[system] / trunk / pg / macros / PG.pl Repository:
ViewVC logotype

View of /trunk/pg/macros/PG.pl

Parent Directory Parent Directory | Revision Log Revision Log


Revision 1050 - (download) (as text) (annotate)
Fri Jun 6 21:39:42 2003 UTC (16 years, 8 months ago) by sh002i
File size: 13008 byte(s)
moved PG modules and macro files from webwork-modperl to pg
-sam

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

aubreyja at gmail dot com
ViewVC Help
Powered by ViewVC 1.0.9