source: trunk/gsdl/perllib/plugins/PDFPlug.pm@ 10580

Last change on this file since 10580 was 10580, checked in by kjdon, 19 years ago

if created from pluginfo.pl (self->info_only == 1)then don't load up the secondary plugins

  • Property svn:keywords set to Author Date Id Revision
File size: 10.9 KB
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1###########################################################################
2#
3# PDFPlug.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 PDFPlug;
26
27use ConvertToPlug;
28use unicode;
29use strict;
30no strict 'refs'; # so we can use a var for filehandles (eg STDERR)
31
32sub BEGIN {
33 @PDFPlug::ISA = ('ConvertToPlug');
34}
35
36my $convert_to_list =
37 [ { 'name' => "auto",
38 'desc' => "{ConvertToPlug.convert_to.auto}" },
39 { 'name' => "html",
40 'desc' => "{ConvertToPlug.convert_to.html}" },
41 { 'name' => "text",
42 'desc' => "{ConvertToPlug.convert_to.text}" },
43 { 'name' => "pagedimg_jpg",
44 'desc' => "{ConvertToPlug.convert_to.pagedimg_jpg}"},
45 { 'name' => "pagedimg_gif",
46 'desc' => "{ConvertToPlug.convert_to.pagedimg_gif}"},
47 { 'name' => "pagedimg_png",
48 'desc' => "{ConvertToPlug.convert_to.pagedimg_png}"},
49 ];
50
51
52my $arguments =
53 [
54 { 'name' => "convert_to",
55 'desc' => "{ConvertToPlug.convert_to}",
56 'type' => "enum",
57 'reqd' => "yes",
58 'list' => $convert_to_list,
59 'deft' => "html" },
60 { 'name' => "process_exp",
61 'desc' => "{BasPlug.process_exp}",
62 'type' => "regexp",
63 'deft' => &get_default_process_exp(),
64 'reqd' => "no" },
65 { 'name' => "block_exp",
66 'desc' => "{BasPlug.block_exp}",
67 'type' => "regexp",
68 'deft' => &get_default_block_exp() },
69 { 'name' => "noimages",
70 'desc' => "{PDFPlug.noimages}",
71 'type' => "flag" },
72 { 'name' => "allowimagesonly",
73 'desc' => "{PDFPlug.allowimagesonly}",
74 'type' => "flag" },
75 { 'name' => "complex",
76 'desc' => "{PDFPlug.complex}",
77 'type' => "flag" },
78 { 'name' => "nohidden",
79 'desc' => "{PDFPlug.nohidden}",
80 'type' => "flag" },
81 { 'name' => "zoom",
82 'desc' => "{PDFPlug.zoom}",
83 'deft' => "2",
84 'range' => "1,3", # actually the range is 0.5-3
85 'type' => "int" },
86 { 'name' => "use_sections",
87 'desc' => "{PDFPlug.use_sections}",
88 'type' => "flag" },
89 { 'name' => "description_tags",
90 'desc' => "{HTMLPlug.description_tags}",
91 'type' => "flag" }
92];
93
94my $options = { 'name' => "PDFPlug",
95 'desc' => "{PDFPlug.desc}",
96 'abstract' => "no",
97 'inherits' => "yes",
98 'args' => $arguments };
99
100sub new {
101 my ($class) = shift (@_);
102 my ($pluginlist,$inputargs,$hashArgOptLists) = @_;
103 push(@$pluginlist, $class);
104
105 push(@$inputargs,"-title_sub");
106 push(@$inputargs,'^(Page\s+\d+)?(\s*1\s+)?');
107
108 if(defined $arguments){ push(@{$hashArgOptLists->{"ArgList"}},@{$arguments});}
109 if(defined $options) { push(@{$hashArgOptLists->{"OptList"}},$options)};
110
111 my @arg_array = @$inputargs;
112 my $self = (defined $hashArgOptLists)? new ConvertToPlug($pluginlist,$inputargs,$hashArgOptLists): new ConvertToPlug($pluginlist,$inputargs);
113
114 if ($self->{'info_only'}) {
115 # don't worry about any options etc
116 return bless $self, $class;
117 }
118
119 # these are passed through to gsConvert.pl by ConvertToPlug.pm
120 my $zoom = $self->{"zoom"};
121 $self->{'convert_options'} = "-pdf_zoom $zoom";
122 $self->{'convert_options'} .= " -pdf_complex" if $self->{"complex"};
123 $self->{'convert_options'} .= " -pdf_nohidden" if $self->{"nohidden"};
124 $self->{'convert_options'} .= " -pdf_ignore_images" if $self->{"noimages"};
125 $self->{'convert_options'} .= " -pdf_allow_images_only" if $self->{"allowimagesonly"};
126
127 my $secondary_plugin_options = $self->{'secondary_plugin_options'};
128
129 if (!defined $secondary_plugin_options->{'HTMLPlug'}) {
130 $secondary_plugin_options->{'HTMLPlug'} = [];
131 }
132 if (!defined $secondary_plugin_options->{'TEXTPlug'}) {
133 $secondary_plugin_options->{'TEXTPlug'} = [];
134 }
135 if (defined $self->{'convert_to'} && $self->{'convert_to'} =~ /pagedimg.*/i) {
136 if (!defined $secondary_plugin_options->{'PagedImgPlug'}){
137 $secondary_plugin_options->{'PagedImgPlug'} = [];
138 my $pagedimg_options = $secondary_plugin_options->{'PagedImgPlug'};
139 push(@$pagedimg_options, "-title_sub", '^(Page\s+\d+)?(\s*1\s+)?');
140 }
141 }
142 my $html_options = $secondary_plugin_options->{'HTMLPlug'};
143 my $text_options = $secondary_plugin_options->{'TEXTPlug'};
144
145 if ($self->{'input_encoding'} eq "auto") {
146 # pdftohtml will always produce html files encoded as utf-8
147 # => restrict primary PDFPlug and secondary HTML plugin to use
148 # utf8 and extract language.
149 $self->{'input_encoding'} = "utf8";
150 $self->{'extract_language'} = 1;
151
152 push(@$html_options,"-input_encoding", "utf8");
153 push(@$html_options,"-extract_language");
154 }
155
156 # Instruct HTMLPlug (when eventually accessed through read_into_doc_obj)
157 # to extract these metadata fields from the HEAD META fields
158 push(@$html_options,"-metadata_fields","Title,GENERATOR,date,author<Creator>");
159
160 if ($self->{'use_sections'} || $self->{'description_tags'}) {
161 $self->{'description_tags'} = 1;
162 push(@$html_options,"-description_tags");
163 }
164
165 # following title_sub removes "Page 1" added by pdftohtml, and a leading
166 # "1", which is often the page number at the top of the page. Bad Luck
167 # if your document title actually starts with "1 " - is there a better way?
168 push(@$html_options , "-title_sub", '^(Page\s+\d+)?(\s*1\s+)?');
169 push(@$text_options , "-title_sub", '^(Page\s+\d+)?(\s*1\s+)?');
170
171 $self = bless $self, $class;
172 $self->load_secondary_plugins($class,$secondary_plugin_options,$hashArgOptLists);
173 return $self;
174}
175
176sub get_default_process_exp {
177 my $self = shift (@_);
178
179 return q^(?i)\.pdf$^;
180}
181
182# so we don't inherit HTMLPlug's block exp...
183sub get_default_block_exp {
184 return "";
185}
186
187sub convert_post_process
188{
189 my $self = shift (@_);
190 my ($conv_filename) = @_;
191
192 my $outhandle=$self->{'outhandle'};
193
194 my ($language, $encoding) = $self->textcat_get_language_encoding ($conv_filename);
195
196 # read in file ($text will be in utf8)
197 my $text = "";
198 $self->read_file ($conv_filename, $encoding, $language, \$text);
199
200 # Calculate number of pages based on <a ...> tags (we have a <a name=1> etc
201 # for each page). Metadata based on this calculation not set until process()
202 #
203 # Note: this is done even if we are not breaking to document into pages as it might
204 # be useful to give an indication of document length in browser through setting
205 # num_pages as metadata.
206 my @pages = ($text =~ /\<[Aa] name=\"?\w+\"?>/ig);
207 my $num_pages = scalar(@pages);
208 $self->{'num_pages'} = $num_pages;
209
210 if ($self->{'use_sections'}
211 && $self->{'converted_to'} eq "HTML") {
212
213 print $outhandle "PDFPlug: Calculating sections...\n";
214
215 # we have "<a name=1></a>" etc for each page
216 # it may be <A name=
217 my @sections = split('<[Aa] name=', $text);
218
219 my $top_section = "";
220
221 if (scalar (@sections) == 1) { #only one section - no split!
222 print $outhandle "PDFPlug: warning - no sections found\n";
223 } else {
224 $top_section .= shift @sections; # keep HTML header etc as top_section
225 }
226
227 # handle first section specially for title? Or all use first 100...
228
229 my $title = $sections[0];
230 $title =~ s/^\"?\w+\"?>//; # specific for pdftohtml...
231 $title =~ s/<\/([^>]+)><\1>//g; # (eg) </b><b> - no space
232 $title =~ s/<[^>]*>/ /g;
233 $title =~ s/(?:&nbsp;|\xc2\xa0)/ /g; # utf-8 for nbsp...
234 $title =~ s/^\s+//s;
235 $title =~ s/\s+$//;
236 $title =~ s/\s+/ /gs;
237 $title =~ s/^$self->{'title_sub'}// if ($self->{'title_sub'});
238 $title =~ s/^\s+//s; # in case title_sub introduced any...
239 $title = substr ($title, 0, 100);
240 $title =~ s/\s\S*$/.../;
241
242
243 if (scalar (@sections) == 1) { # no sections found
244 $top_section .= $sections[0];
245 @sections=();
246 } else {
247 $top_section .= "<!--<Section>\n<Metadata name=\"Title\">$title</Metadata>\n-->\n <!--</Section>-->\n";
248 }
249
250 # add metadata per section...
251 foreach my $section (@sections) {
252 # section names are not always just digits, may be like "outline"
253 $section =~ s@^\"?(\w+)\"?></a>@@; # leftover from split expression...
254
255 $title = $1; # Greenstone does magic if sections are titled digits
256 if (! defined($title) ) {
257 print STDERR "no title: $section\n";
258 $title = " "; # get rid of the undefined warning in next line
259 }
260 my $newsection = "<!-- from PDFPlug -->\n<!-- <Section>\n";
261 $newsection .= "<Metadata name=\"Title\">" . $title
262 . "</Metadata>\n--><p>\n";
263 $newsection .= $section;
264 $newsection .= "<!--</Section>-->\n";
265 $section = $newsection;
266 }
267
268 $text=join('', ($top_section, @sections));
269 }
270
271 # turn any high bytes that aren't valid utf-8 into utf-8.
272 unicode::ensure_utf8(\$text);
273
274 # Write it out again!
275 $self->utf8_write_file (\$text, $conv_filename);
276}
277
278
279# do plugin specific processing of doc_obj for HTML type
280sub process {
281 my $self = shift (@_);
282 my ($textref, $pluginfo, $base_dir, $file, $metadata, $doc_obj, $gli) = @_;
283
284 my $result = $self->process_type("pdf",$base_dir,$file,$doc_obj);
285
286 # fix up the extracted date metadata to be in Greenstone date format,
287 # and fix the capitalisation of 'date'
288 my $cursection = $doc_obj->get_top_section();
289
290 foreach my $datemeta (@{$doc_obj->get_metadata($cursection, "date")}) {
291 $doc_obj->delete_metadata($cursection, "date", $datemeta);
292
293 # We're just interested in the date bit, not the time
294 # some pdf creators (eg "Acrobat 5.0 Scan Plug-in for Windows")
295 # set a /CreationDate, and set /ModDate to 000000000. pdftohtml
296 # extracts the ModDate, so it is 0...
297 $datemeta =~ /(\d+)-(\d+)-(\d+)/;
298 my ($year, $month, $day) = ($1,$2,$3);
299 if (defined($year) && defined($month) && defined($day)) {
300 if ($year == 0) {next}
301 if ($year < 100) {$year += 1900} # just to be safe
302 if ($month =~ /^\d$/) {$month="0$month"} # single digit
303 if ($day =~ /^\d$/) {$day="0$day"} # single digit
304 my $date="$year$month$day";
305 $doc_obj->add_utf8_metadata($cursection, "Date", $date);
306 }
307 }
308
309 $doc_obj->add_utf8_metadata($cursection, "NumPages", $self->{'num_pages'});
310
311 if ($self->{'use_sections'} && $self->{'converted_to'} eq "HTML") {
312 # we explicitly make it a paged document, cos greenstone won't get it
313 # right if any section has an empty title, or one with letters in it
314 $doc_obj->set_utf8_metadata_element ($cursection, "gsdlthistype", "Paged");
315 }
316
317 return $result;
318}
319
3201;
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