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1 : sh002i 440 ################################################################################
2 :     # WeBWorK mod_perl (c) 1995-2002 WeBWorK Team, Univeristy of Rochester
3 :     # $Id$
4 :     ################################################################################
5 :    
6 : sh002i 424 package WeBWorK::PG;
7 : sh002i 414
8 : sh002i 455 =head1 NAME
9 :    
10 : sh002i 476 WeBWorK::PG - Wrap the action of the PG Translator in an easy-to-use API.
11 : sh002i 455
12 :     =cut
13 :    
14 : sh002i 414 use strict;
15 :     use warnings;
16 :     use WeBWorK::DB::Classlist;
17 :     use WeBWorK::DB::WW;
18 :     use WeBWorK::PG::Translator;
19 : sh002i 455 use WeBWorK::Utils qw(readFile formatDateTime);
20 : sh002i 414
21 : sh002i 424 sub new($$$$$$$$) {
22 : sh002i 415 my $invocant = shift;
23 :     my $class = ref($invocant) || $invocant;
24 : sh002i 424 my (
25 :     $courseEnv,
26 :     $userName,
27 :     $key,
28 :     $setName,
29 :     $problemNumber,
30 :     $translationOptions, # hashref containing options for the
31 :     # translator, such as whether to show
32 :     # hints and the display mode to use
33 :     $formFields, # in CGI::Vars format
34 :     ) = @_;
35 : sh002i 415
36 : sh002i 414 # get database information
37 :     my $classlist = WeBWorK::DB::Classlist->new($courseEnv);
38 :     my $wwdb = WeBWorK::DB::WW->new($courseEnv);
39 :     my $user = $classlist->getUser($userName);
40 :     my $set = $wwdb->getSet($userName, $setName);
41 :     my $problem = $wwdb->getProblem($userName, $setName, $problemNumber);
42 :     my $psvn = $wwdb->getPSVN($userName, $setName);
43 :    
44 : sh002i 476 # *** NOTE: in order to support set header files, I propose adding a
45 :     # magic problemNumber (i.e. 0 or -1) which would cuase $problem to
46 :     # contain a dummy problem whose source file is the set header file.
47 :    
48 : sh002i 414 # create a Translator
49 : sh002i 424 warn "PG: creating a Translator\n";
50 : sh002i 414 my $translator = WeBWorK::PG::Translator->new;
51 :    
52 : sh002i 424 # set the directory hash
53 :     warn "PG: setting the directory hash\n";
54 : sh002i 414 $translator->rh_directories({
55 :     courseScriptsDirectory => $courseEnv->{webworkDirs}->{macros},
56 :     macroDirectory => $courseEnv->{courseDirs}->{macros},
57 :     templateDirectory => $courseEnv->{courseDirs}->{templates},
58 :     tempDirectory => $courseEnv->{courseDirs}->{html_temp},
59 :     });
60 :    
61 : sh002i 424 # evaluate modules and "extra packages"
62 :     warn "PG: evaluating modules and \"extra packages\"\n";
63 :     my @modules = @{ $courseEnv->{pg}->{modules} };
64 : sh002i 476 foreach my $module_packages_ref (@modules) {
65 :     my ($module, @extra_packages) = @$module_packages_ref;
66 :     # the first item is the main package
67 :     $translator->evaluate_modules($module);
68 : sh002i 424 # the remaining items are "extra" packages
69 : sh002i 476 $translator->load_extra_packages(@extra_packages);
70 : sh002i 414 }
71 :    
72 : sh002i 424 # set the environment (from defineProblemEnvir)
73 :     warn "PG: setting the environment (from defineProblemEnvir)\n";
74 :     $translator->environment(defineProblemEnvir(
75 :     $courseEnv, $user, $key, $set, $problem, $psvn, $formFields, $translationOptions));
76 : sh002i 414
77 : sh002i 424 # initialize the Translator
78 :     warn "PG: initializing the Translator\n";
79 : sh002i 414 $translator->initialize();
80 :    
81 : sh002i 424 # load PG.pl and dangerousMacros.pl using unrestricted_load
82 : sh002i 425 # i'd like to change this at some point to have the same sort of interface to global.conf
83 :     # that the module loading does -- have a list of macros to load unrestrictedly.
84 : sh002i 424 warn "PG: loading PG.pl and dangerousMacros.pl using unrestricted_load\n";
85 : sh002i 414 my $pg_pl = $courseEnv->{webworkDirs}->{macros} . "/PG.pl";
86 : sh002i 424 my $dangerousMacros_pl = $courseEnv->{webworkDirs}->{macros} . "/dangerousMacros.pl";
87 : sh002i 414 my $err = $translator->unrestricted_load($pg_pl);
88 :     warn "Error while loading $pg_pl: $err" if $err;
89 :     $err = $translator->unrestricted_load($dangerousMacros_pl);
90 :     warn "Error while loading $dangerousMacros_pl: $err" if $err;
91 :    
92 : sh002i 424 # set the opcode mask (using default values)
93 :     warn "PG: setting the opcode mask (using default values)\n";
94 : sh002i 414 $translator->set_mask();
95 :    
96 : sh002i 424 # store the problem source
97 :     warn "PG: storing the problem source\n";
98 : sh002i 414 my $sourceFile = $courseEnv->{courseDirs}->{templates}."/".$problem->source_file;
99 :     $translator->source_string(readFile($sourceFile));
100 :    
101 :     # install a safety filter (&safetyFilter)
102 : sh002i 424 warn "PG: installing a safety filter\n";
103 : sh002i 414 $translator->rf_safety_filter(\&safetyFilter);
104 :    
105 : sh002i 415 # translate the PG source into text
106 : sh002i 424 warn "PG: translating the PG source into text\n";
107 : sh002i 415 $translator->translate();
108 :    
109 : sh002i 476 my ($result, $state); # we'll need these on the other side of the if block!
110 :     if ($translationOptions->{processAnswers}) {
111 :    
112 :     # process student answers
113 :     warn "PG: processing student answers\n";
114 :     $translator->process_answers($formFields);
115 :    
116 :     # retrieve the problem state and give it to the translator
117 :     warn "PG: retrieving the problem state and giving it to the translator\n";
118 :     $translator->rh_problem_state({
119 :     recorded_score => $problem->status,
120 :     num_of_correct_ans => $problem->num_correct,
121 :     num_of_incorrect_ans => $problem->num_incorrect,
122 :     });
123 :    
124 :     # determine an entry order -- the ANSWER_ENTRY_ORDER flag is built by
125 :     # the PG macro package (PG.pl)
126 :     warn "PG: determining an entry order\n";
127 :     my @answerOrder =
128 :     $translator->rh_flags->{ANSWER_ENTRY_ORDER}
129 :     ? @{ $translator->rh_flags->{ANSWER_ENTRY_ORDER} }
130 :     : keys %{ $translator->rh_evaluated_answers };
131 :    
132 :     # install a grader -- use the one specified in the problem,
133 :     # or fall back on the default from the course environment.
134 :     # (two magic strings are accepted, to avoid having to
135 :     # reference code when it would be difficult.)
136 :     warn "PG: installing a grader\n";
137 :     my $grader = $translator->rh_flags->{PROBLEM_GRADER_TO_USE}
138 :     || $courseEnv->{pg}->{options}->{grader};
139 :     $grader = $translator->rf_std_problem_grader
140 :     if $grader eq "std_problem_grader";
141 :     $grader = $translator->rf_avg_problem_grader
142 :     if $grader eq "avg_problem_grader";
143 :     die "Problem grader $grader is not a CODE reference."
144 :     unless ref $grader eq "CODE";
145 :     $translator->rf_problem_grader($grader);
146 :    
147 :     # grade the problem
148 :     warn "PG: grading the problem\n";
149 :     ($result, $state) = $translator->grade_problem(
150 :     answers_submitted => $translationOptions->{processAnswers},
151 :     ANSWER_ENTRY_ORDER => \@answerOrder,
152 :     );
153 :    
154 :     }
155 : sh002i 415
156 : sh002i 424 # return an object which contains the translator and the results of
157 :     # the translation process. this is DIFFERENT from the "format expected
158 :     # by Webwork.pm (and I believe processProblem8, but check.)"
159 :     return bless {
160 :     translator => $translator,
161 :     head_text => ${ $translator->r_header },
162 :     body_text => ${ $translator->r_text },
163 :     answers => $translator->rh_evaluated_answers,
164 :     result => $result,
165 :     state => $state,
166 :     errors => $translator->errors, # *** what is this doing?
167 :     warnings => undef, # *** gotta catch warnings eventually...
168 :     flags => $translator->rh_flags,
169 :     }, $class;
170 : sh002i 414 }
171 :    
172 :     # -----
173 :    
174 : sh002i 424 sub defineProblemEnvir($$$$$$$) {
175 :     my (
176 :     $courseEnv,
177 :     $user,
178 :     $key,
179 :     $set,
180 :     $problem,
181 :     $psvn,
182 :     $formFields,
183 :     $options,
184 :     ) = @_;
185 : sh002i 414
186 :     my %envir;
187 :    
188 :     # PG environment variables
189 :     # from docs/pglanguage/pgreference/environmentvariables as of 06/25/2002
190 :     # any changes are noted by "ADDED:" or "REMOVED:"
191 :    
192 :     # Vital state information
193 : sh002i 476 # ADDED: displayHintsQ, displaySolutionsQ, refreshMath2img
194 : sh002i 414
195 :     $envir{psvn} = $psvn;
196 :     $envir{psvnNumber} = $envir{psvn};
197 :     $envir{probNum} = $problem->id;
198 :     $envir{questionNumber} = $envir{probNum};
199 :     $envir{fileName} = $problem->source_file;
200 :     $envir{probFileName} = $envir{fileName};
201 :     $envir{problemSeed} = $problem->problem_seed;
202 : sh002i 424 $envir{displayMode} = translateDisplayModeNames($options->{displayMode});
203 : sh002i 414 $envir{languageMode} = $envir{displayMode};
204 :     $envir{outputMode} = $envir{displayMode};
205 : sh002i 424 $envir{displayHintsQ} = $options->{hints};
206 :     $envir{displaySolutionsQ} = $options->{solutions};
207 : sh002i 434 $envir{refreshMath2img} = $options->{refreshMath2img};
208 : sh002i 414
209 :     # Problem Information
210 :     # ADDED: courseName
211 :    
212 :     $envir{openDate} = $set->open_date;
213 : sh002i 424 $envir{formattedOpenDate} = formatDateTime($envir{openDate});
214 : sh002i 414 $envir{dueDate} = $set->due_date;
215 : sh002i 424 $envir{formattedDueDate} = formatDateTime($envir{dueDate});
216 : sh002i 414 $envir{answerDate} = $set->answer_date;
217 : sh002i 424 $envir{formattedAnswerDate} = formatDateTime($envir{answerDate});
218 : sh002i 414 $envir{numOfAttempts} = $problem->num_correct + $problem->num_incorrect;
219 :     $envir{problemValue} = $problem->value;
220 : sh002i 424 $envir{sessionKey} = $key;
221 : sh002i 414 $envir{courseName} = $courseEnv->{courseName};
222 :    
223 :     # Student Information
224 :     # ADDED: studentID
225 :    
226 :     $envir{sectionName} = $user->section;
227 :     $envir{sectionNumber} = $envir{sectionName};
228 :     $envir{recitationName} = $user->recitation;
229 :     $envir{recitationNumber} = $envir{recitationName};
230 :     $envir{setNumber} = $set->id;
231 :     $envir{studentLogin} = $user->id;
232 :     $envir{studentName} = $user->first_name . " " . $user->last_name;
233 : sh002i 424 $envir{studentID} = $user->student_id;
234 : sh002i 414
235 :     # Answer Information
236 : sh002i 434 # REMOVED: refSubmittedAnswers
237 : sh002i 414
238 : sh002i 434 $envir{inputs_ref} = $formFields;
239 : sh002i 414
240 : sh002i 433 # External Programs
241 : sh002i 434
242 : sh002i 433 $envir{externalTTHPath} = $courseEnv->{externalPrograms}->{tth};
243 :     $envir{externalMath2imgPath} = $courseEnv->{externalPrograms}->{math2img};
244 : sh002i 414
245 :     # Directories and URLs
246 :     # REMOVED: courseName
247 :    
248 :     $envir{cgiDirectory} = undef;
249 :     $envir{cgiURL} = undef;
250 :     $envir{classDirectory} = undef;
251 : sh002i 424 $envir{courseScriptsDirectory} = $courseEnv->{webworkDirs}->{macros}."/";
252 :     $envir{htmlDirectory} = $courseEnv->{courseDirs}->{html}."/";
253 : sh002i 414 $envir{htmlURL} = $courseEnv->{courseURLs}->{html};
254 : sh002i 424 $envir{macroDirectory} = $courseEnv->{courseDirs}->{macros}."/";
255 :     $envir{templateDirectory} = $courseEnv->{courseDirs}->{templates}."/";
256 :     $envir{tempDirectory} = $courseEnv->{courseDirs}->{html_temp}."/";
257 : sh002i 414 $envir{tempURL} = $courseEnv->{courseURLs}->{html_temp};
258 :     $envir{scriptDirectory} = undef;
259 :     $envir{webworkDocsURL} = $courseEnv->{webworkURLs}->{docs};
260 :    
261 : sh002i 433 # Default values for evaluating answers
262 : sh002i 425
263 : sh002i 433 my $ansEvalDefaults = $courseEnv->{pg}->{ansEvalDefaults};
264 :     $envir{$_} = $ansEvalDefaults->{$_} foreach (keys %$ansEvalDefaults);
265 :    
266 :     # Other things...
267 :    
268 : sh002i 425 $envir{PROBLEM_GRADER_TO_USE} = $courseEnv->{pg}->{options}->{grader};
269 :    
270 : sh002i 414 return \%envir;
271 :     }
272 :    
273 : sh002i 424 sub translateDisplayModeNames($) {
274 :     my $name = shift;
275 :     return {
276 : sh002i 476 tex => "TeX",
277 : sh002i 424 plainText => "HTML",
278 :     formattedText => "HTML_tth",
279 : sh002i 433 images => "HTML_img"
280 : sh002i 424 }->{$name};
281 :     }
282 :    
283 : sh002i 414 sub safetyFilter {
284 : sh002i 415 my $answer = shift; # accepts one answer and checks it
285 : sh002i 414 my $submittedAnswer = $answer;
286 :     $answer = '' unless defined $answer;
287 :     my ($errorno);
288 :     $answer =~ tr/\000-\037/ /;
289 :     # Return if answer field is empty
290 :     unless ($answer =~ /\S/) {
291 :     #$errorno = "<BR>No answer was submitted.";
292 :     $errorno = 0; ## don't report blank answer as error
293 :     return ($answer,$errorno);
294 :     }
295 :     # replace ^ with ** (for exponentiation)
296 :     # $answer =~ s/\^/**/g;
297 :     # Return if forbidden characters are found
298 :     unless ($answer =~ /^[a-zA-Z0-9_\-\+ \t\/@%\*\.\n^\(\)]+$/ ) {
299 :     $answer =~ tr/a-zA-Z0-9_\-\+ \t\/@%\*\.\n^\(\)/#/c;
300 :     $errorno = "<BR>There are forbidden characters in your answer: $submittedAnswer<BR>";
301 :     return ($answer,$errorno);
302 :     }
303 :     $errorno = 0;
304 :     return($answer, $errorno);
305 :     }
306 :    
307 :     1;
308 : sh002i 440
309 :     __END__
310 :    
311 :     =head1 SYNOPSIS
312 :    
313 :     $pg = WeBWorK::PG->new(
314 :     $courseEnv, # a WeBWorK::CourseEnvironment object
315 :     $userName,
316 :     $sessionKey,
317 :     $setName,
318 :     $problemNumber,
319 :     { # translation options
320 :     displayMode => "images", # (plainText|formattedText|images)
321 :     showHints => 1, # (0|1)
322 :     showSolutions => 0, # (0|1)
323 :     refreshMath2img => 0, # (0|1)
324 :     processAnswers => 1, # (0|1)
325 :     },
326 :     $formFields # in WeBWorK::Form::Vars format
327 :     );
328 :    
329 :     $translator = $pg->{translator}; # WeBWorK::PG::Translator
330 :     $body = $pg->{body_text}; # text string
331 :     $header = $pg->{head_text}; # text string
332 :     $answerHash = $pg->{answers}; # WeBWorK::PG::AnswerHash
333 :     $result = $pg->{result}; # hash reference
334 :     $state = $pg->{state}; # hash reference
335 :     $errors = $pg->{errors}; # text string
336 :     $warnings = $pg->{warnings}; # text string
337 :     $flags = $pg->{flags}; # hash reference
338 :    
339 :     =head1 DESCRIPTION
340 :    
341 :     WeBWorK::PG encapsulates the PG translation process, making multiple calls to
342 :     WeBWorK::PG::Translator. Much of the flexibility of the Translator is hidden,
343 :     instead making choices that are appropriate for the webwork-modperl system.
344 :    
345 :     =head1 CONSTRUCTION
346 :    
347 :     =over
348 :    
349 :     =item new (ENVIRONMENT, USER, KEY, SET, PROBLEM, OPTIONS, FIELDS)
350 :    
351 :     The C<new> method creates a translator, initializes it using the parameters
352 :     specified, translates a PG file, and processes answers. It returns a reference
353 :     to a blessed hash containing the results of the translation process.
354 :    
355 :     =back
356 :    
357 :     =head2 Parameters
358 :    
359 :     =over
360 :    
361 :     =item ENVIRONMENT
362 :    
363 :     a WeBWorK::CourseEnvironment object
364 :    
365 :     =item USER
366 :    
367 :     the name of the user for whom to render
368 :    
369 :     =item KEY
370 :    
371 :     the session key of the current session
372 :    
373 :     =item SET
374 :    
375 :     the name of the problem set from which to get the problem
376 :    
377 :     =item PROBLEM
378 :    
379 :     the number of the problem to render
380 :    
381 :     =item OPTIONS
382 :    
383 :     a reference to a hash containing the following data:
384 :    
385 :     =over
386 :    
387 :     =item displayMode
388 :    
389 :     one of "plainText", "formattedText", or "images"
390 :    
391 :     =item showHints
392 :    
393 :     boolean, render hints
394 :    
395 :     =item showSolutions
396 :    
397 :     boolean, render solutions
398 :    
399 :     =item refreshMath2img
400 :    
401 :     boolean, force images created by math2img (in "images" mode) to be recreated,
402 :     even if the PG source has not been updated.
403 :    
404 :     =item processAnswers
405 :    
406 :     boolean, call answer evaluators and graders
407 :    
408 :     =back
409 :    
410 :     =item FIELDS
411 :    
412 :     a reference to a hash (as returned by &WeBWorK::Form::Vars) containing form
413 :     fields submitted by a problem processor. The translator will look for fields
414 :     like "AnSwEr[0-9]" containing submitted student answers.
415 :    
416 :     =back
417 :    
418 :     =head2 RETURN VALUE
419 :    
420 :     The C<new> method returns a blessed hash reference containing the following
421 :     fields. More information can be found in the documentation for
422 :     WeBWorK::PG::Translator.
423 :    
424 :     =over
425 :    
426 :     =item translator
427 :    
428 :     The WeBWorK::PG::Translator object used to render the problem.
429 :    
430 :     =item head_text
431 :    
432 :     HTML code for the E<lt>headE<gt> block of an resulting web page. Used for
433 :     JavaScript features.
434 :    
435 :     =item body_text
436 :    
437 :     HTML code for the E<lt>bodyE<gt> block of an resulting web page.
438 :    
439 :     =item answers
440 :    
441 :     An C<AnswerHash> object containing submitted answers, and results of answer
442 :     evaluation.
443 :    
444 :     =item result
445 :    
446 :     A hash containing the results of grading the problem.
447 :    
448 :     =item state
449 :    
450 :     A hash containing the new problem state.
451 :    
452 :     =item errors
453 :    
454 :     A string containing any errors encountered while rendering the problem.
455 :    
456 :     =item warnings
457 :    
458 :     A string containing any warnings encountered while rendering the problem.
459 :    
460 :     =item flags
461 :    
462 :     A hash containing PG_flags (see the Translator docs).
463 :    
464 :     =back
465 :    
466 :     =head1 OPERATION
467 :    
468 :     WeBWorK::PG goes through the following operations when constructed:
469 :    
470 :     =over
471 :    
472 :     =item Get database information
473 :    
474 :     Retrieve information about the current user, set, and problem from the
475 :     database.
476 :    
477 :     =item Create a translator
478 :    
479 :     Instantiate a WeBWorK::PG::Translator object.
480 :    
481 :     =item Set the directory hash
482 :    
483 :     Set the translator's directory hash (courseScripts, macros, templates, and temp
484 :     directories) from the course environment.
485 :    
486 :     =item Evaluate PG modules
487 :    
488 :     Using the module list from the course environment (pg->modules), perform a
489 :     "use"-like operation to evaluate modules at runtime.
490 :    
491 :     =item Set the problem environment
492 :    
493 :     Use data from the user, set, and problem, as well as the course environemnt and
494 :     translation options, to set the problem environment.
495 :    
496 :     =item Initialize the translator
497 :    
498 :     Call &WeBWorK::PG::Translator::initialize. What more do you want?
499 :    
500 :     =item Load PG.pl and dangerousMacros.pl
501 :    
502 :     These macros must be loaded without opcode masking, so they are loaded here.
503 :    
504 :     =item Set the opcode mask
505 :    
506 :     Set the opcode mask to the default specified by WeBWorK::PG::Translator.
507 :    
508 :     =item Load the problem source
509 :    
510 :     Give the problem source to the translator.
511 :    
512 :     =item Install a safety filter
513 :    
514 :     The safety filter is used to preprocess student input before evaluation. The
515 :     default safety filter, &WeBWorK::PG::safetyFilter, is used.
516 :    
517 :     =item Translate the problem source
518 :    
519 :     Call &WeBWorK::PG::Translator::translate to render the problem source into the
520 :     format given by the display mode.
521 :    
522 :     =item Process student answers
523 :    
524 :     Use form field inputs to evaluate student answers.
525 :    
526 :     =item Load the problem state
527 :    
528 :     Use values from the database to initialize the problem state, so that the
529 :     grader will have a point of reference.
530 :    
531 :     =item Determine an entry order
532 :    
533 :     Use the ANSWER_ENTRY_ORDER flag to determine the order of answers in the
534 :     problem. This is important for problems with dependancies among parts.
535 :    
536 :     =item Install a grader
537 :    
538 :     Use the PROBLEM_GRADER_TO_USE flag, or a default from the course environment,
539 :     to install a grader.
540 :    
541 :     =item Grade the problem
542 :    
543 :     Use the selected grader to grade the problem.
544 :    
545 :     =back
546 :    
547 :     =head1 AUTHOR
548 :    
549 :     Written by Sam Hathaway, sh002i (at) math.rochester.edu.
550 :    
551 :     =cut

aubreyja at gmail dot com
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