format.php in Quiz 6.5

File

includes/moodle/question/format/qti2/format.php

<?php

// $Id$
require_once "{$CFG->dirroot}/question/format/qti2/qt_common.php";

////////////////////////////////////////////////////////////////////////////

/// IMS QTI 2.0 FORMAT

///

/// HISTORY: created 28.01.2005      [e-mail]

////////////////////////////////////////////////////////////////////////////

// Based on format.php, included by ../../import.php

/**
 * @package questionbank
 * @subpackage importexport
 */
define('CLOZE_TRAILING_TEXT_ID', 9999999);
class qformat_qti2 extends qformat_default {
  var $lang;
  function provide_export() {
    return true;
  }
  function indent_xhtml($source, $indenter = ' ') {

    // xml tidier-upper
    // (c) Ari Koivula http://ventionline.com
    // Remove all pre-existing formatting.
    // Remove all newlines.
    $source = str_replace("\n", '', $source);
    $source = str_replace("\r", '', $source);

    // Remove all tabs.
    $source = str_replace("\t", '', $source);

    // Remove all space after ">" and before "<".
    $source = ereg_replace(">( )*", ">", $source);
    $source = ereg_replace("( )*<", "<", $source);

    // Iterate through the source.
    $level = 0;
    $source_len = strlen($source);
    $pt = 0;
    while ($pt < $source_len) {
      if ($source[$pt] === '<') {

        // We have entered a tag.
        // Remember the point where the tag starts.
        $started_at = $pt;
        $tag_level = 1;

        // If the second letter of the tag is "/", assume its an ending tag.
        if ($source[$pt + 1] === '/') {
          $tag_level = -1;
        }

        // If the second letter of the tag is "!", assume its an "invisible" tag.
        if ($source[$pt + 1] === '!') {
          $tag_level = 0;
        }

        // Iterate throught the source until the end of tag.
        while ($source[$pt] !== '>') {
          $pt++;
        }

        // If the second last letter is "/", assume its a self ending tag.
        if ($source[$pt - 1] === '/') {
          $tag_level = 0;
        }
        $tag_lenght = $pt + 1 - $started_at;

        // Decide the level of indention for this tag.
        // If this was an ending tag, decrease indent level for this tag..
        if ($tag_level === -1) {
          $level--;
        }

        // Place the tag in an array with proper indention.
        $array[] = str_repeat($indenter, $level) . substr($source, $started_at, $tag_lenght);

        // If this was a starting tag, increase the indent level after this tag.
        if ($tag_level === 1) {
          $level++;
        }

        // if it was a self closing tag, dont do anything.
      }

      // Were out of the tag.
      // If next letter exists...
      if ($pt + 1 < $source_len) {

        // ... and its not an "<".
        if ($source[$pt + 1] !== '<') {
          $started_at = $pt + 1;

          // Iterate through the source until the start of new tag or until we reach the end of file.
          while ($source[$pt] !== '<' && $pt < $source_len) {
            $pt++;
          }

          // If we found a "<" (we didnt find the end of file)
          if ($source[$pt] === '<') {
            $tag_lenght = $pt - $started_at;

            // Place the stuff in an array with proper indention.
            $array[] = str_repeat($indenter, $level) . substr($source, $started_at, $tag_lenght);
          }

          // If the next tag is "<", just advance pointer and let the tag indenter take care of it.
        }
        else {
          $pt++;
        }

        // If the next letter doesnt exist... Were done... well, almost..
      }
      else {
        break;
      }
    }

    // Replace old source with the new one we just collected into our array.
    $source = implode($array, "\n");
    return $source;
  }
  function importpreprocess() {
    global $CFG;
    error("Sorry, importing this format is not yet implemented!", "{$CFG->wwwroot}/mod/quiz/import.php?category={$category->id}");
  }
  function exportpreprocess() {
    global $CFG;
    require_once "{$CFG->libdir}/smarty/Smarty.class.php";

    // assign the language for the export: by parameter, SESSION, USER, or the default of 'en'
    $lang = current_language();
    $this->lang = $lang;
    return parent::exportpreprocess();
  }
  function export_file_extension() {

    // override default type so extension is .xml
    return ".zip";
  }
  function get_qtype($type_id) {

    // translates question type code number into actual name
    switch ($type_id) {
      case TRUEFALSE:
        $name = 'truefalse';
        break;
      case MULTICHOICE:
        $name = 'multichoice';
        break;
      case SHORTANSWER:
        $name = 'shortanswer';
        break;
      case NUMERICAL:
        $name = 'numerical';
        break;
      case MATCH:
        $name = 'matching';
        break;
      case DESCRIPTION:
        $name = 'description';
        break;
      case MULTIANSWER:
        $name = 'multianswer';
        break;
      default:
        $name = 'Unknown';
    }
    return $name;
  }
  function writetext($raw) {

    // generates <text></text> tags, processing raw text therein
    // for now, don't allow any additional tags in text
    // otherwise xml rules would probably get broken
    $raw = strip_tags($raw);
    return "<text>{$raw}</text>\n";
  }

  /**
   * flattens $object['media'], copies $object['media'] to $path, and sets $object['mediamimetype']
   *
   * @param array &$object containing a field 'media'
   * @param string $path the full path name to where the media files need to be copied
   * @param int $courseid
   * @return: mixed - true on success or in case of an empty media field, an error string if the file copy fails
   */
  function copy_and_flatten(&$object, $path, $courseid) {
    global $CFG;
    if (!empty($object['media'])) {
      $location = $object['media'];
      $object['media'] = $this
        ->flatten_image_name($location);
      if (!@copy("{$CFG->dataroot}/{$courseid}/{$location}", "{$path}/{$object['media']}")) {
        return "Failed to copy {$CFG->dataroot}/{$courseid}/{$location} to {$path}/{$object['media']}";
      }
      if (empty($object['mediamimetype'])) {
        $object['mediamimetype'] = mimeinfo('type', $object['media']);
      }
    }
    return true;
  }

  /**
   * copies all files needed by the questions to the given $path, and flattens the file names
   *
   * @param array $questions the question objects
   * @param string $path the full path name to where the media files need to be copied
   * @param int $courseid
   * @return mixed true on success, an array of error messages otherwise
   */
  function handle_questions_media(&$questions, $path, $courseid) {
    global $CFG;
    $errors = array();
    foreach ($questions as $key => $question) {

      // todo: handle in-line media (specified in the question text)
      if (!empty($question->image)) {
        $location = $questions[$key]->image;
        $questions[$key]->mediaurl = $this
          ->flatten_image_name($location);
        if (!@copy("{$CFG->dataroot}/{$courseid}/{$location}", "{$path}/{$questions[$key]->mediaurl}")) {
          $errors[] = "Failed to copy {$CFG->dataroot}/{$courseid}/{$location} to {$path}/{$questions[$key]->mediaurl}";
        }
        if (empty($question->mediamimetype)) {
          $questions[$key]->mediamimetype = mimeinfo('type', $question->image);
        }
      }
    }
    return empty($errors) ? true : $errors;
  }

  /**
   * exports the questions in a question category to the given location
   *
   * The parent class method was overridden because the IMS export consists of multiple files
   *
   * @param string $filename the directory name which will hold the exported files
   * @return boolean - or errors out
   */
  function exportprocess() {
    global $CFG;
    $courseid = $this->course->id;

    // create a directory for the exports (if not already existing)
    if (!($export_dir = make_upload_directory($this
      ->question_get_export_dir() . '/' . $this->filename))) {
      error(get_string('cannotcreatepath', 'quiz', $export_dir));
    }
    $path = $CFG->dataroot . '/' . $this
      ->question_get_export_dir() . '/' . $this->filename;

    // get the questions (from database) in this category
    // $questions = get_records("question","category",$this->category->id);
    // HACK FIXME EDIT  a rare edit to the Moodle code
    // why load from category when we already have the questions?
    // $questions = get_questions_category( $this->category );
    $questions = $this->questions;
    notify("Exporting " . count($questions) . " questions.");
    $count = 0;

    // create the imsmanifest file
    $smarty =& $this
      ->init_smarty();
    $this
      ->add_qti_info($questions);

    // copy files used by the main questions to the export directory
    $result = $this
      ->handle_questions_media($questions, $path, $courseid);
    if ($result !== true) {
      notify(implode("<br />", $result));
    }
    $manifestquestions = $this
      ->objects_to_array($questions);
    $manifestid = str_replace(array(
      ':',
      '/',
    ), array(
      '-',
      '_',
    ), "question_category_{$this->category->id}---{$CFG->wwwroot}");
    $smarty
      ->assign('externalfiles', 1);
    $smarty
      ->assign('manifestidentifier', $manifestid);
    $smarty
      ->assign('quiztitle', "question_category_{$this->category->id}");
    $smarty
      ->assign('quizinfo', "All questions in category {$this->category->id}");
    $smarty
      ->assign('questions', $manifestquestions);
    $smarty
      ->assign('lang', $this->lang);
    $smarty->error_reporting = 99;
    $expout = $smarty
      ->fetch('imsmanifest.tpl');
    $filepath = $path . '/imsmanifest.xml';
    if (empty($expout)) {
      error("Unkown error - empty imsmanifest.xml");
    }
    if (!($fh = fopen($filepath, "w"))) {
      error("Cannot open for writing: {$filepath}");
    }
    if (!fwrite($fh, $expout)) {
      error("Cannot write exported questions to {$filepath}");
    }
    fclose($fh);

    // iterate through questions
    foreach ($questions as $question) {

      // results are first written into string (and then to a file)
      $count++;
      echo "<hr /><p><b>{$count}</b>. " . stripslashes($question->questiontext) . "</p>";
      $expout = $this
        ->writequestion($question, null, true, $path) . "\n";
      $expout = $this
        ->presave_process($expout);
      $filepath = $path . '/' . $this
        ->get_assesment_item_id($question) . ".xml";
      if (!($fh = fopen($filepath, "w"))) {
        error("Cannot open for writing: {$filepath}");
      }
      if (!fwrite($fh, $expout)) {
        error("Cannot write exported questions to {$filepath}");
      }
      fclose($fh);
    }

    // zip files into single export file
    print "path: {$path}";
    zip_files(array(
      $path,
    ), "{$path}.zip");

    // FIXME TODO EDIT rare edit to Moodle format code
    // how else am I supposed to know what the filename of the zip is?
    $this->filename = basename($path);

    // remove the temporary directory
    remove_dir($path);
    return true;
  }

  /**
   * exports a quiz (as opposed to exporting a category of questions)
   *
   * The parent class method was overridden because the IMS export consists of multiple files
   *
   * @param object $quiz
   * @param array $questions - an array of question objects
   * @param object $result - if set, contains result of calling quiz_grade_responses()
   * @param string $redirect - a URL to redirect to in case of failure
   * @param string $submiturl - the URL for the qti player to send the results to (e.g. attempt.php)
   * @todo use $result in the ouput
   */
  function export_quiz($course, $quiz, $questions, $result, $redirect, $submiturl = null) {
    $this
      ->xml_entitize($course);
    $this
      ->xml_entitize($quiz);
    $this
      ->xml_entitize($questions);
    $this
      ->xml_entitize($result);
    $this
      ->xml_entitize($submiturl);
    if (!$this
      ->exportpreprocess(0, $course)) {

      // Do anything before that we need to
      error("Error occurred during pre-processing!", $redirect);
    }
    if (!$this
      ->exportprocess_quiz($quiz, $questions, $result, $submiturl, $course)) {

      // Process the export data
      error("Error occurred during processing!", $redirect);
    }
    if (!$this
      ->exportpostprocess()) {

      // In case anything needs to be done after
      error("Error occurred during post-processing!", $redirect);
    }
  }

  /**
   * This function is called to export a quiz (as opposed to exporting a category of questions)
   *
   * @uses $USER
   * @param object $quiz
   * @param array $questions - an array of question objects
   * @param object $result - if set, contains result of calling quiz_grade_responses()
   * @todo use $result in the ouput
   */
  function exportprocess_quiz($quiz, $questions, $result, $submiturl, $course) {
    global $USER;
    global $CFG;
    $gradingmethod = array(
      1 => 'GRADEHIGHEST',
      2 => 'GRADEAVERAGE',
      3 => 'ATTEMPTFIRST',
      4 => 'ATTEMPTLAST',
    );
    $questions = $this
      ->quiz_export_prepare_questions($questions, $quiz->id, $course->id, $quiz->shuffleanswers);
    $smarty =& $this
      ->init_smarty();
    $smarty
      ->assign('questions', $questions);

    // quiz level smarty variables
    $manifestid = str_replace(array(
      ':',
      '/',
    ), array(
      '-',
      '_',
    ), "quiz{$quiz->id}-{$CFG->wwwroot}");
    $smarty
      ->assign('manifestidentifier', $manifestid);
    $smarty
      ->assign('submiturl', $submiturl);
    $smarty
      ->assign('userid', $USER->id);
    $smarty
      ->assign('username', htmlspecialchars($USER->username, ENT_COMPAT, 'UTF-8'));
    $smarty
      ->assign('quiz_level_export', 1);
    $smarty
      ->assign('quiztitle', format_string($quiz->name, true));

    //assigned specifically so as not to cause problems with category-level export
    $smarty
      ->assign('quiztimeopen', date('Y-m-d\\TH:i:s', $quiz->timeopen));

    // ditto
    $smarty
      ->assign('quiztimeclose', date('Y-m-d\\TH:i:s', $quiz->timeclose));

    // ditto
    $smarty
      ->assign('grademethod', $gradingmethod[$quiz->grademethod]);
    $smarty
      ->assign('quiz', $quiz);
    $smarty
      ->assign('course', $course);
    $smarty
      ->assign('lang', $this->lang);
    $expout = $smarty
      ->fetch('imsmanifest.tpl');
    echo $expout;
    return true;
  }

  /**
   * Prepares questions for quiz export
   *
   * The questions are changed as follows:
   *   - the question answers atached to the questions
   *   - image set to an http reference instead of a file path
   *   - qti specific info added
   *   - exporttext added, which contains an xml-formatted qti assesmentItem
   *
   * @param array $questions - an array of question objects
   * @param int $quizid
   * @return an array of question arrays
   */
  function quiz_export_prepare_questions($questions, $quizid, $courseid, $shuffleanswers = null) {
    global $CFG;

    // add the answers to the questions and format the image property
    foreach ($questions as $key => $question) {
      $questions[$key] = get_question_data($question);
      $questions[$key]->courseid = $courseid;
      $questions[$key]->quizid = $quizid;
      if ($question->image) {
        if (empty($question->mediamimetype)) {
          $questions[$key]->mediamimetype = mimeinfo('type', $question->image);
        }
        $localfile = substr(strtolower($question->image), 0, 7) == 'http://' ? false : true;
        if ($localfile) {

          // create the http url that the player will need to access the file
          if ($CFG->slasharguments) {

            // Use this method if possible for better caching
            $questions[$key]->mediaurl = "{$CFG->wwwroot}/file.php/{$question->image}";
          }
          else {
            $questions[$key]->mediaurl = "{$CFG->wwwroot}/file.php?file={$question->image}";
          }
        }
        else {
          $questions[$key]->mediaurl = $question->image;
        }
      }
    }
    $this
      ->add_qti_info($questions);
    $questions = $this
      ->questions_with_export_info($questions, $shuffleanswers);
    $questions = $this
      ->objects_to_array($questions);
    return $questions;
  }

  /**
   * calls htmlspecialchars for each string field, to convert, for example, & to &amp;
   *
   * collections are processed recursively
   *
   * @param array $collection - an array or object or string
   */
  function xml_entitize(&$collection) {
    if (is_array($collection)) {
      foreach ($collection as $key => $var) {
        if (is_string($var)) {
          $collection[$key] = htmlspecialchars($var, ENT_COMPAT, 'UTF-8');
        }
        else {
          if (is_array($var) || is_object($var)) {
            $this
              ->xml_entitize($collection[$key]);
          }
        }
      }
    }
    else {
      if (is_object($collection)) {
        $vars = get_object_vars($collection);
        foreach ($vars as $key => $var) {
          if (is_string($var)) {
            $collection->{$key} = htmlspecialchars($var, ENT_COMPAT, 'UTF-8');
          }
          else {
            if (is_array($var) || is_object($var)) {
              $this
                ->xml_entitize($collection->{$key});
            }
          }
        }
      }
      else {
        if (is_string($collection)) {
          $collection = htmlspecialchars($collection, ENT_COMPAT, 'UTF-8');
        }
      }
    }
  }

  /**
   * adds exporttext property to the questions
   *
   * Adds the qti export text to the questions
   *
   * @param array $questions - an array of question objects
   * @return an array of question objects
   */
  function questions_with_export_info($questions, $shuffleanswers = null) {
    $exportquestions = array();
    foreach ($questions as $key => $question) {
      $expout = $this
        ->writequestion($question, $shuffleanswers) . "\n";
      $expout = $this
        ->presave_process($expout);
      $key = $this
        ->get_assesment_item_id($question);
      $exportquestions[$key] = $question;
      $exportquestions[$key]->exporttext = $expout;
    }
    return $exportquestions;
  }

  /**
   * Creates the export text for a question
   *
   * @todo handle in-line media (specified in the question/subquestion/answer text) for course-level exports
   * @param object $question
   * @param boolean $shuffleanswers whether or not to shuffle the answers
   * @param boolean $courselevel whether or not this is a course-level export
   * @param string $path provide the path to copy question media files to, if $courselevel == true
   * @return string containing export text
   */
  function writequestion($question, $shuffleanswers = null, $courselevel = false, $path = '') {

    // turns question into string
    // question reflects database fields for general question and specific to type
    global $CFG;
    $expout = '';

    //need to unencode the html entities in the questiontext field.

    // the whole question object was earlier run throught htmlspecialchars in xml_entitize().
    $question->questiontext = html_entity_decode($question->questiontext, ENT_COMPAT);
    $hasimage = empty($question->image) ? 0 : 1;
    $hassize = empty($question->mediax) ? 0 : 1;
    $allowedtags = '<a><br><b><h1><h2><h3><h4><i><img><li><ol><strong><table><tr><td><th><u><ul><object>';

    // all other tags will be stripped from question text
    $smarty =& $this
      ->init_smarty();
    $assesmentitemid = $this
      ->get_assesment_item_id($question);
    $question_type = $this
      ->get_qtype($question->qtype);
    $questionid = "question{$question->id}{$question_type}";
    $smarty
      ->assign('question_has_image', $hasimage);
    $smarty
      ->assign('hassize', $hassize);
    $smarty
      ->assign('questionid', $questionid);
    $smarty
      ->assign('assessmentitemidentifier', $assesmentitemid);
    $smarty
      ->assign('assessmentitemtitle', $question->name);
    $smarty
      ->assign('courselevelexport', $courselevel);
    if ($question->qtype == MULTIANSWER) {
      $question->questiontext = strip_tags($question->questiontext, $allowedtags . '<intro>');
      $smarty
        ->assign('questionText', $this
        ->get_cloze_intro($question->questiontext));
    }
    else {
      $smarty
        ->assign('questionText', strip_tags($question->questiontext, $allowedtags));
    }
    $smarty
      ->assign('question', $question);

    // the following two are left for compatibility; the templates should be changed, though, to make object tags for the questions

    //$smarty->assign('questionimage', $question->image);

    //$smarty->assign('questionimagealt', "image: $question->image");

    // output depends on question type
    switch ($question->qtype) {
      case TRUEFALSE:
        $qanswers = $question->options->answers;
        $answers[0] = (array) $qanswers['true'];
        $answers[0]['answer'] = get_string("true", "quiz");
        $answers[1] = (array) $qanswers['false'];
        $answers[1]['answer'] = get_string("false", "quiz");
        if (!empty($shuffleanswers)) {
          $answers = $this
            ->shuffle_things($answers);
        }
        if (isset($question->response)) {
          $correctresponseid = $question->response[$questionid];
          if ($answers[0]['id'] == $correctresponseid) {
            $correctresponse = $answers[0];
          }
          else {
            $correctresponse = $answers[1];
          }
        }
        else {
          $correctresponse = '';
        }
        $smarty
          ->assign('correctresponse', $correctresponse);
        $smarty
          ->assign('answers', $answers);
        $expout = $smarty
          ->fetch('choice.tpl');
        break;
      case MULTICHOICE:
        $answers = $this
          ->objects_to_array($question->options->answers);
        $correctresponses = $this
          ->get_correct_answers($answers);
        $correctcount = count($correctresponses);
        $smarty
          ->assign('responsedeclarationcardinality', $question->options->single ? 'single' : 'multiple');
        $smarty
          ->assign('operator', $question->options->single ? 'match' : 'member');
        $smarty
          ->assign('correctresponses', $correctresponses);
        $smarty
          ->assign('answers', $answers);
        $smarty
          ->assign('maxChoices', $question->options->single ? '1' : count($answers));
        $smarty
          ->assign('maxChoices', $question->options->single ? '1' : count($answers));
        $smarty
          ->assign('shuffle', empty($shuffleanswers) ? 'false' : 'true');
        $smarty
          ->assign('generalfeedback', $question->generalfeedback);
        $smarty
          ->assign('correctfeedback', $question->options->correctfeedback);
        $smarty
          ->assign('partiallycorrectfeedback', $question->options->partiallycorrectfeedback);
        $smarty
          ->assign('incorrectfeedback', $question->options->incorrectfeedback);
        $expout = $smarty
          ->fetch('choiceMultiple.tpl');
        break;
      case SHORTANSWER:
        $answers = $this
          ->objects_to_array($question->options->answers);
        if (!empty($shuffleanswers)) {
          $answers = $this
            ->shuffle_things($answers);
        }
        $correctresponses = $this
          ->get_correct_answers($answers);
        $correctcount = count($correctresponses);
        $smarty
          ->assign('responsedeclarationcardinality', $correctcount > 1 ? 'multiple' : 'single');
        $smarty
          ->assign('correctresponses', $correctresponses);
        $smarty
          ->assign('answers', $answers);
        $expout = $smarty
          ->fetch('textEntry.tpl');
        break;
      case NUMERICAL:
        $qanswer = array_pop($question->options->answers);
        $smarty
          ->assign('lowerbound', $qanswer->answer - $qanswer->tolerance);
        $smarty
          ->assign('upperbound', $qanswer->answer + $qanswer->tolerance);
        $smarty
          ->assign('answer', $qanswer->answer);
        $expout = $smarty
          ->fetch('numerical.tpl');
        break;
      case MATCH:
        $this
          ->xml_entitize($question->options->subquestions);
        $subquestions = $this
          ->objects_to_array($question->options->subquestions);
        if (!empty($shuffleanswers)) {
          $subquestions = $this
            ->shuffle_things($subquestions);
        }
        $setcount = count($subquestions);
        $smarty
          ->assign('setcount', $setcount);
        $smarty
          ->assign('matchsets', $subquestions);
        $expout = $smarty
          ->fetch('match.tpl');
        break;
      case DESCRIPTION:
        $expout = $smarty
          ->fetch('extendedText.tpl');
        break;

      // loss of get_answers() from quiz_embedded_close_qtype class during
      // Gustav's refactor breaks MULTIANSWER badly - one for another day!!

      /*
              case MULTIANSWER:
                  $answers = $this->get_cloze_answers_array($question);
                  $questions = $this->get_cloze_questions($question, $answers, $allowedtags);

                  $smarty->assign('cloze_trailing_text_id', CLOZE_TRAILING_TEXT_ID);
                  $smarty->assign('answers', $answers);
                  $smarty->assign('questions', $questions);
                  $expout = $smarty->fetch('composite.tpl');
                  break; */
      default:
        $smarty
          ->assign('questionText', "This question type (Unknown: type {$question_type})  has not yet been implemented");
        $expout = $smarty
          ->fetch('notimplemented.tpl');
    }

    // run through xml tidy function

    //$tidy_expout = $this->indent_xhtml( $expout, '    ' ) . "\n\n";

    //return $tidy_expout;
    return $expout;
  }

  /**
   * Gets an id to use for a qti assesment item
   *
   * @param object $question
   * @return string containing a qti assesment item id
   */
  function get_assesment_item_id($question) {
    return "question{$question->id}";
  }

  /**
   * gets the answers whose grade fraction > 0
   *
   * @param array $answers
   * @return array (0-indexed) containing the answers whose grade fraction > 0
   */
  function get_correct_answers($answers) {
    $correctanswers = array();
    foreach ($answers as $answer) {
      if ($answer['fraction'] > 0) {
        $correctanswers[] = $answer;
      }
    }
    return $correctanswers;
  }

  /**
   * gets a new Smarty object, with the template and compile directories set
   *
   * @return object a smarty object
   */
  function &init_smarty() {
    global $CFG;

    // create smarty compile dir in dataroot
    $path = $CFG->dataroot . "/smarty_c";
    if (!is_dir($path)) {
      if (!mkdir($path, $CFG->directorypermissions)) {
        error("Cannot create path: {$path}");
      }
    }
    $smarty = new Smarty();
    $smarty->template_dir = "{$CFG->dirroot}/question/format/qti2/templates";
    $smarty->compile_dir = "{$path}";
    return $smarty;
  }

  /**
   * converts an array of objects to an array of arrays (not recursively)
   *
   * @param array $objectarray
   * @return array - an array of answer arrays
   */
  function objects_to_array($objectarray) {
    $arrayarray = array();
    foreach ($objectarray as $object) {
      $arrayarray[] = (array) $object;
    }
    return $arrayarray;
  }

  /**
   * gets a question's cloze answer objects as arrays containing only arrays and basic data types
   *
   * @param object $question
   * @return array - an array of answer arrays
   */
  function get_cloze_answers_array($question) {
    $answers = $this
      ->get_answers($question);
    $this
      ->xml_entitize($answers);
    foreach ($answers as $answerkey => $answer) {
      $answers[$answerkey]->subanswers = $this
        ->objects_to_array($answer->subanswers);
    }
    return $this
      ->objects_to_array($answers);
  }

  /**
   * gets an array with text and question arrays for the given cloze question
   *
   * To make smarty processing easier, the returned text and question sub-arrays have an equal number of elements.
   * If it is necessary to add a dummy element to the question sub-array, the question will be given an id of CLOZE_TRAILING_TEXT_ID.
   *
   * @param object $question
   * @param array $answers - an array of arrays containing the question's answers
   * @param string $allowabletags - tags not to strip out of the question text (e.g. '<i><br>')
   * @return array with text and question arrays for the given cloze question
   */
  function get_cloze_questions($question, $answers, $allowabletags) {
    $questiontext = strip_tags($question->questiontext, $allowabletags);
    if (preg_match_all('/(.*){#([0-9]+)}/U', $questiontext, $matches)) {

      // matches[1] contains the text inbetween the question blanks
      // matches[2] contains the id of the question blanks (db: question_multianswer.positionkey)
      // find any trailing text after the last {#XX} and add it to the array
      if (preg_match('/.*{#[0-9]+}(.*)$/', $questiontext, $tail)) {
        $matches[1][] = $tail[1];
        $tailadded = true;
      }
      $questions['text'] = $matches[1];
      $questions['question'] = array();
      foreach ($matches[2] as $key => $questionid) {
        foreach ($answers as $answer) {
          if ($answer['positionkey'] == $questionid) {
            $questions['question'][$key] = $answer;
            break;
          }
        }
      }
      if ($tailadded) {

        // to have a matching number of question and text array entries:
        $questions['question'][] = array(
          'id' => CLOZE_TRAILING_TEXT_ID,
          'answertype' => SHORTANSWER,
        );
      }
    }
    else {
      $questions['text'][0] = $question->questiontext;
      $questions['question'][0] = array(
        'id' => CLOZE_TRAILING_TEXT_ID,
        'answertype' => SHORTANSWER,
      );
    }
    return $questions;
  }

  /**
   * strips out the <intro>...</intro> section, if any, and returns the text
   *
   * changes the text object passed to it.
   *
   * @param string $&text
   * @return string the intro text, if there was an intro tag. '' otherwise.
   */
  function get_cloze_intro(&$text) {
    if (preg_match('/(.*)?\\<intro>(.+)?\\<\\/intro>(.*)/s', $text, $matches)) {
      $text = $matches[1] . $matches[3];
      return $matches[2];
    }
    else {
      return '';
    }
  }

  /**
   * adds qti metadata properties to the questions
   *
   * The passed array of questions is altered by this function
   *
   * @param &questions an array of question objects
   */
  function add_qti_info(&$questions) {
    foreach ($questions as $key => $question) {
      $questions[$key]->qtiinteractiontype = $this
        ->get_qti_interaction_type($question->qtype);
      $questions[$key]->qtiscoreable = $this
        ->get_qti_scoreable($question);
      $questions[$key]->qtisolutionavailable = $this
        ->get_qti_solution_available($question);
    }
  }

  /**
   * returns whether or not a given question is scoreable
   *
   * @param object $question
   * @return boolean
   */
  function get_qti_scoreable($question) {
    switch ($question->qtype) {
      case DESCRIPTION:
        return 'false';
      default:
        return 'true';
    }
  }

  /**
   * returns whether or not a solution is available for a given question
   *
   * The results are based on whether or not Moodle stores answers for the given question type
   *
   * @param object $question
   * @return boolean
   */
  function get_qti_solution_available($question) {
    switch ($question->qtype) {
      case TRUEFALSE:
        return 'true';
      case MULTICHOICE:
        return 'true';
      case SHORTANSWER:
        return 'true';
      case NUMERICAL:
        return 'true';
      case MATCH:
        return 'true';
      case DESCRIPTION:
        return 'false';
      case MULTIANSWER:
        return 'true';
      default:
        return 'true';
    }
  }

  /**
   * maps a moodle question type to a qti 2.0 question type
   *
   * @param int type_id - the moodle question type
   * @return string qti 2.0 question type
   */
  function get_qti_interaction_type($type_id) {
    switch ($type_id) {
      case TRUEFALSE:
        $name = 'choiceInteraction';
        break;
      case MULTICHOICE:
        $name = 'choiceInteraction';
        break;
      case SHORTANSWER:
        $name = 'textInteraction';
        break;
      case NUMERICAL:
        $name = 'textInteraction';
        break;
      case MATCH:
        $name = 'matchInteraction';
        break;
      case DESCRIPTION:
        $name = 'extendedTextInteraction';
        break;
      case MULTIANSWER:
        $name = 'textInteraction';
        break;
      default:
        $name = 'textInteraction';
    }
    return $name;
  }

  /**
   * returns the given array, shuffled
   *
   *
   * @param array $things
   * @return array
   */
  function shuffle_things($things) {
    $things = swapshuffle_assoc($things);
    $oldthings = $things;
    $things = array();
    foreach ($oldthings as $key => $value) {
      $things[] = $value;

      // This loses the index key, but doesn't matter
    }
    return $things;
  }

  /**
   * returns a flattened image name - with all /, \ and : replaced with other characters
   *
   * used to convert a file or url to a qti-permissable identifier
   *
   * @param string name
   * @return string
   */
  function flatten_image_name($name) {
    return str_replace(array(
      '/',
      '\\',
      ':',
    ), array(
      '_',
      '-',
      '.',
    ), $name);
  }
  function file_full_path($file, $courseid) {
    global $CFG;
    if (substr(strtolower($file), 0, 7) == 'http://') {
      $url = $file;
    }
    else {
      if ($CFG->slasharguments) {

        // Use this method if possible for better caching
        $url = "{$CFG->wwwroot}/file.php/{$courseid}/{$file}";
      }
      else {
        $url = "{$CFG->wwwroot}/file.php?file=/{$courseid}/{$file}";
      }
    }
    return $url;
  }

}

Constants

Name	Description
CLOZE_TRAILING_TEXT_ID	@package questionbank @subpackage importexport

Classes

Name	Description
qformat_qti2