question/format/gift/format.php

   1 <?php // $Id$
   2 //
   3 ///////////////////////////////////////////////////////////////
   4 // The GIFT import filter was designed as an easy to use method
   5 // for teachers writing questions as a text file. It supports most
   6 // question types and the missing word format.
   7 //
   8 // Multiple Choice / Missing Word
   9 //     Who's buried in Grant's tomb?{~Grant ~Jefferson =no one}
  10 //     Grant is {~buried =entombed ~living} in Grant's tomb.
  11 // True-False:
  12 //     Grant is buried in Grant's tomb.{FALSE}
  13 // Short-Answer.
  14 //     Who's buried in Grant's tomb?{=no one =nobody}
  15 // Numerical
  16 //     When was Ulysses S. Grant born?{#1822:5}
  17 // Matching
  18 //     Match the following countries with their corresponding
  19 //     capitals.{=Canada->Ottawa =Italy->Rome =Japan->Tokyo}
  20 //
  21 // Comment lines start with a double backslash (//).
  22 // Optional question names are enclosed in double colon(::).
  23 // Answer feedback is indicated with hash mark (#).
  24 // Percentage answer weights immediately follow the tilde (for
  25 // multiple choice) or equal sign (for short answer and numerical),
  26 // and are enclosed in percent signs (% %). See docs and examples.txt for more.
  27 //
  28 // This filter was written through the collaboration of numerous
  29 // members of the Moodle community. It was originally based on
  30 // the missingword format, which included code from Thomas Robb
  31 // and others. Paul Tsuchido Shew wrote this filter in December 2003.
  32 //////////////////////////////////////////////////////////////////////////
  33 // Based on default.php, included by ../import.php
  34 /**
  35  * @package questionbank
  36  * @subpackage importexport
  37  */
  38 class qformat_gift extends qformat_default {
  39
  40     function provide_import() {
  41         return true;
  42     }
  43
  44     function provide_export() {
  45         return true;
  46     }
  47
  48     function answerweightparser(&$answer) {
  49         $answer = substr($answer, 1);                        // removes initial %
  50         $end_position  = strpos($answer, "%");
  51         $answer_weight = substr($answer, 0, $end_position);  // gets weight as integer
  52         $answer_weight = $answer_weight/100;                 // converts to percent
  53         $answer = substr($answer, $end_position+1);          // removes comment from answer
  54         return $answer_weight;
  55     }
  56
  57
  58     function commentparser(&$answer) {
  59         if (strpos($answer,"#") > 0){
  60             $hashpos = strpos($answer,"#");
  61             $comment = substr($answer, $hashpos+1);
  62             $comment = addslashes(trim($this->escapedchar_post($comment)));
  63             $answer  = substr($answer, 0, $hashpos);
  64         } else {
  65             $comment = " ";
  66         }
  67         return $comment;
  68     }
  69
  70     function split_truefalse_comment($comment){
  71         // splits up comment around # marks
  72         // returns an array of true/false feedback
  73         $bits = explode('#',$comment);
  74         $feedback = array('wrong' => $bits[0]);
  75         if (count($bits) >= 2) {
  76             $feedback['right'] = $bits[1];
  77         } else {
  78             $feedback['right'] = '';
  79         }
  80         return $feedback;
  81     }
  82
  83     function escapedchar_pre($string) {
  84         //Replaces escaped control characters with a placeholder BEFORE processing
  85
  86         $escapedcharacters = array("\\:",    "\\#",    "\\=",    "\\{",    "\\}",    "\\~",    "\\n"   );  //dlnsk
  87         $placeholders      = array("&&058;", "&&035;", "&&061;", "&&123;", "&&125;", "&&126;", "&&010" );  //dlnsk
  88
  89         $string = str_replace("\\\\", "&&092;", $string);
  90         $string = str_replace($escapedcharacters, $placeholders, $string);
  91         $string = str_replace("&&092;", "\\", $string);
  92         return $string;
  93     }
  94
  95     function escapedchar_post($string) {
  96         //Replaces placeholders with corresponding character AFTER processing is done
  97         $placeholders = array("&&058;", "&&035;", "&&061;", "&&123;", "&&125;", "&&126;", "&&010"); //dlnsk
  98         $characters   = array(":",     "#",      "=",      "{",      "}",      "~",      "\n"   ); //dlnsk
  99         $string = str_replace($placeholders, $characters, $string);
 100         return $string;
 101     }
 102
 103     function check_answer_count( $min, $answers, $text ) {
 104         $countanswers = count($answers);
 105         if ($countanswers < $min) {
 106             $importminerror = get_string( 'importminerror', 'quiz' );
 107             $this->error( $importminerror, $text );
 108             return false;
 109         }
 110
 111         return true;
 112     }
 113
 114
 115     function readquestion($lines) {
 116     // Given an array of lines known to define a question in this format, this function
 117     // converts it into a question object suitable for processing and insertion into Moodle.
 118
 119         $question = $this->defaultquestion();
 120         $comment = NULL;
 121         // define replaced by simple assignment, stop redefine notices
 122         $gift_answerweight_regex = "^%\-*([0-9]{1,2})\.?([0-9]*)%";
 123
 124         // REMOVED COMMENTED LINES and IMPLODE
 125         foreach ($lines as $key => $line) {
 126             $line = trim($line);
 127             if (substr($line, 0, 2) == "//") {
 128                 $lines[$key] = " ";
 129             }
 130         }
 131
 132         $text = trim(implode(" ", $lines));
 133
 134         if ($text == "") {
 135             return false;
 136         }
 137
 138         // Substitute escaped control characters with placeholders
 139         $text = $this->escapedchar_pre($text);
 140
 141         // Look for category modifier
 142         if (ereg( '^\$CATEGORY:', $text)) {
 143             // $newcategory = $matches[1];
 144             $newcategory = trim(substr( $text, 10 ));
 145
 146             // build fake question to contain category
 147             $question->qtype = 'category';
 148             $question->category = $newcategory;
 149             return $question;
 150         }
 151
 152         // QUESTION NAME parser
 153         if (substr($text, 0, 2) == "::") {
 154             $text = substr($text, 2);
 155
 156             $namefinish = strpos($text, "::");
 157             if ($namefinish === false) {
 158                 $question->name = false;
 159                 // name will be assigned after processing question text below
 160             } else {
 161                 $questionname = substr($text, 0, $namefinish);
 162                 $question->name = addslashes(trim($this->escapedchar_post($questionname)));
 163                 $text = trim(substr($text, $namefinish+2)); // Remove name from text
 164             }
 165         } else {
 166             $question->name = false;
 167         }
 168
 169
 170         // FIND ANSWER section
 171         // no answer means its a description
 172         $answerstart = strpos($text, "{");
 173         $answerfinish = strpos($text, "}");
 174
 175         $description = false;
 176         if (($answerstart === false) and ($answerfinish === false)) {
 177             $description = true;
 178             $answertext = '';
 179             $answerlength = 0;
 180         }
 181         elseif (!(($answerstart !== false) and ($answerfinish !== false))) {
 182             $this->error( get_string( 'braceerror', 'quiz' ), $text );
 183             return false;
 184         }
 185         else {
 186             $answerlength = $answerfinish - $answerstart;
 187             $answertext = trim(substr($text, $answerstart + 1, $answerlength - 1));
 188         }
 189
 190         // Format QUESTION TEXT without answer, inserting "_____" as necessary
 191         if ($description) {
 192             $questiontext = $text;
 193         }
 194         elseif (substr($text, -1) == "}") {
 195             // no blank line if answers follow question, outside of closing punctuation
 196             $questiontext = substr_replace($text, "", $answerstart, $answerlength+1);
 197         } else {
 198             // inserts blank line for missing word format
 199             $questiontext = substr_replace($text, "_____", $answerstart, $answerlength+1);
 200         }
 201
 202         // get questiontext format from questiontext
 203         $oldquestiontext = $questiontext;
 204         $questiontextformat = 0;
 205         if (substr($questiontext,0,1)=='[') {
 206             $questiontext = substr( $questiontext,1 );
 207             $rh_brace = strpos( $questiontext, ']' );
 208             $qtformat= substr( $questiontext, 0, $rh_brace );
 209             $questiontext = substr( $questiontext, $rh_brace+1 );
 210             if (!$questiontextformat = text_format_name( $qtformat )) {
 211                 $questiontext = $oldquestiontext;
 212             }
 213         }
 214         $question->questiontextformat = $questiontextformat;
 215         $question->questiontext = addslashes(trim($this->escapedchar_post($questiontext)));
 216
 217         // set question name if not already set
 218         if ($question->name === false) {
 219             $question->name = $question->questiontext;
 220             }
 221
 222         // ensure name is not longer than 250 characters
 223         $question->name = shorten_text( $question->name, 200 );
 224         $question->name = strip_tags(substr( $question->name, 0, 250 ));
 225
 226         // determine QUESTION TYPE
 227         $question->qtype = NULL;
 228
 229         // give plugins first try
 230         // plugins must promise not to intercept standard qtypes
 231         // MDL-12346, this could be called from lesson mod which has its own base class =(
 232         if (method_exists($this, 'try_importing_using_qtypes') && ($try_question = $this->try_importing_using_qtypes( $lines, $question, $answertext ))) {
 233             return $try_question;
 234         }
 235
 236         if ($description) {
 237             $question->qtype = DESCRIPTION;
 238         }
 239         elseif ($answertext == '') {
 240             $question->qtype = ESSAY;
 241         }
 242         elseif ($answertext{0} == "#"){
 243             $question->qtype = NUMERICAL;
 244
 245         } elseif (strpos($answertext, "~") !== false)  {
 246             // only Multiplechoice questions contain tilde ~
 247             $question->qtype = MULTICHOICE;
 248
 249         } elseif (strpos($answertext, "=")  !== false
 250                 && strpos($answertext, "->") !== false) {
 251             // only Matching contains both = and ->
 252             $question->qtype = MATCH;
 253
 254         } else { // either TRUEFALSE or SHORTANSWER
 255
 256             // TRUEFALSE question check
 257             $truefalse_check = $answertext;
 258             if (strpos($answertext,"#") > 0){
 259                 // strip comments to check for TrueFalse question
 260                 $truefalse_check = trim(substr($answertext, 0, strpos($answertext,"#")));
 261             }
 262
 263             $valid_tf_answers = array("T", "TRUE", "F", "FALSE");
 264             if (in_array($truefalse_check, $valid_tf_answers)) {
 265                 $question->qtype = TRUEFALSE;
 266
 267             } else { // Must be SHORTANSWER
 268                     $question->qtype = SHORTANSWER;
 269             }
 270         }
 271
 272         if (!isset($question->qtype)) {
 273             $giftqtypenotset = get_string('giftqtypenotset','quiz');
 274             $this->error( $giftqtypenotset, $text );
 275             return false;
 276         }
 277
 278         switch ($question->qtype) {
 279             case DESCRIPTION:
 280                 $question->defaultgrade = 0;
 281                 $question->length = 0;
 282                 return $question;
 283                 break;
 284             case ESSAY:
 285                 $question->feedback = '';
 286                 $question->fraction = 0;
 287                 return $question;
 288                 break;
 289             case MULTICHOICE:
 290                 if (strpos($answertext,"=") === false) {
 291                     $question->single = 0;   // multiple answers are enabled if no single answer is 100% correct
 292                 } else {
 293                     $question->single = 1;   // only one answer allowed (the default)
 294                 }
 295
 296                 $answertext = str_replace("=", "~=", $answertext);
 297                 $answers = explode("~", $answertext);
 298                 if (isset($answers[0])) {
 299                     $answers[0] = trim($answers[0]);
 300                 }
 301                 if (empty($answers[0])) {
 302                     array_shift($answers);
 303                 }
 304
 305                 $countanswers = count($answers);
 306
 307                 if (!$this->check_answer_count( 2,$answers,$text )) {
 308                     return false;
 309                     break;
 310                 }
 311
 312                 foreach ($answers as $key => $answer) {
 313                     $answer = trim($answer);
 314
 315                     // determine answer weight
 316                     if ($answer[0] == "=") {
 317                         $answer_weight = 1;
 318                         $answer = substr($answer, 1);
 319
 320                     } elseif (ereg($gift_answerweight_regex, $answer)) {    // check for properly formatted answer weight
 321                         $answer_weight = $this->answerweightparser($answer);
 322
 323                     } else {     //default, i.e., wrong anwer
 324                         $answer_weight = 0;
 325                     }
 326                     $question->fraction[$key] = $answer_weight;
 327                     $question->feedback[$key] = $this->commentparser($answer); // commentparser also removes comment from $answer
 328                     $question->answer[$key]   = addslashes($this->escapedchar_post($answer));
 329                     $question->correctfeedback = '';
 330                     $question->partiallycorrectfeedback = '';
 331                     $question->incorrectfeedback = '';
 332                 }  // end foreach answer
 333
 334                 //$question->defaultgrade = 1;
 335                 //$question->image = "";   // No images with this format
 336                 return $question;
 337                 break;
 338
 339             case MATCH:
 340                 $answers = explode("=", $answertext);
 341                 if (isset($answers[0])) {
 342                     $answers[0] = trim($answers[0]);
 343                 }
 344                 if (empty($answers[0])) {
 345                     array_shift($answers);
 346                 }
 347
 348                 if (!$this->check_answer_count( 2,$answers,$text )) {
 349                     return false;
 350                     break;
 351                 }
 352
 353                 foreach ($answers as $key => $answer) {
 354                     $answer = trim($answer);
 355                     if (strpos($answer, "->") === false) {
 356                         $giftmatchingformat = get_string('giftmatchingformat','quiz');
 357                         $this->error($giftmatchingformat, $answer );
 358                         return false;
 359                         break 2;
 360                     }
 361
 362                     $marker = strpos($answer,"->");
 363                     $question->subquestions[$key] = addslashes(trim($this->escapedchar_post(substr($answer, 0, $marker))));
 364                     $question->subanswers[$key]   = addslashes(trim($this->escapedchar_post(substr($answer, $marker+2))));
 365
 366                 }  // end foreach answer
 367
 368                 return $question;
 369                 break;
 370
 371             case TRUEFALSE:
 372                 $answer = $answertext;
 373                 $comment = $this->commentparser($answer); // commentparser also removes comment from $answer
 374                 $feedback = $this->split_truefalse_comment($comment);
 375
 376                 if ($answer == "T" OR $answer == "TRUE") {
 377                     $question->answer = 1;
 378                     $question->feedbacktrue = $feedback['right'];
 379                     $question->feedbackfalse = $feedback['wrong'];
 380                 } else {
 381                     $question->answer = 0;
 382                     $question->feedbackfalse = $feedback['right'];
 383                     $question->feedbacktrue = $feedback['wrong'];
 384                 }
 385
 386                 $question->penalty = 1;
 387                 $question->correctanswer = $question->answer;
 388
 389                 return $question;
 390                 break;
 391
 392             case SHORTANSWER:
 393                 // SHORTANSWER Question
 394                 $answers = explode("=", $answertext);
 395                 if (isset($answers[0])) {
 396                     $answers[0] = trim($answers[0]);
 397                 }
 398                 if (empty($answers[0])) {
 399                     array_shift($answers);
 400                 }
 401
 402                 if (!$this->check_answer_count( 1,$answers,$text )) {
 403                     return false;
 404                     break;
 405                 }
 406
 407                 foreach ($answers as $key => $answer) {
 408                     $answer = trim($answer);
 409
 410                     // Answer Weight
 411                     if (ereg($gift_answerweight_regex, $answer)) {    // check for properly formatted answer weight
 412                         $answer_weight = $this->answerweightparser($answer);
 413                     } else {     //default, i.e., full-credit anwer
 414                         $answer_weight = 1;
 415                     }
 416                     $question->fraction[$key] = $answer_weight;
 417                     $question->feedback[$key] = $this->commentparser($answer); //commentparser also removes comment from $answer
 418                     $question->answer[$key]   = addslashes($this->escapedchar_post($answer));
 419                 }     // end foreach
 420
 421                 //$question->usecase = 0;  // Ignore case
 422                 //$question->defaultgrade = 1;
 423                 //$question->image = "";   // No images with this format
 424                 return $question;
 425                 break;
 426
 427             case NUMERICAL:
 428                 // Note similarities to ShortAnswer
 429                 $answertext = substr($answertext, 1); // remove leading "#"
 430
 431                 // If there is feedback for a wrong answer, store it for now.
 432                 if (($pos = strpos($answertext, '~')) !== false) {
 433                     $wrongfeedback = substr($answertext, $pos);
 434                     $answertext = substr($answertext, 0, $pos);
 435                 } else {
 436                     $wrongfeedback = '';
 437                 }
 438
 439                 $answers = explode("=", $answertext);
 440                 if (isset($answers[0])) {
 441                     $answers[0] = trim($answers[0]);
 442                 }
 443                 if (empty($answers[0])) {
 444                     array_shift($answers);
 445                 }
 446
 447                 if (count($answers) == 0) {
 448                     // invalid question
 449                     $giftnonumericalanswers = get_string('giftnonumericalanswers','quiz');
 450                     $this->error( $giftnonumericalanswers, $text );
 451                     return false;
 452                     break;
 453                 }
 454
 455                 foreach ($answers as $key => $answer) {
 456                     $answer = trim($answer);
 457
 458                     // Answer weight
 459                     if (ereg($gift_answerweight_regex, $answer)) {    // check for properly formatted answer weight
 460                         $answer_weight = $this->answerweightparser($answer);
 461                     } else {     //default, i.e., full-credit anwer
 462                         $answer_weight = 1;
 463                     }
 464                     $question->fraction[$key] = $answer_weight;
 465                     $question->feedback[$key] = $this->commentparser($answer); //commentparser also removes comment from $answer
 466
 467                     //Calculate Answer and Min/Max values
 468                     if (strpos($answer,"..") > 0) { // optional [min]..[max] format
 469                         $marker = strpos($answer,"..");
 470                         $max = trim(substr($answer, $marker+2));
 471                         $min = trim(substr($answer, 0, $marker));
 472                         $ans = ($max + $min)/2;
 473                         $tol = $max - $ans;
 474                     } elseif (strpos($answer,":") > 0){ // standard [answer]:[errormargin] format
 475                         $marker = strpos($answer,":");
 476                         $tol = trim(substr($answer, $marker+1));
 477                         $ans = trim(substr($answer, 0, $marker));
 478                     } else { // only one valid answer (zero errormargin)
 479                         $tol = 0;
 480                         $ans = trim($answer);
 481                     }
 482
 483                     if (!(is_numeric($ans) || $ans = '*') || !is_numeric($tol)) {
 484                             $errornotnumbers = get_string( 'errornotnumbers' );
 485                             $this->error( $errornotnumbers, $text );
 486                         return false;
 487                         break;
 488                     }
 489
 490                     // store results
 491                     $question->answer[$key] = $ans;
 492                     $question->tolerance[$key] = $tol;
 493                 } // end foreach
 494
 495                 if ($wrongfeedback) {
 496                     $key += 1;
 497                     $question->fraction[$key] = 0;
 498                     $question->feedback[$key] = $this->commentparser($wrongfeedback);
 499                     $question->answer[$key] = '';
 500                     $question->tolerance[$key] = '';
 501                 }
 502
 503                 return $question;
 504                 break;
 505
 506                 default:
 507                     $giftnovalidquestion = get_string('giftnovalidquestion','quiz');
 508                     $this->error( $giftnovalidquestion, $text );
 509                 return false;
 510                 break;
 511
 512         } // end switch ($question->qtype)
 513
 514     }    // end function readquestion($lines)
 515
 516 function repchar( $text, $format=0 ) {
 517     // escapes 'reserved' characters # = ~ { ) : and removes new lines
 518     // also pushes text through format routine
 519     $reserved = array( '#', '=', '~', '{', '}', ':', "\n","\r");
 520     $escaped =  array( '\#','\=','\~','\{','\}','\:','\n',''  ); //dlnsk
 521
 522     $newtext = str_replace( $reserved, $escaped, $text );
 523     $format = 0; // turn this off for now
 524     if ($format) {
 525         $newtext = format_text( $format );
 526     }
 527     return $newtext;
 528     }
 529
 530 function writequestion( $question ) {
 531     // turns question into string
 532     // question reflects database fields for general question and specific to type
 533
 534     // initial string;
 535     $expout = "";
 536
 537     // add comment
 538     $expout .= "// question: $question->id  name: $question->name \n";
 539
 540     // get  question text format
 541     $textformat = $question->questiontextformat;
 542     $tfname = "";
 543     if ($textformat!=FORMAT_MOODLE) {
 544         $tfname = text_format_name( (int)$textformat );
 545         $tfname = "[$tfname]";
 546     }
 547
 548     // output depends on question type
 549     switch($question->qtype) {
 550     case 'category':
 551         // not a real question, used to insert category switch
 552         $expout .= "\$CATEGORY: $question->category\n";
 553         break;
 554     case DESCRIPTION:
 555         $expout .= '::'.$this->repchar($question->name).'::';
 556         $expout .= $tfname;
 557         $expout .= $this->repchar( $question->questiontext, $textformat);
 558         break;
 559     case ESSAY:
 560         $expout .= '::'.$this->repchar($question->name).'::';
 561         $expout .= $tfname;
 562         $expout .= $this->repchar( $question->questiontext, $textformat);
 563         $expout .= "{}\n";
 564         break;
 565     case TRUEFALSE:
 566         $trueanswer = $question->options->answers[$question->options->trueanswer];
 567         $falseanswer = $question->options->answers[$question->options->falseanswer];
 568         if ($trueanswer->fraction == 1) {
 569             $answertext = 'TRUE';
 570             $right_feedback = $trueanswer->feedback;
 571             $wrong_feedback = $falseanswer->feedback;
 572         } else {
 573             $answertext = 'FALSE';
 574             $right_feedback = $falseanswer->feedback;
 575             $wrong_feedback = $trueanswer->feedback;
 576         }
 577
 578         $wrong_feedback = $this->repchar($wrong_feedback);
 579         $right_feedback = $this->repchar($right_feedback);
 580         $expout .= "::".$this->repchar($question->name)."::".$tfname.$this->repchar( $question->questiontext,$textformat )."{".$this->repchar( $answertext );
 581         if ($wrong_feedback) {
 582             $expout .= "#" . $wrong_feedback;
 583         } else if ($right_feedback) {
 584             $expout .= "#";
 585         }
 586         if ($right_feedback) {
 587             $expout .= "#" . $right_feedback;
 588         }
 589         $expout .= "}\n";
 590         break;
 591     case MULTICHOICE:
 592         $expout .= "::".$this->repchar($question->name)."::".$tfname.$this->repchar( $question->questiontext, $textformat )."{\n";
 593         foreach($question->options->answers as $answer) {
 594             if ($answer->fraction==1) {
 595                 $answertext = '=';
 596             }
 597             elseif ($answer->fraction==0) {
 598                 $answertext = '~';
 599             }
 600             else {
 601                 $export_weight = $answer->fraction*100;
 602                 $answertext = "~%$export_weight%";
 603             }
 604             $expout .= "\t".$answertext.$this->repchar( $answer->answer );
 605             if ($answer->feedback!="") {
 606                 $expout .= "#".$this->repchar( $answer->feedback );
 607             }
 608             $expout .= "\n";
 609         }
 610         $expout .= "}\n";
 611         break;
 612     case SHORTANSWER:
 613         $expout .= "::".$this->repchar($question->name)."::".$tfname.$this->repchar( $question->questiontext, $textformat )."{\n";
 614         foreach($question->options->answers as $answer) {
 615             $weight = 100 * $answer->fraction;
 616             $expout .= "\t=%".$weight."%".$this->repchar( $answer->answer )."#".$this->repchar( $answer->feedback )."\n";
 617         }
 618         $expout .= "}\n";
 619         break;
 620     case NUMERICAL:
 621         $expout .= "::".$this->repchar($question->name)."::".$tfname.$this->repchar( $question->questiontext, $textformat )."{#\n";
 622         foreach ($question->options->answers as $answer) {
 623             if ($answer->answer != '') {
 624                 $percentage = '';
 625                 if ($answer->fraction < 1) {
 626                     $pval = $answer->fraction * 100;
 627                     $percentage = "%$pval%";
 628                 }
 629                 $expout .= "\t=$percentage".$answer->answer.":".(float)$answer->tolerance."#".$this->repchar( $answer->feedback )."\n";
 630             } else {
 631                 $expout .= "\t~#".$this->repchar( $answer->feedback )."\n";
 632             }
 633         }
 634         $expout .= "}\n";
 635         break;
 636     case MATCH:
 637         $expout .= "::".$this->repchar($question->name)."::".$tfname.$this->repchar( $question->questiontext, $textformat )."{\n";
 638         foreach($question->options->subquestions as $subquestion) {
 639             $expout .= "\t=".$this->repchar( $subquestion->questiontext )." -> ".$this->repchar( $subquestion->answertext )."\n";
 640         }
 641         $expout .= "}\n";
 642         break;
 643     case DESCRIPTION:
 644         $expout .= "// DESCRIPTION type is not supported\n";
 645         break;
 646     case MULTIANSWER:
 647         $expout .= "// CLOZE type is not supported\n";
 648         break;
 649     default:
 650         // check for plugins
 651         if ($out = $this->try_exporting_using_qtypes( $question->qtype, $question )) {
 652             $expout .= $out;
 653         }
 654         else {
 655             notify("No handler for qtype '$question->qtype' for GIFT export" );
 656         }
 657     }
 658     // add empty line to delimit questions
 659     $expout .= "\n";
 660     return $expout;
 661 }
 662 }
 663 ?>