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Answer labels are now prefixed by a Quiz prefix which allows more than one problem to appear on the same page. -- Mike
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 $@; 129 } 130 131 @main::submittedAnswers = @{$main::refSubmittedAnswers} if defined($main::refSubmittedAnswers); 132 $main::PG_original_problemSeed = $main::problemSeed; 133 $main::PG_random_generator = new PGrandom($main::problemSeed) || die "Can't create random number generator."; 134 $main::ans_rule_count = 0; # counts questions 135 136 # end unpacking of environment variables. 137 $main::QUIZ_PREFIX = '' unless defined($main::QUIZ_PREFIX) 138 } 139 140 # HEADER_TEXT is for material which is destined to be placed in the header of the html problem -- such 141 # as javaScript code. 142 143 =head2 HEADER_TEXT() 144 145 146 HEADER_TEXT("string1", "string2", "string3"); 147 148 The C<HEADER_TEXT()> 149 function concatenates its arguments and places them in the output 150 header text string. It is used for material which is destined to be placed in 151 the header of the html problem -- such as javaScript code. 152 It can be used more than once in a file. 153 154 155 =cut 156 157 sub HEADER_TEXT { 158 my @in = @_; 159 $STRINGforHEADER_TEXT .= join(" ",@in); 160 } 161 162 # TEXT is the function which defines text which will appear in the problem. 163 # All text must be an argument to this function. Any other statements 164 # are calculations (done in perl) which will not directly appear in the 165 # output. Think of this as the "print" function for the .pg language. 166 # It can be used more than once in a file. 167 168 =head2 TEXT() 169 170 TEXT("string1", "string2", "string3"); 171 172 The C<TEXT()> function concatenates its arguments and places them in the output 173 text string. C<TEXT()> is the function which defines text which will appear in the problem. 174 All text must be an argument to this function. Any other statements 175 are calculations (done in perl) which will not directly appear in the 176 output. Think of this as the "print" function for the .pg language. 177 It can be used more than once in a file. 178 179 =cut 180 181 sub TEXT { 182 my @in = @_; 183 $STRINGforOUTPUT .= join(" ",@in); 184 } 185 186 187 188 =head2 ANS() 189 190 ANS(answer_evaluator1, answer_evaluator2, answer_evaluator3,...) 191 192 Places the answer evaluators in the unlabeled answer_evaluator queue. They will be paired 193 with unlabeled answer rules (answer entry blanks) in the order entered. This is the standard 194 method for entering answers. 195 196 LABELED_ANS(answer_evaluater_name1, answer_evaluator1, answer_evaluater_name2,answer_evaluator2,...) 197 198 Places the answer evaluators in the labeled answer_evaluator hash. This allows pairing of 199 labeled answer evaluators and labeled answer rules which may not have been entered in the same 200 order. 201 202 =cut 203 204 sub ANS{ # store answer evaluators which have not been explicitly labeled 205 my @in = @_; 206 while (@in ) { 207 warn("<BR><B>Error in ANS:$in[0]</B> -- inputs must be references to 208 subroutines<BR>") 209 unless ref($in[0]); 210 push(@PG_ANSWERS, shift @in ); 211 } 212 } 213 sub LABELED_ANS { #a better alias for NAMED_ANS 214 &NAMED_ANS; 215 } 216 217 sub NAMED_ANS{ # store answer evaluators which have been explicitly labeled (submitted in a hash) 218 my @in = @_; 219 while (@in ) { 220 my $label = shift @in; 221 $label = $main::QUIZ_PREFIX.$label; 222 my $ans_eval = shift @in; 223 TEXT("<BR><B>Error in NAMED_ANS:$in[0]</B> 224 -- inputs must be references to subroutines<BR>") 225 unless ref($ans_eval); 226 $PG_ANSWERS_HASH{$label}= $ans_eval; 227 } 228 } 229 sub RECORD_ANS_NAME { # this maintains the order in which the answer rules are printed. 230 my $label = shift; 231 push(@main::PG_ANSWER_ENTRY_ORDER, $label); 232 $label; 233 } 234 235 sub NEW_ANS_NAME { # this keeps track of the answers which are entered implicitly, 236 # rather than with a specific label 237 my $number=shift; 238 my $label = "$main::QUIZ_PREFIX$main::ANSWER_PREFIX$number"; 239 push(@PG_UNLABELED_ANSWERS,$label); 240 $label; 241 } 242 sub ANS_NUM_TO_NAME { # This converts a number to an answer label for use in 243 # radio button and check box answers. No new answer 244 # name is recorded. 245 my $number=shift; 246 my $label = "$main::QUIZ_PREFIX$main::ANSWER_PREFIX$number"; 247 $label; 248 } 249 250 my $vecnum; 251 252 sub NEW_ANS_ARRAY_NAME { # this keeps track of the answers which are entered implicitly, 253 # rather than with a specific label 254 my $number=shift; 255 $vecnum = 0; 256 my $row = shift; 257 my $col = shift; 258 my $label = "ArRaY"."$number"."["."$vecnum".","."$row".","."$col"."]"; 259 push(@PG_UNLABELED_ANSWERS,$label); 260 $label; 261 } 262 263 sub NEW_ANS_ARRAY_NAME_EXTENSION { # this keeps track of the answers which are entered implicitly, 264 # rather than with a specific label 265 my $number=shift; 266 my $row = shift; 267 my $col = shift; 268 if( $row == 0 && $col == 0 ){ 269 $vecnum += 1; 270 } 271 my $label = "ArRaY"."$number"."["."$vecnum".","."$row".","."$col"."]"; 272 $label; 273 } 274 275 # ENDDOCUMENT must come at the end of every .pg file. 276 # It exports the resulting text of the problem, the text to be used in HTML header material 277 # (for javaScript), the list of answer evaluators and any other flags. It can appear only once and 278 # it MUST be the last statement in the problem. 279 280 =head2 ENDDOCUMENT() 281 282 ENDDOCUMENT() must the last executable statement in any problem template. It can 283 only appear once. It returns 284 an array consisting of 285 286 A reference to a string containing the rendered text of the problem. 287 A reference to a string containing text to be placed in the header 288 (for javaScript) 289 A reference to the array containing the answer evaluators. 290 (May be changed to a hash soon.) 291 A reference to an associative array (hash) containing various flags. 292 293 The following flags are set by ENDDOCUMENT: 294 (1) showPartialCorrectAnswers -- determines whether students are told which 295 of their answers in a problem are wrong. 296 (2) recordSubmittedAnswers -- determines whether students submitted answers 297 are saved. 298 (3) refreshCachedImages -- determines whether the cached image of the problem 299 in typeset mode is always refreshed (i.e. setting this to 1 means cached 300 images are not used). 301 (4) solutionExits -- indicates the existence of a solution. 302 (5) hintExits -- indicates the existence of a hint. 303 (6) showHintLimit -- determines the number of attempts after which hint(s) will be shown 304 305 (7) PROBLEM_GRADER_TO_USE -- chooses the problem grader to be used in this order 306 (a) A problem grader specified by the problem using: 307 install_problem_grader(\&grader); 308 (b) One of the standard problem graders defined in PGanswermacros.pl when set to 309 'std_problem_grader' or 'avg_problem_grader' by the environment variable 310 $PG_environment{PROBLEM_GRADER_TO_USE} 311 (c) A subroutine referenced by $PG_environment{PROBLEM_GRADER_TO_USE} 312 (d) The default &std_problem_grader defined in PGanswermacros.pl 313 314 315 =cut 316 317 sub ENDDOCUMENT { 318 319 my $index=0; 320 foreach my $label (@PG_UNLABELED_ANSWERS) { 321 if ( defined($PG_ANSWERS[$index]) ) { 322 $PG_ANSWERS_HASH{"$label"}= $PG_ANSWERS[$index]; 323 } else { 324 warn "No answer provided by instructor for answer $label"; 325 } 326 $index++; 327 } 328 329 $STRINGforOUTPUT .="\n"; 330 ##eval q{ #make sure that "main" points to the current safe compartment by evaluating these lines. 331 $main::PG_FLAGS{'showPartialCorrectAnswers'} = $main::showPartialCorrectAnswers; 332 $main::PG_FLAGS{'recordSubmittedAnswers'} = $main::recordSubmittedAnswers; 333 $main::PG_FLAGS{'refreshCachedImages'} = $main::refreshCachedImages; 334 $main::PG_FLAGS{'hintExists'} = $main::hintExists; 335 $main::PG_FLAGS{'showHintLimit'} = $main::showHint; 336 $main::PG_FLAGS{'solutionExists'} = $main::solutionExists; 337 $main::PG_FLAGS{ANSWER_ENTRY_ORDER} = \@main::PG_ANSWER_ENTRY_ORDER; 338 $main::PG_FLAGS{ANSWER_PREFIX} = $main::ANSWER_PREFIX; 339 # install problem grader 340 if (defined($main::PG_FLAGS{PROBLEM_GRADER_TO_USE}) ) { 341 # problem grader defined within problem -- no further action needed 342 } elsif ( defined( $main::envir{PROBLEM_GRADER_TO_USE} ) ) { 343 if (ref($main::envir{PROBLEM_GRADER_TO_USE}) eq 'CODE' ) { # user defined grader 344 $main::PG_FLAGS{PROBLEM_GRADER_TO_USE} = $main::envir{PROBLEM_GRADER_TO_USE}; 345 } elsif ($main::envir{PROBLEM_GRADER_TO_USE} eq 'std_problem_grader' ) { 346 if (defined(&std_problem_grader) ){ 347 $main::PG_FLAGS{PROBLEM_GRADER_TO_USE} = \&std_problem_grader; # defined in PGanswermacros.pl 348 } # std_problem_grader is the default in any case so don't give a warning. 349 } elsif ($main::envir{PROBLEM_GRADER_TO_USE} eq 'avg_problem_grader' ) { 350 if (defined(&avg_problem_grader) ){ 351 $main::PG_FLAGS{PROBLEM_GRADER_TO_USE} = \&avg_problem_grader; # defined in PGanswermacros.pl 352 } 353 #else { # avg_problem_grader will be installed by PGtranslator so there is no need for a warning. 354 # warn "The problem grader 'avg_problem_grader' has not been defined. Has PGanswermacros.pl been loaded?"; 355 #} 356 } else { 357 warn "Error: $main::PG_FLAGS{PROBLEM_GRADER_TO_USE} is not a known program grader."; 358 } 359 } elsif (defined(&std_problem_grader)) { 360 $main::PG_FLAGS{PROBLEM_GRADER_TO_USE} = \&std_problem_grader; # defined in PGanswermacros.pl 361 } else { 362 # PGtranslator will install its default problem grader 363 } 364 ##}; 365 warn "ERROR: The problem grader is not a subroutine" unless ref( $main::PG_FLAGS{PROBLEM_GRADER_TO_USE}) eq 'CODE' 366 or $main::PG_FLAGS{PROBLEM_GRADER_TO_USE} = 'std_problem_grader' 367 or $main::PG_FLAGS{PROBLEM_GRADER_TO_USE} = 'avg_problem_grader'; 368 # return results 369 (\$STRINGforOUTPUT, \$STRINGforHEADER_TEXT,\%PG_ANSWERS_HASH,\%main::PG_FLAGS); 370 } 371 372 373 374 =head2 INITIALIZE_PG() 375 376 This is executed each C<DOCUMENT()> is called. For backward compatibility 377 C<loadMacros> also checks whether the C<macroDirectory> has been defined 378 and if not, it runs C<INITIALIZE_PG()> and issues a warning. 379 380 =cut 381 382 383 1;
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