question/preview.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 page displays a preview of a question
  19  *
  20  * The preview uses the option settings from the activity within which the question
  21  * is previewed or the default settings if no activity is specified. The question session
  22  * information is stored in the session as an array of subsequent states rather
  23  * than in the database.
  24  *
  25  * @package    moodlecore
  26  * @subpackage questionengine
  27  * @copyright  Alex Smith {@link http://maths.york.ac.uk/serving_maths} and
  28  *      numerous contributors.
  29  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  30  */
  31
  32
  33 require_once(dirname(__FILE__) . '/../config.php');
  34 require_once($CFG->libdir . '/questionlib.php');
  35 require_once(dirname(__FILE__) . '/previewlib.php');
  36
  37 /**
  38  * The maximum number of variants previewable. If there are more variants than this for a question
  39  * then we only allow the selection of the first x variants.
  40  * @var integer
  41  */
  42 define('QUESTION_PREVIEW_MAX_VARIANTS', 100);
  43
  44 // Get and validate question id.
  45 $id = required_param('id', PARAM_INT);
  46 $question = question_bank::load_question($id);
  47
  48 // Were we given a particular context to run the question in?
  49 // This affects things like filter settings, or forced theme or language.
  50 if ($cmid = optional_param('cmid', 0, PARAM_INT)) {
  51     $cm = get_coursemodule_from_id(false, $cmid);
  52     require_login($cm->course, false, $cm);
  53     $context = get_context_instance(CONTEXT_MODULE, $cmid);
  54
  55 } else if ($courseid = optional_param('courseid', 0, PARAM_INT)) {
  56     require_login($courseid);
  57     $context = get_context_instance(CONTEXT_COURSE, $courseid);
  58
  59 } else {
  60     require_login();
  61     $category = $DB->get_record('question_categories',
  62             array('id' => $question->category), '*', MUST_EXIST);
  63     $context = get_context_instance_by_id($category->contextid);
  64     $PAGE->set_context($context);
  65     // Note that in the other cases, require_login will set the correct page context.
  66 }
  67 question_require_capability_on($question, 'use');
  68 $PAGE->set_pagelayout('popup');
  69
  70 // Get and validate display options.
  71 $maxvariant = min($question->get_num_variants(), QUESTION_PREVIEW_MAX_VARIANTS);
  72 $options = new question_preview_options($question);
  73 $options->load_user_defaults();
  74 $options->set_from_request();
  75 $PAGE->set_url(question_preview_url($id, $options->behaviour, $options->maxmark,
  76         $options, $options->variant, $context));
  77
  78 // Get and validate exitsing preview, or start a new one.
  79 $previewid = optional_param('previewid', 0, PARAM_INT);
  80
  81 if ($previewid) {
  82     if (!isset($SESSION->question_previews[$previewid])) {
  83         print_error('notyourpreview', 'question');
  84     }
  85
  86     try {
  87         $quba = question_engine::load_questions_usage_by_activity($previewid);
  88
  89     } catch (Exception $e) {
  90         // This may not seem like the right error message to display, but
  91         // actually from the user point of view, it makes sense.
  92         print_error('submissionoutofsequencefriendlymessage', 'question',
  93                 question_preview_url($question->id, $options->behaviour,
  94                 $options->maxmark, $options, $options->variant, $context), null, $e);
  95     }
  96
  97     $slot = $quba->get_first_question_number();
  98     $usedquestion = $quba->get_question($slot);
  99     if ($usedquestion->id != $question->id) {
 100         print_error('questionidmismatch', 'question');
 101     }
 102     $question = $usedquestion;
 103     $options->variant = $quba->get_variant($slot);
 104
 105 } else {
 106     $quba = question_engine::make_questions_usage_by_activity(
 107             'core_question_preview', $context);
 108     $quba->set_preferred_behaviour($options->behaviour);
 109     $slot = $quba->add_question($question, $options->maxmark);
 110
 111     if ($options->variant) {
 112         $options->variant = min($maxvariant, max(1, $options->variant));
 113     } else {
 114         $options->variant = rand(1, $maxvariant);
 115     }
 116
 117     $quba->start_question($slot, $options->variant);
 118
 119     $transaction = $DB->start_delegated_transaction();
 120     question_engine::save_questions_usage_by_activity($quba);
 121     $transaction->allow_commit();
 122
 123     $SESSION->question_previews[$quba->get_id()] = true;
 124 }
 125 $options->behaviour = $quba->get_preferred_behaviour();
 126 $options->maxmark = $quba->get_question_max_mark($slot);
 127
 128 // Create the settings form, and initialise the fields.
 129 $optionsform = new preview_options_form(question_preview_form_url($question->id, $context),
 130         array('quba' => $quba, 'maxvariant' => $maxvariant));
 131 $optionsform->set_data($options);
 132
 133 // Process change of settings, if that was requested.
 134 if ($newoptions = $optionsform->get_submitted_data()) {
 135     // Set user preferences
 136     $options->save_user_preview_options($newoptions);
 137     if (!isset($newoptions->variant)) {
 138         $newoptions->variant = $options->variant;
 139     }
 140     restart_preview($previewid, $question->id, $newoptions, $context);
 141 }
 142
 143 // Prepare a URL that is used in various places.
 144 $actionurl = question_preview_action_url($question->id, $quba->get_id(), $options, $context);
 145
 146 // Process any actions from the buttons at the bottom of the form.
 147 if (data_submitted() && confirm_sesskey()) {
 148
 149     try {
 150
 151         if (optional_param('restart', false, PARAM_BOOL)) {
 152             restart_preview($previewid, $question->id, $options, $context);
 153
 154         } else if (optional_param('fill', null, PARAM_BOOL)) {
 155             $correctresponse = $quba->get_correct_response($slot);
 156             if (!is_null($correctresponse)) {
 157                 $quba->process_action($slot, $correctresponse);
 158
 159                 $transaction = $DB->start_delegated_transaction();
 160                 question_engine::save_questions_usage_by_activity($quba);
 161                 $transaction->allow_commit();
 162             }
 163             redirect($actionurl);
 164
 165         } else if (optional_param('finish', null, PARAM_BOOL)) {
 166             $quba->process_all_actions();
 167             $quba->finish_all_questions();
 168
 169             $transaction = $DB->start_delegated_transaction();
 170             question_engine::save_questions_usage_by_activity($quba);
 171             $transaction->allow_commit();
 172             redirect($actionurl);
 173
 174         } else {
 175             $quba->process_all_actions();
 176
 177             $transaction = $DB->start_delegated_transaction();
 178             question_engine::save_questions_usage_by_activity($quba);
 179             $transaction->allow_commit();
 180
 181             $scrollpos = optional_param('scrollpos', '', PARAM_RAW);
 182             if ($scrollpos !== '') {
 183                 $actionurl->param('scrollpos', (int) $scrollpos);
 184             }
 185             redirect($actionurl);
 186         }
 187
 188     } catch (question_out_of_sequence_exception $e) {
 189         print_error('submissionoutofsequencefriendlymessage', 'question', $actionurl);
 190
 191     } catch (Exception $e) {
 192         // This sucks, if we display our own custom error message, there is no way
 193         // to display the original stack trace.
 194         $debuginfo = '';
 195         if (!empty($e->debuginfo)) {
 196             $debuginfo = $e->debuginfo;
 197         }
 198         print_error('errorprocessingresponses', 'question', $actionurl,
 199                 $e->getMessage(), $debuginfo);
 200     }
 201 }
 202
 203 if ($question->length) {
 204     $displaynumber = '1';
 205 } else {
 206     $displaynumber = 'i';
 207 }
 208 $restartdisabled = '';
 209 $finishdisabled = '';
 210 $filldisabled = '';
 211 if ($quba->get_question_state($slot)->is_finished()) {
 212     $finishdisabled = ' disabled="disabled"';
 213     $filldisabled = ' disabled="disabled"';
 214 }
 215 // If question type cannot give us a correct response, disable this button.
 216 if (is_null($quba->get_correct_response($slot))) {
 217     $filldisabled = ' disabled="disabled"';
 218 }
 219 if (!$previewid) {
 220     $restartdisabled = ' disabled="disabled"';
 221 }
 222
 223 // Output
 224 $title = get_string('previewquestion', 'question', format_string($question->name));
 225 $headtags = question_engine::initialise_js() . $quba->render_question_head_html($slot);
 226 $PAGE->set_title($title);
 227 $PAGE->set_heading($title);
 228 echo $OUTPUT->header();
 229
 230 // Start the question form.
 231 echo '<form method="post" action="' . $actionurl .
 232         '" enctype="multipart/form-data" id="responseform">', "\n";
 233 echo '<div>';
 234 echo '<input type="hidden" name="sesskey" value="' . sesskey() . '" />', "\n";
 235 echo '<input type="hidden" name="slots" value="' . $slot . '" />', "\n";
 236 echo '</div>';
 237
 238 // Output the question.
 239 echo $quba->render_question($slot, $options, $displaynumber);
 240
 241 echo '<p class="notifytiny">' . get_string('behaviourbeingused', 'question',
 242         question_engine::get_behaviour_name(
 243         $quba->get_question_attempt($slot)->get_behaviour_name())) . '</p>';
 244 // Finish the question form.
 245 echo '<div id="previewcontrols" class="controls">';
 246 echo '<input type="submit" name="restart"' . $restartdisabled .
 247         ' value="' . get_string('restart', 'question') . '" />', "\n";
 248 echo '<input type="submit" name="fill"' . $filldisabled .
 249         ' value="' . get_string('fillincorrect', 'question') . '" />', "\n";
 250 echo '<input type="submit" name="finish"' . $finishdisabled .
 251         ' value="' . get_string('submitandfinish', 'question') . '" />', "\n";
 252 echo '<input type="hidden" name="scrollpos" id="scrollpos" value="" />';
 253 echo '</div>';
 254 echo '</form>';
 255
 256 // Display the settings form.
 257 $optionsform->display();
 258
 259 $PAGE->requires->js_init_call('M.core_question_preview.init', null, false, array(
 260         'name' => 'core_question_preview',
 261         'fullpath' => '/question/preview.js',
 262         'requires' => array('base', 'dom', 'event-delegate', 'event-key', 'core_question_engine'),
 263         'strings' => array(
 264             array('closepreview', 'question'),
 265         )));
 266 echo $OUTPUT->footer();
 267