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lontexconvert.pm
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Wed Aug 12 20:31:08 2009 UTC (14 years, 11 months ago) by
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Mimetex alt-argument for screen readers:
* do not remove original math enviroment delimiters
* change double quotes into double primes (so we do not have alt="..."...")
* remove artificial math delimiters
1: # The LearningOnline Network with CAPA
2: # TeX Conversion Module
3: #
4: # $Id: lontexconvert.pm,v 1.97 2009/08/12 20:31:08 www Exp $
5: #
6: # Copyright Michigan State University Board of Trustees
7: #
8: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
9: #
10: # LON-CAPA 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: # LON-CAPA 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 LON-CAPA; if not, write to the Free Software
22: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23: #
24: # /home/httpd/html/adm/gpl.txt
25: #
26: # http://www.lon-capa.org/
27: #
28: # Copyright for TtHfunc and TtMfunc by Ian Hutchinson.
29: # TtHfunc and TtMfunc (the "Code") may be compiled and linked into
30: # binary executable programs or libraries distributed by the
31: # Michigan State University (the "Licensee"), but any binaries so
32: # distributed are hereby licensed only for use in the context
33: # of a program or computational system for which the Licensee is the
34: # primary author or distributor, and which performs substantial
35: # additional tasks beyond the translation of (La)TeX into HTML.
36: # The C source of the Code may not be distributed by the Licensee
37: # to any other parties under any circumstances.
38: #
39:
40: package Apache::lontexconvert;
41:
42: use strict;
43: use tth();
44: use vars qw($errorstring);
45: #use Apache::lonxml();
46: use Apache::lonlocal;
47: use Apache::lonnet;
48: use lib '/home/httpd/lib/perl/';
49: use LONCAPA;
50: use URI::Escape;
51: use IO::Socket::INET;
52: use IO::Socket::SSL;
53:
54: # ====================================================================== Header
55:
56: sub init_tth {
57: my $options=$env{'course.'.$env{'request.course.id'}.'.tthoptions'};
58: if ($options =~ /\S/) {
59: $options = ' '.$options;
60: } else {
61: undef($options);
62: }
63: if ($env{'browser.mathml'}) {
64: &tth::ttminit();
65: if ($env{'browser.unicode'}) {
66: &tth::ttmoptions('-L -u1'.$options);
67: } else {
68: &tth::ttmoptions('-L -u0'.$options);
69: }
70: } else {
71: &tth::tthinit();
72: if ($env{'browser.unicode'}) {
73: &tth::tthoptions('-L -u1'.$options);
74: } else {
75: &tth::tthoptions('-L -u0'.$options);
76: }
77: }
78: }
79:
80: # ================================================================== Conversion
81:
82: $Apache::lontexconvert::messedup=0;
83:
84:
85: sub convert_real {
86: my ($texstring)=@_;
87: my ($xmlstring,$errorstring);
88: local $SIG{SEGV}=sub { $Apache::lontexconvert::messedup=1; die; };
89: local $SIG{ALRM}=sub {
90: &Apache::lonnet::logthis("ALRM");
91: $xmlstring='['.&mt("TeX unconverted due to errors").']';
92: $Apache::lontexconvert::messedup=1;
93: die &mt("TeX unconverted due to errors");
94: };
95: &Apache::lonxml::start_alarm();
96: if ($env{'browser.mathml'}) {
97: $xmlstring=&tth::ttm($$texstring);
98: $xmlstring=~s/\<math\>/\<math xmlns=\"\&mathns\;\"\>/g;
99: $xmlstring=~s/\<br\>/\<br\/\>/g;
100: $xmlstring=~s/\<p\>/\<p\>\<\/p\>/g;
101: $errorstring.=&tth::ttmerror();
102: } else {
103: $xmlstring=&tth::tth($$texstring);
104: $errorstring.=&tth::ttherror();
105: $xmlstring=~s-</font(\s*)>-</font>-g;
106: }
107: $xmlstring=~s/^\s*\<br clear\=\"all\"/\<br/s;
108: $xmlstring=~s/^\s*//;
109: $xmlstring=~s/\s*$//;
110: #
111: # \rightleftharpoons is not converted by tth but maps
112: # reasonably well to ⇔. If we get many more of these,
113: # we're going to need to have a translation sub.
114: #
115: my $lrharpoon = pack("U", 0x21cc);
116: $xmlstring=~s/\\rightleftharpoons/$lrharpoon/g;
117:
118: &Apache::lonxml::end_alarm();
119: return ($xmlstring,$errorstring);
120: }
121:
122: sub tth_converted {
123: my $texstring=shift;
124: my $xmlstring='['.&mt('UNDISPLAYABLE').']';
125: if ($Apache::lontexconvert::messedup) {
126: return '['.&mt('TeX unconverted due to previous errors').']';
127: }
128: $$texstring ='\\documentstyle{article}'.$$texstring;
129:
130: eval(<<'ENDCONV');
131: ($xmlstring,$errorstring)=&convert_real($texstring)
132: ENDCONV
133: if ($@) {
134: $errorstring.=&mt("Evaluation Error: ").$@;
135: $Apache::lontexconvert::messedup=1;
136: }
137: if ($Apache::lontexconvert::messedup || &tth::tthmessedup() ||
138: $errorstring) {
139: &Apache::lonnet::logthis("Trying to kill myself");
140: $Apache::lontexconvert::messedup=1;
141: if (ref($Apache::lonxml::request)) {
142: $Apache::lonxml::request->child_terminate();
143: } else {
144: my $request;
145: eval { $request=Apache->request; };
146: if (!$request) {
147: eval { $request=Apache2::RequestUtil->request; };
148: }
149: if ($request) {
150: $request->child_terminate();
151: } else {
152: &Apache::lonnet::logthis("Unable to find a request to do child_terminate on");
153: }
154: }
155: }
156: return $xmlstring;
157: }
158:
159: sub clean_out_math_mode {
160: my ($texstring)=@_;
161: $$texstring=~s/(?<!\\)\$//g;
162: $$texstring=~s/\\[\)\(\]\[]//g;
163: $$texstring=~s/\\ensuremath//g;
164: return '';
165: }
166:
167: sub displaystyle {
168: my ($texstring)=@_;
169: #has a $$ or \[ or \displaystyle in it, guessinng it's display mode
170: if ($$texstring=~/[^\\]\$\$/ ||
171: $$texstring=~/\\\[/ ||
172: $$texstring=~/\\displaystyle/) { return 1; }
173: return 0;
174: }
175:
176: sub jsMath_converted {
177: my $texstring=shift;
178: my $tag='span';
179: if (&displaystyle($texstring)) { $tag='div'; }
180: &clean_out_math_mode($texstring);
181: return &jsMath_header().
182: '<'.$tag.' class="math">'.$$texstring.'</'.$tag.'>';
183: }
184:
185: {
186: my @jsMath_sent_header;
187: sub jsMath_reset {
188: undef(@jsMath_sent_header);
189: }
190: sub jsMath_push {
191: push(@jsMath_sent_header,0);
192: }
193: sub jsMath_header {
194: if (!@jsMath_sent_header) {
195: &Apache::lonnet::logthis("mismatched calls of jsMath_header and jsMath_process");
196: return '';
197: }
198: return '' if $jsMath_sent_header[-1];
199: $jsMath_sent_header[-1]=1;
200: return
201: '<script type="text/javascript">
202: function NoFontMessage () {}
203: jsMath = {Parser: {prototype: {environments: {\'eqnarray*\' :[\'Array\',null,null,\'rcl\',[5/18,5/18],3,\'D\']}}}};
204: </script>'."\n".
205: '<script type="text/javascript" src="/adm/jsMath/jsMath.js"></script>'."\n";
206: }
207: sub jsMath_process {
208: my $state = pop(@jsMath_sent_header);
209: return '' if !$state;
210: return "\n".
211: '<script type="text/javascript">jsMath.Process()</script>'."\n";
212: }
213: sub jsMath_state {
214: my ($level) = @_;
215: return $jsMath_sent_header[$level];
216: }
217: }
218:
219: sub tex_engine {
220: if (exists($env{'form.texengine'})) {
221: if ($env{'form.texengine'} ne '') {
222: return $env{'form.texengine'};
223: }
224: }
225: if ($env{'request.course.id'}
226: && exists($env{'course.'.$env{'request.course.id'}.'.texengine'})) {
227: return $env{'course.'.$env{'request.course.id'}.'.texengine'};
228: }
229: if (exists($env{'environment.texengine'})) {
230: return $env{'environment.texengine'};
231: }
232: return 'tth';
233: }
234:
235: sub init_math_support {
236: my ($inherit_jsmath) = @_;
237: &init_tth();
238: &Apache::lontexconvert::jsMath_push();
239: if (lc(&tex_engine()) eq 'jsmath' ||
240: ($inherit_jsmath && &jsMath_state(-2))) {
241: return &Apache::lontexconvert::jsMath_header();
242: }
243: return;
244: }
245:
246: sub mimetex_valign {
247: my ($esc_texstring)=@_;
248: my $valign = 0;
249: my $lonhost = $Apache::lonnet::perlvar{'lonHostID'};
250: my $hostname = &Apache::lonnet::hostname($lonhost);
251: my $protocol = $Apache::lonnet::protocol{$lonhost};
252: my $path = '/cgi-bin/mimetex.cgi?'.$esc_texstring;
253: my $socket;
254: &Apache::lonxml::start_alarm();
255: if ($protocol eq 'https') {
256: $socket = IO::Socket::SSL->new(PeerAddr => $hostname,
257: PeerPort => 'https(443)',
258: Proto => 'tcp');
259: } else {
260: $socket = IO::Socket::INET->new(PeerAddr => $hostname,
261: PeerPort => 'http(80)',
262: Proto => 'tcp');
263: }
264: if ($socket) {
265: my $headreq = "HEAD $path HTTP/1.0\r\n\r\n";
266: print $socket $headreq;
267: while (<$socket>) {
268: if (/Vertical\-Align\:\s*?([\-\d]+)/) {
269: $valign = $1;
270: }
271: }
272: if ($protocol eq 'https') {
273: $socket->close(SSL_no_shutdown => 1,
274: SSL_ctx_free => 1);
275: } else {
276: $socket->close();
277: }
278: }
279: &Apache::lonxml::end_alarm();
280: return $valign;
281: }
282:
283: sub mimetex_converted {
284: my $texstring=shift;
285:
286: # Alt-Argument for screen readers
287: my $alt_string=$$texstring;
288: $alt_string=~s/\"/\'\'/g;
289:
290: # Is this displaystyle?
291:
292: my $displaystyle=&displaystyle($texstring);
293:
294: # Remove math environment delimiters
295:
296: &clean_out_math_mode($texstring);
297:
298: if ($displaystyle) {
299: $$texstring='\\displaystyle \\Large '.$$texstring;
300: }
301: my $esc_texstring = &uri_escape($$texstring);
302: my $valign = &mimetex_valign($esc_texstring);
303: my $result='<img src="/cgi-bin/mimetex.cgi?'.$esc_texstring.'" style="vertical-align:'.$valign.'px" alt="'.$alt_string.'" />';
304: if ($displaystyle) {
305: $result='<center>'.$result.'</center>';
306: }
307: return $result;
308: }
309:
310: sub converted {
311: my ($string,$mode)=@_;
312: if ($mode eq '') { $mode = &tex_engine(); }
313: if ($mode =~ /tth/i) {
314: return &tth_converted($string);
315: } elsif ($mode =~ /jsmath/i) {
316: return &jsMath_converted($string);
317: } elsif ($mode =~ /mimetex/i) {
318: return &mimetex_converted($string);
319: }
320: return &tth_converted($string);
321: }
322:
323: # ------------------------------------------------------------ Message display
324:
325: sub to_convert {
326: my ($string) = @_;
327: $string=~s/\<br\s*\/?\>/ /gs;
328: # $string=~s/\s/ /gs;
329: $string=&HTML::Entities::decode($string);
330: return &converted(\$string);
331: }
332:
333: sub smiley {
334: my $expression=shift;
335: if ($env{'browser.imagesuppress'} eq 'on') { return $expression; }
336: my %smileys=('\:\-\)' => 'smiley',
337: '8\-\)' => 'coolsmile',
338: '8\-(I|\|)' => 'coolindiff',
339: ':\-(I|\|)' => 'neutral',
340: '\:\-(o|O|\(\))' => 'shocked',
341: ':\-\(' => 'frowny',
342: '\;\-\)' => 'wink',
343: '\:\-P' => 'baeh',
344: '\:\-(\\\|\\/)' => 'hrrm',
345: '\:\-D' => 'bigsmile',
346: '\:\-C' => 'angry',
347: '\:(\'|\`)\-\(' => 'cry',
348: '\:\-(X|\#)' => 'lipsrsealed',
349: '\:\-S' => 'huh');
350: my $iconpath=$Apache::lonnet::perlvar{'lonIconsURL'};
351: foreach my $smiley (keys(%smileys)) {
352: $expression=~s/$smiley/\<img src="$iconpath\/$smileys{$smiley}.gif" \/\>/gs;
353: }
354: return $expression;
355: }
356:
357: sub msgtexconverted {
358: my ($message,$email) = @_;
359: $errorstring='';
360: &init_tth();
361: my $outmessage='';
362: my $tex=0;
363: foreach my $fragment (split(/(?:\<\;|\<)\/*m\s*(?:\>\;|\>)/i,$message)) {
364: if ($tex) {
365: if ($email) {
366: $outmessage.='</pre><tt>'.&to_convert($fragment).'</tt><pre>';
367: $tex=0;
368: } else {
369: $outmessage.=&to_convert($fragment);
370: $tex=0;
371: }
372: } else {
373: $outmessage.=&smiley($fragment);
374: $tex=1;
375: }
376: }
377: $message=$outmessage; $outmessage=''; $tex=0;
378: foreach my $fragment (split(/(?:\<\;|\<)\/*algebra\s*(?:\>\;|\>)/i,
379: $message)) {
380: if ($tex) {
381: if ($email) {
382: $outmessage.='</pre><tt>'.&algebra($fragment,'web').'</tt><pre>';
383: $tex=0;
384: } else {
385: $outmessage.=&algebra($fragment,'web');
386: $tex=0;
387: }
388: } else {
389: $outmessage.=$fragment;
390: $tex=1;
391: }
392: }
393: if (wantarray) {
394: return ($outmessage,$errorstring);
395: } else {
396: return $outmessage.$errorstring;
397: }
398: }
399:
400: sub algebra {
401: use AlgParser;
402:
403: my ($string,$target,$style,$parstack,$safeeval)=@_;
404: my $parser = new AlgParserWithImplicitExpand;
405: $string=&prepare_algebra($string);
406: my $ret = $parser->parse($string);
407: my $result='['.&mt('Algebra unconverted due to previous errors').']';
408: if ( ref($ret) ) {
409: #$parser->tostring();
410: $parser->normalize();
411: my $latex=$parser->tolatex();
412: $latex=&postprocess_algebra($latex);
413: if ($style eq 'display') {
414: $latex='$$'.$latex.'$$x';
415: } else {
416: # style is 'inline'
417: $latex='\\ensuremath{'.$latex.'}';
418: }
419: if ($target eq 'web' || $target eq 'analyze') {
420: my $display=&Apache::lonxml::get_param('display',$parstack,$safeeval);
421: $result = &converted(\$latex,$display);
422: # $result = &converted(\$latex);
423: } else {
424: $result = $latex;
425: }
426: } else {
427: &Apache::lonxml::error($parser->{'htmlerror'});
428: }
429: }
430:
431: sub prepare_algebra {
432: my ($string)=@_;
433:
434: # makes the decision about what is a minus sign easier supposedly
435: $string =~ s/(\<\>|\<\=|\>\=[\=\>\<] *)-/$1 zeroplace -/g;
436:
437: return $string;
438: }
439:
440: sub postprocess_algebra {
441: my ($string)=@_;
442:
443: # moodle had these and I don't know why, ignoring them for now
444: # $string =~s/\\fun/ /g;
445:
446: # sqrt(3,4) means the 4 root of 3
447: $string =~s/\\sqrt{([^,]+),([^\}]+)}/\\sqrt[$2]{$1}/gs;
448:
449: # log(3,4) means the log base 4 of 3
450: $string =~s/\\log\\left\((.+?),(.+?)\\right\)/\\log_{$2}\\left($1\\right)/gs;
451:
452: # log(3,4) means the log base 4 of 3
453: $string =~s/\\((?:sin|cos|tan|sec|csc|cot)(?:h)?)\\left\((.+?),(.+?)\\right\)/\\$1^{$3}\\left($2\\right)/gs;
454:
455: # int(3,a,b) integral from a to b of 3
456: $string =~s/\\int\\left\((.+?),(.+?),(.+?)\\right\)/\\int_{$2}^{$3}\\left($1\\right)/gs;
457:
458: # int( ... dx) -> ...
459: $string =~s/\\int\\left\((.+?)d[a-z]\\right\)/$1/gs;
460:
461: #
462: $string =~s/\\lim\\left\((.+?),(.+?),(.+?)\\right\)/\\lim_{$2\\to $3}$1/gs;
463: return $string;
464: }
465: 1;
466: __END__
467:
468:
469: =pod
470:
471: =head1 NAME
472:
473: Apache::lontexconvert;
474:
475: =head1 SYNOPSIS
476:
477: Access to tth/ttm
478:
479: This is part of the LearningOnline Network with CAPA project
480: described at http://www.lon-capa.org.
481:
482:
483: =head1 SUBROUTINES
484:
485: =over
486:
487: =item init_tth()
488:
489: Header
490:
491: =item convert_real()
492:
493: we need this routine because &converted can get called from inside
494: of the safespace (through &xmlparse('<m>stuff</m>') which doesn't
495: allow the opcode for alarm, so we need to compile this before we get
496: into the safe space since opcode checks only occur at compile time
497:
498: =item tth_converted()
499:
500:
501: =item clean_out_math_mode()
502:
503:
504: =item displaystyle()
505:
506:
507: =item jsMath_converted()
508:
509:
510: =item tex_engine()
511:
512:
513: =item init_math_support()
514:
515:
516: =item mimetex_converted()
517:
518:
519: =item converted()
520:
521:
522: =item to_convert()
523:
524: message display
525:
526: =item smiley()
527:
528: ???
529:
530: =item msgtexconverted()
531:
532: =item algebra()
533:
534: =item prepare_algebra()
535:
536: =item postprocess_algebra()
537:
538: =back
539:
540: =cut
541:
542:
543:
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