
135    # The following used to be passed in as a parameter to XML::Parser,
136    # if the version of perl was greater than or equal to 5.8.
137    # The svn commit comment explaining the reason for adding this was
138    # not very clear and also said that it was quick fix and hadn't
139    # been tested under windows.
140    # More recent work has been to make strings in Perl "Unicode-aware"
141    # and so this line might actually be potentially harmful, however
142    # it is not the case that we encountered an actual error leading to
143    # its removal, rather it has been eliminated in an attempt to tighten
144    # up the code. For example, this protocol encoding is not used in
145    # ReadXMLFile.
146    # 'ProtocolEncoding' => 'ISO-8859-1',
147
148    # create XML::Parser object for parsing metadata.xml files
149    my $parser = new XML::Parser('Style' => 'Stream',
150                                  'PluginObj' => $self,
151                                  'Pkg' => 'MetadataXMLPlugin',
152                  'Handlers' => {'Char' => \&Char,
153                         'Doctype' => \&Doctype
154                         });
155
156    $self->{'parser'} = $parser;
157    $self->{'in_filename'} = 0;
158   
159   
160    return bless $self, $class;
161}
162
163
164sub get_default_process_exp
165{
166    return q^metadata\.xml$^;
167}
168
169sub get_doctype {
170    my $self = shift(@_);
171   
172    return "(Greenstone)?DirectoryMetadata"
173}
174
175sub can_process_this_file {
176    my $self = shift(@_);
177    my ($filename) = @_;
178
179    if (-f $filename && $self->SUPER::can_process_this_file($filename) && $self->check_doctype($filename)) {
180    return 1; # its a file for us
181    }
182    return 0;
183}
184
185sub check_doctype {
186    my $self = shift (@_);
187   
188    my ($filename) = @_;
189
190    if (open(XMLIN,"<$filename")) {
191    my $doctype = $self->get_doctype();
192    ## check whether the doctype has the same name as the root element tag
193    while (defined (my $line = <XMLIN>)) {
194        ## find the root element
195        if ($line =~ /<([\w\d:]+)[\s>]/){
196        my $root = $1;
197        if ($root !~ $doctype){
198            close(XMLIN);
199            return 0;
200        }
201        else {
202            close(XMLIN);
203            return 1;
204        }
205        }
206    }
207    close(XMLIN);
208    }
209   
210    return undef; # haven't found a valid line
211   
212}
213
214sub file_block_read {
215    my $self = shift (@_);
216    my ($pluginfo, $base_dir, $file, $block_hash, $metadata, $gli) = @_;
217   
218    my $filename_full_path = &util::filename_cat($base_dir, $file);
219    return undef unless $self->can_process_this_file($filename_full_path);   
220
221    if ($ENV{'GSDLOS'} =~ m/^windows$/) {
222       
223        my $lower_drive = $filename_full_path;
224        $lower_drive =~ s/^([A-Z]):/\l$1:/i;
225       
226        my $upper_drive = $filename_full_path;
227        $upper_drive =~ s/^([A-Z]):/\u$1:/i;
228       
229        $block_hash->{'metadata_files'}->{$lower_drive} = 1;
230        $block_hash->{'metadata_files'}->{$upper_drive} = 1;       
231    }
232    else {
233        $block_hash->{'metadata_files'}->{$filename_full_path} = 1;
234    }
235
236    return 1;
237}
238
239sub metadata_read
240{
241    my $self = shift (@_);
242    my ($pluginfo, $base_dir, $file, $block_hash,
243    $extrametakeys, $extrametadata,$extrametafile,
244    $processor, $gli, $aux) = @_;
245
246    my $filename = &util::filename_cat($base_dir, $file);
247    return undef unless $self->can_process_this_file($filename);   
248
249    $self->{'metadata-file'} = $file;
250    $self->{'metadata-filename'} = $filename;
251   
252    my $outhandle = $self->{'outhandle'};
253   
254    print STDERR "\n<Processing n='$file' p='MetadataXMLPlugin'>\n" if ($gli);
255    print $outhandle "MetadataXMLPlugin: processing $file\n" if ($self->{'verbosity'})> 1;
256    # 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
257    &util::block_filename($block_hash,$filename);
258
259    $self->{'metadataref'} = $extrametadata;
260    $self->{'metafileref'} = $extrametafile;
261    $self->{'metakeysref'} = $extrametakeys;
262   
263    eval {
264    $self->{'parser'}->parsefile($filename);
265    };
266
267    if ($@) {
268    my $plugin_name = ref ($self);
269    my $failhandle = $self->{'failhandle'};
270    print $outhandle "$plugin_name failed to process $file ($@)\n";
271    print $failhandle "$plugin_name failed to process $file ($@)\n";
272    print STDERR "<ProcessingError n='$file'>\n" if ($gli);
273    return -1; #error
274    }
275
276    return 1;
277
278}
279
280
281# Updated by Jeffrey 2010/04/16 @ DL Consulting Ltd.
282# Get rid off the global $self as it cause problems when there are 2+ MetadataXMLPlugin in your collect.cfg...
283# For example when you have an OAIMetadataXMLPlugin that is a child of MetadataXMLPlugin
284sub Doctype {$_[0]->{'PluginObj'}->xml_doctype(@_);}
285sub StartTag {$_[0]->{'PluginObj'}->xml_start_tag(@_);}
286sub EndTag {$_[0]->{'PluginObj'}->xml_end_tag(@_);}
287sub Text {$_[0]->{'PluginObj'}->xml_text(@_);}
288
289
290sub xml_doctype {
291    my $self = shift(@_);
292    my ($expat, $name, $sysid, $pubid, $internal) = @_;
293
294    # allow the short-lived and badly named "GreenstoneDirectoryMetadata" files
295    # to be processed as well as the "DirectoryMetadata" files which should now
296    # be created by import.pl
297    die if ($name !~ /^(Greenstone)?DirectoryMetadata$/);
298}
299
300sub xml_start_tag {
301    my $self = shift(@_);
302    my ($expat, $element) = @_;
303
304    if ($element eq "FileSet") {
305    $self->{'saved_targets'} = [];
306    $self->{'saved_metadata'} = {};
307    }
308    elsif ($element eq "FileName") {
309    $self->{'in_filename'} = 1;
310    }
311    elsif ($element eq "Metadata") {
312    $self->{'metadata_name'} = $_{'name'};
313    $self->{'metadata_value'} = "";
314    if ((defined $_{'mode'}) && ($_{'mode'} eq "accumulate")) {
315        $self->{'metadata_accumulate'} = 1;
316    } else {
317        $self->{'metadata_accumulate'} = 0;
318    }
319    }
320}
321
322sub xml_end_tag {
323    my $self = shift(@_);
324    my ($expat, $element) = @_;
325
326    if ($element eq "FileSet") {
327    foreach my $target (@{$self->{'saved_targets'}}) {
328        my $file_metadata = $self->{'metadataref'}->{$target};
329        my $saved_metadata = $self->{'saved_metadata'};
330
331        if (!defined $file_metadata) {
332        $self->{'metadataref'}->{$target} = $saved_metadata;
333
334        # not had target before
335        push (@{$self->{'metakeysref'}}, $target);
336        }
337        else {
338        &metadatautil::combine_metadata_structures($file_metadata,$saved_metadata);
339        }
340
341       
342        # now record which metadata.xml file it came from
343
344        my $file = $self->{'metadata-file'};
345        my $filename = $self->{'metadata-filename'};
346
347        if (!defined $self->{'metafileref'}->{$target}) {
348            $self->{'metafileref'}->{$target} = {};
349        }
350
351        $self->{'metafileref'}->{$target}->{$file} = $filename
352    }
353    }
354    elsif ($element eq "FileName") {
355    $self->{'in_filename'} = 0;
356    }
357    elsif ($element eq "Metadata") {
358    my $metadata_name = decode("utf8",$self->{'metadata_name'});
359    my $metadata_value = decode("utf8",$self->{'metadata_value'});
360   
361    &metadatautil::store_saved_metadata($self,
362                        $metadata_name, $metadata_value,
363                        $self->{'metadata_accumulate'});
364    $self->{'metadata_name'} = "";
365    }
366
367}
368
369sub xml_text {
370    my $self = shift(@_);
371
372    if ($self->{'in_filename'}) {
373    # $_ == FileName content
374    push (@{$self->{'saved_targets'}}, $_);
375    }
376    elsif (defined ($self->{'metadata_name'}) && $self->{'metadata_name'} ne "") {
377    # $_ == Metadata content
378    $self->{'metadata_value'} = $_;
379    }
380}
381
382# This Char function overrides the one in XML::Parser::Stream to overcome a
383# problem where $expat->{Text} is treated as the return value, slowing
384# things down significantly in some cases.
385sub Char {
386    if ($]<5.008) {
387    use bytes;  # Necessary to prevent encoding issues with XML::Parser 2.31+ and Perl 5.6
388    }
389    $_[0]->{'Text'} .= $_[1];
390    return undef;
391}
392
393
394
3951;
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