source: gsdl/trunk/perllib/plugins/DBPlugin.pm@ 17026

Last change on this file since 17026 was 17026, checked in by kjdon, 16 years ago

OID generation modifications: OIDtype and OIDmetadata options now available for plugins as well as import. OIDtype for plugins defaults to auto - if set to auto, then use the values from import. All plugins now call self->add_OID instead of doc_obj->set_OID. This sets the doc_obj OIDtype so that doesn't need to be donein other places any more. all plugins have the get_oid_hash_type method - normally returns hash_on_file, but can be overridden to return hash_on_ga_xml for those plugins that don't want hashing on file (MP3,OggVorbis...)

  • Property svn:keywords set to Author Date Id Revision
File size: 11.2 KB
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1###########################################################################
2#
3# DBPlugin.pm -- plugin to import records from a database
4#
5# A component of the Greenstone digital library software
6# from the New Zealand Digital Library Project at the
7# University of Waikato, New Zealand.
8#
9# Copyright (C) 2003 New Zealand Digital Library Project
10#
11# This program is free software; you can redistribute it and/or modify
12# it under the terms of the GNU General Public License as published by
13# the Free Software Foundation; either version 2 of the License, or
14# (at your option) any later version.
15#
16# This program is distributed in the hope that it will be useful,
17# but WITHOUT ANY WARRANTY; without even the implied warranty of
18# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19# GNU General Public License for more details.
20#
21# You should have received a copy of the GNU General Public License
22# along with this program; if not, write to the Free Software
23# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24#
25###########################################################################
26
27# A plugin that imports records from a database. This uses perl's DBI module,
28# which includes back-ends for mysql, postgresql, comma separated values (CSV),
29# MS Excel, ODBC, sybase, etc... Extra modules may need to be installed to
30# use this. See <GSDLHOME>/etc/packages/example.dbi for an example config file.
31#
32
33# Written by John McPherson for the NZDL project
34# Mar, Apr 2003
35
36package DBPlugin;
37
38use strict;
39no strict 'refs'; # allow variable as a filehandle
40
41use AutoExtractMetadata;
42use unicode;
43
44sub BEGIN {
45 @DBPlugin::ISA = ('AutoExtractMetadata');
46}
47
48my $arguments =
49 [ { 'name' => "process_exp",
50 'desc' => "{BasePlugin.process_exp}",
51 'type' => "regexp",
52 'deft' => &get_default_process_exp(),
53 'reqd' => "no" }];
54
55my $options = { 'name' => "DBPlugin",
56 'desc' => "{DBPlugin.desc}",
57 'abstract' => "no",
58 'inherits' => "yes",
59 'args' => $arguments };
60
61sub new {
62 my ($class) = shift (@_);
63 my ($pluginlist,$inputargs,$hashArgOptLists) = @_;
64 push(@$pluginlist, $class);
65
66 push(@{$hashArgOptLists->{"ArgList"}},@{$arguments});
67 push(@{$hashArgOptLists->{"OptList"}},$options);
68
69 my $self = new AutoExtractMetadata($pluginlist, $inputargs, $hashArgOptLists);
70
71 return bless $self, $class;
72}
73
74sub get_default_process_exp {
75 my $self = shift (@_);
76
77 return q^(?i)\.dbi$^;
78}
79
80sub read {
81 my $self = shift (@_);
82 my ($pluginfo, $base_dir, $file, $block_hash, $metadata, $processor, $maxdocs,$total_count,$gli) = @_;
83
84 #see if we can handle the passed file...
85 my ($filename_full_path, $filename_no_path) = &util::get_full_filenames($base_dir, $file);
86 return undef unless $self->can_process_this_file($filename_full_path);
87
88 my $outhandle = $self->{'outhandle'};
89 my $verbosity = $self->{'verbosity'};
90
91 print STDERR "<Processing n='$file' p='DBPlugin'>\n" if ($gli);
92 print $outhandle "DBPlugin: processing $file\n"
93 if $self->{'verbosity'} > 1;
94
95 require DBI; # database independent stuff
96
97 # calculate the document hash, for document ids
98 my $hash="0";
99
100
101 # default options - may be overridden by config file
102 my $language=undef;
103 my $encoding=undef;
104 my $dbplug_debug=0;
105 my $username='';
106 my $password='';
107
108 # these settings must be set by the config file:
109 my $db=undef;
110
111 # get id of pages from "nonempty", get latest version number from
112 # "recent", and then get pagename from "page" and content from "version" !
113
114 my $sql_query_prime = undef ;
115 my $sql_query = undef ;
116
117 my %db_to_greenstone_fields=();
118 my %callbacks=();
119
120
121 # read in config file.
122 if (!open (CONF, $filename_full_path)) {
123 print $outhandle "DBPlugin: can't read $filename_full_path: $!\n";
124 return 0;
125 }
126
127 my $line;
128 my $statement="";
129 my $callback="";
130 while (defined($line=<CONF>)) {
131 chomp $line;
132 $line .= " "; # for multi-line statements - don't conjoin!
133 $line =~ s/\s*\#.*$//mg; # remove comments
134 $statement .= $line;
135
136 if ($line =~ /^\}\s*$/ && $callback) { # ends the callback
137 $callback .= $statement ; $statement = "";
138 # try to check that the function is "safe"
139 if ($callback =~ /\b(?:system|open|pipe|readpipe|qx|kill|eval|do|use|require|exec|fork)\b/ ||
140 $callback =~ /[\`]|\|\-/) {
141 # no backticks or functions that start new processes allowed
142 print $outhandle "DBPlugin: bad function in callback\n";
143 return 0;
144 }
145 $callback =~ s/sub (\w+?)_callback/sub/;
146 my $fieldname = $1;
147 my $ret = eval "\$callbacks{'$fieldname'} = $callback ; 1";
148 if (!defined($ret)) {
149 print $outhandle "DBPlugin: error eval'ing callback: $@\n";
150 exit(1);
151 }
152 $callback="";
153 print $outhandle "DBPlugin: callback registered for '$fieldname'\n"
154 if $dbplug_debug;
155 } elsif ($callback) {
156 # add this line to the callback function
157 $callback .= $statement;
158 $statement = "";
159 } elsif ($statement =~ m/;\s*$/) { # ends with ";"
160 # check that it is safe
161 # assignment
162 if ($statement =~ m~(\$\w+)\s* = \s*
163 (\d # digits
164 | ".*?(?<!\\)" # " up to the next " not preceded by a \
165 | '.*?(?<!\\)' # ' up to the next ' not preceded by a \
166 )\s*;~x || # /x means ignore comments and whitespace in rx
167 $statement =~ m~(\%\w+)\s*=\s*(\([\w\s\"\',:=>]+\))\s*;~ ) {
168 # evaluate the assignment, return 1 on success "
169 if (!eval "$1=$2; 1") {
170 my $err=$@;
171 chomp $err;
172 $err =~ s/\.$//; # remove a trailing .
173 print $outhandle "DBPlugin: error evaluating `$statement'\n";
174 print $outhandle " $err (in $filename_full_path)\n";
175 return 0; # there was an error reading the config file
176 }
177 } elsif ($statement =~ /sub \w+_callback/) {
178 # this is the start of a callback function definition
179 $callback = $statement;
180 $statement = "";
181 } else {
182 print $outhandle "DBPlugin: skipping statement `$statement'\n";
183 }
184 $statement = "";
185 }
186 }
187 close CONF;
188
189
190 if (!defined($db)) {
191 print $outhandle "DBPlugin: error: $filename_full_path does not specify a db!\n";
192 return 0;
193 }
194 if (!defined($sql_query)) {
195 print $outhandle "DBPlugin: error: no SQL query specified!\n";
196 return 0;
197 }
198 # connect to database
199 my $dbhandle=DBI->connect($db, $username, $password);
200
201 if (!defined($dbhandle)) {
202 die "DBPlugin: could not connect to database, exiting.\n";
203 }
204 if (defined($dbplug_debug) && $dbplug_debug==1) {
205 print $outhandle "DBPlugin (debug): connected ok\n";
206 }
207
208 my $statement_hand;
209
210 # The user gave 2 sql statements to execute?
211 if ($sql_query_prime) {
212 $statement_hand=$dbhandle->prepare($sql_query_prime);
213 $statement_hand->execute;
214 if ($statement_hand->err) {
215 print $outhandle "Error: " . $statement_hand->errstr . "\n";
216 return undef;
217 }
218 }
219
220
221 $statement_hand=$dbhandle->prepare($sql_query);
222 $statement_hand->execute;
223 if ($statement_hand->err) {
224 print $outhandle "Error:" . $statement_hand->errstr . "\n";
225 return undef;
226 }
227
228 # get the array-ref for the field names and cast it to array
229 my @field_names;
230 @field_names=@{ $statement_hand->{NAME} };
231
232 foreach my $fieldname (@field_names) {
233 if (defined($db_to_greenstone_fields{$fieldname})) {
234 if (defined($dbplug_debug) && $dbplug_debug==1) {
235 print $outhandle "DBPlugin (debug): mapping db field "
236 . "'$fieldname' to "
237 . $db_to_greenstone_fields{$fieldname} . "\n";
238 }
239 $fieldname=$db_to_greenstone_fields{$fieldname};
240 }
241 }
242
243 # get rows
244
245 my $count = 0;
246 my @row_array;
247
248 @row_array=$statement_hand->fetchrow_array; # fetchrow_hashref?
249
250 my $base_oid = undef;
251 while (scalar(@row_array)) {
252 if (defined($dbplug_debug) && $dbplug_debug==1) {
253 print $outhandle "DBPlugin (debug): retrieved a row from query\n";
254 }
255
256 # create a new document
257 my $doc_obj = new doc ($filename_full_path, "indexed_doc");
258
259 my $cursection = $doc_obj->get_top_section();
260
261 # if $language not set in config file, will use BasePlugin's default
262 if (defined($language)) {
263 $doc_obj->add_utf8_metadata($cursection, "Language", $language);
264 }
265 # if $encoding not set in config file, will use BasePlugin's default
266 if (defined($encoding)) {
267 # allow some common aliases
268 if ($encoding =~ m/^utf[-_]8$/i) {$encoding="utf8"}
269 $encoding =~ s/-/_/g; # greenstone uses eg iso_8859_1
270 $doc_obj->add_utf8_metadata($cursection, "Encoding", $encoding);
271 }
272 $self->set_Source_metadata($doc_obj, $db, $encoding);
273
274 if ($self->{'cover_image'}) {
275 $self->associate_cover_image($doc_obj, $filename_full_path);
276 }
277 $doc_obj->add_utf8_metadata($doc_obj->get_top_section(), "Plugin", "$self->{'plugin_type'}");
278
279 $doc_obj->add_metadata($doc_obj->get_top_section(), "FileFormat", "DB");
280
281 # include any metadata passed in from previous plugins
282 # note that this metadata is associated with the top level section
283 $self->extra_metadata ($doc_obj, $cursection,
284 $metadata);
285
286 # do any automatic metadata extraction
287 $self->auto_extract_metadata ($doc_obj);
288
289 my $unique_id=undef;
290
291 foreach my $fieldname (@field_names) {
292 my $fielddata=shift @row_array;
293
294 if (! defined($fielddata) ) {
295 next; # this field was "" or NULL
296 }
297 # use the specified encoding, defaulting to utf-8
298 if (defined($encoding) && $encoding ne "ascii"
299 && $encoding ne "utf8") {
300 $fielddata=&unicode::unicode2utf8(
301 &unicode::convert2unicode($encoding, \$fielddata)
302 );
303 }
304 # see if we have a ****_callback() function defined
305 if (exists $callbacks{$fieldname}) {
306 my $funcptr = $callbacks{$fieldname};
307 $fielddata = &$funcptr($fielddata);
308 }
309
310 if ($fieldname eq "text") {
311 # add as document text
312 $fielddata=~s@<@&lt;@g;
313 $fielddata=~s@>@&gt;@g; # for xml protection...
314 $fielddata=~s@_@\\_@g; # for macro language protection...
315 $doc_obj->add_utf8_text($cursection, $fielddata);
316 } elsif ($fieldname eq "Identifier") {
317 # use as greenstone's unique record id
318 if ($fielddata =~ /^\d+$/) {
319 # don't allow IDs that are completely numeric
320 $unique_id="id" . $fielddata;
321 } else {
322 $unique_id=$fielddata;
323 }
324 } else {
325 # add as document metadata
326 $fielddata=~s/\[/&#91;/g;
327 $fielddata=~s/\]/&#93;/g;
328 $doc_obj->add_utf8_metadata($cursection,
329 $fieldname, $fielddata);
330
331 }
332 }
333
334
335 if (!defined $unique_id) {
336 if (!defined $base_oid) {
337 $self->add_OID($doc_obj);
338 $base_oid = $doc_obj->get_OID();
339 }
340 $doc_obj->set_OID($base_oid."s$count");
341 } else {
342 # use our id from the database...
343 $doc_obj->set_OID($unique_id);
344 }
345
346
347 # process the document
348 $processor->process($doc_obj);
349
350 $count++;
351
352 # get next row
353 @row_array=$statement_hand->fetchrow_array; # fetchrow_hashref?
354 } # end of row_array is not empty
355
356 # check "$sth->err" if empty array for error
357 if ($statement_hand->err) {
358 print $outhandle "DBPlugin: received error: \"" .
359 $statement_hand->errstr . "\"\n";
360 }
361
362 # clean up connection to database
363 $statement_hand->finish();
364 $dbhandle->disconnect();
365
366 # num of input files, rather than documents created?
367 $self->{'num_processed'}++;
368
369 if (defined($dbplug_debug) && $dbplug_debug==1) {
370 print $outhandle "DBPlugin: imported $count DB records as documents.\n";
371 }
372 $count;
373}
374
3751;
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