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         $continue = false;
  40     }
  41
  42     require_login();
  43
  44     if (!isteacherinanycourse()) {
  45         error('This page is for teachers only');
  46     }
  47
  48     if (!$continue) {
  49         // Start a new attempt; delete the old session
  50         unset($SESSION->quizpreview);
  51         // Redirect to ourselves but with continue=1; prevents refreshing the page
  52         // from restarting an attempt (needed so that random questions don't change)
  53         $quizid = $quizid ? '&amp;quizid=' . $quizid : '';
  54         redirect($CFG->wwwroot . '/question/preview.php?id=' . $id . $quizid .
  55          '&amp;continue=1');
  56     }
  57
  58     if (empty($quizid)) {
  59         $quiz = new cmoptions;
  60         $quiz->id = 0;
  61         $quiz->review = $CFG->quiz_review;
  62
  63     } else if (!$quiz = get_record('quiz', 'id', $quizid)) {
  64         error("Quiz id $quizid does not exist");
  65     }
  66
  67     // Load the question information
  68     if (!$questions = get_records('question', 'id', $id)) {
  69         error('Could not load question');
  70     }
  71     if ($maxgrade = get_field('quiz_question_instances', 'grade', 'quiz', $quiz->id, 'question', $id)) {
  72         $questions[$id]->maxgrade = $maxgrade;
  73     } else {
  74         $questions[$id]->maxgrade = $questions[$id]->defaultgrade;
  75     }
  76
  77     $quiz->id = 0; // just for safety
  78     $quiz->questions = $id;
  79
  80     if (!$category = get_record("question_categories", "id", $questions[$id]->category)) {
  81         error("This question doesn't belong to a valid category!");
  82     }
  83
  84     if (!isteacher($category->course) and !$category->publish) {
  85         error("You can't preview these questions!");
  86     }
  87     $quiz->course = $category->course;
  88
  89     // Load the question type specific information
  90     if (!get_question_options($questions)) {
  91         error(get_string('newattemptfail', 'quiz'));
  92     }
  93
  94     // Create a dummy quiz attempt
  95     // TODO: find out what of the following we really need. What is $attempt
  96     //       really used for?
  97     $timenow = time();
  98     $attempt->quiz = $quiz->id;
  99     $attempt->userid = $USER->id;
 100     $attempt->attempt = 0;
 101     $attempt->sumgrades = 0;
 102     $attempt->timestart = $timenow;
 103     $attempt->timefinish = 0;
 104     $attempt->timemodified = $timenow;
 105     $attempt->uniqueid = 0;
 106     $attempt->id = 0;
 107
 108     // Restore the history of question sessions from the moodle session or create
 109     // new sessions. Make $states a reference to the states array in the moodle
 110     // session.
 111     if (isset($SESSION->quizpreview->states) and $SESSION->quizpreview->questionid
 112      == $id) {
 113         // Reload the question session history from the moodle session
 114         $states =& $SESSION->quizpreview->states;
 115         $historylength = count($states) - 1;
 116         if ($back && $historylength > 0) {
 117             // Go back one step in the history
 118             unset($states[$historylength]);
 119             $historylength--;
 120         }
 121     } else {
 122         // Record the question id in the moodle session
 123         $SESSION->quizpreview->questionid = $id;
 124         // Create an empty session for the question
 125         if (!$newstates =
 126          get_question_states($questions, $quiz, $attempt)) {
 127             error(get_string('newattemptfail', 'quiz'));
 128         }
 129         $SESSION->quizpreview->states = array($newstates);
 130         $states =& $SESSION->quizpreview->states;
 131         $historylength = 0;
 132     }
 133
 134     if (!$fillcorrect && !$back && ($form = data_submitted())) {
 135         $form = (array)$form;
 136         $submitted = true;
 137
 138         // Create a new item in the history of question states (don't simplify!)
 139         $states[$historylength + 1] = array();
 140         $states[$historylength + 1][$id] = clone($states[$historylength][$id]);
 141         $historylength++;
 142         $curstate =& $states[$historylength][$id];
 143         $curstate->changed = false;
 144
 145         // Process the responses
 146         unset($form['id']);
 147         unset($form['quizid']);
 148         unset($form['continue']);
 149         unset($form['markall']);
 150         unset($form['finishattempt']);
 151         unset($form['back']);
 152         unset($form['startagain']);
 153
 154         $event = $finishattempt ? QUESTION_EVENTCLOSE : QUESTION_EVENTSUBMIT;
 155         if ($actions = question_extract_responses($questions, $form, $event)) {
 156             $actions[$id]->timestamp = 0; // We do not care about timelimits here
 157             question_process_responses($questions[$id], $curstate, $actions[$id], $quiz, $attempt);
 158             if (!$curstate->changed) {
 159                 // Update the current state rather than creating a new one
 160                 $historylength--;
 161                 unset($states[$historylength]);
 162                 $states = array_values($states);
 163                 $curstate =& $states[$historylength][$id];
 164             }
 165         }
 166     } else {
 167         $submitted = false;
 168         $curstate =& $states[$historylength][$id];
 169     }
 170
 171     // TODO: should not use quiz-specific function here
 172     $options = quiz_get_renderoptions($quiz->review, $curstate);
 173
 174     // Fill in the correct responses (unless the question is in readonly mode)
 175     if ($fillcorrect && !$options->readonly) {
 176         $curstate->responses = $QTYPES[$questions[$id]->qtype]
 177          ->get_correct_responses($questions[$id], $curstate);
 178     }
 179
 180     $strpreview = get_string('preview', 'quiz').' '.s($questions[$id]->name);
 181     print_header($strpreview);
 182     print_heading($strpreview);
 183
 184     if (!empty($quizid)) {
 185         echo '<p class="quemodname">'.get_string('modulename', 'quiz') . ': ';
 186         p(format_string($quiz->name));
 187         echo "</p>\n";
 188     }
 189     $number = 1;
 190     echo "<form method=\"post\" action=\"preview.php\" autocomplete=\"off\">\n";
 191     echo "<input type=\"hidden\" name=\"id\" value=\"$id\" />\n";
 192     echo "<input type=\"hidden\" name=\"quizid\" value=\"$quizid\" />\n";
 193     echo "<input type=\"hidden\" name=\"continue\" value=\"1\" />\n";
 194
 195     print_question($questions[$id], $curstate, $number, $quiz, $options);
 196
 197     echo '<br />';
 198     echo '<center>';
 199
 200     // Print the mark and finish attempt buttons
 201     echo '<input name="markall" type="submit" value="' . get_string('markall',
 202      'quiz') . "\" />\n";
 203     echo '<input name="finishattempt" type="submit" value="' .
 204      get_string('finishattempt', 'quiz') . "\" />\n";
 205     echo '<br />';
 206     echo '<br />';
 207     // Print the fill correct button (unless the question is in readonly mode)
 208     if (!$options->readonly) {
 209         echo '<input name="fillcorrect" type="submit" value="' .
 210          get_string('fillcorrect', 'quiz') . "\" />\n";
 211     }
 212     // Print the navigation buttons
 213     if ($historylength > 0) {
 214         echo '<input name="back" type="submit" value="' . get_string('previous',
 215          'quiz') . "\" />\n";
 216     }
 217     // Print the start again button
 218     echo '<input name="startagain" type="submit" value="' .
 219      get_string('startagain', 'quiz') . "\" />\n";
 220     // Print the close window button
 221     echo '<input type="button" onclick="window.close()" value="' .
 222      get_string('closepreview', 'quiz') . "\" />";
 223     echo '</center>';
 224     echo '</form>';
 225     print_footer();
 226 ?>