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added implementation for <lm>

    1: # The LearningOnline Network with CAPA 
    2: # <lm>: math with the LON-CAPA syntax
    3: #
    4: # $Id: loncapamath.pm,v 1.1 2015/06/29 15:42:07 damieng 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: 
   29: 
   30: package Apache::loncapamath; 
   31: 
   32: use strict;
   33: use warnings;
   34: use utf8;
   35: 
   36: use Try::Tiny;
   37: 
   38: use aliased 'Apache::math_parser::CalcException';
   39: use aliased 'Apache::math_parser::ParseException';
   40: use aliased 'Apache::math_parser::Parser';
   41: use aliased 'Apache::math_parser::ENode';
   42: use aliased 'Apache::math_parser::CalcEnv';
   43: 
   44: 
   45: BEGIN {
   46:     &Apache::lonxml::register('Apache::loncapamath',('lm'));
   47: }
   48: 
   49: sub start_lm {
   50:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
   51:     # Implementation note: this is using ENode::toTex, but we could also
   52:     # use a client-side implementation to display <lm>.
   53:     # While we use LaTeX for printing, turning the math into TeX for the web
   54:     # ensures that results will be more similar between web and print targets
   55:     # than they would be with a client-side implementation turning the
   56:     # parsed math directly into MathML.
   57:     $Apache::lonxml::post_evaluate = 0;
   58:     if ($target ne 'web' && $target ne 'tex') {
   59:         return;
   60:     }
   61:     my $text = &Apache::lonxml::get_all_text_unbalanced("/lm", $parser);
   62:     my $mode = &Apache::lonxml::get_param('mode',$parstack,$safeeval);
   63:     $text = &Apache::run::evaluate($text, $safeeval, $$parstack[-1]);
   64:     my $tex;
   65:     my $implicit_operators = 1;
   66:     my $unit_mode;
   67:     if (defined $mode && $mode eq 'units') {
   68:         $unit_mode = 1;
   69:     } else {
   70:         $unit_mode = 0;
   71:     }
   72:     my ($p, $root, $env);
   73:     my $result;
   74:     try {
   75:         $p = Parser->new($implicit_operators, $unit_mode);
   76:         $root = $p->parse($text);
   77:         $env = CalcEnv->new($unit_mode);
   78:         $tex = $root->toTeX();
   79:     } catch {
   80:         # NOTE: return cannot be used within a try/catch with Try::Tiny
   81:         if (UNIVERSAL::isa($_,CalcException)) {
   82:             $result = "Calculation error: ".$_->getLocalizedMessage();
   83:         } elsif (UNIVERSAL::isa($_,ParseException)) {
   84:             $result = "Parsing error: ".$_->getLocalizedMessage();
   85:         } else {
   86:             $result = "Internal error: $_";
   87:         }
   88:     };
   89:     if (defined $result) {
   90:         if ($target eq 'web') {
   91:             return '<b>'.$result.'</b>';
   92:         } elsif ($target eq 'tex') {
   93:             return '\bf{'.$result.'}';
   94:         }
   95:     }
   96:     if ($target eq 'web') {
   97:         my $display = &Apache::lonxml::get_param('display', $parstack, $safeeval);
   98:         $tex = '$'.$tex.'$';
   99:         $result = &Apache::lontexconvert::converted(\$tex, $display);
  100:     } elsif ($target eq 'tex') {
  101:         $result = '\ensuremath{'.$tex.'}';
  102:     }
  103:     
  104:     return $result;
  105: }
  106: 
  107: sub end_lm {
  108:     my ($target,$token,$tagstack,$parstack,$parser,$safeeval) = @_;
  109:     return '';
  110: }
  111: 
  112: 
  113: 1;
  114: __END__