mod/quiz/startattempt.php

   1 <?php
   2 // This file is part of Moodle - http://moodle.org/
   3 //
   4 // Moodle is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // Moodle is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 /**
  18  * This script deals with starting a new attempt at a quiz.
  19  *
  20  * Normally, it will end up redirecting to attempt.php - unless a password form is displayed.
  21  *
  22  * This code used to be at the top of attempt.php, if you are looking for CVS history.
  23  *
  24  * @package    mod
  25  * @subpackage quiz
  26  * @copyright  2009 The Open University
  27  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  28  */
  29
  30 require_once(dirname(__FILE__) . '/../../config.php');
  31 require_once($CFG->dirroot . '/mod/quiz/locallib.php');
  32
  33 // Get submitted parameters.
  34 $id = required_param('cmid', PARAM_INT); // Course module id
  35 $forcenew = optional_param('forcenew', false, PARAM_BOOL); // Used to force a new preview
  36 $page = optional_param('page', 0, PARAM_INT); // Page to jump to in the attempt.
  37
  38 if (!$cm = get_coursemodule_from_id('quiz', $id)) {
  39     print_error('invalidcoursemodule');
  40 }
  41 if (!$course = $DB->get_record('course', array('id' => $cm->course))) {
  42     print_error("coursemisconf");
  43 }
  44 if (!$quiz = $DB->get_record('quiz', array('id' => $cm->instance))) {
  45     print_error('invalidcoursemodule');
  46 }
  47
  48 $quizobj = quiz::create($quiz->id, $USER->id);
  49 // This script should only ever be posted to, so set page URL to the view page.
  50 $PAGE->set_url($quizobj->view_url());
  51
  52 // Check login and sesskey.
  53 require_login($quizobj->get_courseid(), false, $quizobj->get_cm());
  54 require_sesskey();
  55 $PAGE->set_pagelayout('base');
  56
  57 // if no questions have been set up yet redirect to edit.php or display an error.
  58 if (!$quizobj->has_questions()) {
  59     if ($quizobj->has_capability('mod/quiz:manage')) {
  60         redirect($quizobj->edit_url());
  61     } else {
  62         print_error('cannotstartnoquestions', 'quiz', $quizobj->view_url());
  63     }
  64 }
  65
  66 // Create an object to manage all the other (non-roles) access rules.
  67 $accessmanager = $quizobj->get_access_manager(time());
  68 if ($quizobj->is_preview_user() && $forcenew) {
  69     $accessmanager->clear_password_access();
  70 }
  71
  72 // Check capabilities.
  73 if (!$quizobj->is_preview_user()) {
  74     $quizobj->require_capability('mod/quiz:attempt');
  75 }
  76
  77 // Check to see if a new preview was requested.
  78 if ($quizobj->is_preview_user() && $forcenew) {
  79     // To force the creation of a new preview, we set a finish time on the
  80     // current attempt (if any). It will then automatically be deleted below
  81     $DB->set_field('quiz_attempts', 'timefinish', time(),
  82             array('quiz' => $quiz->id, 'userid' => $USER->id));
  83 }
  84
  85 // Look for an existing attempt.
  86 $attempts = quiz_get_user_attempts($quiz->id, $USER->id, 'all');
  87 $lastattempt = end($attempts);
  88
  89 // If an in-progress attempt exists, check password then redirect to it.
  90 if ($lastattempt && !$lastattempt->timefinish) {
  91     $accessmanager->do_password_check($quizobj->is_preview_user());
  92     redirect($quizobj->attempt_url($lastattempt->id, $page));
  93 }
  94
  95 // Get number for the next or unfinished attempt
  96 if ($lastattempt && !$lastattempt->preview && !$quizobj->is_preview_user()) {
  97     $attemptnumber = $lastattempt->attempt + 1;
  98 } else {
  99     $lastattempt = false;
 100     $attemptnumber = 1;
 101 }
 102
 103 // Check access.
 104 $messages = $accessmanager->prevent_access() +
 105         $accessmanager->prevent_new_attempt(count($attempts), $lastattempt);
 106 if (!$quizobj->is_preview_user() && $messages) {
 107     $output = $PAGE->get_renderer('mod_quiz');
 108     print_error('attempterror', 'quiz', $quizobj->view_url(),
 109             $output->access_messages($messages));
 110 }
 111 $accessmanager->do_password_check($quizobj->is_preview_user());
 112
 113 // Delete any previous preview attempts belonging to this user.
 114 quiz_delete_previews($quiz, $USER->id);
 115
 116 $quba = question_engine::make_questions_usage_by_activity('mod_quiz', $quizobj->get_context());
 117 $quba->set_preferred_behaviour($quiz->preferredbehaviour);
 118
 119 // Create the new attempt and initialize the question sessions
 120 $attempt = quiz_create_attempt($quiz, $attemptnumber, $lastattempt, time(),
 121         $quizobj->is_preview_user());
 122
 123 if (!($quiz->attemptonlast && $lastattempt)) {
 124     // Starting a normal, new, quiz attempt.
 125
 126     // Fully load all the questions in this quiz.
 127     $quizobj->preload_questions();
 128     $quizobj->load_questions();
 129
 130     // Add them all to the $quba.
 131     $idstoslots = array();
 132     $questionsinuse = array_keys($quizobj->get_questions());
 133     foreach ($quizobj->get_questions() as $i => $questiondata) {
 134         if ($questiondata->qtype != 'random') {
 135             if (!$quiz->shuffleanswers) {
 136                 $questiondata->options->shuffleanswers = false;
 137             }
 138             $question = question_bank::make_question($questiondata);
 139
 140         } else {
 141             $question = question_bank::get_qtype('random')->choose_other_question(
 142                     $questiondata, $questionsinuse, $quiz->shuffleanswers);
 143             if (is_null($question)) {
 144                 throw new moodle_exception('notenoughrandomquestions', 'quiz',
 145                         $quizobj->view_url(), $questiondata);
 146             }
 147         }
 148
 149         $idstoslots[$i] = $quba->add_question($question, $questiondata->maxmark);
 150         $questionsinuse[] = $question->id;
 151     }
 152
 153     // Start all the questions.
 154     if ($attempt->preview) {
 155         $variantoffset = rand(1, 100);
 156     } else {
 157         $variantoffset = $attemptnumber;
 158     }
 159     $quba->start_all_questions(
 160             new question_variant_pseudorandom_no_repeats_strategy($variantoffset),
 161             time());
 162
 163     // Update attempt layout.
 164     $newlayout = array();
 165     foreach (explode(',', $attempt->layout) as $qid) {
 166         if ($qid != 0) {
 167             $newlayout[] = $idstoslots[$qid];
 168         } else {
 169             $newlayout[] = 0;
 170         }
 171     }
 172     $attempt->layout = implode(',', $newlayout);
 173
 174 } else {
 175     // Starting a subsequent attempt in each attempt builds on last mode.
 176
 177     $oldquba = question_engine::load_questions_usage_by_activity($lastattempt->uniqueid);
 178
 179     $oldnumberstonew = array();
 180     foreach ($oldquba->get_attempt_iterator() as $oldslot => $oldqa) {
 181         $newslot = $quba->add_question($oldqa->get_question(), $oldqa->get_max_mark());
 182
 183         $quba->start_question_based_on($newslot, $oldqa);
 184
 185         $oldnumberstonew[$oldslot] = $newslot;
 186     }
 187
 188     // Update attempt layout.
 189     $newlayout = array();
 190     foreach (explode(',', $lastattempt->layout) as $oldslot) {
 191         if ($oldslot != 0) {
 192             $newlayout[] = $oldnumberstonew[$oldslot];
 193         } else {
 194             $newlayout[] = 0;
 195         }
 196     }
 197     $attempt->layout = implode(',', $newlayout);
 198 }
 199
 200 // Save the attempt in the database.
 201 $transaction = $DB->start_delegated_transaction();
 202 question_engine::save_questions_usage_by_activity($quba);
 203 $attempt->uniqueid = $quba->get_id();
 204 $attempt->id = $DB->insert_record('quiz_attempts', $attempt);
 205
 206 // Log the new attempt.
 207 if ($attempt->preview) {
 208     add_to_log($course->id, 'quiz', 'preview', 'view.php?id=' . $quizobj->get_cmid(),
 209             $quizobj->get_quizid(), $quizobj->get_cmid());
 210 } else {
 211     add_to_log($course->id, 'quiz', 'attempt', 'review.php?attempt=' . $attempt->id,
 212             $quizobj->get_quizid(), $quizobj->get_cmid());
 213 }
 214
 215 // Trigger event
 216 $eventdata = new stdClass();
 217 $eventdata->component = 'mod_quiz';
 218 $eventdata->attemptid = $attempt->id;
 219 $eventdata->timestart = $attempt->timestart;
 220 $eventdata->userid    = $attempt->userid;
 221 $eventdata->quizid    = $quizobj->get_quizid();
 222 $eventdata->cmid      = $quizobj->get_cmid();
 223 $eventdata->courseid  = $quizobj->get_courseid();
 224 events_trigger('quiz_attempt_started', $eventdata);
 225
 226 $transaction->allow_commit();
 227
 228 // Redirect to the attempt page.
 229 redirect($quizobj->attempt_url($attempt->id, $page));