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     $quizid = optional_param('quizid', 0, PARAM_INT);
  25     // if no quiz id is specified then tell us the course
  26     if (empty($quizid)) {
  27         $courseid = required_param('courseid', PARAM_INT);
  28     }
  29
  30     // Test if we are continuing an attempt at a question
  31     $continue = optional_param('continue', 0, PARAM_BOOL);
  32     // Check for any of the submit buttons
  33     $fillcorrect = optional_param('fillcorrect', 0, PARAM_BOOL);
  34     $markall = optional_param('markall', 0, PARAM_BOOL);
  35     $finishattempt = optional_param('finishattempt', 0, PARAM_BOOL);
  36     $back = optional_param('back', 0, PARAM_BOOL);
  37     $startagain = optional_param('startagain', 0, PARAM_BOOL);
  38     // We are always continuing an attempt if a submit button was pressed with the
  39     // exception of the start again button
  40     if ($fillcorrect || $markall || $finishattempt || $back) {
  41         $continue = true;
  42     } else if ($startagain) {
  43         $continue = false;
  44     }
  45
  46     $url = new moodle_url($CFG->wwwroot . '/question/preview.php');
  47     $url->param('id', $id);
  48     if ($quizid) {
  49         $url->param('quizid', $quizid);
  50     } else {
  51         $url->param('courseid', $courseid);
  52     }
  53     $url->param('continue', 1);
  54     if (!$continue) {
  55         // Start a new attempt; delete the old session
  56         unset($SESSION->quizpreview);
  57         // Redirect to ourselves but with continue=1; prevents refreshing the page
  58         // from restarting an attempt (needed so that random questions don't change)
  59         redirect($url->out());
  60     }
  61     // Load the question information
  62     if (!$questions = get_records('question', 'id', $id)) {
  63         error('Could not load question');
  64     }
  65     if (empty($quizid)) {
  66         $quiz = new cmoptions;
  67         $quiz->id = 0;
  68         $quiz->review = $CFG->quiz_review;
  69         require_login($courseid, false);
  70         $quiz->course = $courseid;
  71     } else if (!$quiz = get_record('quiz', 'id', $quizid)) {
  72         error("Quiz id $quizid does not exist");
  73     } else {
  74         require_login($quiz->course, false, get_coursemodule_from_instance('quiz', $quizid, $quiz->course));
  75     }
  76
  77
  78
  79     if ($maxgrade = get_field('quiz_question_instances', 'grade', 'quiz', $quiz->id, 'question', $id)) {
  80         $questions[$id]->maxgrade = $maxgrade;
  81     } else {
  82         $questions[$id]->maxgrade = $questions[$id]->defaultgrade;
  83     }
  84
  85     $quiz->id = 0; // just for safety
  86     $quiz->questions = $id;
  87
  88     if (!$category = get_record("question_categories", "id", $questions[$id]->category)) {
  89         error("This question doesn't belong to a valid category!");
  90     }
  91
  92     if (!question_has_capability_on($questions[$id], 'use', $questions[$id]->category)){
  93         error("You can't preview these questions!");
  94     }
  95     if (isset($COURSE)){
  96         $quiz->course = $COURSE->id;
  97     }
  98
  99     // Load the question type specific information
 100     if (!get_question_options($questions)) {
 101         print_error('newattemptfail', 'quiz');
 102     }
 103
 104     // Create a dummy quiz attempt
 105     // TODO: find out what of the following we really need. What is $attempt
 106     //       really used for?
 107     $timenow = time();
 108     $attempt->quiz = $quiz->id;
 109     $attempt->userid = $USER->id;
 110     $attempt->attempt = 0;
 111     $attempt->sumgrades = 0;
 112     $attempt->timestart = $timenow;
 113     $attempt->timefinish = 0;
 114     $attempt->timemodified = $timenow;
 115     $attempt->uniqueid = 0;
 116     $attempt->id = 0;
 117
 118     // Restore the history of question sessions from the moodle session or create
 119     // new sessions. Make $states a reference to the states array in the moodle
 120     // session.
 121     if (isset($SESSION->quizpreview->states) and $SESSION->quizpreview->questionid == $id) {
 122         // Reload the question session history from the moodle session
 123         $states =& $SESSION->quizpreview->states;
 124         $historylength = count($states) - 1;
 125         if ($back && $historylength > 0) {
 126             // Go back one step in the history
 127             unset($states[$historylength]);
 128             $historylength--;
 129         }
 130     } else {
 131         // Record the question id in the moodle session
 132         $SESSION->quizpreview->questionid = $id;
 133         // Create an empty session for the question
 134         if (!$newstates =
 135          get_question_states($questions, $quiz, $attempt)) {
 136             print_error('newattemptfail', 'quiz');
 137         }
 138         $SESSION->quizpreview->states = array($newstates);
 139         $states =& $SESSION->quizpreview->states;
 140         $historylength = 0;
 141     }
 142
 143     if (!$fillcorrect && !$back && ($form = data_submitted())) {
 144         $form = (array)$form;
 145         $submitted = true;
 146
 147         // Create a new item in the history of question states (don't simplify!)
 148         $states[$historylength + 1] = array();
 149         $states[$historylength + 1][$id] = clone($states[$historylength][$id]);
 150         $historylength++;
 151         $curstate =& $states[$historylength][$id];
 152         $curstate->changed = false;
 153
 154         // Process the responses
 155         unset($form['id']);
 156         unset($form['quizid']);
 157         unset($form['continue']);
 158         unset($form['markall']);
 159         unset($form['finishattempt']);
 160         unset($form['back']);
 161         unset($form['startagain']);
 162
 163         $event = $finishattempt ? QUESTION_EVENTCLOSE : QUESTION_EVENTSUBMIT;
 164         if ($actions = question_extract_responses($questions, $form, $event)) {
 165             $actions[$id]->timestamp = 0; // We do not care about timelimits here
 166             if (!question_process_responses($questions[$id], $curstate, $actions[$id], $quiz, $attempt)) {
 167                 unset($SESSION->quizpreview);
 168                 print_error('errorprocessingresponses', 'question', $url->out());
 169             }
 170             if (!$curstate->changed) {
 171                 // Update the current state rather than creating a new one
 172                 $historylength--;
 173                 unset($states[$historylength]);
 174                 $states = array_values($states);
 175                 $curstate =& $states[$historylength][$id];
 176             }
 177         }
 178     } else {
 179         $submitted = false;
 180         $curstate =& $states[$historylength][$id];
 181     }
 182
 183     // TODO: should not use quiz-specific function here
 184     $options = quiz_get_renderoptions($quiz->review, $curstate);
 185
 186     // Fill in the correct responses (unless the question is in readonly mode)
 187     if ($fillcorrect && !$options->readonly) {
 188         $curstate->responses = $QTYPES[$questions[$id]->qtype]
 189          ->get_correct_responses($questions[$id], $curstate);
 190     }
 191
 192     $strpreview = get_string('preview', 'quiz').' '.format_string($questions[$id]->name);
 193     $questionlist = array($id);
 194     $headtags = get_html_head_contributions($questionlist, $questions, $states[$historylength]);
 195     print_header($strpreview, '', '', '', $headtags);
 196     print_heading($strpreview);
 197
 198     if (!empty($quizid)) {
 199         echo '<p class="quemodname">'.get_string('modulename', 'quiz') . ': ';
 200         p(format_string($quiz->name));
 201         echo "</p>\n";
 202     }
 203     $number = 1;
 204     echo '<form method="post" action="'.$url->out(true).'" enctype="multipart/form-data" id="responseform">', "\n";
 205     print_question($questions[$id], $curstate, $number, $quiz, $options);
 206
 207     echo '<div class="controls">';
 208     echo $url->hidden_params_out();
 209
 210     // Print the mark and finish attempt buttons
 211     echo '<input name="markall" type="submit" value="' . get_string('markall',
 212      'quiz') . "\" />\n";
 213     echo '<input name="finishattempt" type="submit" value="' .
 214      get_string('finishattempt', 'quiz') . "\" />\n";
 215     echo '<br />';
 216     echo '<br />';
 217     // Print the fill correct button (unless the question is in readonly mode)
 218     if (!$options->readonly) {
 219         echo '<input name="fillcorrect" type="submit" value="' .
 220          get_string('fillcorrect', 'quiz') . "\" />\n";
 221     }
 222     // Print the navigation buttons
 223     if ($historylength > 0) {
 224         echo '<input name="back" type="submit" value="' . get_string('previous',
 225          'quiz') . "\" />\n";
 226     }
 227     // Print the start again button
 228     echo '<input name="startagain" type="submit" value="' .
 229      get_string('startagain', 'quiz') . "\" />\n";
 230     // Print the close window button
 231     echo '<input type="button" onclick="window.close()" value="' .
 232      get_string('closepreview', 'quiz') . "\" />";
 233     echo '</div>';
 234     echo '</form>';
 235     print_footer();
 236 ?>