question/preview.php

   1 <?php // $Id$
   2 /**
   3 * This page displays a preview of a question
   4 *
   5 * The preview uses the option settings from the activity within which the question
   6 * is previewed or the default settings if no activity is specified. The question session
   7 * information is stored in the session as an array of subsequent states rather
   8 * than in the database.
   9 *
  10 * TODO: make this work with activities other than quiz
  11 *
  12 * @version $Id$
  13 * @author Alex Smith as part of the Serving Mathematics project
  14 *         {@link http://maths.york.ac.uk/serving_maths}
  15 * @license http://www.gnu.org/copyleft/gpl.html GNU Public License
  16 * @package question
  17 */
  18
  19     require_once("../config.php");
  20     require_once($CFG->libdir.'/questionlib.php');
  21     require_once($CFG->dirroot.'/mod/quiz/locallib.php'); // We really want to get rid of this
  22
  23     $id = required_param('id', PARAM_INT);        // question id
  24     // if no quiz id is specified then a dummy quiz with default options is used
  25     $quizid = optional_param('quizid', 0, PARAM_INT);
  26     // Test if we are continuing an attempt at a question
  27     $continue = optional_param('continue', 0, PARAM_BOOL);
  28     // Check for any of the submit buttons
  29     $fillcorrect = optional_param('fillcorrect', 0, PARAM_BOOL);
  30     $markall = optional_param('markall', 0, PARAM_BOOL);
  31     $finishattempt = optional_param('finishattempt', 0, PARAM_BOOL);
  32     $back = optional_param('back', 0, PARAM_BOOL);
  33     $startagain = optional_param('startagain', 0, PARAM_BOOL);
  34     // We are always continuing an attempt if a submit button was pressed with the
  35     // exception of the start again button
  36     if ($fillcorrect || $markall || $finishattempt || $back) {
  37         $continue = true;
  38     } else if ($startagain) {
  39         $continue = false;
  40     }
  41
  42     require_login();
  43
  44     // this might break things in the future
  45     if (!isteacherinanycourse()) {
  46         error('This page is for teachers only');
  47     }
  48
  49     if (!$continue) {
  50         // Start a new attempt; delete the old session
  51         unset($SESSION->quizpreview);
  52         // Redirect to ourselves but with continue=1; prevents refreshing the page
  53         // from restarting an attempt (needed so that random questions don't change)
  54         $quizid = $quizid ? '&amp;quizid=' . $quizid : '';
  55         redirect($CFG->wwwroot . '/question/preview.php?id=' . $id . $quizid .
  56          '&amp;continue=1');
  57     }
  58
  59     if (empty($quizid)) {
  60         $quiz = new cmoptions;
  61         $quiz->id = 0;
  62         $quiz->review = $CFG->quiz_review;
  63
  64     } else if (!$quiz = get_record('quiz', 'id', $quizid)) {
  65         error("Quiz id $quizid does not exist");
  66     }
  67
  68     // Load the question information
  69     if (!$questions = get_records('question', 'id', $id)) {
  70         error('Could not load question');
  71     }
  72     if ($maxgrade = get_field('quiz_question_instances', 'grade', 'quiz', $quiz->id, 'question', $id)) {
  73         $questions[$id]->maxgrade = $maxgrade;
  74     } else {
  75         $questions[$id]->maxgrade = $questions[$id]->defaultgrade;
  76     }
  77
  78     $quiz->id = 0; // just for safety
  79     $quiz->questions = $id;
  80
  81     if (!$category = get_record("question_categories", "id", $questions[$id]->category)) {
  82         error("This question doesn't belong to a valid category!");
  83     }
  84
  85     if (!has_capability('moodle/question:manage', get_context_instance(CONTEXT_COURSE, $category->course)) and !$category->publish) {
  86         error("You can't preview these questions!");
  87     }
  88     $quiz->course = $category->course;
  89
  90     // Load the question type specific information
  91     if (!get_question_options($questions)) {
  92         error(get_string('newattemptfail', 'quiz'));
  93     }
  94
  95     // Create a dummy quiz attempt
  96     // TODO: find out what of the following we really need. What is $attempt
  97     //       really used for?
  98     $timenow = time();
  99     $attempt->quiz = $quiz->id;
 100     $attempt->userid = $USER->id;
 101     $attempt->attempt = 0;
 102     $attempt->sumgrades = 0;
 103     $attempt->timestart = $timenow;
 104     $attempt->timefinish = 0;
 105     $attempt->timemodified = $timenow;
 106     $attempt->uniqueid = 0;
 107     $attempt->id = 0;
 108
 109     // Restore the history of question sessions from the moodle session or create
 110     // new sessions. Make $states a reference to the states array in the moodle
 111     // session.
 112     if (isset($SESSION->quizpreview->states) and $SESSION->quizpreview->questionid
 113      == $id) {
 114         // Reload the question session history from the moodle session
 115         $states =& $SESSION->quizpreview->states;
 116         $historylength = count($states) - 1;
 117         if ($back && $historylength > 0) {
 118             // Go back one step in the history
 119             unset($states[$historylength]);
 120             $historylength--;
 121         }
 122     } else {
 123         // Record the question id in the moodle session
 124         $SESSION->quizpreview->questionid = $id;
 125         // Create an empty session for the question
 126         if (!$newstates =
 127          get_question_states($questions, $quiz, $attempt)) {
 128             error(get_string('newattemptfail', 'quiz'));
 129         }
 130         $SESSION->quizpreview->states = array($newstates);
 131         $states =& $SESSION->quizpreview->states;
 132         $historylength = 0;
 133     }
 134
 135     if (!$fillcorrect && !$back && ($form = data_submitted())) {
 136         $form = (array)$form;
 137         $submitted = true;
 138
 139         // Create a new item in the history of question states (don't simplify!)
 140         $states[$historylength + 1] = array();
 141         $states[$historylength + 1][$id] = clone($states[$historylength][$id]);
 142         $historylength++;
 143         $curstate =& $states[$historylength][$id];
 144         $curstate->changed = false;
 145
 146         // Process the responses
 147         unset($form['id']);
 148         unset($form['quizid']);
 149         unset($form['continue']);
 150         unset($form['markall']);
 151         unset($form['finishattempt']);
 152         unset($form['back']);
 153         unset($form['startagain']);
 154
 155         $event = $finishattempt ? QUESTION_EVENTCLOSE : QUESTION_EVENTSUBMIT;
 156         if ($actions = question_extract_responses($questions, $form, $event)) {
 157             $actions[$id]->timestamp = 0; // We do not care about timelimits here
 158             question_process_responses($questions[$id], $curstate, $actions[$id], $quiz, $attempt);
 159             if (!$curstate->changed) {
 160                 // Update the current state rather than creating a new one
 161                 $historylength--;
 162                 unset($states[$historylength]);
 163                 $states = array_values($states);
 164                 $curstate =& $states[$historylength][$id];
 165             }
 166         }
 167     } else {
 168         $submitted = false;
 169         $curstate =& $states[$historylength][$id];
 170     }
 171
 172     // TODO: should not use quiz-specific function here
 173     $options = quiz_get_renderoptions($quiz->review, $curstate);
 174
 175     // Fill in the correct responses (unless the question is in readonly mode)
 176     if ($fillcorrect && !$options->readonly) {
 177         $curstate->responses = $QTYPES[$questions[$id]->qtype]
 178          ->get_correct_responses($questions[$id], $curstate);
 179     }
 180
 181     $strpreview = get_string('preview', 'quiz').' '.s($questions[$id]->name);
 182     print_header($strpreview);
 183     print_heading($strpreview);
 184
 185     if (!empty($quizid)) {
 186         echo '<p align="center">'.get_string('modulename', 'quiz') . ': ';
 187         p($quiz->name);
 188         echo "</p>\n";
 189     }
 190     $number = 1;
 191     echo "<form method=\"post\" action=\"preview.php\" autocomplete=\"off\">\n";
 192     echo "<input type=\"hidden\" name=\"id\" value=\"$id\" />\n";
 193     echo "<input type=\"hidden\" name=\"quizid\" value=\"$quizid\" />\n";
 194     echo "<input type=\"hidden\" name=\"continue\" value=\"1\" />\n";
 195
 196     print_question($questions[$id], $curstate, $number, $quiz, $options);
 197
 198     echo '<br />';
 199     echo '<center>';
 200
 201     // Print the mark and finish attempt buttons
 202     echo '<input name="markall" type="submit" value="' . get_string('markall',
 203      'quiz') . "\" />\n";
 204     echo '<input name="finishattempt" type="submit" value="' .
 205      get_string('finishattempt', 'quiz') . "\" />\n";
 206     echo '<br />';
 207     echo '<br />';
 208     // Print the fill correct button (unless the question is in readonly mode)
 209     if (!$options->readonly) {
 210         echo '<input name="fillcorrect" type="submit" value="' .
 211          get_string('fillcorrect', 'quiz') . "\" />\n";
 212     }
 213     // Print the navigation buttons
 214     if ($historylength > 0) {
 215         echo '<input name="back" type="submit" value="' . get_string('previous',
 216          'quiz') . "\" />\n";
 217     }
 218     // Print the start again button
 219     echo '<input name="startagain" type="submit" value="' .
 220      get_string('startagain', 'quiz') . "\" />\n";
 221     // Print the close window button
 222     echo '<input type="button" onclick="window.close()" value="' .
 223      get_string('closepreview', 'quiz') . "\" />";
 224     echo '</center>';
 225     echo '</form>';
 226     print_footer();
 227 ?>