root/main/trunk/greenstone2/perllib/plugins/PDFv2Plugin.pm @ 32499

Revision 32499, 32.5 KB (checked in by ak19, 12 months ago)

Fix for PDFv2 plugin's page buckets.

Line 
1###########################################################################
2#
3# PDFv2Plugin.pm -- pdf plugin that uses xpdftools and pdfbox to process PDFs.
4# It only works out of the box for GS3 since it assumes the pdfbox extension
5# is installed.
6# A component of the Greenstone digital library software
7# from the New Zealand Digital Library Project at the
8# University of Waikato, New Zealand.
9#
10# Copyright (C) 1999-2001 New Zealand Digital Library Project
11#
12# This program is free software; you can redistribute it and/or modify
13# it under the terms of the GNU General Public License as published by
14# the Free Software Foundation; either version 2 of the License, or
15# (at your option) any later version.
16#
17# This program is distributed in the hope that it will be useful,
18# but WITHOUT ANY WARRANTY; without even the implied warranty of
19# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20# GNU General Public License for more details.
21#
22# You should have received a copy of the GNU General Public License
23# along with this program; if not, write to the Free Software
24# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25#
26###########################################################################
27package PDFv2Plugin;
28
29use strict;
30no strict 'refs'; # so we can use a var for filehandles (e.g. STDERR)
31no strict 'subs'; # allow filehandles to be variables and viceversa
32
33use ConvertBinaryFile;
34use PDFBoxConverter;
35use ReadTextFile;
36
37use unicode;
38use Mojo::DOM; # for HTML parsing
39
40
41@PDFv2Plugin::ISA = ('ConvertBinaryFile', 'PDFBoxConverter', 'ReadTextFile');
42
43
44my $convert_to_list =
45    [ { 'name' => "auto", # pretty_html using xpdftools' pdftohtml
46    'desc' => "{ConvertBinaryFile.convert_to.auto}" },
47      { 'name' => "text", # xpdftools' pdftotext
48    'desc' => "{ConvertBinaryFile.convert_to.text}" },
49      { 'name' => "paged_text", # pdfbox
50    'desc' => "{ConvertBinaryFile.convert_to.paged_text}" },
51     
52      { 'name' => "html", # pdfbox ## TODO: rename this to html_without_imgs?
53    'desc' => "{PDFPlugin.convert_to.html}" },
54      { 'name' => "pretty_html", # xpdftools
55    'desc' => "{PDFPlugin.convert_to.pretty_html}" },
56      { 'name' => "paged_pretty_html", # xpdftools
57    'desc' => "{PDFPlugin.convert_to.paged_pretty_html}"},
58
59      # pdfbox for all pagedimg(txt) output formats:
60      { 'name' => "pagedimg_jpg",
61    'desc' => "{ConvertBinaryFile.convert_to.pagedimg_jpg}"},
62      { 'name' => "pagedimg_png",
63    'desc' => "{ConvertBinaryFile.convert_to.pagedimg_png}"},
64     
65      { 'name' => "pagedimgtxt_jpg",
66    'desc' => "{ConvertBinaryFile.convert_to.pagedimgtxt_jpg}"},
67      { 'name' => "pagedimgtxt_png",
68    'desc' => "{ConvertBinaryFile.convert_to.pagedimgtxt_png}"},
69      ];
70
71
72my $arguments =
73    [
74     { 'name' => "convert_to",
75       'desc' => "{ConvertBinaryFile.convert_to}",
76       'type' => "enum",
77       'reqd' => "yes",
78       'list' => $convert_to_list,
79       'deft' => "paged_pretty_html" }, 
80     { 'name' => "process_exp",
81       'desc' => "{BaseImporter.process_exp}",
82       'type' => "regexp",
83       'deft' => &get_default_process_exp(),
84       'reqd' => "no" },
85     { 'name' => "block_exp",
86       'desc' => "{CommonUtil.block_exp}",
87       'type' => "regexp",
88       'deft' => &get_default_block_exp() },
89#     { 'name' => "metadata_fields",
90#       'desc' => "{HTMLPlugin.metadata_fields}",
91#       'type' => "string",
92#       'deft' => "Title,Author,Subject,Keywords" },
93#     { 'name' => "metadata_field_separator",
94#   'desc' => "{HTMLPlugin.metadata_field_separator}",
95#   'type' => "string",
96#   'deft' => "" },
97     { 'name' => "dpi",
98       'desc' => "{PDFv2Plugin.dpi}",
99       'deft' => "96",
100       'type' => "int" }, # 72DPI is xpdf's pdftohtml's default. pdfbox' default is 96DPI in headless mode else detected from the screen resolution, see https://pdfbox.apache.org/2.0/commandline.html#pdftoimage
101#     { 'name' => "use_sections",
102#       'desc' => "{PDFPlugin.use_sections}",
103#       'type' => "flag" },
104#     { 'name' => "description_tags",
105#       'desc' => "{HTMLPlugin.description_tags}",
106#       'type' => "flag" },
107      { 'name' => "use_realistic_book",
108        'desc' => "{PDFPlugin.use_realistic_book}",
109    'type' => "flag" }
110     ];
111
112my $options = { 'name'     => "PDFv2Plugin",
113        'desc'     => "{PDFv2Plugin.desc}",
114        'abstract' => "no",
115        'inherits' => "yes",
116        'srcreplaceable' => "yes", # Source docs in PDF can be replaced with GS-generated html     
117        'args'     => $arguments };
118
119sub new {
120    my ($class) = shift (@_);
121    my ($pluginlist,$inputargs,$hashArgOptLists) = @_;
122    push(@$pluginlist, $class);
123
124    push(@{$hashArgOptLists->{"ArgList"}},@{$arguments});
125    push(@{$hashArgOptLists->{"OptList"}},$options);
126
127    # the 1 at the end of the first constructor call is to allow extra arguments to remain after
128    # parsing. There should be no extra args after the final constructor call, because all args
129    # should have been parsed by then, so don't pass 1 to the last constructor.
130    my $pdfbox_converter_self = new PDFBoxConverter($pluginlist, $inputargs, $hashArgOptLists, 1);
131    my $cbf_self = new ConvertBinaryFile($pluginlist, $inputargs, $hashArgOptLists);
132    my $self = BaseImporter::merge_inheritance($pdfbox_converter_self, $cbf_self); # this param order seems necessary to preserve the default/user-selected value for the convert_to option
133   
134    if ($self->{'info_only'}) {
135    # don't worry about any options etc
136    return bless $self, $class;
137    }
138   
139    $self = bless $self, $class;
140    $self->{'file_type'} = "PDF";
141
142    # convert_options are passed through to gsConvert.pl by ConvertBinaryFile.pm
143   
144    # the most important option is the tool that's used to do the conversion
145    $self->{'convert_options'} = "-pdf_tool xpdftools"; # default for PDFv2Plugin. If pdfbox_conversion is on, the pdfbpox GS extension sets pdf_tool to pdfbox
146
147    # Setting dpi has meaning for xpdftools pdftohtml (so paged_pretty_html and pretty_html)
148    # and for when pdfbox outputs an image for each page (pagedimg, pagedimgtxt).
149    # dpi has no effect on (paged_)text and html output modes.
150    my $dpi = $self->{"dpi"};
151    $self->{'convert_options'} .= " -pdf_dpi $dpi";
152
153    # The old pdftohtml tool used by PDFPlugin didn't do PDF to txt conversion on Windows
154    # But PDFv2Plugin now supports PDF to txt conversion on Windows too using XPDFTools' pdftotext
155
156    if ($self->{'convert_to'} eq "auto") {
157    # defaulting to paged_pretty_html, as it's the best default option when using xpdftools
158    $self->{'convert_to'} = "paged_pretty_html";
159    &gsprintf::gsprintf(STDERR, "PDFv2Plugin: {PDFv2Plugin.auto_output_default}\n", $self->{'convert_to'});
160    }
161    if ($self->{'use_realistic_book'}) {
162    if ($self->{'convert_to'} ne "html") {
163        &gsprintf::gsprintf(STDERR, "PDFv2Plugin: {PDFPlugin.html_for_realistic_book}\n");
164        $self->{'convert_to'} = "html";
165    }
166    }
167   
168    # set convert_to_plugin and convert_to_ext
169    $self->set_standard_convert_settings();
170
171    my $secondary_plugin_name = $self->{'convert_to_plugin'};
172    my $secondary_plugin_options = $self->{'secondary_plugin_options'};
173
174    if (!defined $secondary_plugin_options->{$secondary_plugin_name}) {
175    $secondary_plugin_options->{$secondary_plugin_name} = [];
176    }
177    my $specific_options = $secondary_plugin_options->{$secondary_plugin_name};
178
179    my $associate_tail_re = $self->{'associate_tail_re'};
180    if ((defined $associate_tail_re) && ($associate_tail_re ne "")) {
181    push(@$specific_options, "-associate_tail_re", $associate_tail_re);
182    }
183    push(@$specific_options, "-file_rename_method", "none");
184   
185    if ($secondary_plugin_name eq "HTMLPlugin") {
186    # pdftohtml always produces utf8 - What about pdfbox???
187    # push(@$specific_options, "-input_encoding", "utf8");
188    push(@$specific_options, "-extract_language") if $self->{'extract_language'};
189    push(@$specific_options, "-processing_tmp_files");
190    # Instruct HTMLPlug (when eventually accessed through read_into_doc_obj)
191    # to extract these metadata fields from the HEAD META fields
192    if (defined $self->{'metadata_fields'} && $self->{'metadata_fields'} =~ /\S/) {
193        push(@$specific_options,"-metadata_fields",$self->{'metadata_fields'});
194    } else {
195        push(@$specific_options,"-metadata_fields","Title,GENERATOR,date,author<Creator>");
196    }
197    if (defined $self->{'metadata_field_separator'} && $self->{'metadata_field_separator'} =~ /\S/) {
198        push(@$specific_options,"-metadata_field_separator",$self->{'metadata_field_separator'});
199    }
200    if ($self->{'use_sections'} || $self->{'description_tags'}) {
201        $self->{'description_tags'} = 1;
202        push(@$specific_options, "-description_tags");
203    }
204    if ($self->{'use_realistic_book'}) {
205        push(@$specific_options, "-use_realistic_book");
206    }
207    if($self->{'convert_to'} eq "paged_pretty_html") { # for paged pretty html, the default should be to sectionalise
208        # the single superpage, the one containing divs representing individual pages as sections, on headings
209        push(@$specific_options, "sectionalise_using_h_tags");
210    }
211    }
212    elsif ($secondary_plugin_name eq "PagedImagePlugin") {
213    push(@$specific_options, "-screenviewsize", "1000");
214    push(@$specific_options, "-enable_cache");
215    push(@$specific_options, "-processing_tmp_files");
216    }
217
218    $self = bless $self, $class;
219    $self->load_secondary_plugins($class,$secondary_plugin_options,$hashArgOptLists);
220    return $self;
221}
222
223sub get_default_process_exp {
224    my $self = shift (@_);
225
226    return q^(?i)\.pdf$^;
227}
228
229# so we don't inherit HTMLPlug's block exp...
230sub get_default_block_exp {
231    return "";
232}
233
234sub init {
235    my $self = shift (@_);
236
237    # ConvertBinaryFile init
238    $self->SUPER::init(@_);
239    $self->PDFBoxConverter::init(@_);
240
241}
242
243sub begin {
244    my $self = shift (@_);
245
246    $self->PDFBoxConverter::begin(@_);
247    $self->SUPER::begin(@_);
248
249}
250
251sub deinit {
252    my $self = shift (@_);
253
254    $self->PDFBoxConverter::deinit(@_);
255    $self->SUPER::deinit(@_);
256
257}
258 
259# By setting hashing to be on ga xml this ensures that two
260# PDF files that are identical except for the metadata
261# to hash to different values. Without this, when each PDF
262# file is converted to HTML there is a chance that they
263# will both be *identical* if the conversion utility does
264# not embed the metadata in the generated HTML. This is
265# certainly the case when PDFBOX is being used.
266
267# This change makes this convert to based plugin more
268# consistent with the original vision that the same document
269# with different metadata should
270# be seen as different.
271
272sub get_oid_hash_type {
273    my $self = shift (@_);
274    return "hash_on_ga_xml";
275}
276 
277
278sub tmp_area_convert_file {
279
280    my $self = shift (@_);
281    my ($output_ext, $input_filename, $textref) = @_;
282   
283    if($self->{'convert_to'} eq "text" || $self->{'convert_to'} =~ m/pretty_html$/) { # use xpdftools
284    return $self->ConvertBinaryFile::tmp_area_convert_file(@_);
285    }
286   
287    # for all other output formats, use pdfbox:
288   
289    # Here, we now do directly what AutoLoadConverters::tmp_area_convert_file(@_)
290    # does with PDFBoxConverter:
291    my ($result, $result_str, $new_filename) = $self->PDFBoxConverter::convert($input_filename, $output_ext);
292    if (defined $result && $result != 0) {
293    return $new_filename;
294    }
295    my $outhandle=$self->{'outhandle'};
296    print $outhandle "PDFBoxConverter had a conversion error\n";
297    print $outhandle "$@\n";
298    if (defined $result_str) {
299    print $outhandle "$result_str\n";
300    }
301    return "";
302}
303
304# Overriding to do some extra handling for pretty_html/paged_pretty_html output mode
305sub run_conversion_command {
306    my $self = shift (@_);
307    my ($tmp_dirname, $tmp_inputPDFname, $utf8_tailname, $lc_suffix, $tailname, $suffix) = @_;   
308
309    if($self->{'convert_to'} !~ m/pretty_html$/) {
310    return $self->ConvertBinaryFile::run_conversion_command(@_);
311    }
312
313    # else, paged_pretty_html or pretty_html
314
315    # if output mode is (paged_)pretty_html, we use Xpdf tools' pdftohtml and tell it
316    # to create a subdir called "pages" in the tmp area to puts its products
317    # in there. (Xpdf's pdftohtml needs to be passed a *non-existent* directory
318    # parameter, the "pages" subdir). If Xpdf's pdftohtml has successfully run,
319    # the intermediary output file tmp/<random-num>/pages/index.html should
320    # exist (besides other output products there)
321
322    # We let ConvertBinaryFile proceed normally, but the return value should reflect
323    # that on success it should expect the intermediary product tmpdir/pages/index.html
324    # (which is the product of xpdftohtml conversion).
325    my $output_filename = $self->ConvertBinaryFile::run_conversion_command(@_);
326    $output_filename = &FileUtils::filenameConcatenate($tmp_dirname, "pages", "index.html");
327
328    # However, when convert_post_process() is done, it should have output the final
329    # product of the (paged_)pretty_html conversion: an html file of the same name and in the
330    # same tmp location as the input PDF file.
331
332    my ($name_prefix, $output_dir, $ext)
333    = &File::Basename::fileparse($tmp_inputPDFname, "\\.[^\\.]+\$");
334    $self->{'conv_filename_after_post_process'} = &FileUtils::filenameConcatenate($output_dir, $name_prefix.".html");
335#    print STDERR "@@@@@ final paged html file will be: " . $self->{'conv_filename_after_post_process'} . "\n";
336
337    return $output_filename;
338}
339
340sub convert_post_process
341{
342    my $self = shift (@_);
343    my ($conv_filename) = @_;
344
345    my $outhandle=$self->{'outhandle'};
346
347    if($self->{'convert_to'} =~ /pretty_html/) { # (paged_)pretty_html
348    # special post-processing for (paged_)pretty_html mode, as HTML pages generated
349    # by xpdf's pdftohtml need to be massaged into the form we want
350    $self->xpdftohtml_convert_post_process($conv_filename);
351    }
352    else { # use original PDFPlugin's usual post processing
353    $self->default_convert_post_process($conv_filename);
354    }
355}
356
357# Called after gsConvert.pl has been run to convert a PDF to (paged_)pretty_html
358# using Xpdftools' pdftohtml
359# This method will do some cleanup of the HTML files produced after XPDF has produced
360# an HTML doc for each PDF page: it first gets rid of the default index.html.
361# Instead, it constructs a single html page containing each original HTML page
362# <body> nested as divs instead, with simple section information inserted at the top
363# of each 'page' <div> and some further styling customisation. This HTML manipulation
364# is to be done with the Mojo::DOM perl package.
365# Note that since xpdf's pdftohtml would have failed if the output dir already
366# existed and for simpler naming, the output files are created in a new "pages"
367# subdirectory of the tmp location parent of $conv_filename instead
368sub xpdftohtml_convert_post_process
369{
370    my $self = shift (@_);
371    my ($pages_index_html) = @_; # = tmp/<rand>/pages/index.html for (paged_)pretty_html output mode
372    my $output_filename = $self->{'conv_filename_after_post_process'};
373
374    # Read in all the html files in tmp's "pages" subdir, except for index.html.
375    # and use it to create a new html file called $self->{'conv_filename_after_post_process'}
376    # which will consist of a slightly modified version of
377    # each of the other html files concatenated together.
378
379    my $outhandle=$self->{'outhandle'};
380
381    my ($tailname, $pages_subdir, $suffix)
382    = &File::Basename::fileparse($pages_index_html, "\\.[^\\.]+\$");
383
384    # Code from util::create_itemfile()
385    # Read in all the files
386    opendir(DIR, $pages_subdir) || die "can't opendir $pages_subdir: $!";
387    my @page_files = grep {-f "$pages_subdir/$_"} readdir(DIR);
388    closedir DIR;
389    # Sort files in the directory by page_num
390    # files are named index.html, page1.html, page2.html, ..., pagen.html
391    sub page_number {
392    my ($dir) = @_;
393    my ($pagenum) =($dir =~ m/^page(\d+)\.html?$/i);
394    $pagenum = 0 unless defined $pagenum; # index.html will be given pagenum=0
395    return $pagenum;
396    }
397    # sort the files in the directory in the order of page_num rather than lexically.
398    @page_files = sort { page_number($a) <=> page_number($b) } @page_files;
399
400    #my $num_html_pages = (scalar(@page_files) - 1)/2; # skip index file.
401              # For every html file there's an img file, so halve the total num.
402              # What about other file types that may potentially be there too???
403    my $num_html_pages = 0;
404    foreach my $pagefile (@page_files) {
405    $num_html_pages++ if $pagefile =~ m/\.html?$/ && $pagefile !~ /^index\.html?/i;
406    }
407
408    # Prepare to create our new html page that will contain all the individual
409    # htmls generated by xpdf's pdftohtml in sequence.
410    # First write the opening html tags out to the output file. These are the
411    # same tags and their contents, including <meta>, as is generated by
412    # Xpdf's pdftohtml for each of its individual html pages.
413    my $start_text = "<html>\n<head>\n";
414    my ($output_tailname, $tmp_subdir, $html_suffix)
415    = &File::Basename::fileparse($output_filename, "\\.[^\\.]+\$");
416    $start_text .= "<title>$output_tailname</title>\n";
417    $start_text .= "<meta http-equiv=\"Content-Type\" content=\"text/html; charset=UTF-8\">\n";
418    $start_text .= "</head>\n<body>\n\n";
419   
420    if($self->{'convert_to'} =~ /paged_pretty_html/) { # then add the <h>tags for sectionalising
421    $start_text .= "<h1>$output_tailname</h1>\n\n";
422    }
423
424    #handle content encodings the same way that default_convert_post_process does
425    # $self->utf8_write_file ($start_text, $conv_filename); # will close file after write   
426    # Don't want to build a giant string in memory of all the pages concatenated
427    # and then write it out in one go. Instead, build up the final single page
428    # by writing each modified (paged_)pretty_html file out to it as this is processed.
429    # Copying file open/close code from CommonUtil::utf8_write_file()
430    if (!open (OUTFILE, ">:utf8", $output_filename)) {
431    &gsprintf::gsprintf(STDERR, "PDFv2Plugin::xpdftohtml_convert_post_process {CommonUtil.could_not_open_for_writing} ($!)\n", $output_filename);
432    die "\n";
433    }
434    print OUTFILE $start_text;
435
436    # Get the contents of each individual HTML page generated by Xpdf, after first
437    # modifying each, and write each out into our single all-encompassing html
438    foreach my $pagefile (@page_files) {
439    if ($pagefile =~ m/\.html?$/ && $pagefile !~ /^index\.html?/i) {
440        my $page_num = page_number($pagefile);   
441        # get full path to pagefile
442        $pagefile = &FileUtils::filenameConcatenate($pages_subdir, $pagefile);
443#       print STDERR "@@@ About to process html file $pagefile (num $page_num)\n";
444        my $modified_page_contents = $self->_process_pretty_html_page($pagefile, $page_num, $num_html_pages);
445        print OUTFILE "$modified_page_contents\n\n";
446    }
447    }
448
449    # we've now created a single HTML file by concatenating (a modified version)
450    # of each paged html file
451    print OUTFILE "</body>\n</html>\n"; # write out closing tags
452    close OUTFILE; # done
453
454    # Get rid of all the htm(l) files incl index.html in the associated "pages"
455    # subdir, since we've now processed them all into a single html file
456    # one folder level up and we don't want HTMLPlugin to process all of them next.
457    &FileUtils::removeFilesFiltered($pages_subdir, "\.html?\$"); #  no specific whitelist, but blacklist htm(l)
458
459    # now the tmp area should contain a single html file contain all the html pages'
460    # contents in sequence, and a "pages" subdir containing the screenshot images
461    # of each page.   
462    # HTMLPlugin will process these further in the plugin pipeline
463}
464
465# For whatever reason, most html <tags> don't get printed out in GLI
466# So when debugging, use this function to print them out as [tags] instead.
467sub _debug_print_html
468{
469    my $self = shift (@_);
470    my ($string_or_dom) = @_;
471
472    # can't seem to determine type of string with ref/reftype
473    # https://stackoverflow.com/questions/1731333/how-do-i-tell-what-type-of-value-is-in-a-perl-variable
474    # Not needed, as $dom objects seem to get correctly stringified in string contexts
475    # $dom.to_string/$dom.stringify seem to get called, no need to call them
476    # https://stackoverflow.com/questions/5214543/what-is-stringification-in-perl
477    my $escapedTxt = $string_or_dom;
478    $escapedTxt =~ s@\<@[@sg;
479    $escapedTxt =~ s@\>@]@sg;
480
481    print STDERR "#### $escapedTxt\n";
482}
483
484# Helper function for (paged_)pretty_html
485# to read in each page of pretty_html generated by Xpdf's pdftohtml
486# then modify the html suitably using the HTML parsing functions offered by
487# Mojo::DOM, then return the modified HTML content as a string.
488# For paged_pretty_html, some additional modification is done to sectionalise the final html
489# See https://mojolicious.org/perldoc/Mojo/DOM
490sub _process_pretty_html_page
491{
492    my $self = shift (@_);
493    my ($pagefile, $page_num, $num_html_pages) = @_;
494
495    my $text = "";
496
497    # handling content encoding the same way default_convert_post_process does
498    $self->read_file ($pagefile, "utf8", "", \$text);
499
500    my $dom = Mojo::DOM->new($text);
501
502#    $self->_debug_print_html($dom);
503
504    # there's a <style> element on the <html>, we need to shift it into the <div>
505    # tag that we'll be creating. We'll first slightly modify the <style> element
506    # store the first style element, which is the only one and in the <body>
507    # we'll later insert it as child of an all-encompassing div that we'll create
508    my $page_style_tag_str = $dom->at('html')->at('style')->to_string;
509    # In the style tag, convert id style references to class style references
510    my $css_class = ".p".$page_num."f";
511    $page_style_tag_str =~ s@\#f@$css_class@sg;
512    my $style_element = Mojo::DOM->new($page_style_tag_str)->at('style'); # modified   
513#$self->_debug_print_html($style_element);
514
515    # need to know the image's height to set the height of the surrounding
516    # div that's to replace this page's <body>:
517    my $img_height = $dom->find('img')->[0]{height};
518
519    # 2. Adjust the img#background src attribute to point to the pages subdir for imgs
520    # 3. Set that img tag's class=background, and change its id to background+$page_num
521    my $bg_img_tag=$dom->find('img#background')->[0];
522    my $img_src_str = $bg_img_tag->{src};
523    $img_src_str = "pages/$img_src_str";
524    $bg_img_tag->attr(src => $img_src_str); # reset
525#$self->_debug_print_html($bg_img_tag);
526    # set both class and modified id attributes in one step:
527    $bg_img_tag->attr({class => "background", id => "background".$page_num});
528#$self->_debug_print_html($bg_img_tag);
529
530    # get all the <span> nested inside <div class="txt"> elements and
531    # 1. set their class attr to be "p + page_num + id-of-the-span",
532    # 2. then delete the id, because the span ids have been reused when element
533    # ids ought to be unique. Which is why we set the modified ids to be the
534    # value of the class attribute instead
535    $dom->find('div.txt span')->each(sub {
536    $_->attr(class => "p". $page_num. $_->{id});
537    delete $_->{id};
538                     }); # both changes done in one find() operation
539#$self->_debug_print_html($dom->find('div.txt span')->last);
540
541    # Finally can create our new dom, starting with a div tag for the current page
542    # Must be: <div id="$page_num" style="position:relative; height:$img_height;"/>
543#    my $new_dom = Mojo::DOM->new_tag('div', id => "page".$page_num, style => "position: relative; height: ".$img_height."px;" )
544    my $new_dom = Mojo::DOM->new_tag('div', style => "position: relative; height: ".$img_height."px;" );
545#$self->_debug_print_html($new_dom);
546    $new_dom->at('div')->append_content($style_element)->root;
547
548
549#$self->_debug_print_html($new_dom);
550    # Copy across all the old html's body tag's child nodes into the new dom's new div tag
551    $dom->at('body')->child_nodes->each(sub { $new_dom->at('div')->append_content($_)}); #$_->to_string
552#$self->_debug_print_html($new_dom);
553
554    # build up the outer div
555    my $inner_div_str = $new_dom->to_string;
556    my $page_div = "<div id=\"page".$page_num."\">\n";
557
558    # If paged_pretty_html, then add <h>tags for sectionalising
559    if($self->{'convert_to'} =~ /paged_pretty_html/) {
560   
561    # Append a page range bucket heading if applicable: if we have more than 10 pages
562    # to display in the current bucket AND we're on the first page of each bucket of 10 pages.
563    # Dr Bainbridge thinks for now we need only consider PDFs where the
564    # total number of pages < 1000 and create buckets of size 10 (e.g. 1-10, ... 51-60, ...)
565    # If number of remaining pages >= 10, then create new bucket heading
566    # e.g. "Pages 30-40"
567    if(($page_num % 10) == 1 && ($num_html_pages > 10)) {
568        # Double-digit page numbers that start with 2
569        # i.e. 21 to 29 (and 30) should be in 21 to 30 range
570        my $start_range = $page_num - ($page_num % 10) + 1;
571        my $end_range = $page_num + 10 - ($page_num % 10);
572        $page_div .= "<h2 style=\"font-size:1em;font-weight:normal;\">Pages ".$start_range . "-" . $end_range."</h2>\n";
573    }
574
575    # Every page is now a section too, not just buckets.
576    # Whether we're starting a new bucket or not, add a simpler heading: just the pagenumber, "Page #"
577    # However, this should be <H3> when there are buckets and <H2> when there aren't any.
578    if($num_html_pages > 10) {
579        $page_div .= "<h3 style=\"font-size:1em;font-weight:normal;\">Page ".$page_num."</h3>\n";       
580    } else { # PDF has less than 10 pages in total
581        $page_div .= "<h2 style=\"font-size:1em;font-weight:normal;\">Page ".$page_num."</h2>\n";       
582    }
583    }
584
585    $page_div .= $inner_div_str;
586    $page_div .= "\n</div>";
587
588    # Finished processing a single html page of the (paged_)pretty_html output generated by
589    # Xpdf's pdftohtml: finished massaging that single html page into the right form
590    return $page_div;
591}
592
593# This subroutine is called to do the PDFv2Plugin post-processing for all cases
594# except the "pretty_html" or "paged_pretty_html" conversion modes.
595# This is what PDFPlugin always used to do:
596sub default_convert_post_process
597{
598    my $self = shift (@_);
599    my ($conv_filename) = @_;
600    my $outhandle=$self->{'outhandle'};
601
602    #$self->{'input_encoding'} = "utf8"; # TODO: The output is always in utf8 (is it?? it is for html, but what about other types?)
603    #my ($language, $encoding) = $self->textcat_get_language_encoding ($conv_filename);
604
605    # read in file ($text will be in utf8)
606    my $text = "";
607    # encoding will be utf8 for html files - what about other types? will we do this step for them anyway?
608    $self->read_file ($conv_filename, "utf8", "", \$text);
609
610    # To support the use_sections option with PDFBox: Greenstone splits PDFs into pages for
611    # sections. The PDFPlugin code wants each new page to be prefixed with <a name=pagenum></a>,
612    # which it then splits on to generate page-based sections. However, that's not what PDFBox
613    # generates in its HTML output. Fortunately, PDFBox does have its own page-separator: it
614    # embeds each page in an extra div. The div opener is:
615    # <div style=\"page-break-before:always; page-break-after:always\">
616    # The PDFPlugin now looks for this and prefixes <a name=0></a> to each such div. (The
617    # pagenumber is fixed at 0 since I'm unable to work out how to increment the pagenum during
618    # a regex substitution even with regex extensions on.) Later, when we process each section
619    # to get the pagenum, PDFBox's output for this is pre-processed by having a loopcounter
620    # that increments the pagenum for each subsequent section.
621
622    #$pdfbox_pageheader="\<div style=\"page-break-before:always; page-break-after:always\">";
623    my $loopcounter = 0; # used later on!
624    $text =~ s@\<div style=\"page-break-before:always; page-break-after:always\">@<a name=$loopcounter></a><div style=\"page-break-before:always; page-break-after:always\">@g;
625
626
627    # Calculate number of pages based on <a ...> tags (we have a <a name=1> etc
628    # for each page).  Metadata based on this calculation not set until process()
629    #
630    # Note: this is done even if we are not breaking the document into pages as it might
631    # be useful to give an indication of document length in browser through setting
632    # num_pages as metadata.
633    # Clean html from low and hight surrogates D800–DFFF
634    $text =~ s@[\N{U+D800}-\N{U+DFFF}]@\ @g;
635    my @pages = ($text =~ m/\<[Aa] name=\"?\w+\"?>/ig); #<div style=\"?page-break-before:always; page-break-after:always\"?>
636    my $num_pages = scalar(@pages);
637    $self->{'num_pages'} = $num_pages;
638
639    if ($self->{'use_sections'}
640    && $self->{'converted_to'} eq "HTML") {
641
642    print $outhandle "PDFv2Plugin: Calculating sections...\n";
643
644    # we have "<a name=1></a>" etc for each page
645    # it may be <A name=
646    my @sections = split('<[Aa] name=', $text);
647
648    my $top_section = "";
649
650    if (scalar (@sections) == 1) { #only one section - no split!
651        print $outhandle "PDFv2Plugin: warning - no sections found\n";
652    } else {
653        $top_section .= shift @sections; # keep HTML header etc as top_section
654    }
655
656    # handle first section specially for title? Or all use first 100...
657   
658    my $title = $sections[0];
659    $title =~ s/^\"?\w+\"?>//; # specific for old pdftohtml...
660    $title =~ s/<\/([^>]+)><\1>//g; # (eg) </b><b> - no space
661    $title =~ s/<[^>]*>/ /g;
662    $title =~ s/(?:&nbsp;|\xc2\xa0)/ /g; # utf-8 for nbsp...
663    $title =~ s/^\s+//s;
664    $title =~ s/\s+$//;
665    $title =~ s/\s+/ /gs;
666    $title =~ s/^\s+//s; # in case title_sub (of old PDFPlugin's old pdftohtml) introduced any... Generally still useful to remove spaces at the start?
667    $title = substr ($title, 0, 100);
668    $title =~ s/\s\S*$/.../;
669
670
671    if (scalar (@sections) == 1) { # no sections found
672        $top_section .= $sections[0];
673        @sections=();
674    } else {
675        $top_section .= "<!--<Section>\n<Metadata name=\"Title\">$title</Metadata>\n-->\n <!--</Section>-->\n";
676    }
677
678    # add metadata per section...
679    foreach my $section (@sections) {
680        # section names are not always just digits, may be like "outline"
681        $section =~ s@^\"?(\w+)\"?></a>@@; # leftover from split expression...
682
683        $title = $1; # Greenstone does magic if sections are titled digits
684
685        # A title of pagenum=0 means use_sections is being applied on output from PDFBox,
686        # which didn't originally have a <a name=incremented pagenumber></a> to split each page.
687        # Our Perl code then prefixed <a name=0></a> to it. Now need to increment the pagenum here:
688        if($loopcounter > 0 || ($title eq 0 && $loopcounter == 0)) { # implies use_sections with PDFBox
689        $title = ++$loopcounter;
690        }
691
692        if (! defined($title) ) {
693        print STDERR "no title: $section\n";
694        $title = " "; # get rid of the undefined warning in next line
695        }
696        my $newsection = "<!-- from PDFv2Plugin -->\n<!-- <Section>\n";
697        $newsection .= "<Metadata name=\"Title\">" . $title
698        . "</Metadata>\n--><br />\n";
699        $newsection .= $section;
700        $newsection .= "<!--</Section>-->\n";
701        $section = $newsection;
702    }
703
704    $text=join('', ($top_section, @sections));
705    }
706
707    if ($self->{'use_sections'}
708    && $self->{'converted_to'} eq "text") {
709    print STDERR "**** When converting PDF to text, cannot apply use_sections\n";
710    }
711
712
713    # The following should no longer be needed, now that strings
714    # read in are Unicode aware (in the Perl sense) rather than
715    # raw binary strings that just happen to be UTF-8 compliant
716
717    # turn any high bytes that aren't valid utf-8 into utf-8.
718##    unicode::ensure_utf8(\$text);
719
720    # Write it out again!
721    $self->utf8_write_file (\$text, $conv_filename);
722}
723
724
725# do plugin specific processing of doc_obj for HTML type
726sub process {
727    my $self = shift (@_);
728    my ($pluginfo, $base_dir, $file, $metadata, $doc_obj, $gli) = @_;
729
730    my $result = $self->process_type($base_dir,$file,$doc_obj);
731
732    # fix up the extracted date metadata to be in Greenstone date format,
733    # and fix the capitalisation of 'date'
734    my $cursection = $doc_obj->get_top_section();
735    foreach my $datemeta (@{$doc_obj->get_metadata($cursection, "date")}) {
736    $doc_obj->delete_metadata($cursection, "date", $datemeta);
737
738    # We're just interested in the date bit, not the time
739    # some pdf creators (eg "Acrobat 5.0 Scan Plug-in for Windows")
740    # set a /CreationDate, and set /ModDate to 000000000. pdftohtml
741    # extracts the ModDate, so it is 0...
742    $datemeta =~ /(\d+)-(\d+)-(\d+)/;
743    my ($year, $month, $day) = ($1,$2,$3);
744    if (defined($year) && defined($month) && defined($day)) {
745        if ($year == 0) {next}
746        if ($year < 100) {$year += 1900} # just to be safe
747        if ($month =~ /^\d$/) {$month="0$month"} # single digit
748        if ($day =~ /^\d$/) {$day="0$day"} # single digit
749        my $date="$year$month$day";
750        $doc_obj->add_utf8_metadata($cursection, "Date", $date);
751    }
752    }
753
754    $doc_obj->add_utf8_metadata($cursection, "NumPages", $self->{'num_pages'}) if defined $self->{'num_pages'};
755   
756    if ($self->{'use_sections'} && $self->{'converted_to'} eq "HTML") {
757    # For gs2 we explicitly make it a paged document, cos greenstone won't get it
758    # right if any section has an empty title, or one with letters in it
759    if (&util::is_gs3()) {
760        # but for gs3, paged docs currently use image slider which is ugly if there are no images
761        $doc_obj->set_utf8_metadata_element ($cursection, "gsdlthistype", "Hierarchy");
762    } else {
763        $doc_obj->set_utf8_metadata_element ($cursection, "gsdlthistype", "Paged");
764    }
765    }
766
767    return $result;
768}
769
7701;
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