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Revision 634 - (download) (as text) (annotate)
Wed Nov 20 19:12:44 2002 UTC (10 years, 7 months ago) by sh002i
File size: 18474 byte(s)
removed old comment.
-sam

    1 ################################################################################
    2 # WeBWorK mod_perl (c) 2000-2002 WeBWorK Project
    3 # $Id$
    4 ################################################################################
    5 
    6 package WeBWorK::ContentGenerator::Problem;
    7 
    8 =head1 NAME
    9 
   10 WeBWorK::ContentGenerator::Problem - Allow a student to interact with a problem.
   11 
   12 =cut
   13 
   14 use strict;
   15 use warnings;
   16 use base qw(WeBWorK::ContentGenerator);
   17 use CGI qw();
   18 use File::Temp qw(tempdir);
   19 use WeBWorK::Form;
   20 use WeBWorK::PG;
   21 use WeBWorK::PG::IO;
   22 use WeBWorK::Utils qw(writeLog encodeAnswers decodeAnswers ref2string);
   23 
   24 ############################################################
   25 #
   26 # user
   27 # key
   28 #
   29 # displayMode
   30 # showOldAnswers
   31 # showCorrectAnswers
   32 # showHints
   33 # showSolutions
   34 #
   35 # AnSwEr# - answer blanks in problem
   36 #
   37 # redisplay - name of the "Redisplay Problem" button
   38 # submitAnswers - name of "Submit Answers" button
   39 #
   40 ############################################################
   41 
   42 sub pre_header_initialize {
   43   my ($self, $setName, $problemNumber) = @_;
   44   my $courseEnv = $self->{courseEnvironment};
   45   my $r = $self->{r};
   46   my $userName = $r->param('user');
   47 
   48   ##### database setup #####
   49 
   50   my $cldb   = WeBWorK::DB::Classlist->new($courseEnv);
   51   my $wwdb   = WeBWorK::DB::WW->new($courseEnv);
   52   my $authdb = WeBWorK::DB::Auth->new($courseEnv);
   53 
   54   my $user            = $cldb->getUser($userName);
   55   my $set             = $wwdb->getSet($userName, $setName);
   56   my $problem         = $wwdb->getProblem($userName, $setName, $problemNumber);
   57   my $psvn            = $wwdb->getPSVN($userName, $setName);
   58   my $permissionLevel = $authdb->getPermissions($userName);
   59 
   60   ##### form processing #####
   61 
   62   # set options from form fields (see comment at top of file for names)
   63   my $displayMode        = $r->param("displayMode")        || $courseEnv->{pg}->{options}->{displayMode};
   64   my $redisplay          = $r->param("redisplay");
   65   my $submitAnswers      = $r->param("submitAnswers");
   66   my $previewAnswers     = $r->param("previewAnswers");
   67 
   68   # coerce form fields into CGI::Vars format
   69   my $formFields = { WeBWorK::Form->new_from_paramable($r)->Vars };
   70 
   71   ##### permissions #####
   72 
   73   # what does the user want to do?
   74   my %want = (
   75     showOldAnswers     => $r->param("showOldAnswers")     || $courseEnv->{pg}->{options}->{showOldAnswers},
   76     showCorrectAnswers => $r->param("showCorrectAnswers") || $courseEnv->{pg}->{options}->{showCorrectAnswers},
   77     showHints          => $r->param("showHints")          || $courseEnv->{pg}->{options}->{showHints},
   78     showSolutions      => $r->param("showSolutions")      || $courseEnv->{pg}->{options}->{showSolutions},
   79     recordAnswers      => $r->param("recordAnswers")      || 1,
   80   );
   81 
   82   # are certain options enforced?
   83   my %must = (
   84     showOldAnswers     => 0,
   85     showCorrectAnswers => 0,
   86     showHints          => 0,
   87     showSolutions      => 0,
   88     recordAnswers      => mustRecordAnswers($permissionLevel),
   89   );
   90 
   91   # does the user have permission to use certain options?
   92   my %can = (
   93     showOldAnswers     => 1,
   94     showCorrectAnswers => canShowCorrectAnswers($permissionLevel, $set->answer_date),
   95     showHints          => 1,
   96     showSolutions      => canShowSolutions($permissionLevel, $set->answer_date),
   97     recordAnswers      => canRecordAnswers($permissionLevel, $set->open_date, $set->due_date,
   98       $problem->max_attempts, $problem->num_correct + $problem->num_incorrect + 1),
   99       # num_correct+num_incorrect+1 -- as this happens before updating $problem
  100   );
  101 
  102   # final values for options
  103   my %will;
  104   foreach (keys %must) {
  105     $will{$_} = $can{$_} && ($want{$_} || $must{$_});
  106     #warn "$_: can? $can{$_} want? $want{$_} must? $must{$_} will? $will{$_}\n";
  107   }
  108 
  109   ##### sticky answers #####
  110 
  111   if (not $submitAnswers and $will{showOldAnswers}) {
  112     # do this only if new answers are NOT being submitted
  113     my %oldAnswers = decodeAnswers($problem->last_answer);
  114     $formFields->{$_} = $oldAnswers{$_} foreach keys %oldAnswers;
  115   }
  116 
  117   ##### translation #####
  118 
  119   my $pg = WeBWorK::PG->new(
  120     $courseEnv,
  121     $user,
  122     $r->param('key'),
  123     $set,
  124     $problem,
  125     $psvn,
  126     $formFields,
  127     { # translation options
  128       displayMode     => $displayMode,
  129       showHints       => $will{showHints},
  130       showSolutions   => $will{showSolutions},
  131       refreshMath2img => $will{showHints} || $will{showSolutions},
  132       # try leaving processAnswers on all the time?
  133       processAnswers  => 1, #$submitAnswers ? 1 : 0,
  134     },
  135   );
  136 
  137   ##### store fields #####
  138 
  139   $self->{cldb}            = $cldb;
  140   $self->{wwdb}            = $wwdb;
  141   $self->{authdb}          = $authdb;
  142 
  143   $self->{user}            = $user;
  144   $self->{set}             = $set;
  145   $self->{problem}         = $problem;
  146   $self->{permissionLevel} = $permissionLevel;
  147 
  148   $self->{displayMode}    = $displayMode;
  149   $self->{redisplay}      = $redisplay;
  150   $self->{submitAnswers}  = $submitAnswers;
  151   $self->{previewAnswers} = $previewAnswers;
  152   $self->{formFields}     = $formFields;
  153 
  154   $self->{want} = \%want;
  155   $self->{must} = \%must;
  156   $self->{can}  = \%can;
  157   $self->{will} = \%will;
  158 
  159   $self->{pg} = $pg;
  160 }
  161 
  162 sub if_warnings($$) {
  163   my ($self, $arg) = @_;
  164   return $self->{pg}->{warnings} ne "";
  165 }
  166 
  167 sub if_errors($$) {
  168   my ($self, $arg) = @_;
  169   return $self->{pg}->{flags}->{error_flag};
  170 }
  171 
  172 sub head {
  173   my $self = shift;
  174 
  175   return $self->{pg}->{head_text} if $self->{pg}->{head_text};
  176 }
  177 
  178 sub path {
  179   my $self = shift;
  180   my $args = $_[-1];
  181   my $setName = $self->{set}->id;
  182   my $problemNumber = $self->{problem}->id;
  183 
  184   my $ce = $self->{courseEnvironment};
  185   my $root = $ce->{webworkURLs}->{root};
  186   my $courseName = $ce->{courseName};
  187   return $self->pathMacro($args,
  188     "Home" => "$root",
  189     $courseName => "$root/$courseName",
  190     $setName => "$root/$courseName/$setName",
  191     "Problem $problemNumber" => "",
  192   );
  193 }
  194 
  195 sub siblings {
  196   my $self = shift;
  197   my $setName = $self->{set}->id;
  198   my $problemNumber = $self->{problem}->id;
  199 
  200   my $ce = $self->{courseEnvironment};
  201   my $root = $ce->{webworkURLs}->{root};
  202   my $courseName = $ce->{courseName};
  203 
  204   print CGI::strong("Problems"), CGI::br();
  205 
  206   my $wwdb = $self->{wwdb};
  207   my $user = $self->{r}->param("user");
  208   my @problems;
  209   push @problems, $wwdb->getProblem($user, $setName, $_)
  210     foreach ($wwdb->getProblems($user, $setName));
  211   foreach my $problem (sort { $a->id <=> $b->id } @problems) {
  212     print CGI::a({-href=>"$root/$courseName/$setName/".$problem->id."/?"
  213       . $self->url_authen_args}, "Problem ".$problem->id), CGI::br();
  214   }
  215 }
  216 
  217 sub nav {
  218   my $self = shift;
  219   my $args = $_[-1];
  220   my $setName = $self->{set}->id;
  221   my $problemNumber = $self->{problem}->id;
  222 
  223   my $ce = $self->{courseEnvironment};
  224   my $root = $ce->{webworkURLs}->{root};
  225   my $courseName = $ce->{courseName};
  226 
  227   my $wwdb = $self->{wwdb};
  228   my $user = $self->{r}->param("user");
  229 
  230   my @links = ("Problem List" => "$root/$courseName/$setName");
  231 
  232   my $prevProblem = $wwdb->getProblem($user, $setName, $problemNumber-1);
  233   my $nextProblem = $wwdb->getProblem($user, $setName, $problemNumber+1);
  234   unshift @links, "Previous Problem" => $prevProblem
  235     ? "$root/$courseName/$setName/".$prevProblem->id
  236     : "";
  237   push @links, "Next Problem" => $nextProblem
  238     ? "$root/$courseName/$setName/".$nextProblem->id
  239     : "";
  240 
  241   return $self->navMacro($args, @links);
  242 }
  243 
  244 sub title {
  245   my $self = shift;
  246   my $setName = $self->{set}->id;
  247   my $problemNumber = $self->{problem}->id;
  248 
  249   return "$setName : Problem $problemNumber";
  250 }
  251 
  252 sub body {
  253   my $self = shift;
  254 
  255   # unpack some useful variables
  256   my $r               = $self->{r};
  257   my $wwdb            = $self->{wwdb};
  258   my $set             = $self->{set};
  259   my $problem         = $self->{problem};
  260   my $permissionLevel = $self->{permissionLevel};
  261   my $submitAnswers   = $self->{submitAnswers};
  262   my $previewAnswers  = $self->{previewAnswers};
  263   my %will            = %{ $self->{will} };
  264   my $pg              = $self->{pg};
  265 
  266   ##### translation errors? #####
  267 
  268   if ($pg->{flags}->{error_flag}) {
  269     return translationError($pg->{errors}, $pg->{body_text});
  270   }
  271 
  272   ##### answer processing #####
  273 
  274   # if answers were submitted:
  275   if ($submitAnswers) {
  276     # store answers in DB for sticky answers
  277     my %answersToStore;
  278     my %answerHash = %{ $pg->{answers} };
  279     $answersToStore{$_} = $answerHash{$_}->{original_student_ans}
  280       foreach (keys %answerHash);
  281     my $answerString = encodeAnswers(%answersToStore,
  282       @{ $pg->{flags}->{ANSWER_ENTRY_ORDER} });
  283     $problem->last_answer($answerString);
  284     $wwdb->setProblem($problem);
  285 
  286     # store state in DB if it makes sense
  287     if ($will{recordAnswers}) {
  288       $problem->attempted(1);
  289       $problem->status($pg->{state}->{recorded_score});
  290       $problem->num_correct($pg->{state}->{num_of_correct_ans});
  291       $problem->num_incorrect($pg->{state}->{num_of_incorrect_ans});
  292       $wwdb->setProblem($problem);
  293       # write to the transaction log, just to make sure
  294       writeLog($self->{courseEnvironment}, "transaction",
  295         $problem->id."\t".
  296         $problem->set_id."\t".
  297         $problem->login_id."\t".
  298         $problem->source_file."\t".
  299         $problem->value."\t".
  300         $problem->max_attempts."\t".
  301         $problem->problem_seed."\t".
  302         $problem->status."\t".
  303         $problem->attempted."\t".
  304         $problem->last_answer."\t".
  305         $problem->num_correct."\t".
  306         $problem->num_incorrect
  307       );
  308     }
  309   }
  310 
  311   ##### output #####
  312 
  313   # attempt summary
  314   if ($submitAnswers or $will{showCorrectAnswers}) {
  315     # print this if user submitted answers OR requested correct answers
  316     print $self->attemptResults($pg, $submitAnswers, $will{showCorrectAnswers},
  317       $pg->{flags}->{showPartialCorrectAnswers});
  318   } elsif ($previewAnswers) {
  319     # print this if user previewed answers
  320     print $self->attemptResults($pg, 1, 0, 0);
  321       # don't show correctness
  322       # don't show correct answers
  323   }
  324 
  325   # score summary
  326   my $attempts = $problem->num_correct + $problem->num_incorrect;
  327   my $attemptsNoun = $attempts != 1 ? "times" : "time";
  328   my $lastScore = int ($problem->status * 100) . "%";
  329   my ($attemptsLeft, $attemptsLeftNoun);
  330   if ($problem->max_attempts == -1) {
  331     # unlimited attempts
  332     $attemptsLeft = "unlimited";
  333     $attemptsLeftNoun = "attempts";
  334   } else {
  335     $attemptsLeft = $problem->max_attempts - $attempts;
  336     $attemptsLeftNoun = $attemptsLeft == 1 ? "attempt" : "attempts";
  337   }
  338   my $setClosedMessage;
  339   if (time < $set->open_date or time > $set->due_date) {
  340     $setClosedMessage = "This problem set is closed.";
  341     if ($permissionLevel > 0) {
  342       $setClosedMessage .= " Since you are a privileged user, additional attempts will be recorded.";
  343     } else {
  344       $setClosedMessage .= " Additional attempts will not be recorded.";
  345     }
  346   }
  347   print CGI::p(
  348     "You have attempted this problem $attempts $attemptsNoun.", CGI::br(),
  349     $problem->attempted
  350       ? "Your recorded score is $lastScore." . CGI::br()
  351       : "",
  352     "You have $attemptsLeft $attemptsLeftNoun remaining.", CGI::br(),
  353     $setClosedMessage,
  354   );
  355 
  356   print CGI::hr();
  357 
  358   # main form
  359   print
  360     CGI::startform("POST", $r->uri),
  361     $self->hidden_authen_fields,
  362     $self->viewOptions,
  363     CGI::p(CGI::i($pg->{result}->{msg})),
  364     CGI::p($pg->{body_text}),
  365     CGI::p(
  366       CGI::submit(-name=>"submitAnswers", -label=>"Submit Answers"),
  367       CGI::submit(-name=>"previewAnswers", -label=>"Preview Answers"),
  368     ),
  369     CGI::endform();
  370 
  371   # warning output
  372   if ($pg->{warnings} ne "") {
  373     print CGI::hr(), warningOutput($pg->{warnings});
  374   }
  375 
  376   # debugging stuff
  377   #print
  378   # CGI::hr(),
  379   # CGI::h2("debugging information"),
  380   # CGI::h3("form fields"),
  381   # ref2string($self->{formFields}),
  382   # CGI::h3("user object"),
  383   # ref2string($self->{user}),
  384   # CGI::h3("set object"),
  385   # ref2string($set),
  386   # CGI::h3("problem object"),
  387   # ref2string($problem),
  388   # CGI::h3("PG object"),
  389   # ref2string($pg, {'WeBWorK::PG::Translator' => 1});
  390 
  391   return "";
  392 }
  393 
  394 ##### output utilities #####
  395 
  396 # this is used by ProblemSet.pm too, so don't fuck it up
  397 sub translationError($$) {
  398   my ($error, $details) = @_;
  399   return
  400     CGI::h2("Software Error"),
  401     CGI::p(<<EOF),
  402 WeBWorK has encountered a software error while attempting to process this problem.
  403 It is likely that there is an error in the problem itself.
  404 If you are a student, contact your professor to have the error corrected.
  405 If you are a professor, please consut the error output below for more informaiton.
  406 EOF
  407     CGI::h3("Error messages"), CGI::blockquote(CGI::pre($error)),
  408     CGI::h3("Error context"), CGI::blockquote(CGI::pre($details));
  409 }
  410 
  411 # this is used by ProblemSet.pm too, so don't fuck it up
  412 sub warningOutput($) {
  413   my $warnings = shift;
  414 
  415   return
  416     CGI::h2("Software Warnings"),
  417     CGI::p(<<EOF),
  418 WeBWorK has encountered warnings while attempting to process this problem.
  419 It is likely that this indicates an error or ambiguity in the problem itself.
  420 If you are a student, contact your professor to have the problem corrected.
  421 If you are a professor, please consut the error output below for more informaiton.
  422 EOF
  423     CGI::h3("Warning messages"),
  424     CGI::blockquote(CGI::pre($warnings)),
  425   ;
  426 }
  427 
  428 sub attemptResults($$$$$) {
  429   my $self = shift;
  430   my $pg = shift;
  431   my $showAttemptAnswers = shift;
  432   my $showCorrectAnswers = shift;
  433   my $showAttemptResults = $showAttemptAnswers && shift;
  434   my $problemResult = $pg->{result}; # the overall result of the problem
  435   my @answerNames = @{ $pg->{flags}->{ANSWER_ENTRY_ORDER} };
  436 
  437   my $header = CGI::th("answer");
  438   $header .= $showAttemptAnswers ? CGI::th("attempt")  : "";
  439   $header .= $showAttemptAnswers ? CGI::th("preview")  : "";
  440   $header .= $showCorrectAnswers ? CGI::th("correct")  : "";
  441   $header .= $showAttemptResults ? CGI::th("result")   : "";
  442   $header .= $showAttemptAnswers ? CGI::th("messages") : "";
  443   my @tableRows = ( $header );
  444   my $numCorrect;
  445   foreach my $name (@answerNames) {
  446     my $answerResult  = $pg->{answers}->{$name};
  447     my $studentAnswer = $answerResult->{student_ans}; # original_student_ans
  448     my $preview       = $self->previewAnswer($answerResult);
  449     my $correctAnswer = $answerResult->{correct_ans};
  450     my $answerScore   = $answerResult->{score};
  451     my $answerMessage = $showAttemptAnswers ? $answerResult->{ans_message} : "";
  452 
  453     $numCorrect += $answerScore > 0;
  454     my $resultString = $answerScore ? "correct" : "incorrect";
  455 
  456     # get rid of the goofy prefix on the answer names (supposedly, the format
  457     # of the answer names is changeable. this only fixes
  458     $name =~ s/^AnSwEr//;
  459 
  460     my $row = CGI::td($name);
  461     $row .= $showAttemptAnswers ? CGI::td($studentAnswer) : "";
  462     $row .= $showAttemptAnswers ? CGI::td($preview)       : "";
  463     $row .= $showCorrectAnswers ? CGI::td($correctAnswer) : "";
  464     $row .= $showAttemptResults ? CGI::td($resultString)  : "";
  465     $row .= $answerMessage      ? CGI::td($answerMessage) : "";
  466     push @tableRows, $row;
  467   }
  468 
  469   my $numCorrectNoun = $numCorrect == 1 ? "question" : "questions";
  470   my $scorePercent = int ($problemResult->{score} * 100) . "\%";
  471   my $summary = "On this attempt, you answered $numCorrect $numCorrectNoun out of "
  472     . scalar @answerNames . " correct, for a score of $scorePercent.";
  473   return CGI::table({-border=>1}, CGI::Tr(\@tableRows)) . CGI::p($summary);
  474 }
  475 
  476 sub viewOptions($) {
  477   my $self = shift;
  478   my $displayMode = $self->{displayMode};
  479   my %must = %{ $self->{must} };
  480   my %can  = %{ $self->{can}  };
  481   my %will = %{ $self->{will} };
  482 
  483   my $optionLine;
  484   $can{showOldAnswers} and $optionLine .= join "",
  485     "Show: &nbsp;",
  486     CGI::checkbox(
  487       -name    => "showOldAnswers",
  488       -checked => $will{showOldAnswers},
  489       -label   => "Saved answers",
  490     ), "&nbsp;&nbsp;";
  491   $can{showCorrectAnswers} and $optionLine .= join "",
  492     CGI::checkbox(
  493       -name    => "showCorrectAnswers",
  494       -checked => $will{showCorrectAnswers},
  495       -label   => "Correct answers",
  496     ), "&nbsp;&nbsp;";
  497   $can{showHints} and $optionLine .= join "",
  498     CGI::checkbox(
  499       -name    => "showHints",
  500       -checked => $will{showHints},
  501       -label   => "Hints",
  502     ), "&nbsp;&nbsp;";
  503   $can{showSolutions} and $optionLine .= join "",
  504     CGI::checkbox(
  505       -name    => "showSolutions",
  506       -checked => $will{showSolutions},
  507       -label   => "Solutions",
  508     ), "&nbsp;&nbsp;";
  509   $optionLine and $optionLine .= join "", CGI::br();
  510 
  511   return CGI::div({-style=>"border: thin groove; padding: 1ex; margin: 2ex"},
  512       "View equations as: &nbsp;",
  513     CGI::radio_group(
  514       -name    => "displayMode",
  515       -values  => ['plainText', 'formattedText', 'images'],
  516       -default => $displayMode,
  517       -labels  => {
  518         plainText     => "plain text",
  519         formattedText => "formatted text",
  520         images        => "images",
  521       }
  522     ), CGI::br(),
  523     $optionLine,
  524     CGI::submit(-name=>"redisplay", -label=>"Redisplay Problem"),
  525   );
  526 }
  527 
  528 sub previewAnswer($$) {
  529   my ($self, $answerResult) = @_;
  530   my $ce      = $self->{courseEnvironment};
  531   my $user    = $self->{user};
  532   my $set     = $self->{set};
  533   my $problem = $self->{problem};
  534 
  535   # how are we going to name this?
  536   my $targetPathCommon = "/png/"
  537     . $user->id . "."
  538     . $set->id . "."
  539     . $problem->id . "."
  540     . $answerResult->{ans_name} . ".png";
  541 
  542   # figure out where to put things
  543   my $wd = tempdir("webwork-dvipng-XXXXXXXX", DIR => $ce->{courseDirs}->{html_temp});
  544   my $latex = $ce->{externalPrograms}->{latex};
  545   my $dvipng = $ce->{externalPrograms}->{dvipng};
  546   my $tex = $answerResult->{preview_latex_string};
  547   my $targetPath = $ce->{courseDirs}->{html_temp} . $targetPathCommon;
  548       # should use surePathToTmpFile, but we have to
  549       # isolate it from the problem enivronment first
  550   my $targetURL = $ce->{courseURLs}->{html_temp} . $targetPathCommon;
  551 
  552   # call dvipng to generate a preview
  553   dvipng($wd, $latex, $dvipng, $tex, $targetPath);
  554   if (-e $targetPath) {
  555     return "<img src=\"$targetURL\" alt=\"$tex\" />";
  556   } else {
  557     return "<b>[math2img failed]</b>";
  558   }
  559 }
  560 
  561 ##### permission queries #####
  562 
  563 # this stuff should be abstracted out into the permissions system
  564 # however, the permission system only knows about things in the
  565 # course environment and the username. hmmm...
  566 
  567 # also, i should fix these so that they have a consistent calling
  568 # format -- perhaps:
  569 #   canPERM($courseEnv, $user, $set, $problem, $permissionLevel)
  570 
  571 sub canShowCorrectAnswers($$) {
  572   my ($permissionLevel, $answerDate) = @_;
  573   return $permissionLevel > 0 || time > $answerDate;
  574 }
  575 
  576 sub canShowSolutions($$) {
  577   my ($permissionLevel, $answerDate) = @_;
  578   return canShowCorrectAnswers($permissionLevel, $answerDate);
  579 }
  580 
  581 sub canRecordAnswers($$$$$) {
  582   my ($permissionLevel, $openDate, $dueDate, $maxAttempts, $attempts) = @_;
  583   my $permHigh = $permissionLevel > 0;
  584   my $timeOK = time >= $openDate && time <= $dueDate;
  585   my $attemptsOK = $maxAttempts == -1 || $attempts <= $maxAttempts;
  586   my $recordAnswers = $permHigh || ($timeOK && $attemptsOK);
  587   return $recordAnswers;
  588 }
  589 
  590 sub mustRecordAnswers($) {
  591   my ($permissionLevel) = @_;
  592   return $permissionLevel == 0;
  593 }
  594 
  595 1;

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