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  * @author Alex Smith as part of the Serving Mathematics project
  13  *         {@link http://maths.york.ac.uk/serving_maths}
  14  * @license http://www.gnu.org/copyleft/gpl.html GNU Public License
  15  * @package questionbank
  16  */
  17
  18     require_once("../config.php");
  19     require_once($CFG->libdir.'/questionlib.php');
  20     require_once($CFG->dirroot.'/mod/quiz/locallib.php'); // We really want to get rid of this
  21
  22     $id = required_param('id', PARAM_INT);        // question id
  23     // if no quiz id is specified then a dummy quiz with default options is used
  24     $quizid = optional_param('quizid', 0, PARAM_INT);
  25     // Test if we are continuing an attempt at a question
  26     $continue = optional_param('continue', 0, PARAM_BOOL);
  27     // Check for any of the submit buttons
  28     $fillcorrect = optional_param('fillcorrect', 0, PARAM_BOOL);
  29     $markall = optional_param('markall', 0, PARAM_BOOL);
  30     $finishattempt = optional_param('finishattempt', 0, PARAM_BOOL);
  31     $back = optional_param('back', 0, PARAM_BOOL);
  32     $startagain = optional_param('startagain', 0, PARAM_BOOL);
  33     // We are always continuing an attempt if a submit button was pressed with the
  34     // exception of the start again button
  35     if ($fillcorrect || $markall || $finishattempt || $back) {
  36         $continue = true;
  37     } else if ($startagain) {
  38         $continue = false;
  39     }
  40
  41     require_login();
  42
  43     // this might break things in the future
  44     if (!isteacherinanycourse()) {
  45         error('This page is for teachers only');
  46     }
  47
  48     if (!$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         $url = $CFG->wwwroot . '/question/preview.php?id=' . $id;
  54         if ($quizid) {
  55             $url .= '&amp;quizid=' . $quizid;
  56         }
  57         $url .= '&amp;continue=1';
  58         redirect($url);
  59     }
  60
  61     if (empty($quizid)) {
  62         $quiz = new cmoptions;
  63         $quiz->id = 0;
  64         $quiz->review = $CFG->quiz_review;
  65
  66     } else if (!$quiz = get_record('quiz', 'id', $quizid)) {
  67         error("Quiz id $quizid does not exist");
  68     }
  69
  70     // Load the question information
  71     if (!$questions = get_records('question', 'id', $id)) {
  72         error('Could not load question');
  73     }
  74     if ($maxgrade = get_field('quiz_question_instances', 'grade', 'quiz', $quiz->id, 'question', $id)) {
  75         $questions[$id]->maxgrade = $maxgrade;
  76     } else {
  77         $questions[$id]->maxgrade = $questions[$id]->defaultgrade;
  78     }
  79
  80     $quiz->id = 0; // just for safety
  81     $quiz->questions = $id;
  82
  83     if (!$category = get_record("question_categories", "id", $questions[$id]->category)) {
  84         error("This question doesn't belong to a valid category!");
  85     }
  86
  87     if (!has_capability('moodle/question:manage', get_context_instance(CONTEXT_COURSE, $category->course)) and !$category->publish) {
  88         error("You can't preview these questions!");
  89     }
  90     $quiz->course = $category->course;
  91
  92     // Load the question type specific information
  93     if (!get_question_options($questions)) {
  94         error(get_string('newattemptfail', 'quiz'));
  95     }
  96
  97     // Create a dummy quiz attempt
  98     // TODO: find out what of the following we really need. What is $attempt
  99     //       really used for?
 100     $timenow = time();
 101     $attempt->quiz = $quiz->id;
 102     $attempt->userid = $USER->id;
 103     $attempt->attempt = 0;
 104     $attempt->sumgrades = 0;
 105     $attempt->timestart = $timenow;
 106     $attempt->timefinish = 0;
 107     $attempt->timemodified = $timenow;
 108     $attempt->uniqueid = 0;
 109     $attempt->id = 0;
 110
 111     // Restore the history of question sessions from the moodle session or create
 112     // new sessions. Make $states a reference to the states array in the moodle
 113     // session.
 114     if (isset($SESSION->quizpreview->states) and $SESSION->quizpreview->questionid
 115      == $id) {
 116         // Reload the question session history from the moodle session
 117         $states =& $SESSION->quizpreview->states;
 118         $historylength = count($states) - 1;
 119         if ($back && $historylength > 0) {
 120             // Go back one step in the history
 121             unset($states[$historylength]);
 122             $historylength--;
 123         }
 124     } else {
 125         // Record the question id in the moodle session
 126         $SESSION->quizpreview->questionid = $id;
 127         // Create an empty session for the question
 128         if (!$newstates =
 129          get_question_states($questions, $quiz, $attempt)) {
 130             error(get_string('newattemptfail', 'quiz'));
 131         }
 132         $SESSION->quizpreview->states = array($newstates);
 133         $states =& $SESSION->quizpreview->states;
 134         $historylength = 0;
 135     }
 136
 137     if (!$fillcorrect && !$back && ($form = data_submitted())) {
 138         $form = (array)$form;
 139         $submitted = true;
 140
 141         // Create a new item in the history of question states (don't simplify!)
 142         $states[$historylength + 1] = array();
 143         $states[$historylength + 1][$id] = clone($states[$historylength][$id]);
 144         $historylength++;
 145         $curstate =& $states[$historylength][$id];
 146         $curstate->changed = false;
 147
 148         // Process the responses
 149         unset($form['id']);
 150         unset($form['quizid']);
 151         unset($form['continue']);
 152         unset($form['markall']);
 153         unset($form['finishattempt']);
 154         unset($form['back']);
 155         unset($form['startagain']);
 156
 157         $event = $finishattempt ? QUESTION_EVENTCLOSE : QUESTION_EVENTSUBMIT;
 158         if ($actions = question_extract_responses($questions, $form, $event)) {
 159             $actions[$id]->timestamp = 0; // We do not care about timelimits here
 160             question_process_responses($questions[$id], $curstate, $actions[$id], $quiz, $attempt);
 161             if (!$curstate->changed) {
 162                 // Update the current state rather than creating a new one
 163                 $historylength--;
 164                 unset($states[$historylength]);
 165                 $states = array_values($states);
 166                 $curstate =& $states[$historylength][$id];
 167             }
 168         }
 169     } else {
 170         $submitted = false;
 171         $curstate =& $states[$historylength][$id];
 172     }
 173
 174     // TODO: should not use quiz-specific function here
 175     $options = quiz_get_renderoptions($quiz->review, $curstate);
 176
 177     // Fill in the correct responses (unless the question is in readonly mode)
 178     if ($fillcorrect && !$options->readonly) {
 179         $curstate->responses = $QTYPES[$questions[$id]->qtype]
 180          ->get_correct_responses($questions[$id], $curstate);
 181     }
 182
 183     $strpreview = get_string('preview', 'quiz').' '.format_string($questions[$id]->name);
 184     $questionlist = array($id);
 185     $headtags = get_html_head_contributions($questionlist, $questions, $states[$historylength]);
 186     print_header($strpreview, '', '', '', $headtags);
 187     print_heading($strpreview);
 188
 189     if (!empty($quizid)) {
 190         echo '<p class="quemodname">'.get_string('modulename', 'quiz') . ': ';
 191         p($quiz->name);
 192         echo "</p>\n";
 193     }
 194     $number = 1;
 195     echo '<form method="post" action="preview.php" enctype="multipart/form-data">', "\n";
 196     print_question($questions[$id], $curstate, $number, $quiz, $options);
 197     echo '<br />';
 198
 199
 200
 201     echo '<div class="controls">';
 202     echo "<input type=\"hidden\" name=\"id\" value=\"$id\" />\n";
 203     echo "<input type=\"hidden\" name=\"quizid\" value=\"$quizid\" />\n";
 204     echo "<input type=\"hidden\" name=\"continue\" value=\"1\" />\n";
 205
 206     // Print the mark and finish attempt buttons
 207     echo '<input name="markall" type="submit" value="' . get_string('markall',
 208      'quiz') . "\" />\n";
 209     echo '<input name="finishattempt" type="submit" value="' .
 210      get_string('finishattempt', 'quiz') . "\" />\n";
 211     echo '<br />';
 212     echo '<br />';
 213     // Print the fill correct button (unless the question is in readonly mode)
 214     if (!$options->readonly) {
 215         echo '<input name="fillcorrect" type="submit" value="' .
 216          get_string('fillcorrect', 'quiz') . "\" />\n";
 217     }
 218     // Print the navigation buttons
 219     if ($historylength > 0) {
 220         echo '<input name="back" type="submit" value="' . get_string('previous',
 221          'quiz') . "\" />\n";
 222     }
 223     // Print the start again button
 224     echo '<input name="startagain" type="submit" value="' .
 225      get_string('startagain', 'quiz') . "\" />\n";
 226     // Print the close window button
 227     echo '<input type="button" onclick="window.close()" value="' .
 228      get_string('closepreview', 'quiz') . "\" />";
 229     echo '</div>';
 230     echo '</form>';
 231     print_footer();
 232 ?>