question/format/learnwise/format.php

   1 <?php    // $Id$
   2 // Alton College, Hampshire, UK - Tom Flannaghan, Andrew Walker
   3 // Imports learnwise multiple choice quizzes (single and multiple answers)
   4 // currently ignores the deduct attribute for multiple answer questions
   5 // deductions are currently simply found by dividing the award for the incorrect
   6 // answer by the total number of options
   7 // Based on format.php, included by ../../import.php
   8 /**
   9  * @package questionbank
  10  * @subpackage importexport
  11  */
  12
  13 class qformat_learnwise extends qformat_default {
  14
  15     function provide_import() {
  16       return true;
  17     }
  18
  19     function readquestions($lines) {
  20         $questions = array();
  21         $currentquestion = array();
  22
  23         foreach($lines as $line) {
  24             $line = trim($line);
  25             $currentquestion[] = $line;
  26
  27             if ($question = $this->readquestion($currentquestion)) {
  28                 $questions[] = $question;
  29                 $currentquestion = array();
  30             }
  31         }
  32         return $questions;
  33     }
  34
  35     function readquestion($lines) {
  36         $text = implode(' ', $lines);
  37         $text = str_replace(array('\t','\n','\r','\''), array('','','','\\\''), $text);
  38
  39         $startpos = strpos($text, '<question type');
  40         $endpos = strpos($text, '</question>');
  41         if ($startpos === false || $endpos === false) {
  42             return false;
  43         }
  44
  45         preg_match("/<question type=[\"\']([^\"\']+)[\"\']>/i", $text, $matches);
  46         $type = strtolower($matches[1]); // multichoice or multianswerchoice
  47
  48         $questiontext = $this->unhtmlentities($this->stringbetween($text, '<text>', '</text>'));
  49         $questionhint = $this->unhtmlentities($this->stringbetween($text, '<hint>', '</hint>'));
  50         $questionaward = $this->stringbetween($text, '<award>', '</award>');
  51         $optionlist = $this->stringbetween($text, '<answer>', '</answer>');
  52
  53         $optionlist = explode('<option', $optionlist);
  54
  55         $n = 0;
  56
  57         $optionscorrect = array();
  58         $optionstext = array();
  59
  60         if ($type == 'multichoice') {
  61             foreach ($optionlist as $option) {
  62                 $correct = $this->stringbetween($option, ' correct="', '">');
  63                 $answer = $this->stringbetween($option, '">', '</option>');
  64                 $optionscorrect[$n] = $correct;
  65                 $optionstext[$n] = $this->unhtmlentities($answer);
  66                 ++$n;
  67             }
  68         } else if ($type == 'multianswerchoice') {
  69             $numcorrect = 0;
  70             $totalaward = 0;
  71
  72             $optionsaward = array();
  73
  74             foreach ($optionlist as $option) {
  75                 preg_match("/correct=\"([^\"]*)\"/i", $option, $correctmatch);
  76                 preg_match("/award=\"([^\"]*)\"/i", $option, $awardmatch);
  77
  78                 $correct = $correctmatch[1];
  79                 $award = $awardmatch[1];
  80                 if ($correct == 'yes') {
  81                     $totalaward += $award;
  82                     ++$numcorrect;
  83                 }
  84
  85                 $answer = $this->stringbetween($option, '">', '</option>');
  86
  87                 $optionscorrect[$n] = $correct;
  88                 $optionstext[$n] = $this->unhtmlentities($answer);
  89                 $optionsaward[$n] = $award;
  90                 ++$n;
  91             }
  92
  93         } else {
  94             echo "<p>I don't understand this question type (type = <strong>$type</strong>).</p>\n";
  95         }
  96
  97         $question = $this->defaultquestion();
  98         $question->qtype = MULTICHOICE;
  99         $question->name = substr($questiontext, 0, 30);
 100         if (strlen($questiontext) > 30) {
 101             $question->name .= '...';
 102         }
 103
 104         $question->questiontext = $questiontext;
 105         $question->single = ($type == 'multichoice') ? 1 : 0;
 106         $question->feedback[] = '';
 107
 108         $question->fraction = array();
 109         $question->answer = array();
 110         for ($n = 0; $n < count($optionstext); ++$n) {
 111             if ($optionstext[$n]) {
 112                 if (!isset($numcorrect)) { // single answer
 113                     if ($optionscorrect[$n] == 'yes') {
 114                         $fraction = (int) $questionaward;
 115                     } else {
 116                         $fraction = 0;
 117                     }
 118                 } else { // mulitple answers
 119                     if ($optionscorrect[$n] == 'yes') {
 120                         $fraction = $optionsaward[$n] / $totalaward;
 121                     } else {
 122                         $fraction = -$optionsaward[$n] / count($optionstext);
 123                     }
 124                 }
 125                 $question->fraction[] = $fraction;
 126                 $question->answer[] = $optionstext[$n];
 127                 $question->feedback[] = ''; // no feedback in this type
 128             }
 129         }
 130
 131         return $question;
 132     }
 133
 134     function stringbetween($text, $start, $end) {
 135         $startpos = strpos($text, $start) + strlen($start);
 136         $endpos = strpos($text, $end);
 137
 138         if ($startpos <= $endpos) {
 139             return substr($text, $startpos, $endpos - $startpos);
 140         }
 141     }
 142
 143     function unhtmlentities($string) {
 144         $transtable = get_html_translation_table(HTML_ENTITIES);
 145         $transtable = array_flip($transtable);
 146         return strtr($string, $transtable);
 147     }
 148
 149 }
 150
 151 ?>