source: trunk/gsdl/perllib/plugins/HTMLPlug.pm@ 900

Last change on this file since 900 was 900, checked in by sjboddie, 21 years ago

tweaked the way associated files are handled at build time - some
individual plugins may still need catching up.

  • Property svn:executable set to *
  • Property svn:keywords set to Author Date Id Revision
File size: 14.2 KB
Line 
1###########################################################################
2#
3# HTMLPlug.pm -- basic html plugin
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) 1999 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#
28# Note that this plugin handles frames only in a very simple way
29# i.e. each frame is treated as a separate document. This means
30# search results will contain links to individual frames rather
31# than linking to the top level frameset.
32# There may also be some problems caused by the _parent target
33# (it's removed by this plugin)
34# To use frames properly you'll need to use the WebPlug plugin.
35#
36
37
38package HTMLPlug;
39
40use BasPlug;
41use html;
42use util;
43use parsargv;
44
45sub BEGIN {
46 @ISA = ('BasPlug');
47}
48
49use strict;
50
51sub print_usage {
52 print STDERR "\nIncorrect options passed to HTMLPlug, check your collect.cfg configuration file\n";
53
54 print STDERR "\n usage: plugin HTMLPlug [options]\n\n";
55 print STDERR " options:\n";
56 print STDERR " -process_exp A perl regular expression to match against filenames.\n";
57 print STDERR " Matching filenames will be processed by this plugin.\n";
58 print STDERR " Defaults to '(?i)\.html?\$' i.e. all documents ending in\n";
59 print STDERR " .htm or .html (case-insensitive).\n";
60 print STDERR " -nolinks Don't make any attempt to trap links (setting this flag may\n";
61 print STDERR " improve speed of building/importing but any relative links within\n";
62 print STDERR " documents will be broken).\n";
63 print STDERR " -block_exp Files matching this regular expression will be blocked from\n";
64 print STDERR " being passed to any further plugins in the list. By default\n";
65 print STDERR " HTMLPlug blocks any files with .gif, .jpg, .jpeg, .png, .pdf,\n";
66 print STDERR " .rtf or .css file extensions.\n";
67 print STDERR " -keep_head Don't remove headers from html files.\n";
68 print STDERR " -no_metadata Don't attempt to extract any metadata from files.\n";
69 print STDERR " -metadata_fields Comma separated list of metadata fields to attempt to extract.\n";
70 print STDERR " Defaults to 'Title'\n";
71 print STDERR " -w3mir Set if w3mir was used to generate input file structure.\n";
72 print STDERR " w3mir \n";
73 print STDERR " -rename_assoc_files Renames files associated with documents (e.g. images). Also\n";
74 print STDERR " creates much shallower directory structure (useful when creating\n";
75 print STDERR " collections to go on cd-rom).\n\n";
76}
77
78sub new {
79 my $class = shift (@_);
80 my $self = new BasPlug ();
81
82 if (!parsargv::parse(\@_,
83 q^process_exp/.*/(?i)\.html?$^, \$self->{'process_exp'},
84 q^nolinks^, \$self->{'nolinks'},
85 q^block_exp/.*/(?i)\.(gif|jpe?g|png|pdf|rtf|css)$^, \$self->{'block_exp'},
86 q^keep_head^, \$self->{'keep_head'},
87 q^no_metadata^, \$self->{'no_metadata'},
88 q^metadata_fields/.*/Title^, \$self->{'metadata_fields'},
89 q^w3mir^, \$self->{'w3mir'},
90 q^rename_assoc_files^, \$self->{'rename_assoc_files'})) {
91 &print_usage();
92 die "\n";
93 }
94
95 $self->{'aux_files'} = {};
96 $self->{'dir_num'} = 0;
97 $self->{'file_num'} = 0;
98
99 return bless $self, $class;
100}
101
102sub is_recursive {
103 my $self = shift (@_);
104
105 return 0; # this is not a recursive plugin
106}
107
108# return number of files processed, undef if can't process
109# Note that $base_dir might be "" and that $file might
110# include directories
111sub read {
112 my $self = shift (@_);
113 my ($pluginfo, $base_dir, $file, $metadata, $processor) = @_;
114
115 my $filename = &util::filename_cat($base_dir, $file);
116 return 0 if $filename =~ /$self->{'block_exp'}/;
117 if ($filename !~ /$self->{'process_exp'}/ || !-f $filename) {
118 return undef;
119 }
120 $file =~ s/^[\/\\]+//;
121
122 $self->{'verbosity'} = $processor->{'verbosity'};
123 print STDERR "HTMLPlug: processing $file\n"
124 if $self->{'verbosity'} > 1;
125
126 # create a new document
127 my $doc_obj = new doc ($file, "indexed_doc");
128 my $cursection = $doc_obj->get_top_section();
129
130 # read in HTML file
131 open (FILE, $filename) || die "HTMLPlug::read - can't open $filename\n";
132 undef $/;
133 my $text = <FILE>;
134 $/ = "\n";
135 close FILE;
136 if ($text !~ /\w/) {
137 print STDERR "HTMLPlug: ERROR: $file contains no text\n" if $self->{'verbosity'};
138 return 0;
139 }
140
141 $self->extra_metadata ($doc_obj, $cursection, $metadata);
142 $self->extract_metadata (\$text, $metadata, $doc_obj, $cursection)
143 unless $self->{'no_metadata'};
144
145 # Store URL for page as metadata - this can be used for an
146 # altavista style search interface. The URL won't be valid
147 # unless the file structure contains the domain name (i.e.
148 # like when w3mir is used to download a website).
149 my $web_url = "http://$file";
150 $web_url =~ s/\\/\//g; # for windows
151 $doc_obj->add_metadata($cursection, "URL", $web_url);
152
153 # remove header and footer
154 if (!$self->{'keep_head'}) {
155 $text =~ s/^.*?<body[^>]*>//is;
156 $text =~ s/(<\/body[^>]*>|<\/html[^>]*>)//isg;
157 }
158
159 # trap links
160 if (!$self->{'nolinks'}) {
161
162 # usemap="./#index" not handled correctly => change to "#index"
163 $text =~ s/(<img[^>]*?usemap\s*=\s*\"?)([^\">\s]+)(\"?[^>]*>)/
164 $self->replace_usemap_links($1, $2, $3)/isge;
165
166 $text =~ s/(<(?:a|area|frame|link)\s+[^>]*?(?:href|src)\s*=\s*\"?)([^\">\s]+)(\"?[^>]*>)/
167 $self->replace_href_links ($1, $2, $3, $base_dir, $file, $doc_obj, $cursection)/isge;
168 }
169
170 # trap images
171 $text =~ s/(<img[^>]*?src\s*=\s*\"?)([^\">\s]+)(\"?[^>]*>)/
172 $self->replace_images ($1, $2, $3, $base_dir, $file, $doc_obj, $cursection)/isge;
173
174 $doc_obj->add_text ($cursection, $text);
175
176 # add an OID
177 $doc_obj->set_OID();
178
179 # process the document
180 $processor->process($doc_obj);
181
182 return 1; # processed the file
183}
184
185sub replace_images {
186 my $self = shift (@_);
187 my ($front, $link, $back, $base_dir,
188 $file, $doc_obj, $section) = @_;
189
190 $link =~ s/\n/ /g;
191
192 my ($href, $hash_part, $rl) = $self->format_link ($link, $base_dir, $file);
193 return $front . $self->add_file ($href, $base_dir, $doc_obj, $section) . $back;
194}
195
196sub replace_href_links {
197 my $self = shift (@_);
198 my ($front, $link, $back, $base_dir, $file, $doc_obj, $section) = @_;
199
200 # attempt to sort out targets - frames are not handled
201 # well in this plugin and some cases will screw things
202 # up - e.g. the _parent target (so we'll just remove
203 # them all ;-)
204 $front =~ s/(target=\"?)_top(\"?)/$1_gsdltop_$2/is;
205 $back =~ s/(target=\"?)_top(\"?)/$1_gsdltop_$2/is;
206 $front =~ s/target=\"?_parent\"?//is;
207 $back =~ s/target=\"?_parent\"?//is;
208
209 return $front . $link . $back if $link =~ /^\#/s;
210 $link =~ s/\n/ /g;
211
212 my ($href, $hash_part, $rl) = $self->format_link ($link, $base_dir, $file);
213
214 my ($filename) = $href =~ /^(?:.*?):(?:\/\/)?(.*)/;
215
216 ##### leave all these links alone (they won't be picked up by intermediate
217 ##### pages). I think that's safest when dealing with frames, targets etc.
218 ##### (at least until I think of a better way to do it). Problems occur with
219 ##### mailto links from within small frames, the intermediate page is displayed
220 ##### within that frame and can't be seen. There is still potential for this to
221 ##### happen even with html pages - the solution seems to be to somehow tell
222 ##### the browser from the server side to display the page being sent (i.e.
223 ##### the intermediate page) in the top level window - I'm not sure if that's
224 ##### possible - the following line should probably be deleted if that can be done
225 return $front . $link . $back if $href =~ /^(mailto|news|gopher|nntp|telnet|javascript):/is;
226
227
228 if (($rl == 0) || ($filename =~ /$self->{'process_exp'}/) ||
229 ($href =~ /\/$/) || ($href =~ /^(mailto|news|gopher|nntp|telnet|javascript):/i)) {
230 &html::urlsafe ($href);
231 return $front . "_httpextlink_&rl=" . $rl . "&href=" . $href . $hash_part . $back;
232
233 } else {
234 # link is to some other type of file (image, pdf etc.) so we'll
235 # need to associate that file
236 return $front . $self->add_file ($href, $base_dir, $doc_obj, $section) . $back;
237 }
238}
239
240sub add_file {
241 my $self = shift (@_);
242 my ($href, $base_dir, $doc_obj, $section) = @_;
243 my ($newname);
244
245 my $filename = $href;
246 $filename =~ s/^[^:]*:\/\///;
247 $filename = &util::filename_cat ($base_dir, $filename);
248 my ($ext) = $filename =~ /(\.[^\.]*)$/;
249 if ($self->{'rename_assoc_files'}) {
250 if (defined $self->{'aux_files'}->{$href}) {
251 $newname = $self->{'aux_files'}->{$href}->{'dir_num'} . "/" .
252 $self->{'aux_files'}->{$href}->{'file_num'} . $ext;
253 } else {
254 $newname = $self->{'dir_num'} . "/" . $self->{'file_num'} . $ext;
255 $self->inc_filecount ();
256 }
257 $doc_obj->associate_file($filename, $newname, undef, $section);
258 return "_httpcollimg_/$newname";
259
260 } else {
261 ($newname) = $filename =~ /([^\/\\]*)$/;
262 $doc_obj->associate_file($filename, $newname, undef, $section);
263 return "_httpcollimg_/_thisOID_/$newname";
264 }
265}
266
267
268sub format_link {
269 my $self = shift (@_);
270 my ($link, $base_dir, $file) = @_;
271
272 my ($before_hash, $hash_part) = $link =~ /^([^\#]*)(\#?.*)$/;
273 $hash_part = "" if !defined $hash_part;
274 if (!defined $before_hash || $before_hash !~ /[\w\.\/]/) {
275 print STDERR "HTMLPlug: ERROR - badly formatted tag ignored ($link)\n"
276 if $self->{'verbosity'};
277 return ($link, "", 0);
278 }
279
280 if ($before_hash =~ s/^((?:http|ftp|file):\/\/)//i) {
281 my $type = $1;
282
283 if ($link =~ /^(http|ftp):/i) {
284 # Turn url (using /) into file name (possibly using \ on windows)
285 my @http_dir_split = split('/', $before_hash);
286 $before_hash = &util::filename_cat(@http_dir_split);
287 }
288
289 $before_hash = $self->eval_dir_dots($before_hash);
290
291 my $linkfilename = &util::filename_cat ($base_dir, $before_hash);
292
293 my $rl = 0;
294 $rl = 1 if (-e $linkfilename);
295
296 # make sure there's a slash on the end if it's a directory
297 if ($before_hash !~ /\/$/) {
298 $before_hash .= "/" if (-d $linkfilename);
299 }
300
301 return ($type . $before_hash, $hash_part, $rl);
302
303 } elsif ($link !~ /^(mailto|news|gopher|nntp|telnet|javascript):/i) {
304
305 if ($before_hash =~ s/^\///) {
306 # the first directory will be the domain name if w3mir was used
307 # to generate archives, otherwise we'll assume all files are
308 # from the same site and base_dir is the root
309 if ($self->{'w3mir'}) {
310 my @dirs = split /[\/\\]/, $file;
311 my $domname = shift (@dirs);
312 $before_hash = &util::filename_cat($domname, $before_hash);
313 $before_hash =~ s/\\/\//g; # for windows
314 }
315
316 } else {
317 # Turn relative file path into full path
318 my $dirname = &File::Basename::dirname($file);
319 $before_hash = &util::filename_cat($dirname, $before_hash);
320 $before_hash = $self->eval_dir_dots($before_hash);
321 }
322
323 # make sure there's a slash on the end if it's a directory
324 my $linkfilename = &util::filename_cat ($base_dir, $before_hash);
325 if ($before_hash !~ /\/$/) {
326 $before_hash .= "/" if (-d $linkfilename);
327 }
328
329 return ("http://" . $before_hash, $hash_part, 1);
330
331 } else {
332 # mailto, news, nntp, telnet, javascript or gopher link
333 return ($before_hash, "", 0);
334 }
335}
336
337sub extract_metadata {
338 my $self = shift (@_);
339 my ($textref, $metadata, $doc_obj, $section) = @_;
340
341 foreach my $field (split /,/, $self->{'metadata_fields'}) {
342
343 # don't need to extract field if it was passed in from a previous
344 # (recursive) plugin
345 next if defined $metadata->{$field};
346
347 # see if there's a <meta> tag for this field
348 if ($$textref =~ /<meta(.*?)(?:name|http-equiv)\s*=\s*\"?$field\"?([^>]*)/is) {
349 my $content = $1 . $2;
350 if ($content =~ /content\s*=\s*\"?(.*?)\"?/is) {
351 if (defined $1) {
352 my $value = $1;
353 $value =~ s/\s+/ /gs;
354 $doc_obj->add_metadata($section, $field, $value);
355 next;
356 }
357 }
358 }
359
360 # special case for Title metadata - try <title> tags
361 # then first 100 characters of text
362
363 if ($field =~ /^title$/i) {
364
365 # see if there's a <title> tag
366 if ($$textref =~ /<title[^>]*>([^<]*)<\/title[^>]*>/is) {
367 if (defined $1) {
368 my $title = $1;
369 if ($title =~ /\w/) {
370 $title =~ s/\s+/ /gs;
371 $doc_obj->add_metadata ($section, $field, $title);
372 next;
373 }
374 }
375 }
376
377 # if no title use first 100 characters
378 my $tmptext = $$textref;
379 $tmptext =~ s/<[^>]*>//g;
380 my $title = substr ($tmptext, 0, 100);
381 $title =~ s/\s+/ /gs;
382 $doc_obj->add_metadata ($section, $field, $title);
383 }
384 }
385}
386
387# evaluate any "../" to next directory up
388# evaluate any "./" as here
389sub eval_dir_dots {
390 my $self = shift (@_);
391 my ($filename) = @_;
392
393 my $dirsep_os = &util::get_os_dirsep();
394 my @dirsep = split(/$dirsep_os/,$filename);
395
396 my @eval_dirs = ();
397 foreach my $d (@dirsep) {
398 if ($d eq "..") {
399 pop(@eval_dirs);
400
401 } elsif ($d eq ".") {
402 # do nothing!
403
404 } else {
405 push(@eval_dirs,$d);
406 }
407 }
408
409 return &util::filename_cat(@eval_dirs);
410}
411
412sub replace_usemap_links {
413 my $self = shift (@_);
414 my ($front, $link, $back) = @_;
415
416 $link =~ s/^\.\///;
417 return $front . $link . $back;
418}
419
420sub inc_filecount {
421 my $self = shift (@_);
422
423 if ($self->{'file_num'} == 1000) {
424 $self->{'dir_num'} ++;
425 $self->{'file_num'} = 0;
426 } else {
427 $self->{'file_num'} ++;
428 }
429}
430
4311;
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