1: # The LearningOnline Network with CAPA
2: # TeX Conversion Module
3: #
4: # $Id: lontexconvert.pm,v 1.120 2017/10/07 00:50:57 raeburn 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($errorstring);
45: #use Apache::lonxml();
46: use Apache::lonlocal;
47: use Apache::lonnet;
48: use lib '/home/httpd/lib/perl/';
49: use LONCAPA;
50: use URI::Escape;
51: use IO::Socket::INET;
52:
53:
54: #
55: # Table of substitutions to unicode characters.
56: #
57:
58: my %unicode_harpoons = (
59: '\rightleftharpoons' => 0x21cc,
60: );
61:
62: my %unicode_translations = (
63:
64: # Brackets - unicode for browsers/OS which support it.
65:
66: '' => 0x23a1,
67: '' => 0x23a2,
68: '' => 0x23a3,
69: '' => 0x23a4,
70: '' => 0x23a5,
71: '' => 0x23a6,
72:
73: # Parens - unicode for browsers/OS which support it
74:
75: '' => 0x239b,
76: '' => 0x239c,
77: '' => 0x239d,
78: '' => 0x239e,
79: '' => 0x239f,
80: '' => 0x23a0,
81:
82: );
83:
84: my %ascii_8bit_translations = (
85:
86: # Brackets - pure 8-bit ascii ugliness for browsers/OS which can't handle unicode
87:
88: '' => 0x5b,
89: '' => 0x5b, # '['
90: '' => 0x5b,
91: '' => 0x5d, # ']'
92: '' => 0x5d,
93: '' => 0x5d,
94:
95: # Parens - pure 8-bit ascii ugliness for browsers/OS which can't handle unicode
96:
97: '' => 0x28,
98: '' => 0x28, # '('
99: '' => 0x28,
100: '' => 0x29,
101: '' => 0x29, # '('
102: '' => 0x29,
103:
104: );
105:
106: ##
107: # Utility to convert elements of a string to unicode:
108: #
109: # @param input - Input string
110: # @param pattern - Pattern to convert
111: # @param unicode - Unicode to substitute for pattern.
112: #
113: # @return string - resulting string.
114: #
115: sub unicode_subst {
116: my ($input, $pattern, $unicode) = @_;
117:
118: my $char = pack('U', $unicode);
119:
120: $input =~ s/$pattern/$char/g;
121:
122: return $input;
123: }
124:
125: # ====================================================================== Header
126:
127: sub init_tth {
128: my $options=$env{'course.'.$env{'request.course.id'}.'.tthoptions'};
129: if ($options =~ /\S/) {
130: $options = ' '.$options;
131: } else {
132: undef($options);
133: }
134: if ($env{'browser.mathml'}) {
135: &tth::ttminit();
136: if ($env{'browser.unicode'}) {
137: &tth::ttmoptions('-L -u1'.$options);
138: } else {
139: &tth::ttmoptions('-L -u0'.$options);
140: }
141: } else {
142: &tth::tthinit();
143: if ($env{'browser.unicode'}) {
144: &tth::tthoptions('-L -u1'.$options);
145: } else {
146: &tth::tthoptions('-L -u0'.$options);
147: }
148: }
149: }
150:
151: # ================================================================== Conversion
152:
153: $Apache::lontexconvert::messedup=0;
154:
155:
156: sub convert_real {
157: my ($texstring)=@_;
158: my ($xmlstring,$errorstring);
159: local $SIG{SEGV}=sub { $Apache::lontexconvert::messedup=1; die; };
160: local $SIG{ALRM}=sub {
161: &Apache::lonnet::logthis("ALRM");
162: $xmlstring='['.&mt("TeX unconverted due to errors").']';
163: $Apache::lontexconvert::messedup=1;
164: die &mt("TeX unconverted due to errors");
165: };
166: &Apache::lonxml::start_alarm();
167: if ($env{'browser.mathml'}) {
168: $xmlstring=&tth::ttm($$texstring);
169: $xmlstring=~s/\<math\>/\<math xmlns=\"\&mathns\;\"\>/g;
170: $xmlstring=~s/\<br\>/\<br\/\>/g;
171: $xmlstring=~s/\<p\>/\<p\>\<\/p\>/g;
172: $errorstring.=&tth::ttmerror();
173: } else {
174: $xmlstring=&tth::tth($$texstring);
175: $errorstring.=&tth::ttherror();
176: $xmlstring=~s-</font(\s*)>-</font>-g;
177: }
178: $xmlstring=~s/^\s*\<br clear\=\"all\"/\<br/s;
179: $xmlstring=~s/^\s*//;
180: $xmlstring=~s/\s*$//;
181: $xmlstring=~s/^<br \/><table/<table/;
182: &Apache::lonxml::end_alarm();
183:
184: #
185: # Several strings produced by tth require
186: # transliteration -> unicode equivalents to render reliably
187: # in browsers. %unicode_translations and %unicode_harpoons are tables of
188: # string->substitution which we now apply. (%ascii_8bit_translations used
189: # instead for Windows XP and mobile devices.
190:
191: my $use_ascii;
192: if ($env{'browser.os'} eq 'win') {
193: if (($env{'browser.osversion'}) && ($env{'browser.osversion'} < 6.0)) {
194: $use_ascii = 1;
195: }
196: }
197: if ($env{'browser.mobile'}) {
198: $use_ascii = 1;
199: }
200:
201: foreach my $pattern (keys(%unicode_translations)) {
202: my $unicode = $unicode_translations{$pattern};
203: if ($use_ascii) {
204: $unicode = $ascii_8bit_translations{$pattern};
205: }
206: $xmlstring = &unicode_subst($xmlstring, $pattern, $unicode);
207: }
208:
209: foreach my $pattern (keys(%unicode_harpoons)) {
210: $xmlstring = &unicode_subst($xmlstring, $pattern, $unicode_harpoons{$pattern});
211: }
212:
213: return ($xmlstring,$errorstring);
214: }
215:
216: sub tth_converted {
217: my $texstring=shift;
218: my $xmlstring='['.&mt('UNDISPLAYABLE').']';
219: if ($Apache::lontexconvert::messedup) {
220: return '['.&mt('TeX unconverted due to previous errors').']';
221: }
222: $$texstring ='\\documentstyle{article}'.$$texstring;
223:
224: eval(<<'ENDCONV');
225: ($xmlstring,$errorstring)=&convert_real($texstring)
226: ENDCONV
227: if ($@) {
228: $errorstring.=&mt("Evaluation Error: ").$@;
229: $Apache::lontexconvert::messedup=1;
230: }
231: if ($Apache::lontexconvert::messedup || &tth::tthmessedup() ||
232: $errorstring) {
233: &Apache::lonnet::logthis("Trying to kill myself");
234: $Apache::lontexconvert::messedup=1;
235: if (ref($Apache::lonxml::request)) {
236: $Apache::lonxml::request->child_terminate();
237: } else {
238: my $request;
239: eval { $request=Apache->request; };
240: if (!$request) {
241: eval { $request=Apache2::RequestUtil->request; };
242: }
243: if ($request) {
244: $request->child_terminate();
245: } else {
246: &Apache::lonnet::logthis("Unable to find a request to do child_terminate on");
247: }
248: }
249: }
250: return $xmlstring;
251: }
252:
253: sub clean_out_math_mode {
254: my ($texstring)=@_;
255: $$texstring=~s/(?<!\\)\$//g;
256: $$texstring=~s/\\[\)\(\]\[]//g;
257: $$texstring=~s/\\ensuremath//g;
258: return '';
259: }
260:
261: sub displaystyle {
262: my ($texstring)=@_;
263: #has a $$ or \[ or \displaystyle or eqnarray in it, guessinng it's display mode
264: if ($$texstring=~/[^\\]\$\$/ ||
265: $$texstring=~/\\\[/ ||
266: $$texstring=~/\\displaystyle/ ||
267: $$texstring=~/eqnarray/
268: ) { return 1; }
269: return 0;
270: }
271:
272: sub MathJax_converted {
273: my $texstring=shift;
274: my $tag='math/tex;';
275: if (&displaystyle($texstring)) { $tag='math/tex; mode=display'; }
276: &clean_out_math_mode($texstring);
277: return &MathJax_header().
278: '<script type="'.$tag.'">'.$$texstring.'</script>';
279: }
280:
281: {
282: #Relies heavily on the previous jsMath installation
283: my @MathJax_sent_header;
284: sub MathJax_reset {
285: undef(@MathJax_sent_header);
286: }
287: sub MathJax_push {
288: push(@MathJax_sent_header,0);
289: }
290: sub MathJax_header {
291: if (!@MathJax_sent_header) {
292: &Apache::lonnet::logthis("mismatched calls of MathJax_header and MathJax_process");
293: return '';
294: }
295: return '' if $MathJax_sent_header[-1];
296: $MathJax_sent_header[-1]=1;
297: return
298: '<script type="text/javascript" src="/adm/MathJax/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>'."\n";
299: }
300: #sub MathJax_process {
301: # my $state = pop(@MathJax_sent_header);
302: # return '' if !$state;
303: # return "\n".
304: # '<script type="text/javascript">MathJax.Process()</script>'."\n";
305: #}
306: #sub MathJax_state {
307: # my ($level) = @_;
308: # return $MathJax_sent_header[$level];
309: #}
310: }
311:
312: sub tex_engine {
313: if (exists($env{'form.texengine'})) {
314: if ($env{'form.texengine'} ne '') {
315: if (lc($env{'form.texengine'}) eq 'jsmath') {
316: return 'MathJax';
317: }
318: return $env{'form.texengine'};
319: }
320: }
321: if ($env{'request.course.id'}
322: && exists($env{'course.'.$env{'request.course.id'}.'.texengine'})) {
323: if (lc($env{'course.'.$env{'request.course.id'}.'.texengine'}) eq 'jsmath') {
324: return 'MathJax';
325: }
326: return $env{'course.'.$env{'request.course.id'}.'.texengine'};
327: }
328: if (exists($env{'environment.texengine'})) {
329: if (lc($env{'environment.texengine'}) eq 'jsmath') {
330: return 'MathJax';
331: }
332: return $env{'environment.texengine'};
333: }
334: my $dom = $env{'request.role.domain'} || $env{'user.domain'};
335: my %domdefaults = &Apache::lonnet::get_domain_defaults($dom);
336: if ($domdefaults{'texengine'} ne '') {
337: return $domdefaults{'texengine'};
338: }
339: return 'MathJax';
340: }
341:
342: sub init_math_support {
343: &init_tth();
344: &Apache::lontexconvert::MathJax_push();
345: if (lc(&tex_engine()) eq 'mathjax') {
346: return &Apache::lontexconvert::MathJax_header();
347: }
348: return;
349: }
350:
351: sub mimetex_valign {
352: my ($esc_texstring)=@_;
353: my $valign = 0;
354: my $path = '/cgi-bin/mimetex.cgi?'.$esc_texstring;
355: my $socket;
356: &Apache::lonxml::start_alarm();
357: $socket = IO::Socket::INET->new(PeerAddr => 'localhost',
358: PeerPort => 'http(80)',
359: Proto => 'tcp');
360: if ($socket) {
361: my $headreq = "HEAD $path HTTP/1.0\r\n\r\n";
362: print $socket $headreq;
363: while (<$socket>) {
364: if (/Vertical\-Align\:\s*?([\-\d]+)/) {
365: $valign = $1;
366: }
367: }
368: $socket->close();
369: }
370: &Apache::lonxml::end_alarm();
371: return $valign;
372: }
373:
374: sub mimetex_converted {
375: my $texstring=shift;
376:
377: # Alt-Argument for screen readers
378: my $alt_string=$$texstring;
379: $alt_string=~s/\"/\'\'/g;
380:
381: # Is this displaystyle?
382:
383: my $displaystyle=&displaystyle($texstring);
384:
385: # Remove math environment delimiters
386:
387: &clean_out_math_mode($texstring);
388:
389: if ($displaystyle) {
390: $$texstring='\\displaystyle \\Large '.$$texstring;
391: }
392: my $esc_texstring = &uri_escape($$texstring);
393: my $valign = &mimetex_valign($esc_texstring);
394: my $result='<img src="/cgi-bin/mimetex.cgi?'.$esc_texstring.'" style="vertical-align:'.$valign.'px" alt="'.$alt_string.'" />';
395: if ($displaystyle) {
396: $result='<div style="text-align:center">'.$result.'</div>';
397: }
398: return $result;
399: }
400:
401: sub converted {
402: my ($string,$mode)=@_;
403: if ($mode eq '') { $mode = &tex_engine(); }
404: if ($mode =~ /tth/i) {
405: return &tth_converted($string);
406: } elsif ($mode =~ /jsmath/i) {
407: return &MathJax_converted($string);
408: } elsif ($mode =~ /mathjax/i) {
409: return &MathJax_converted($string);
410: } elsif ($mode =~ /mimetex/i) {
411: return &mimetex_converted($string);
412: } elsif ($mode =~ /raw/i) {
413: return $$string;
414: }
415: return &tth_converted($string);
416: }
417:
418: # ------------------------------------------------------------ Message display
419:
420: sub to_convert {
421: my ($string) = @_;
422: &init_tth();
423: $string=~s/\<br\s*\/?\>/ /gs;
424: # $string=~s/\s/ /gs;
425: $string=&HTML::Entities::decode($string);
426: return &converted(\$string);
427: }
428:
429: sub smiley {
430: my $expression=shift;
431: my %smileys=(
432: '\:\-*\)' => 'face-smile.png',
433: '8\-\)' => 'face-cool.png',
434: '8\-(I|\|)' => 'face-glasses.png',
435: '\:\-(I|\|)' => 'face-plain.png',
436: '\:\-(o|O|\(\))' => 'face-surprise.png',
437: ':\-\(' => 'face-sad.png',
438: '\;\-\)' => 'face-wink.png',
439: '\:\-(P|p)' => 'face-raspberry.png',
440: '\:\-(\\\|\\/)' => 'face-uncertain.png',
441: '\:\-D' => 'face-smile-big.png',
442: '\:\-(C|\@)' => 'face-angry.png',
443: '\:(\'|\`)\-*\(' => 'face-crying.png',
444: '\:\-(X|x|\#)' => 'face-quiet.png',
445: '\:\-(s|S)' => 'face-uncertain.png',
446: '\:\-\$' => 'face-embarrassed.png',
447: '\:\-\*' => 'face-kiss.png',
448: '\+O\(' => 'face-sick.png',
449: '(\<\;3|\(heart\))' => 'heart.png',
450: '\(rose\)' => 'rose.png',
451: '\(pizza\)' => 'food-pizza.png',
452: '\(cake\)' => 'food-cake.png',
453: '\(ninja\)' => 'face-ninja.png',
454: '\(pirate\)' => 'face-pirate.png',
455: '\((agree|yes)\)' => 'opinion-agree.png',
456: '\((disagree|nay)\)' => 'opinion-disagree.png',
457: '(o|O)\-\)' => 'face-angel.png',
458: );
459: my $iconpath=$Apache::lonnet::perlvar{'lonIconsURL'};
460: foreach my $smiley (keys(%smileys)) {
461: $expression=~s/$smiley/\<img src="$iconpath\/$smileys{$smiley}" \/\>/gs;
462: }
463: return $expression;
464: }
465:
466: sub msgtexconverted {
467: my ($message,$email) = @_;
468: $errorstring='';
469: my $outmessage='';
470: my $tex=0;
471: foreach my $fragment (split(/(?:\<\;|\<)\/*m\s*(?:\>\;|\>)/i,$message)) {
472: if ($tex) {
473: if ($email) {
474: $outmessage.='</pre><tt>'.&to_convert($fragment).'</tt><pre>';
475: $tex=0;
476: } else {
477: $outmessage.=&to_convert($fragment);
478: $tex=0;
479: }
480: } else {
481: $outmessage.=&smiley($fragment);
482: $tex=1;
483: }
484: }
485: $message=$outmessage; $outmessage=''; $tex=0;
486: foreach my $fragment (split(/(?:\<\;|\<)\/*algebra\s*(?:\>\;|\>)/i,
487: $message)) {
488: if ($tex) {
489: my $algebra = &algebra($fragment, 'web', undef, undef, undef, 'tth');
490: if ($email) {
491: $outmessage.='</pre><tt>'.$algebra.'</tt><pre>';
492: $tex=0;
493: } else {
494: $outmessage.=$algebra;
495: $tex=0;
496: }
497: } else {
498: $outmessage.=$fragment;
499: $tex=1;
500: }
501: }
502: if (wantarray) {
503: return ($outmessage,$errorstring);
504: } else {
505: return $outmessage.$errorstring;
506: }
507: }
508:
509: sub algebra {
510: use AlgParser;
511: my ($string,$target,$style,$parstack,$safeeval,$tth)=@_;
512: my $parser = new AlgParserWithImplicitExpand;
513: if ($tth eq 'tth') {&init_tth();}
514: $string=&prepare_algebra($string);
515: my $ret = $parser->parse($string);
516: my $result='['.&mt('Algebra unconverted due to previous errors').']';
517: if ( ref($ret) ) {
518: #$parser->tostring();
519: $parser->normalize();
520: my $latex=$parser->tolatex();
521: $latex=&postprocess_algebra($latex);
522: if ($style eq 'display') {
523: $latex='$$'.$latex.'$$x';
524: } else {
525: # style is 'inline'
526: $latex='\\ensuremath{'.$latex.'}';
527: }
528: if ($target eq 'web' || $target eq 'analyze') {
529: my $display=&Apache::lonxml::get_param('display',$parstack,$safeeval);
530: $result = &converted(\$latex,$display);
531: # $result = &converted(\$latex);
532: } else {
533: $result = $latex;
534: }
535: } else {
536: &Apache::lonxml::error($parser->{'htmlerror'});
537: }
538: }
539:
540: sub prepare_algebra {
541: my ($string)=@_;
542:
543: # makes the decision about what is a minus sign easier supposedly
544: $string =~ s/(\<\>|\<\=|\>\=[\=\>\<] *)-/$1 zeroplace -/g;
545:
546: return $string;
547: }
548:
549: sub postprocess_algebra {
550: my ($string)=@_;
551:
552: # moodle had these and I don't know why, ignoring them for now
553: # $string =~s/\\fun/ /g;
554:
555: # sqrt(3,4) means the 4 root of 3
556: $string =~s/\\sqrt\{([^,]+),([^\}]+)}/\\sqrt[$2]{$1}/gs;
557:
558: # log(3,4) means the log base 4 of 3
559: $string =~s/\\log\\left\((.+?),(.+?)\\right\)/\\log_{$2}\\left($1\\right)/gs;
560:
561: # log(3,4) means the log base 4 of 3
562: $string =~s/\\((?:sin|cos|tan|sec|csc|cot)(?:h)?)\\left\((.+?),(.+?)\\right\)/\\$1^{$3}\\left($2\\right)/gs;
563:
564: # int(3,a,b) integral from a to b of 3
565: $string =~s/\\int\\left\((.+?),(.+?),(.+?)\\right\)/\\int_{$2}^{$3}\\left($1\\right)/gs;
566:
567: # int( ... dx) -> ...
568: $string =~s/\\int\\left\((.+?)d[a-z]\\right\)/$1/gs;
569:
570: #
571: $string =~s/\\lim\\left\((.+?),(.+?),(.+?)\\right\)/\\lim_{$2\\to $3}$1/gs;
572: return $string;
573: }
574:
575:
576: 1;
577: __END__
578:
579:
580: =pod
581:
582: =head1 NAME
583:
584: Apache::lontexconvert;
585:
586: =head1 SYNOPSIS
587:
588: Access to tth/ttm
589:
590: This is part of the LearningOnline Network with CAPA project
591: described at http://www.lon-capa.org.
592:
593:
594: =head1 SUBROUTINES
595:
596: =over
597:
598: =item init_tth()
599:
600: Header
601:
602: =item convert_real()
603:
604: we need this routine because &converted can get called from inside
605: of the safespace (through &xmlparse('<m>stuff</m>') which doesn't
606: allow the opcode for alarm, so we need to compile this before we get
607: into the safe space since opcode checks only occur at compile time
608:
609: =item tth_converted()
610:
611:
612: =item clean_out_math_mode()
613:
614:
615: =item displaystyle()
616:
617:
618: =item MathJax_converted()
619:
620: =item tex_engine()
621:
622: =item init_math_support()
623:
624: =item mimetex_valign()
625:
626: Makes a HEAD call to /cgi-bin/mimetex.cgi via IO:: to retrieve the
627: vertical alignment, before the subsequent call to mimetex_converted()
628: which generates the <img> tag and the corresponding image.
629:
630: Input: 1. $esc_texstring (escaped TeX to be rendered by mimetex).
631: Output: 1. $valign - number of pixels: positive or negative integer
632: which will be included in <img> tag for mimetex image to
633: support vertical alignment of image within a line of text.
634:
635: If a server is running SSL, and Apache rewrite rules are in place
636: to rewrite requests for http to https, modification will most likely
637: be needed for pass through for HEAD requests for /cgi-bin/mimetex.cgi.
638:
639: Example rewrite rules which rewrite all http traffic to https,
640: except HEAD requests for /cgi-bin/mimetex.cgi are:
641:
642: <IfModule mod_rewrite.c>
643: RewriteEngine On
644: RewriteLogLevel 0
645:
646: RewriteCond %{HTTPS} off
647: RewriteCond %{HTTP:Host} (.*)
648: RewriteCond %{REQUEST_METHOD} !HEAD
649: RewriteRule ^/(.*) https://%1/$1 [R=301,L]
650:
651: RewriteCond %{HTTPS} off
652: RewriteCond %{HTTP:Host} (.*)
653: RewriteCond %{REQUEST_METHOD} HEAD
654: RewriteCond %{REQUEST_URI} !^/cgi-bin/mimetex.cgi
655: RewriteRule ^/(.*) https://%1/$1 [R=301,L]
656: </IfModule>
657:
658: =item mimetex_converted()
659:
660:
661: =item converted()
662:
663:
664: =item to_convert()
665:
666: message display
667:
668: =item smiley()
669:
670: ???
671:
672: =item msgtexconverted()
673:
674: =item algebra()
675:
676: =item prepare_algebra()
677:
678: =item postprocess_algebra()
679:
680: =back
681:
682: =cut
683:
684:
685:
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