1: # The LearningOnline Network with CAPA
2: # TeX Conversion Module
3: #
4: # $Id: lontexconvert.pm,v 1.112.2.6 2016/08/05 21:24:01 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: &Apache::lonxml::end_alarm();
182:
183: #
184: # Several strings produced by tth require
185: # transliteration -> unicode equivalents to render reliably
186: # in browsers. %unicode_translations and %unicode_harpoons are tables of
187: # string->substitution which we now apply. (%ascii_8bit_translations used
188: # instead for Windows XP and mobile devices.
189:
190: my $use_ascii;
191: if ($env{'browser.os'} eq 'win') {
192: if (($env{'browser.osversion'}) && ($env{'browser.osversion'} < 6.0)) {
193: $use_ascii = 1;
194: }
195: }
196: if ($env{'browser.mobile'}) {
197: $use_ascii = 1;
198: }
199:
200: foreach my $pattern (keys(%unicode_translations)) {
201: my $unicode = $unicode_translations{$pattern};
202: if ($use_ascii) {
203: $unicode = $ascii_8bit_translations{$pattern};
204: }
205: $xmlstring = &unicode_subst($xmlstring, $pattern, $unicode);
206: }
207:
208: foreach my $pattern (keys(%unicode_harpoons)) {
209: $xmlstring = &unicode_subst($xmlstring, $pattern, $unicode_harpoons{$pattern});
210: }
211:
212: return ($xmlstring,$errorstring);
213: }
214:
215: sub tth_converted {
216: my $texstring=shift;
217: my $xmlstring='['.&mt('UNDISPLAYABLE').']';
218: if ($Apache::lontexconvert::messedup) {
219: return '['.&mt('TeX unconverted due to previous errors').']';
220: }
221: $$texstring ='\\documentstyle{article}'.$$texstring;
222:
223: eval(<<'ENDCONV');
224: ($xmlstring,$errorstring)=&convert_real($texstring)
225: ENDCONV
226: if ($@) {
227: $errorstring.=&mt("Evaluation Error: ").$@;
228: $Apache::lontexconvert::messedup=1;
229: }
230: if ($Apache::lontexconvert::messedup || &tth::tthmessedup() ||
231: $errorstring) {
232: &Apache::lonnet::logthis("Trying to kill myself");
233: $Apache::lontexconvert::messedup=1;
234: if (ref($Apache::lonxml::request)) {
235: $Apache::lonxml::request->child_terminate();
236: } else {
237: my $request;
238: eval { $request=Apache->request; };
239: if (!$request) {
240: eval { $request=Apache2::RequestUtil->request; };
241: }
242: if ($request) {
243: $request->child_terminate();
244: } else {
245: &Apache::lonnet::logthis("Unable to find a request to do child_terminate on");
246: }
247: }
248: }
249: return $xmlstring;
250: }
251:
252: sub clean_out_math_mode {
253: my ($texstring)=@_;
254: $$texstring=~s/(?<!\\)\$//g;
255: $$texstring=~s/\\[\)\(\]\[]//g;
256: $$texstring=~s/\\ensuremath//g;
257: return '';
258: }
259:
260: sub displaystyle {
261: my ($texstring)=@_;
262: #has a $$ or \[ or \displaystyle or eqnarray in it, guessinng it's display mode
263: if ($$texstring=~/[^\\]\$\$/ ||
264: $$texstring=~/\\\[/ ||
265: $$texstring=~/\\displaystyle/ ||
266: $$texstring=~/eqnarray/
267: ) { return 1; }
268: return 0;
269: }
270:
271: sub MathJax_converted {
272: my $texstring=shift;
273: my $tag='math/tex;';
274: if (&displaystyle($texstring)) { $tag='math/tex; mode=display'; }
275: &clean_out_math_mode($texstring);
276: return &MathJax_header().
277: '<script type="'.$tag.'">'.$$texstring.'</script>';
278: }
279:
280: {
281: #Relies heavily on the previous jsMath installation
282: my @MathJax_sent_header;
283: sub MathJax_reset {
284: undef(@MathJax_sent_header);
285: }
286: sub MathJax_push {
287: push(@MathJax_sent_header,0);
288: }
289: sub MathJax_header {
290: if (!@MathJax_sent_header) {
291: &Apache::lonnet::logthis("mismatched calls of MathJax_header and MathJax_process");
292: return '';
293: }
294: return '' if $MathJax_sent_header[-1];
295: $MathJax_sent_header[-1]=1;
296: return
297: '<script type="text/javascript" src="/adm/MathJax/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>'."\n";
298: }
299: }
300:
301: sub tex_engine {
302: if (exists($env{'form.texengine'})) {
303: if ($env{'form.texengine'} ne '') {
304: if (lc($env{'form.texengine'}) eq 'jsmath') {
305: return 'MathJax';
306: }
307: return $env{'form.texengine'};
308: }
309: }
310: if ($env{'request.course.id'}
311: && exists($env{'course.'.$env{'request.course.id'}.'.texengine'})) {
312: if (lc($env{'course.'.$env{'request.course.id'}.'.texengine'}) eq 'jsmath') {
313: return 'MathJax';
314: }
315: return $env{'course.'.$env{'request.course.id'}.'.texengine'};
316: }
317: if (exists($env{'environment.texengine'})) {
318: if (lc($env{'environment.texengine'}) eq 'jsmath') {
319: return 'MathJax';
320: }
321: return $env{'environment.texengine'};
322: }
323: return 'tth';
324: }
325:
326: sub init_math_support {
327: &init_tth();
328: &Apache::lontexconvert::MathJax_push();
329: if (lc(&tex_engine()) eq 'mathjax') {
330: return &Apache::lontexconvert::MathJax_header();
331: }
332: return;
333: }
334:
335: sub mimetex_valign {
336: my ($esc_texstring)=@_;
337: my $valign = 0;
338: my $path = '/cgi-bin/mimetex.cgi?'.$esc_texstring;
339: my $socket;
340: &Apache::lonxml::start_alarm();
341: $socket = IO::Socket::INET->new(PeerAddr => 'localhost',
342: PeerPort => 'http(80)',
343: Proto => 'tcp');
344: if ($socket) {
345: my $headreq = "HEAD $path HTTP/1.0\r\n\r\n";
346: print $socket $headreq;
347: while (<$socket>) {
348: if (/Vertical\-Align\:\s*?([\-\d]+)/) {
349: $valign = $1;
350: }
351: }
352: $socket->close();
353: }
354: &Apache::lonxml::end_alarm();
355: return $valign;
356: }
357:
358: sub mimetex_converted {
359: my $texstring=shift;
360:
361: # Alt-Argument for screen readers
362: my $alt_string=$$texstring;
363: $alt_string=~s/\"/\'\'/g;
364:
365: # Is this displaystyle?
366:
367: my $displaystyle=&displaystyle($texstring);
368:
369: # Remove math environment delimiters
370:
371: &clean_out_math_mode($texstring);
372:
373: if ($displaystyle) {
374: $$texstring='\\displaystyle \\Large '.$$texstring;
375: }
376: my $esc_texstring = &uri_escape($$texstring);
377: my $valign = &mimetex_valign($esc_texstring);
378: my $result='<img src="/cgi-bin/mimetex.cgi?'.$esc_texstring.'" style="vertical-align:'.$valign.'px" alt="'.$alt_string.'" />';
379: if ($displaystyle) {
380: $result='<div style="text-align:center">'.$result.'</div>';
381: }
382: return $result;
383: }
384:
385: sub converted {
386: my ($string,$mode)=@_;
387: if ($mode eq '') { $mode = &tex_engine(); }
388: if ($mode =~ /tth/i) {
389: return &tth_converted($string);
390: } elsif ($mode =~ /jsmath/i) {
391: return &MathJax_converted($string);
392: } elsif ($mode =~ /mathjax/i) {
393: return &MathJax_converted($string);
394: } elsif ($mode =~ /mimetex/i) {
395: return &mimetex_converted($string);
396: } elsif ($mode =~ /raw/i) {
397: return $$string;
398: }
399: return &tth_converted($string);
400: }
401:
402: # ------------------------------------------------------------ Message display
403:
404: sub to_convert {
405: my ($string) = @_;
406: &init_tth();
407: $string=~s/\<br\s*\/?\>/ /gs;
408: # $string=~s/\s/ /gs;
409: $string=&HTML::Entities::decode($string);
410: return &converted(\$string);
411: }
412:
413: sub smiley {
414: my $expression=shift;
415: my %smileys=(
416: '\:\-*\)' => 'face-smile.png',
417: '8\-\)' => 'face-cool.png',
418: '8\-(I|\|)' => 'face-glasses.png',
419: '\:\-(I|\|)' => 'face-plain.png',
420: '\:\-(o|O|\(\))' => 'face-surprise.png',
421: ':\-\(' => 'face-sad.png',
422: '\;\-\)' => 'face-wink.png',
423: '\:\-(P|p)' => 'face-raspberry.png',
424: '\:\-(\\\|\\/)' => 'face-uncertain.png',
425: '\:\-D' => 'face-smile-big.png',
426: '\:\-(C|\@)' => 'face-angry.png',
427: '\:(\'|\`)\-*\(' => 'face-crying.png',
428: '\:\-(X|x|\#)' => 'face-quiet.png',
429: '\:\-(s|S)' => 'face-uncertain.png',
430: '\:\-\$' => 'face-embarrassed.png',
431: '\:\-\*' => 'face-kiss.png',
432: '\+O\(' => 'face-sick.png',
433: '(\<\;3|\(heart\))' => 'heart.png',
434: '\(rose\)' => 'rose.png',
435: '\(pizza\)' => 'food-pizza.png',
436: '\(cake\)' => 'food-cake.png',
437: '\(ninja\)' => 'face-ninja.png',
438: '\(pirate\)' => 'face-pirate.png',
439: '\((agree|yes)\)' => 'opinion-agree.png',
440: '\((disagree|nay)\)' => 'opinion-disagree.png',
441: '(o|O)\-\)' => 'face-angel.png',
442: );
443: my $iconpath=$Apache::lonnet::perlvar{'lonIconsURL'};
444: foreach my $smiley (keys(%smileys)) {
445: $expression=~s/$smiley/\<img src="$iconpath\/$smileys{$smiley}" \/\>/gs;
446: }
447: return $expression;
448: }
449:
450: sub msgtexconverted {
451: my ($message,$email) = @_;
452: $errorstring='';
453: my $outmessage='';
454: my $tex=0;
455: foreach my $fragment (split(/(?:\<\;|\<)\/*m\s*(?:\>\;|\>)/i,$message)) {
456: if ($tex) {
457: if ($email) {
458: $outmessage.='</pre><tt>'.&to_convert($fragment).'</tt><pre>';
459: $tex=0;
460: } else {
461: $outmessage.=&to_convert($fragment);
462: $tex=0;
463: }
464: } else {
465: $outmessage.=&smiley($fragment);
466: $tex=1;
467: }
468: }
469: $message=$outmessage; $outmessage=''; $tex=0;
470: foreach my $fragment (split(/(?:\<\;|\<)\/*algebra\s*(?:\>\;|\>)/i,
471: $message)) {
472: if ($tex) {
473: my $algebra = &algebra($fragment, 'web', undef, undef, undef, 'tth');
474: if ($email) {
475: $outmessage.='</pre><tt>'.$algebra.'</tt><pre>';
476: $tex=0;
477: } else {
478: $outmessage.=$algebra;
479: $tex=0;
480: }
481: } else {
482: $outmessage.=$fragment;
483: $tex=1;
484: }
485: }
486: if (wantarray) {
487: return ($outmessage,$errorstring);
488: } else {
489: return $outmessage.$errorstring;
490: }
491: }
492:
493: sub algebra {
494: use AlgParser;
495: my ($string,$target,$style,$parstack,$safeeval,$tth)=@_;
496: my $parser = new AlgParserWithImplicitExpand;
497: if ($tth eq 'tth') {&init_tth();}
498: $string=&prepare_algebra($string);
499: my $ret = $parser->parse($string);
500: my $result='['.&mt('Algebra unconverted due to previous errors').']';
501: if ( ref($ret) ) {
502: #$parser->tostring();
503: $parser->normalize();
504: my $latex=$parser->tolatex();
505: $latex=&postprocess_algebra($latex);
506: if ($style eq 'display') {
507: $latex='$$'.$latex.'$$x';
508: } else {
509: # style is 'inline'
510: $latex='\\ensuremath{'.$latex.'}';
511: }
512: if ($target eq 'web' || $target eq 'analyze') {
513: my $display=&Apache::lonxml::get_param('display',$parstack,$safeeval);
514: $result = &converted(\$latex,$display);
515: # $result = &converted(\$latex);
516: } else {
517: $result = $latex;
518: }
519: } else {
520: &Apache::lonxml::error($parser->{'htmlerror'});
521: }
522: }
523:
524: sub prepare_algebra {
525: my ($string)=@_;
526:
527: # makes the decision about what is a minus sign easier supposedly
528: $string =~ s/(\<\>|\<\=|\>\=[\=\>\<] *)-/$1 zeroplace -/g;
529:
530: return $string;
531: }
532:
533: sub postprocess_algebra {
534: my ($string)=@_;
535:
536: # moodle had these and I don't know why, ignoring them for now
537: # $string =~s/\\fun/ /g;
538:
539: # sqrt(3,4) means the 4 root of 3
540: $string =~s/\\sqrt\{([^,]+),([^\}]+)}/\\sqrt[$2]{$1}/gs;
541:
542: # log(3,4) means the log base 4 of 3
543: $string =~s/\\log\\left\((.+?),(.+?)\\right\)/\\log_{$2}\\left($1\\right)/gs;
544:
545: # log(3,4) means the log base 4 of 3
546: $string =~s/\\((?:sin|cos|tan|sec|csc|cot)(?:h)?)\\left\((.+?),(.+?)\\right\)/\\$1^{$3}\\left($2\\right)/gs;
547:
548: # int(3,a,b) integral from a to b of 3
549: $string =~s/\\int\\left\((.+?),(.+?),(.+?)\\right\)/\\int_{$2}^{$3}\\left($1\\right)/gs;
550:
551: # int( ... dx) -> ...
552: $string =~s/\\int\\left\((.+?)d[a-z]\\right\)/$1/gs;
553:
554: #
555: $string =~s/\\lim\\left\((.+?),(.+?),(.+?)\\right\)/\\lim_{$2\\to $3}$1/gs;
556: return $string;
557: }
558:
559:
560: 1;
561: __END__
562:
563:
564: =pod
565:
566: =head1 NAME
567:
568: Apache::lontexconvert;
569:
570: =head1 SYNOPSIS
571:
572: Access to tth/ttm
573:
574: This is part of the LearningOnline Network with CAPA project
575: described at http://www.lon-capa.org.
576:
577:
578: =head1 SUBROUTINES
579:
580: =over
581:
582: =item init_tth()
583:
584: Header
585:
586: =item convert_real()
587:
588: we need this routine because &converted can get called from inside
589: of the safespace (through &xmlparse('<m>stuff</m>') which doesn't
590: allow the opcode for alarm, so we need to compile this before we get
591: into the safe space since opcode checks only occur at compile time
592:
593: =item tth_converted()
594:
595:
596: =item clean_out_math_mode()
597:
598:
599: =item displaystyle()
600:
601:
602: =item MathJax_converted()
603:
604: =item tex_engine()
605:
606: =item init_math_support()
607:
608: =item mimetex_valign()
609:
610: Makes a HEAD call to /cgi-bin/mimetex.cgi via IO:: to retrieve the
611: vertical alignment, before the subsequent call to mimetex_converted()
612: which generates the <img> tag and the corresponding image.
613:
614: Input: 1. $esc_texstring (escaped TeX to be rendered by mimetex).
615: Output: 1. $valign - number of pixels: positive or negative integer
616: which will be included in <img> tag for mimetex image to
617: support vertical alignment of image within a line of text.
618:
619: If a server is running SSL, and Apache rewrite rules are in place
620: to rewrite requests for http to https, modification will most likely
621: be needed for pass through for HEAD requests for /cgi-bin/mimetex.cgi.
622:
623: Example rewrite rules which rewrite all http traffic to https,
624: except HEAD requests for /cgi-bin/mimetex.cgi are:
625:
626: <IfModule mod_rewrite.c>
627: RewriteEngine On
628: RewriteLogLevel 0
629:
630: RewriteCond %{HTTPS} off
631: RewriteCond %{HTTP:Host} (.*)
632: RewriteCond %{REQUEST_METHOD} !HEAD
633: RewriteRule ^/(.*) https://%1/$1 [R=301,L]
634:
635: RewriteCond %{HTTPS} off
636: RewriteCond %{HTTP:Host} (.*)
637: RewriteCond %{REQUEST_METHOD} HEAD
638: RewriteCond %{REQUEST_URI} !^/cgi-bin/mimetex.cgi
639: RewriteRule ^/(.*) https://%1/$1 [R=301,L]
640: </IfModule>
641:
642: =item mimetex_converted()
643:
644:
645: =item converted()
646:
647:
648: =item to_convert()
649:
650: message display
651:
652: =item smiley()
653:
654: ???
655:
656: =item msgtexconverted()
657:
658: =item algebra()
659:
660: =item prepare_algebra()
661:
662: =item postprocess_algebra()
663:
664: =back
665:
666: =cut
667:
668:
669:
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