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Thu Sep 25 00:29:59 2003 UTC (16 years, 5 months ago) by sh002i
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    1 # This file provided the fundamental macros for the pg language
    2 # These macros define the interface between the problems written by
    3 # the professor and the processing which occurs in the script
    4 # processProblem.pl
    5 
    6 
    7 BEGIN {
    8   be_strict();
    9 }
   10 
   11 sub _PG_init{
   12 
   13 }
   14 
   15 #package PG;
   16 
   17 
   18 =head1 NAME
   19 
   20   PG.pl --- located in the courseScripts directory.
   21   Defines the Program Generating language at the most basic level.
   22 
   23 =head1 SYNPOSIS
   24 
   25   The basic PG problem structure:
   26 
   27   DOCUMENT();          # should be the first statment in the problem
   28   loadMacros(.....);   # (optional) load other macro files if needed.
   29                        # (loadMacros is defined in F<dangerousMacros.pl>)
   30 
   31   HEADER_TEXT(...);    # (optional) used only for inserting javaScript into problems.
   32 
   33   #            #  insert text of problems
   34   TEXT("Problem text to be",
   35        "displayed. Enter 1 in this blank:",
   36        ANS_RULE(1,30)  #  ANS_RULE() defines an answer blank 30 characters long.
   37                        #  It is defined in F<PGbasicmacros.pl>
   38        );
   39 
   40 
   41   ANS( answer_evalutors);  # see F<PGanswermacros.pl> for examples of answer evaluatiors.
   42 
   43   ENDDOCUMENT()        # must be the last statement in the problem
   44 
   45 
   46 
   47 =head1 DESCRIPTION
   48 
   49 As described in the synopsis, this file and the macros C<DOCUMENT()> and C<ENDDOCUMENT()> determine
   50 the interface between problems written in the PG language and the rest of B<WeBWorK>, in particular
   51 the subroutine C<createPGtext(()> in the file F<translate.pl>.
   52 
   53 C<DOCUMENT()> must be the first statement in each problem template.
   54 It  initializes variables,
   55 in particular all of the contents of the
   56 environment variable  become defined in the problem enviroment.
   57 (See
   58 L</webwork_system_html/docs/techdescription/pglanguage/PGenvironment.html>)
   59 
   60 ENDDOCUMENT() must the last executable statement in any problem template.  It returns
   61 the rendered problem, answer evaluators and other flags to the rest of B<WeBWorK>, specificially
   62 to the routine C<createPGtext()> defined in F<translate.pl>
   63 
   64 
   65 The C<HEADER_TEXT()>, C<TEXT()>, and C<ANS()> functions load the
   66 header text string, the problem text string.
   67 and the answer evaulator queue respectively.
   68 
   69 
   70 =cut
   71 
   72 
   73 #  Private variables for the PG.pl file.
   74 
   75 my ($STRINGforOUTPUT, $STRINGforHEADER_TEXT, @PG_ANSWERS, @PG_UNLABELED_ANSWERS);
   76 my %PG_ANSWERS_HASH ;
   77 
   78 # my variables are unreliable if two DOCUMENTS were to be called before and ENDDOCUMENT
   79 # there could be conflicts.  As I understand the behavior of the Apache child
   80 # this cannot occur -- a child finishes with one request before obtaining the next
   81 
   82 #   DOCUMENT must come early in every .pg file, before any answers or text are
   83 # defined.  It initializes the variables.
   84 # It can appear only once.
   85 
   86 =head2 DOCUMENT()
   87 
   88 C<DOCUMENT()> must be the first statement in each problem template.  It can
   89 only be used once in each problem.
   90 
   91 C<DOCUMENT()> initializes some empty variables and via C<INITIALIZE_PG()> unpacks the
   92 variables in the C<%envir> variable which is implicitly passed to the problem. It must
   93 be the first statement in any problem template. It
   94 also unpacks any answers submitted and places them in the C<@submittedAnswer> list,
   95 saves the problem seed in C<$PG_original_problemSeed> in case you need it later, and
   96 initializes the pseudo random number generator object in C<$PG_random_generator>.
   97 
   98 You can reset the standard number generator using the command:
   99 
  100   $PG_random_generator->srand($new_seed_value);
  101 
  102 (See also C<SRAND> in the L<PGbasicmacros.pl> file.)
  103 
  104 The
  105 environment variable contents is defined in
  106 L</webwork_system_html/docs/techdescription/pglanguage/PGenvironment.html>
  107 
  108 
  109 =cut
  110 
  111 sub DOCUMENT {
  112 
  113   $STRINGforOUTPUT ="";
  114     $STRINGforHEADER_TEXT ="";
  115   @PG_ANSWERS=();
  116 
  117   @PG_UNLABELED_ANSWERS = ();
  118   %PG_ANSWERS_HASH = ();
  119   # FIXME:  We are initializing these variables into both Safe::Root1 (the cached safe compartment)
  120   # and Safe::Root2 (the current one)
  121   # There is a good chance they won't be properly updated in one or the other of these compartments.
  122 
  123 #   @main::PG_ANSWER_ENTRY_ORDER = ();
  124 #   $main::ANSWER_PREFIX = 'AnSwEr';
  125 #   %main::PG_FLAGS=();  #global flags
  126 #   $main::showPartialCorrectAnswers = 0 unless defined($main::showPartialCorrectAnswers );
  127 #   $main::showHint = 1 unless defined($main::showHint);
  128 #   $main::solutionExists =0;
  129 #   $main::hintExists =0;
  130 #   %main::gifs_created = ();
  131   eval(q!
  132   @main::PG_ANSWER_ENTRY_ORDER = ();
  133   $main::ANSWER_PREFIX = 'AnSwEr';
  134   %main::PG_FLAGS=();  #global flags
  135   $main::showPartialCorrectAnswers = 0 unless defined($main::showPartialCorrectAnswers );
  136   $main::showHint = 1 unless defined($main::showHint);
  137   $main::solutionExists =0;
  138   $main::hintExists =0;
  139   %main::gifs_created = ();
  140 
  141     !);
  142 #    warn eval(q! "PG.pl:  The envir variable $main::{envir} is".join(" ",%main::envir)!);
  143     my $rh_envir = eval(q!\%main::envir!);
  144     my %envir    = %$rh_envir;
  145     #no strict;
  146     foreach  my  $var (keys %envir) {
  147       eval(q!$main::!.$var.q! = $main::envir{!.$var.q!}! );  #whew!! makes sure $var is interpolated but $main:: is evaluated at run time.
  148     #    warn eval(q! "var $var is defined ". $main::!.$var);
  149         warn "Problem defining ", q{\$main::}.$var, " while initializing the PG problem: $@" if $@;
  150     }
  151     #use strict;
  152     #FIXME these strict pragmas don't seem to be needed and they cause trouble in perl 5.6.0
  153 
  154 
  155 
  156     eval(q!
  157   @main::submittedAnswers = @{$main::refSubmittedAnswers} if defined($main::refSubmittedAnswers);
  158   $main::PG_original_problemSeed = $main::problemSeed;
  159   $main::PG_random_generator = new PGrandom($main::problemSeed) || die "Can't create random number generator.";
  160   $main::ans_rule_count = 0;  # counts questions
  161 
  162     # end unpacking of environment variables.
  163     $main::QUIZ_PREFIX = '' unless defined($main::QUIZ_PREFIX)
  164 
  165   !);
  166 #   @main::submittedAnswers = @{$main::refSubmittedAnswers} if defined($main::refSubmittedAnswers);
  167 #   $main::PG_original_problemSeed = $main::problemSeed;
  168 #   $main::PG_random_generator = new PGrandom($main::problemSeed) || die "Can't create random number generator.";
  169 #   $main::ans_rule_count = 0;  # counts questions
  170 
  171     # end unpacking of environment variables.
  172 #   $main::QUIZ_PREFIX = '' unless defined($main::QUIZ_PREFIX)
  173 
  174 }
  175 
  176 sub inc_ans_rule_count {
  177   eval(q!++$main::ans_rule_count!); # evalute at runtime to get correct main::
  178 }
  179 # HEADER_TEXT is for material which is destined to be placed in the header of the html problem -- such
  180 #   as javaScript code.
  181 
  182 =head2 HEADER_TEXT()
  183 
  184 
  185   HEADER_TEXT("string1", "string2", "string3");
  186 
  187 The C<HEADER_TEXT()>
  188 function concatenates its arguments and places them in the output
  189 header text string.  It is used for material which is destined to be placed in
  190 the header of the html problem -- such as javaScript code.
  191  It can be used more than once in a file.
  192 
  193 
  194 =cut
  195 
  196 sub HEADER_TEXT {
  197   my @in = @_;
  198   $STRINGforHEADER_TEXT .= join(" ",@in);
  199   }
  200 
  201 # TEXT is the function which defines text which will appear in the problem.
  202 # All text must be an argument to this function.  Any other statements
  203 #   are calculations (done in perl) which will not directly appear in the
  204 # output.  Think of this as the "print" function for the .pg language.
  205 # It can be used more than once in a file.
  206 
  207 =head2 TEXT()
  208 
  209   TEXT("string1", "string2", "string3");
  210 
  211 The C<TEXT()> function concatenates its arguments and places them in the output
  212 text string. C<TEXT()> is the function which defines text which will appear in the problem.
  213 All text must be an argument to this function.  Any other statements
  214 are calculations (done in perl) which will not directly appear in the
  215 output.  Think of this as the "print" function for the .pg language.
  216 It can be used more than once in a file.
  217 
  218 =cut
  219 
  220 sub TEXT {
  221   my @in = @_;
  222   $STRINGforOUTPUT .= join(" ",@in);
  223   }
  224 
  225 
  226 
  227 =head2 ANS()
  228 
  229   ANS(answer_evaluator1, answer_evaluator2, answer_evaluator3,...)
  230 
  231 Places the answer evaluators in the unlabeled answer_evaluator queue.  They will be paired
  232 with unlabeled answer rules (answer entry blanks) in the order entered.  This is the standard
  233 method for entering answers.
  234 
  235   LABELED_ANS(answer_evaluater_name1, answer_evaluator1, answer_evaluater_name2,answer_evaluator2,...)
  236 
  237 Places the answer evaluators in the labeled answer_evaluator hash.  This allows pairing of
  238 labeled answer evaluators and labeled answer rules which may not have been entered in the same
  239 order.
  240 
  241 =cut
  242 
  243 sub ANS{             # store answer evaluators which have not been explicitly labeled
  244   my @in = @_;
  245   while (@in ) {
  246          warn("<BR><B>Error in ANS:$in[0]</B> -- inputs must be references to
  247                       subroutines<BR>")
  248       unless ref($in[0]);
  249       push(@PG_ANSWERS, shift @in );
  250       }
  251 }
  252 sub LABELED_ANS {  #a better alias for NAMED_ANS
  253   &NAMED_ANS;
  254 }
  255 
  256 sub NAMED_ANS{     # store answer evaluators which have been explicitly labeled (submitted in a hash)
  257   my @in = @_;
  258   while (@in ) {
  259     my $label = shift @in;
  260     $label = eval(q!$main::QUIZ_PREFIX.$label!);
  261     my $ans_eval = shift @in;
  262     TEXT("<BR><B>Error in NAMED_ANS:$in[0]</B>
  263           -- inputs must be references to subroutines<BR>")
  264       unless ref($ans_eval);
  265     $PG_ANSWERS_HASH{$label}= $ans_eval;
  266   }
  267 }
  268 sub RECORD_ANS_NAME {     # this maintains the order in which the answer rules are printed.
  269   my $label = shift;
  270   eval(q!push(@main::PG_ANSWER_ENTRY_ORDER, $label)!);
  271   $label;
  272 }
  273 
  274 sub NEW_ANS_NAME {        # this keeps track of the answers which are entered implicitly,
  275                           # rather than with a specific label
  276     my $number=shift;
  277     my $prefix = eval(q!$main::QUIZ_PREFIX.$main::ANSWER_PREFIX!);
  278     my $label = $prefix.$number;
  279     push(@PG_UNLABELED_ANSWERS,$label);
  280     $label;
  281 }
  282 sub ANS_NUM_TO_NAME {     # This converts a number to an answer label for use in
  283                           # radio button and check box answers. No new answer
  284                           # name is recorded.
  285     my $number=shift;
  286     my $label = eval(q!$main::QUIZ_PREFIX$main::ANSWER_PREFIX$number"!);
  287     $label;
  288 }
  289 
  290 my $vecnum;
  291 
  292 sub NEW_ANS_ARRAY_NAME {        # this keeps track of the answers which are entered implicitly,
  293                           # rather than with a specific label
  294     my $number=shift;
  295     $vecnum = 0;
  296     my $row = shift;
  297     my $col = shift;
  298     my $label = "ArRaY"."$number"."["."$vecnum".","."$row".","."$col"."]";
  299     push(@PG_UNLABELED_ANSWERS,$label);
  300     $label;
  301 }
  302 
  303 sub NEW_ANS_ARRAY_NAME_EXTENSION {        # this keeps track of the answers which are entered implicitly,
  304                           # rather than with a specific label
  305     my $number=shift;
  306     my $row = shift;
  307     my $col = shift;
  308     if( $row == 0 && $col == 0 ){
  309       $vecnum += 1;
  310     }
  311     my $label = "ArRaY"."$number"."["."$vecnum".","."$row".","."$col"."]";
  312     eval(q!push(@main::KEPT_EXTRA_ANSWERS, $label)!);#put the labels into the hash to be caught later for recording purposes
  313     $label;
  314 }
  315 
  316 # ENDDOCUMENT must come at the end of every .pg file.
  317 #   It exports the resulting text of the problem, the text to be used in HTML header material
  318 #   (for javaScript), the list of answer evaluators and any other flags.  It can appear only once and
  319 #   it MUST be the last statement in the problem.
  320 
  321 =head2 ENDDOCUMENT()
  322 
  323 ENDDOCUMENT() must the last executable statement in any problem template.  It can
  324 only appear once.  It returns
  325 an array consisting of
  326 
  327   A reference to a string containing the rendered text of the problem.
  328   A reference to a string containing text to be placed in the header
  329                (for javaScript)
  330   A reference to the array containing the answer evaluators.
  331                (May be changed to a hash soon.)
  332   A reference to an associative array (hash) containing various flags.
  333 
  334   The following flags are set by ENDDOCUMENT:
  335   (1) showPartialCorrectAnswers  -- determines whether students are told which
  336       of their answers in a problem are wrong.
  337   (2) recordSubmittedAnswers  -- determines whether students submitted answers
  338       are saved.
  339   (3) refreshCachedImages  -- determines whether the cached image of the problem
  340       in typeset mode is always refreshed (i.e. setting this to 1 means cached
  341       images are not used).
  342   (4) solutionExits   -- indicates the existence of a solution.
  343   (5) hintExits   -- indicates the existence of a hint.
  344   (6) showHintLimit -- determines the number of attempts after which hint(s) will be shown
  345 
  346   (7) PROBLEM_GRADER_TO_USE -- chooses the problem grader to be used in this order
  347     (a) A problem grader specified by the problem using:
  348         install_problem_grader(\&grader);
  349     (b) One of the standard problem graders defined in PGanswermacros.pl when set to
  350         'std_problem_grader' or 'avg_problem_grader' by the environment variable
  351         $PG_environment{PROBLEM_GRADER_TO_USE}
  352     (c) A subroutine referenced by $PG_environment{PROBLEM_GRADER_TO_USE}
  353     (d) The default &std_problem_grader defined in PGanswermacros.pl
  354 
  355 
  356 =cut
  357 
  358 sub ENDDOCUMENT {
  359 
  360     my $index=0;
  361     foreach my $label (@PG_UNLABELED_ANSWERS) {
  362         if ( defined($PG_ANSWERS[$index]) ) {
  363         $PG_ANSWERS_HASH{"$label"}= $PG_ANSWERS[$index];
  364       #warn "recording answer label = $label";
  365       } else {
  366         warn "No answer provided by instructor for answer $label";
  367       }
  368       $index++;
  369     }
  370 
  371     $STRINGforOUTPUT .="\n";
  372    eval q{  #make sure that "main" points to the current safe compartment by evaluating these lines.
  373     $main::PG_FLAGS{'showPartialCorrectAnswers'} = $main::showPartialCorrectAnswers;
  374     $main::PG_FLAGS{'recordSubmittedAnswers'} = $main::recordSubmittedAnswers;
  375     $main::PG_FLAGS{'refreshCachedImages'} = $main::refreshCachedImages;
  376     $main::PG_FLAGS{'hintExists'} = $main::hintExists;
  377     $main::PG_FLAGS{'showHintLimit'} = $main::showHint;
  378     $main::PG_FLAGS{'solutionExists'} = $main::solutionExists;
  379     $main::PG_FLAGS{ANSWER_ENTRY_ORDER} = \@main::PG_ANSWER_ENTRY_ORDER;
  380     $main::PG_FLAGS{KEPT_EXTRA_ANSWERS} = \@main::KEPT_EXTRA_ANSWERS;##need to keep array labels that don't call "RECORD_ANS_NAME"
  381     $main::PG_FLAGS{ANSWER_PREFIX} = $main::ANSWER_PREFIX;
  382     # install problem grader
  383     if (defined($main::PG_FLAGS{PROBLEM_GRADER_TO_USE}) ) {
  384       # problem grader defined within problem -- no further action needed
  385     } elsif ( defined( $main::envir{PROBLEM_GRADER_TO_USE} ) ) {
  386       if (ref($main::envir{PROBLEM_GRADER_TO_USE}) eq 'CODE' ) {         # user defined grader
  387         $main::PG_FLAGS{PROBLEM_GRADER_TO_USE} = $main::envir{PROBLEM_GRADER_TO_USE};
  388       } elsif ($main::envir{PROBLEM_GRADER_TO_USE} eq 'std_problem_grader' ) {
  389         if (defined(&std_problem_grader) ){
  390           $main::PG_FLAGS{PROBLEM_GRADER_TO_USE} = \&std_problem_grader; # defined in PGanswermacros.pl
  391         } # std_problem_grader is the default in any case so don't give a warning.
  392       } elsif ($main::envir{PROBLEM_GRADER_TO_USE} eq 'avg_problem_grader' ) {
  393         if (defined(&avg_problem_grader) ){
  394           $main::PG_FLAGS{PROBLEM_GRADER_TO_USE} = \&avg_problem_grader; # defined in PGanswermacros.pl
  395         }
  396         #else { # avg_problem_grader will be installed by PGtranslator so there is no need for a warning.
  397         # warn "The problem grader 'avg_problem_grader' has not been defined.  Has PGanswermacros.pl been loaded?";
  398         #}
  399       } else {
  400         warn "Error:  $main::PG_FLAGS{PROBLEM_GRADER_TO_USE} is not a known program grader.";
  401       }
  402     } elsif (defined(&std_problem_grader)) {
  403       $main::PG_FLAGS{PROBLEM_GRADER_TO_USE} = \&std_problem_grader; # defined in PGanswermacros.pl
  404     } else {
  405       # PGtranslator will install its default problem grader
  406     }
  407 
  408     warn "ERROR: The problem grader is not a subroutine" unless ref( $main::PG_FLAGS{PROBLEM_GRADER_TO_USE}) eq 'CODE'
  409                      or $main::PG_FLAGS{PROBLEM_GRADER_TO_USE} = 'std_problem_grader'
  410                      or $main::PG_FLAGS{PROBLEM_GRADER_TO_USE} = 'avg_problem_grader';
  411      # return results
  412     };
  413 
  414   (\$STRINGforOUTPUT, \$STRINGforHEADER_TEXT,\%PG_ANSWERS_HASH,eval(q!\%main::PG_FLAGS!));
  415 }
  416 
  417 
  418 
  419 =head2 INITIALIZE_PG()
  420 
  421 This is executed each C<DOCUMENT()> is called.  For backward compatibility
  422 C<loadMacros> also checks whether the C<macroDirectory> has been defined
  423 and if not, it runs C<INITIALIZE_PG()> and issues a warning.
  424 
  425 =cut
  426 
  427 
  428 1;

aubreyja at gmail dot com
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