source: gsdl/trunk/perllib/plugins/PDFPlugin.pm@ 18406

Last change on this file since 18406 was 18406, checked in by ak19, 15 years ago

Modified srcreplaceable plugins (plugins which operate on docs where the source file can be replaced with their converted htmls) to set the file_rename_method to none for secondary plugins (for Text, HTML, and PagedImage plugins) so that the file is not renamed several times.

  • Property svn:keywords set to Author Date Id Revision
File size: 12.5 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' => "noimages",
75 'desc' => "{PDFPlugin.noimages}",
76 'type' => "flag" },
77 { 'name' => "allowimagesonly",
78 'desc' => "{PDFPlugin.allowimagesonly}",
79 'type' => "flag" },
80 { 'name' => "complex",
81 'desc' => "{PDFPlugin.complex}",
82 'type' => "flag" },
83 { 'name' => "nohidden",
84 'desc' => "{PDFPlugin.nohidden}",
85 'type' => "flag" },
86 { 'name' => "zoom",
87 'desc' => "{PDFPlugin.zoom}",
88 'deft' => "2",
89 'range' => "1,3", # actually the range is 0.5-3
90 'type' => "int" },
91 { 'name' => "use_sections",
92 'desc' => "{PDFPlugin.use_sections}",
93 'type' => "flag" },
94 { 'name' => "description_tags",
95 'desc' => "{HTMLPlugin.description_tags}",
96 'type' => "flag" }
97 ];
98
99my $options = { 'name' => "PDFPlugin",
100 'desc' => "{PDFPlugin.desc}",
101 'abstract' => "no",
102 'inherits' => "yes",
103 'srcreplaceable' => "yes", # Source docs in PDF can be replaced with GS-generated html
104 'args' => $arguments };
105
106sub new {
107 my ($class) = shift (@_);
108 my ($pluginlist,$inputargs,$hashArgOptLists) = @_;
109 push(@$pluginlist, $class);
110
111 push(@$inputargs,"-title_sub");
112 push(@$inputargs,'^(Page\s+\d+)?(\s*1\s+)?');
113
114 push(@{$hashArgOptLists->{"ArgList"}},@{$arguments});
115 push(@{$hashArgOptLists->{"OptList"}},$options);
116
117 my @arg_array = @$inputargs;
118 my $self = new ConvertBinaryFile($pluginlist, $inputargs, $hashArgOptLists);
119
120 if ($self->{'info_only'}) {
121 # don't worry about any options etc
122 return bless $self, $class;
123 }
124
125 $self->{'filename_extension'} = "pdf";
126 $self->{'file_type'} = "PDF";
127
128 # these are passed through to gsConvert.pl by ConvertBinaryFile.pm
129 my $zoom = $self->{"zoom"};
130 $self->{'convert_options'} = "-pdf_zoom $zoom";
131 $self->{'convert_options'} .= " -pdf_complex" if $self->{"complex"};
132 $self->{'convert_options'} .= " -pdf_nohidden" if $self->{"nohidden"};
133 $self->{'convert_options'} .= " -pdf_ignore_images" if $self->{"noimages"};
134 $self->{'convert_options'} .= " -pdf_allow_images_only" if $self->{"allowimagesonly"};
135
136 my $secondary_plugin_options = $self->{'secondary_plugin_options'};
137
138 if (!defined $secondary_plugin_options->{'HTMLPlugin'}) {
139 $secondary_plugin_options->{'HTMLPlugin'} = [];
140 }
141 if (!defined $secondary_plugin_options->{'TextPlugin'}) {
142 $secondary_plugin_options->{'TextPlugin'} = [];
143 }
144 if (defined $self->{'convert_to'} && $self->{'convert_to'} =~ m/(pagedimage|pagedimg).*/i) {
145 if (!defined $secondary_plugin_options->{'PagedImagePlugin'}){
146 $secondary_plugin_options->{'PagedImagePlugin'} = [];
147 my $pagedimg_options = $secondary_plugin_options->{'PagedImagePlugin'};
148 push(@$pagedimg_options, "-title_sub", '^(Page\s+\d+)?(\s*1\s+)?');
149 push(@$pagedimg_options, "-screenviewsize", "1000");
150 }
151 }
152 my $html_options = $secondary_plugin_options->{'HTMLPlugin'};
153 my $text_options = $secondary_plugin_options->{'TextPlugin'};
154 my $pagedimg_options = $secondary_plugin_options->{'PagedImagePlugin'};
155
156# if ($self->{'input_encoding'} eq "auto") {
157# $self->{'input_encoding'} = "utf8";
158# }
159
160 # if pdftohtml is always producing utf8, then htmlplug always needs this option
161 push(@$html_options,"-input_encoding", "utf8");
162 push(@$html_options,"-extract_language") if $self->{'extract_language'};
163 # Instruct HTMLPlug (when eventually accessed through read_into_doc_obj)
164 # to extract these metadata fields from the HEAD META fields
165 my $required_metadata;
166 if (defined $self->{'metadata_fields'} && $self->{'metadata_fields'} =~ /\S/) {
167 push(@$html_options,"-metadata_fields",$self->{'metadata_fields'});
168 } else {
169 push(@$html_options,"-metadata_fields","Title,GENERATOR,date,author<Creator>");
170 }
171 #push(@$html_options,"-metadata_fields","Title,GENERATOR,date,author<Creator>");
172
173 if ($self->{'use_sections'} || $self->{'description_tags'}) {
174 $self->{'description_tags'} = 1;
175 push(@$html_options,"-description_tags");
176 }
177
178 # following title_sub removes "Page 1" added by pdftohtml, and a leading
179 # "1", which is often the page number at the top of the page. Bad Luck
180 # if your document title actually starts with "1 " - is there a better way?
181 push(@$html_options , "-title_sub", '^(Page\s+\d+)?(\s*1\s+)?');
182 push(@$text_options , "-title_sub", '^(Page\s+\d+)?(\s*1\s+)?');
183
184 my $associate_tail_re = $self->{'associate_tail_re'};
185 if ((defined $associate_tail_re) && ($associate_tail_re ne "")) {
186 push(@$html_options, "-associate_tail_re", $associate_tail_re);
187 push(@$text_options, "-associate_tail_re", $associate_tail_re);
188 push(@$pagedimg_options, "-associate_tail_re", $associate_tail_re) if defined $pagedimg_options;
189 }
190
191 push(@$html_options, "-file_rename_method", "none");
192 push(@$text_options, "-file_rename_method", "none");
193 push(@$pagedimg_options, "-file_rename_method", "none") if defined $pagedimg_options;
194
195 $self = bless $self, $class;
196 $self->load_secondary_plugins($class,$secondary_plugin_options,$hashArgOptLists);
197 return $self;
198}
199
200sub get_default_process_exp {
201 my $self = shift (@_);
202
203 return q^(?i)\.pdf$^;
204}
205
206# so we don't inherit HTMLPlug's block exp...
207sub get_default_block_exp {
208 return "";
209}
210
211sub convert_post_process
212{
213 my $self = shift (@_);
214 my ($conv_filename) = @_;
215
216 my $outhandle=$self->{'outhandle'};
217
218 #$self->{'input_encoding'} = "utf8"; # The output is always in utf8 (is it?? it is for html, but what about other types?)
219 #my ($language, $encoding) = $self->textcat_get_language_encoding ($conv_filename);
220
221 # read in file ($text will be in utf8)
222 my $text = "";
223 # encoding will be utf8 for html files - what about other types? will we do this step for them anyway?
224 $self->read_file ($conv_filename, "utf8", "", \$text);
225
226 # Calculate number of pages based on <a ...> tags (we have a <a name=1> etc
227 # for each page). Metadata based on this calculation not set until process()
228 #
229 # Note: this is done even if we are not breaking to document into pages as it might
230 # be useful to give an indication of document length in browser through setting
231 # num_pages as metadata.
232 my @pages = ($text =~ /\<[Aa] name=\"?\w+\"?>/ig);
233 my $num_pages = scalar(@pages);
234 $self->{'num_pages'} = $num_pages;
235
236 if ($self->{'use_sections'}
237 && $self->{'converted_to'} eq "HTML") {
238
239 print $outhandle "PDFPlugin: Calculating sections...\n";
240
241 # we have "<a name=1></a>" etc for each page
242 # it may be <A name=
243 my @sections = split('<[Aa] name=', $text);
244
245 my $top_section = "";
246
247 if (scalar (@sections) == 1) { #only one section - no split!
248 print $outhandle "PDFPlugin: warning - no sections found\n";
249 } else {
250 $top_section .= shift @sections; # keep HTML header etc as top_section
251 }
252
253 # handle first section specially for title? Or all use first 100...
254
255 my $title = $sections[0];
256 $title =~ s/^\"?\w+\"?>//; # specific for pdftohtml...
257 $title =~ s/<\/([^>]+)><\1>//g; # (eg) </b><b> - no space
258 $title =~ s/<[^>]*>/ /g;
259 $title =~ s/(?:&nbsp;|\xc2\xa0)/ /g; # utf-8 for nbsp...
260 $title =~ s/^\s+//s;
261 $title =~ s/\s+$//;
262 $title =~ s/\s+/ /gs;
263 $title =~ s/^$self->{'title_sub'}// if ($self->{'title_sub'});
264 $title =~ s/^\s+//s; # in case title_sub introduced any...
265 $title = substr ($title, 0, 100);
266 $title =~ s/\s\S*$/.../;
267
268
269 if (scalar (@sections) == 1) { # no sections found
270 $top_section .= $sections[0];
271 @sections=();
272 } else {
273 $top_section .= "<!--<Section>\n<Metadata name=\"Title\">$title</Metadata>\n-->\n <!--</Section>-->\n";
274 }
275
276 # add metadata per section...
277 foreach my $section (@sections) {
278 # section names are not always just digits, may be like "outline"
279 $section =~ s@^\"?(\w+)\"?></a>@@; # leftover from split expression...
280
281 $title = $1; # Greenstone does magic if sections are titled digits
282 if (! defined($title) ) {
283 print STDERR "no title: $section\n";
284 $title = " "; # get rid of the undefined warning in next line
285 }
286 my $newsection = "<!-- from PDFPlugin -->\n<!-- <Section>\n";
287 $newsection .= "<Metadata name=\"Title\">" . $title
288 . "</Metadata>\n--><p>\n";
289 $newsection .= $section;
290 $newsection .= "<!--</Section>-->\n";
291 $section = $newsection;
292 }
293
294 $text=join('', ($top_section, @sections));
295 }
296
297 # turn any high bytes that aren't valid utf-8 into utf-8.
298 unicode::ensure_utf8(\$text);
299
300 # Write it out again!
301 $self->utf8_write_file (\$text, $conv_filename);
302}
303
304
305# do plugin specific processing of doc_obj for HTML type
306sub process {
307 my $self = shift (@_);
308 my ($pluginfo, $base_dir, $file, $metadata, $doc_obj, $gli) = @_;
309
310 my $result = $self->process_type($base_dir,$file,$doc_obj);
311
312 # fix up the extracted date metadata to be in Greenstone date format,
313 # and fix the capitalisation of 'date'
314 my $cursection = $doc_obj->get_top_section();
315 foreach my $datemeta (@{$doc_obj->get_metadata($cursection, "date")}) {
316 $doc_obj->delete_metadata($cursection, "date", $datemeta);
317
318 # We're just interested in the date bit, not the time
319 # some pdf creators (eg "Acrobat 5.0 Scan Plug-in for Windows")
320 # set a /CreationDate, and set /ModDate to 000000000. pdftohtml
321 # extracts the ModDate, so it is 0...
322 $datemeta =~ /(\d+)-(\d+)-(\d+)/;
323 my ($year, $month, $day) = ($1,$2,$3);
324 if (defined($year) && defined($month) && defined($day)) {
325 if ($year == 0) {next}
326 if ($year < 100) {$year += 1900} # just to be safe
327 if ($month =~ /^\d$/) {$month="0$month"} # single digit
328 if ($day =~ /^\d$/) {$day="0$day"} # single digit
329 my $date="$year$month$day";
330 $doc_obj->add_utf8_metadata($cursection, "Date", $date);
331 }
332 }
333
334 $doc_obj->add_utf8_metadata($cursection, "NumPages", $self->{'num_pages'});
335
336 if ($self->{'use_sections'} && $self->{'converted_to'} eq "HTML") {
337 # we explicitly make it a paged document, cos greenstone won't get it
338 # right if any section has an empty title, or one with letters in it
339 $doc_obj->set_utf8_metadata_element ($cursection, "gsdlthistype", "Paged");
340 }
341
342 return $result;
343}
344
3451;
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