source: main/trunk/greenstone2/perllib/plugins/PDFPlugin.pm@ 21800

Last change on this file since 21800 was 21800, checked in by kjdon, 14 years ago

added a new option, metadata_field_separator, which specifies what to split on for multi-valued metadata

  • Property svn:keywords set to Author Date Id Revision
File size: 12.8 KB
Line 
1###########################################################################
2#
3# PDFPlugin.pm -- reasonably with-it pdf plugin
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) 1999-2001 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###########################################################################
25package PDFPlugin;
26
27use ConvertBinaryFile;
28use ReadTextFile;
29use unicode;
30use strict;
31no strict 'refs'; # so we can use a var for filehandles (eg STDERR)
32
33sub BEGIN {
34 @PDFPlugin::ISA = ('ConvertBinaryFile', 'ReadTextFile');
35}
36
37my $convert_to_list =
38 [ { 'name' => "auto",
39 'desc' => "{ConvertBinaryFile.convert_to.auto}" },
40 { 'name' => "html",
41 'desc' => "{ConvertBinaryFile.convert_to.html}" },
42 { 'name' => "text",
43 'desc' => "{ConvertBinaryFile.convert_to.text}" },
44 { 'name' => "pagedimg_jpg",
45 'desc' => "{ConvertBinaryFile.convert_to.pagedimg_jpg}"},
46 { 'name' => "pagedimg_gif",
47 'desc' => "{ConvertBinaryFile.convert_to.pagedimg_gif}"},
48 { 'name' => "pagedimg_png",
49 'desc' => "{ConvertBinaryFile.convert_to.pagedimg_png}"},
50 ];
51
52
53my $arguments =
54 [
55 { 'name' => "convert_to",
56 'desc' => "{ConvertBinaryFile.convert_to}",
57 'type' => "enum",
58 'reqd' => "yes",
59 'list' => $convert_to_list,
60 'deft' => "html" },
61 { 'name' => "process_exp",
62 'desc' => "{BasePlugin.process_exp}",
63 'type' => "regexp",
64 'deft' => &get_default_process_exp(),
65 'reqd' => "no" },
66 { 'name' => "block_exp",
67 'desc' => "{BasePlugin.block_exp}",
68 'type' => "regexp",
69 'deft' => &get_default_block_exp() },
70 { 'name' => "metadata_fields",
71 'desc' => "{HTMLPlugin.metadata_fields}",
72 'type' => "string",
73 'deft' => "" },
74 { 'name' => "metadata_field_separator",
75 'desc' => "{HTMLPlugin.metadata_field_separator}",
76 'type' => "string",
77 'deft' => "" },
78 { 'name' => "noimages",
79 'desc' => "{PDFPlugin.noimages}",
80 'type' => "flag" },
81 { 'name' => "allowimagesonly",
82 'desc' => "{PDFPlugin.allowimagesonly}",
83 'type' => "flag" },
84 { 'name' => "complex",
85 'desc' => "{PDFPlugin.complex}",
86 'type' => "flag" },
87 { 'name' => "nohidden",
88 'desc' => "{PDFPlugin.nohidden}",
89 'type' => "flag" },
90 { 'name' => "zoom",
91 'desc' => "{PDFPlugin.zoom}",
92 'deft' => "2",
93 'range' => "1,3", # actually the range is 0.5-3
94 'type' => "int" },
95 { 'name' => "use_sections",
96 'desc' => "{PDFPlugin.use_sections}",
97 'type' => "flag" },
98 { 'name' => "description_tags",
99 'desc' => "{HTMLPlugin.description_tags}",
100 'type' => "flag" }
101 ];
102
103my $options = { 'name' => "PDFPlugin",
104 'desc' => "{PDFPlugin.desc}",
105 'abstract' => "no",
106 'inherits' => "yes",
107 'srcreplaceable' => "yes", # Source docs in PDF can be replaced with GS-generated html
108 'args' => $arguments };
109
110sub new {
111 my ($class) = shift (@_);
112 my ($pluginlist,$inputargs,$hashArgOptLists) = @_;
113 push(@$pluginlist, $class);
114
115 push(@$inputargs,"-title_sub");
116 push(@$inputargs,'^(Page\s+\d+)?(\s*1\s+)?');
117
118 push(@{$hashArgOptLists->{"ArgList"}},@{$arguments});
119 push(@{$hashArgOptLists->{"OptList"}},$options);
120
121 my @arg_array = @$inputargs;
122 my $self = new ConvertBinaryFile($pluginlist, $inputargs, $hashArgOptLists);
123
124 if ($self->{'info_only'}) {
125 # don't worry about any options etc
126 return bless $self, $class;
127 }
128
129 $self->{'filename_extension'} = "pdf";
130 $self->{'file_type'} = "PDF";
131
132 # these are passed through to gsConvert.pl by ConvertBinaryFile.pm
133 my $zoom = $self->{"zoom"};
134 $self->{'convert_options'} = "-pdf_zoom $zoom";
135 $self->{'convert_options'} .= " -pdf_complex" if $self->{"complex"};
136 $self->{'convert_options'} .= " -pdf_nohidden" if $self->{"nohidden"};
137 $self->{'convert_options'} .= " -pdf_ignore_images" if $self->{"noimages"};
138 $self->{'convert_options'} .= " -pdf_allow_images_only" if $self->{"allowimagesonly"};
139
140 my $secondary_plugin_options = $self->{'secondary_plugin_options'};
141
142 if (!defined $secondary_plugin_options->{'HTMLPlugin'}) {
143 $secondary_plugin_options->{'HTMLPlugin'} = [];
144 }
145 if (!defined $secondary_plugin_options->{'TextPlugin'}) {
146 $secondary_plugin_options->{'TextPlugin'} = [];
147 }
148 if (defined $self->{'convert_to'} && $self->{'convert_to'} =~ m/(pagedimage|pagedimg).*/i) {
149 if (!defined $secondary_plugin_options->{'PagedImagePlugin'}){
150 $secondary_plugin_options->{'PagedImagePlugin'} = [];
151 my $pagedimg_options = $secondary_plugin_options->{'PagedImagePlugin'};
152 push(@$pagedimg_options, "-title_sub", '^(Page\s+\d+)?(\s*1\s+)?');
153 push(@$pagedimg_options, "-screenviewsize", "1000");
154 push(@$pagedimg_options, "-enable_cache");
155 }
156 }
157 my $html_options = $secondary_plugin_options->{'HTMLPlugin'};
158 my $text_options = $secondary_plugin_options->{'TextPlugin'};
159 my $pagedimg_options = $secondary_plugin_options->{'PagedImagePlugin'};
160
161# if ($self->{'input_encoding'} eq "auto") {
162# $self->{'input_encoding'} = "utf8";
163# }
164
165 # if pdftohtml is always producing utf8, then htmlplug always needs this option
166 push(@$html_options,"-input_encoding", "utf8");
167 push(@$html_options,"-extract_language") if $self->{'extract_language'};
168
169 push(@$html_options, "-processing_tmp_files");
170 push(@$pagedimg_options, "-processing_tmp_files");
171
172 # Instruct HTMLPlug (when eventually accessed through read_into_doc_obj)
173 # to extract these metadata fields from the HEAD META fields
174 my $required_metadata;
175 if (defined $self->{'metadata_fields'} && $self->{'metadata_fields'} =~ /\S/) {
176 push(@$html_options,"-metadata_fields",$self->{'metadata_fields'});
177 } else {
178 push(@$html_options,"-metadata_fields","Title,GENERATOR,date,author<Creator>");
179 }
180 if (defined $self->{'metadata_field_separator'} && $self->{'metadata_field_separator'} =~ /\S/) {
181 push(@$html_options,"-metadata_field_separator",$self->{'metadata_field_separator'});
182 }
183
184 if ($self->{'use_sections'} || $self->{'description_tags'}) {
185 $self->{'description_tags'} = 1;
186 push(@$html_options,"-description_tags");
187 }
188
189 # following title_sub removes "Page 1" added by pdftohtml, and a leading
190 # "1", which is often the page number at the top of the page. Bad Luck
191 # if your document title actually starts with "1 " - is there a better way?
192 push(@$html_options , "-title_sub", '^(Page\s+\d+)?(\s*1\s+)?');
193 push(@$text_options , "-title_sub", '^(Page\s+\d+)?(\s*1\s+)?');
194
195 my $associate_tail_re = $self->{'associate_tail_re'};
196 if ((defined $associate_tail_re) && ($associate_tail_re ne "")) {
197 push(@$html_options, "-associate_tail_re", $associate_tail_re);
198 push(@$text_options, "-associate_tail_re", $associate_tail_re);
199 push(@$pagedimg_options, "-associate_tail_re", $associate_tail_re) if defined $pagedimg_options;
200 }
201
202 push(@$html_options, "-file_rename_method", "none");
203 push(@$text_options, "-file_rename_method", "none");
204 push(@$pagedimg_options, "-file_rename_method", "none") if defined $pagedimg_options;
205
206 $self = bless $self, $class;
207 $self->load_secondary_plugins($class,$secondary_plugin_options,$hashArgOptLists);
208 return $self;
209}
210
211sub get_default_process_exp {
212 my $self = shift (@_);
213
214 return q^(?i)\.pdf$^;
215}
216
217# so we don't inherit HTMLPlug's block exp...
218sub get_default_block_exp {
219 return "";
220}
221
222sub convert_post_process
223{
224 my $self = shift (@_);
225 my ($conv_filename) = @_;
226
227 my $outhandle=$self->{'outhandle'};
228
229 #$self->{'input_encoding'} = "utf8"; # The output is always in utf8 (is it?? it is for html, but what about other types?)
230 #my ($language, $encoding) = $self->textcat_get_language_encoding ($conv_filename);
231
232 # read in file ($text will be in utf8)
233 my $text = "";
234 # encoding will be utf8 for html files - what about other types? will we do this step for them anyway?
235 $self->read_file ($conv_filename, "utf8", "", \$text);
236
237 # Calculate number of pages based on <a ...> tags (we have a <a name=1> etc
238 # for each page). Metadata based on this calculation not set until process()
239 #
240 # Note: this is done even if we are not breaking to document into pages as it might
241 # be useful to give an indication of document length in browser through setting
242 # num_pages as metadata.
243 my @pages = ($text =~ /\<[Aa] name=\"?\w+\"?>/ig);
244 my $num_pages = scalar(@pages);
245 $self->{'num_pages'} = $num_pages;
246
247 if ($self->{'use_sections'}
248 && $self->{'converted_to'} eq "HTML") {
249
250 print $outhandle "PDFPlugin: Calculating sections...\n";
251
252 # we have "<a name=1></a>" etc for each page
253 # it may be <A name=
254 my @sections = split('<[Aa] name=', $text);
255
256 my $top_section = "";
257
258 if (scalar (@sections) == 1) { #only one section - no split!
259 print $outhandle "PDFPlugin: warning - no sections found\n";
260 } else {
261 $top_section .= shift @sections; # keep HTML header etc as top_section
262 }
263
264 # handle first section specially for title? Or all use first 100...
265
266 my $title = $sections[0];
267 $title =~ s/^\"?\w+\"?>//; # specific for pdftohtml...
268 $title =~ s/<\/([^>]+)><\1>//g; # (eg) </b><b> - no space
269 $title =~ s/<[^>]*>/ /g;
270 $title =~ s/(?:&nbsp;|\xc2\xa0)/ /g; # utf-8 for nbsp...
271 $title =~ s/^\s+//s;
272 $title =~ s/\s+$//;
273 $title =~ s/\s+/ /gs;
274 $title =~ s/^$self->{'title_sub'}// if ($self->{'title_sub'});
275 $title =~ s/^\s+//s; # in case title_sub introduced any...
276 $title = substr ($title, 0, 100);
277 $title =~ s/\s\S*$/.../;
278
279
280 if (scalar (@sections) == 1) { # no sections found
281 $top_section .= $sections[0];
282 @sections=();
283 } else {
284 $top_section .= "<!--<Section>\n<Metadata name=\"Title\">$title</Metadata>\n-->\n <!--</Section>-->\n";
285 }
286
287 # add metadata per section...
288 foreach my $section (@sections) {
289 # section names are not always just digits, may be like "outline"
290 $section =~ s@^\"?(\w+)\"?></a>@@; # leftover from split expression...
291
292 $title = $1; # Greenstone does magic if sections are titled digits
293 if (! defined($title) ) {
294 print STDERR "no title: $section\n";
295 $title = " "; # get rid of the undefined warning in next line
296 }
297 my $newsection = "<!-- from PDFPlugin -->\n<!-- <Section>\n";
298 $newsection .= "<Metadata name=\"Title\">" . $title
299 . "</Metadata>\n--><p>\n";
300 $newsection .= $section;
301 $newsection .= "<!--</Section>-->\n";
302 $section = $newsection;
303 }
304
305 $text=join('', ($top_section, @sections));
306 }
307
308 # turn any high bytes that aren't valid utf-8 into utf-8.
309 unicode::ensure_utf8(\$text);
310
311 # Write it out again!
312 $self->utf8_write_file (\$text, $conv_filename);
313}
314
315
316# do plugin specific processing of doc_obj for HTML type
317sub process {
318 my $self = shift (@_);
319 my ($pluginfo, $base_dir, $file, $metadata, $doc_obj, $gli) = @_;
320
321 my $result = $self->process_type($base_dir,$file,$doc_obj);
322
323 # fix up the extracted date metadata to be in Greenstone date format,
324 # and fix the capitalisation of 'date'
325 my $cursection = $doc_obj->get_top_section();
326 foreach my $datemeta (@{$doc_obj->get_metadata($cursection, "date")}) {
327 $doc_obj->delete_metadata($cursection, "date", $datemeta);
328
329 # We're just interested in the date bit, not the time
330 # some pdf creators (eg "Acrobat 5.0 Scan Plug-in for Windows")
331 # set a /CreationDate, and set /ModDate to 000000000. pdftohtml
332 # extracts the ModDate, so it is 0...
333 $datemeta =~ /(\d+)-(\d+)-(\d+)/;
334 my ($year, $month, $day) = ($1,$2,$3);
335 if (defined($year) && defined($month) && defined($day)) {
336 if ($year == 0) {next}
337 if ($year < 100) {$year += 1900} # just to be safe
338 if ($month =~ /^\d$/) {$month="0$month"} # single digit
339 if ($day =~ /^\d$/) {$day="0$day"} # single digit
340 my $date="$year$month$day";
341 $doc_obj->add_utf8_metadata($cursection, "Date", $date);
342 }
343 }
344
345 $doc_obj->add_utf8_metadata($cursection, "NumPages", $self->{'num_pages'});
346
347 if ($self->{'use_sections'} && $self->{'converted_to'} eq "HTML") {
348 # we explicitly make it a paged document, cos greenstone won't get it
349 # right if any section has an empty title, or one with letters in it
350 $doc_obj->set_utf8_metadata_element ($cursection, "gsdlthistype", "Paged");
351 }
352
353 return $result;
354}
355
3561;
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