Merge branch 'master' of git.uio.no:usit-rt
[usit-rt.git] / lib / RT / I18N.pm
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48
49=head1 NAME
50
51RT::I18N - a base class for localization of RT
52
53=cut
54
55package RT::I18N;
56
57use strict;
58use warnings;
59
60
61use Locale::Maketext 1.04;
62use Locale::Maketext::Lexicon 0.25;
63use base 'Locale::Maketext::Fuzzy';
64
65use Encode;
66use MIME::Entity;
67use MIME::Head;
68use File::Glob;
69
70# I decree that this project's first language is English.
71
72our %Lexicon = (
73 'TEST_STRING' => 'Concrete Mixer',
74
75 '__Content-Type' => 'text/plain; charset=utf-8',
76
77 '_AUTO' => 1,
78 # That means that lookup failures can't happen -- if we get as far
79 # as looking for something in this lexicon, and we don't find it,
80 # then automagically set $Lexicon{$key} = $key, before possibly
81 # compiling it.
82
83 # The exception is keys that start with "_" -- they aren't auto-makeable.
84
85);
86# End of lexicon.
87
88=head2 Init
89
90Initializes the lexicons used for localization.
91
92
93=cut
94
95sub Init {
96
97 my @lang = RT->Config->Get('LexiconLanguages');
98 @lang = ('*') unless @lang;
99
100 # load default functions
101 require substr(__FILE__, 0, -3) . '/i_default.pm';
102
103 # Load language-specific functions
104 foreach my $file ( File::Glob::bsd_glob(substr(__FILE__, 0, -3) . "/*.pm") ) {
105 unless ( $file =~ /^([-\w\s\.\/\\~:]+)$/ ) {
106 warn("$file is tainted. not loading");
107 next;
108 }
109 $file = $1;
110
111 my ($lang) = ($file =~ /([^\\\/]+?)\.pm$/);
112 next unless grep $_ eq '*' || $_ eq $lang, @lang;
113 require $file;
114 }
115
116 my %import;
117 foreach my $l ( @lang ) {
118 $import{$l} = [
119 Gettext => $RT::LexiconPath."/$l.po",
120 ];
121 push @{ $import{$l} }, map {(Gettext => "$_/$l.po")} RT->PluginDirs('po');
122 push @{ $import{$l} }, (Gettext => $RT::LocalLexiconPath."/*/$l.po",
123 Gettext => $RT::LocalLexiconPath."/$l.po");
124 }
125
126 # Acquire all .po files and iterate them into lexicons
127 Locale::Maketext::Lexicon->import({ _decode => 1, %import });
128
129 return 1;
130}
131
132sub LoadLexicons {
133
134 no strict 'refs';
135 foreach my $k (keys %{RT::I18N::} ) {
136 next if $k eq 'main::';
137 next unless index($k, '::', -2) >= 0;
138 next unless exists ${ 'RT::I18N::'. $k }{'Lexicon'};
139
140 my $lex = *{ ${'RT::I18N::'. $k }{'Lexicon'} }{HASH};
141 # run fetch to force load
142 my $tmp = $lex->{'foo'};
143 # XXX: untie may fail with "untie attempted
144 # while 1 inner references still exist"
145 # TODO: untie that has to lower fetch impact
146 # untie %$lex if tied %$lex;
147 }
148}
149
150=head2 encoding
151
152Returns the encoding of the current lexicon, as yanked out of __ContentType's "charset" field.
153If it can't find anything, it returns 'ISO-8859-1'
154
155
156
157=cut
158
159
160sub encoding { 'utf-8' }
161
162
163=head2 SetMIMEEntityToUTF8 $entity
164
165An utility function which will try to convert entity body into utf8.
166It's now a wrap-up of SetMIMEEntityToEncoding($entity, 'utf-8').
167
168=cut
169
170sub SetMIMEEntityToUTF8 {
171 RT::I18N::SetMIMEEntityToEncoding(shift, 'utf-8');
172}
173
174
175
176=head2 IsTextualContentType $type
177
178An utility function that determines whether $type is I<textual>, meaning
179that it can sensibly be converted to Unicode text.
180
181Currently, it returns true iff $type matches this regular expression
182(case-insensitively):
183
184 ^(?:text/(?:plain|html)|message/rfc822)\b
185
186
187=cut
188
189sub IsTextualContentType {
190 my $type = shift;
191 ($type =~ m{^(?:text/(?:plain|html)|message/rfc822)\b}i) ? 1 : 0;
192}
193
194
195=head2 SetMIMEEntityToEncoding $entity, $encoding
196
197An utility function which will try to convert entity body into specified
198charset encoding (encoded as octets, *not* unicode-strings). It will
199iterate all the entities in $entity, and try to convert each one into
200specified charset if whose Content-Type is 'text/plain'.
201
202This function doesn't return anything meaningful.
203
204=cut
205
206sub SetMIMEEntityToEncoding {
207 my ( $entity, $enc, $preserve_words ) = ( shift, shift, shift );
208
209 # do the same for parts first of all
210 SetMIMEEntityToEncoding( $_, $enc, $preserve_words ) foreach $entity->parts;
211
212 my $charset = _FindOrGuessCharset($entity) or return;
213
214 SetMIMEHeadToEncoding(
215 $entity->head,
216 _FindOrGuessCharset($entity, 1) => $enc,
217 $preserve_words
218 );
219
220 my $head = $entity->head;
221
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222 # If this is a textual entity, we'd need to preserve its original encoding
223 $head->replace( "X-RT-Original-Encoding" => $charset )
224 if $head->mime_attr('content-type.charset') or IsTextualContentType($head->mime_type);
225
226 return unless IsTextualContentType($head->mime_type);
227
228 my $body = $entity->bodyhandle;
229
dab09ea8 230 if ( $body && ($enc ne $charset || $enc =~ /^utf-?8(?:-strict)?$/i) ) {
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231 my $string = $body->as_string or return;
232
233 $RT::Logger->debug( "Converting '$charset' to '$enc' for "
234 . $head->mime_type . " - "
235 . ( $head->get('subject') || 'Subjectless message' ) );
236
237 # NOTE:: see the comments at the end of the sub.
238 Encode::_utf8_off($string);
239 Encode::from_to( $string, $charset => $enc );
240
241 my $new_body = MIME::Body::InCore->new($string);
242
243 # set up the new entity
244 $head->mime_attr( "content-type" => 'text/plain' )
245 unless ( $head->mime_attr("content-type") );
246 $head->mime_attr( "content-type.charset" => $enc );
247 $entity->bodyhandle($new_body);
248 }
249}
250
251# NOTES: Why Encode::_utf8_off before Encode::from_to
252#
253# All the strings in RT are utf-8 now. Quotes from Encode POD:
254#
255# [$length =] from_to($octets, FROM_ENC, TO_ENC [, CHECK])
256# ... The data in $octets must be encoded as octets and not as
257# characters in Perl's internal format. ...
258#
259# Not turning off the UTF-8 flag in the string will prevent the string
260# from conversion.
261
262
263
264=head2 DecodeMIMEWordsToUTF8 $raw
265
266An utility method which mimics MIME::Words::decode_mimewords, but only
267limited functionality. This function returns an utf-8 string.
268
269It returns the decoded string, or the original string if it's not
270encoded. Since the subroutine converts specified string into utf-8
271charset, it should not alter a subject written in English.
272
273Why not use MIME::Words directly? Because it fails in RT when I
274tried. Maybe it's ok now.
275
276=cut
277
278sub DecodeMIMEWordsToUTF8 {
279 my $str = shift;
280 return DecodeMIMEWordsToEncoding($str, 'utf-8', @_);
281}
282
283sub DecodeMIMEWordsToEncoding {
284 my $str = shift;
285 my $to_charset = _CanonicalizeCharset(shift);
286 my $field = shift || '';
287
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288 # handle filename*=ISO-8859-1''%74%E9%73%74%2E%74%78%74, parameter value
289 # continuations, and similar syntax from RFC 2231
290 if ($field =~ /^Content-(Type|Disposition)/i) {
291 # This concatenates continued parameters and normalizes encoded params
292 # to QB encoded-words which we handle below
293 $str = MIME::Field::ParamVal->parse($str)->stringify;
294 }
295
296 # XXX TODO: use decode('MIME-Header', ...) and Encode::Alias to replace our
297 # custom MIME word decoding and charset canonicalization. We can't do this
298 # until we parse before decode, instead of the other way around.
299 my @list = $str =~ m/(.*?) # prefix
300 =\? # =?
301 ([^?]+?) # charset
302 (?:\*[^?]+)? # optional '*language'
303 \? # ?
304 ([QqBb]) # encoding
305 \? # ?
306 ([^?]+) # encoded string
307 \?= # ?=
308 ([^=]*) # trailing
309 /xgcs;
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310
311 if ( @list ) {
312 # add everything that hasn't matched to the end of the latest
313 # string in array this happen when we have 'key="=?encoded?="; key="plain"'
314 $list[-1] .= substr($str, pos $str);
315
316 $str = "";
317 while (@list) {
318 my ($prefix, $charset, $encoding, $enc_str, $trailing) =
319 splice @list, 0, 5;
320 $charset = _CanonicalizeCharset($charset);
321 $encoding = lc $encoding;
322
323 $trailing =~ s/\s?\t?$//; # Observed from Outlook Express
324
325 if ( $encoding eq 'q' ) {
326 use MIME::QuotedPrint;
327 $enc_str =~ tr/_/ /; # Observed from Outlook Express
328 $enc_str = decode_qp($enc_str);
329 } elsif ( $encoding eq 'b' ) {
330 use MIME::Base64;
331 $enc_str = decode_base64($enc_str);
332 } else {
333 $RT::Logger->warning("Incorrect encoding '$encoding' in '$str', "
334 ."only Q(uoted-printable) and B(ase64) are supported");
335 }
336
337 # now we have got a decoded subject, try to convert into the encoding
dab09ea8 338 if ( $charset ne $to_charset || $charset =~ /^utf-?8(?:-strict)?$/i ) {
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339 Encode::from_to( $enc_str, $charset, $to_charset );
340 }
341
342 # XXX TODO: RT doesn't currently do the right thing with mime-encoded headers
343 # We _should_ be preserving them encoded until after parsing is completed and
344 # THEN undo the mime-encoding.
345 #
346 # This routine should be translating the existing mimeencoding to utf8 but leaving
347 # things encoded.
348 #
349 # It's legal for headers to contain mime-encoded commas and semicolons which
350 # should not be treated as address separators. (Encoding == quoting here)
351 #
352 # until this is fixed, we must escape any string containing a comma or semicolon
353 # this is only a bandaid
354
355 # Some _other_ MUAs encode quotes _already_, and double quotes
356 # confuse us a lot, so only quote it if it isn't quoted
357 # already.
358 $enc_str = qq{"$enc_str"}
359 if $enc_str =~ /[,;]/
360 and $enc_str !~ /^".*"$/
361 and (!$field || $field =~ /^(?:To$|From$|B?Cc$|Content-)/i);
362
363 $str .= $prefix . $enc_str . $trailing;
364 }
365 }
366
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367 # We might have \n without trailing whitespace, which will result in
368 # invalid headers.
369 $str =~ s/\n//g;
370
371 return ($str)
372}
373
374
375
376=head2 _FindOrGuessCharset MIME::Entity, $head_only
377
378When handed a MIME::Entity will first attempt to read what charset the message is encoded in. Failing that, will use Encode::Guess to try to figure it out
379
380If $head_only is true, only guesses charset for head parts. This is because header's encoding (e.g. filename="...") may be different from that of body's.
381
382=cut
383
384sub _FindOrGuessCharset {
385 my $entity = shift;
386 my $head_only = shift;
387 my $head = $entity->head;
388
389 if ( my $charset = $head->mime_attr("content-type.charset") ) {
390 return _CanonicalizeCharset($charset);
391 }
392
393 if ( !$head_only and $head->mime_type =~ m{^text/} ) {
394 my $body = $entity->bodyhandle or return;
395 return _GuessCharset( $body->as_string );
396 }
397 else {
398
399 # potentially binary data -- don't guess the body
400 return _GuessCharset( $head->as_string );
401 }
402}
403
404
405
406=head2 _GuessCharset STRING
407
408use Encode::Guess to try to figure it out the string's encoding.
409
410=cut
411
412use constant HAS_ENCODE_GUESS => do { local $@; eval { require Encode::Guess; 1 } };
413use constant HAS_ENCODE_DETECT => do { local $@; eval { require Encode::Detect::Detector; 1 } };
414
415sub _GuessCharset {
416 my $fallback = _CanonicalizeCharset('iso-8859-1');
417
418 # if $_[0] is null/empty, we don't guess its encoding
419 return $fallback
420 unless defined $_[0] && length $_[0];
421
422 my @encodings = RT->Config->Get('EmailInputEncodings');
423 unless ( @encodings ) {
424 $RT::Logger->warning("No EmailInputEncodings set, fallback to $fallback");
425 return $fallback;
426 }
427
428 if ( $encodings[0] eq '*' ) {
429 shift @encodings;
430 if ( HAS_ENCODE_DETECT ) {
431 my $charset = Encode::Detect::Detector::detect( $_[0] );
432 if ( $charset ) {
433 $RT::Logger->debug("Encode::Detect::Detector guessed encoding: $charset");
434 return _CanonicalizeCharset( Encode::resolve_alias( $charset ) );
435 }
436 else {
437 $RT::Logger->debug("Encode::Detect::Detector failed to guess encoding");
438 }
439 }
440 else {
441 $RT::Logger->error(
442 "You requested to guess encoding, but we couldn't"
443 ." load Encode::Detect::Detector module"
444 );
445 }
446 }
447
448 unless ( @encodings ) {
449 $RT::Logger->warning("No EmailInputEncodings set except '*', fallback to $fallback");
450 return $fallback;
451 }
452
453 unless ( HAS_ENCODE_GUESS ) {
454 $RT::Logger->error("We couldn't load Encode::Guess module, fallback to $fallback");
455 return $fallback;
456 }
457
458 Encode::Guess->set_suspects( @encodings );
459 my $decoder = Encode::Guess->guess( $_[0] );
460 unless ( defined $decoder ) {
461 $RT::Logger->warning("Encode::Guess failed: decoder is undefined; fallback to $fallback");
462 return $fallback;
463 }
464
465 if ( ref $decoder ) {
466 my $charset = $decoder->name;
467 $RT::Logger->debug("Encode::Guess guessed encoding: $charset");
468 return _CanonicalizeCharset( $charset );
469 }
470 elsif ($decoder =~ /(\S+ or .+)/) {
471 my %matched = map { $_ => 1 } split(/ or /, $1);
472 return 'utf-8' if $matched{'utf8'}; # one and only normalization
473
474 foreach my $suspect (RT->Config->Get('EmailInputEncodings')) {
475 next unless $matched{$suspect};
476 $RT::Logger->debug("Encode::Guess ambiguous ($decoder); using $suspect");
477 return _CanonicalizeCharset( $suspect );
478 }
479 }
480 else {
481 $RT::Logger->warning("Encode::Guess failed: $decoder; fallback to $fallback");
482 }
483
484 return $fallback;
485}
486
487=head2 _CanonicalizeCharset NAME
488
489canonicalize charset, return lowercase version.
490special cases are: gb2312 => gbk, utf8 => utf-8
491
492=cut
493
494sub _CanonicalizeCharset {
495 my $charset = lc shift;
496 return $charset unless $charset;
497
498 # Canonicalize aliases if they're known
499 if (my $canonical = Encode::resolve_alias($charset)) {
500 $charset = $canonical;
501 }
502
503 if ( $charset eq 'utf8' || $charset eq 'utf-8-strict' ) {
504 return 'utf-8';
505 }
506 elsif ( $charset eq 'euc-cn' ) {
507 # gbk is superset of gb2312/euc-cn so it's safe
508 return 'gbk';
509 # XXX TODO: gb18030 is an even larger, more permissive superset of gbk,
510 # but needs Encode::HanExtra installed
511 }
512 else {
513 return $charset;
514 }
515}
516
517
518=head2 SetMIMEHeadToEncoding HEAD OLD_CHARSET NEW_CHARSET
519
520Converts a MIME Head from one encoding to another. This totally violates the RFC.
521We should never need this. But, Surprise!, MUAs are badly broken and do this kind of stuff
522all the time
523
524
525=cut
526
527sub SetMIMEHeadToEncoding {
528 my ( $head, $charset, $enc, $preserve_words ) = ( shift, shift, shift, shift );
529
530 $charset = _CanonicalizeCharset($charset);
531 $enc = _CanonicalizeCharset($enc);
532
533 return if $charset eq $enc and $preserve_words;
534
535 foreach my $tag ( $head->tags ) {
536 next unless $tag; # seen in wild: headers with no name
537 my @values = $head->get_all($tag);
538 $head->delete($tag);
539 foreach my $value (@values) {
dab09ea8 540 if ( $charset ne $enc || $enc =~ /^utf-?8(?:-strict)?$/i ) {
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541 Encode::_utf8_off($value);
542 Encode::from_to( $value, $charset => $enc );
543 }
544 $value = DecodeMIMEWordsToEncoding( $value, $enc, $tag )
545 unless $preserve_words;
546
547 # We intentionally add a leading space when re-adding the
548 # header; Mail::Header strips it before storing, but it
549 # serves to prevent it from "helpfully" canonicalizing
550 # $head->add("Subject", "Subject: foo") into the same as
551 # $head->add("Subject", "foo");
552 $head->add( $tag, " " . $value );
553 }
554 }
555
556}
557
558RT::Base->_ImportOverlays();
559
5601; # End of module.
561