question/previewlib.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  * Library functions used by question/preview.php.
  19  *
  20  * @package    moodlecore
  21  * @subpackage questionengine
  22  * @copyright  2010 The Open University
  23  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24  */
  25
  26
  27 defined('MOODLE_INTERNAL') || die();
  28
  29 require_once($CFG->libdir . '/formslib.php');
  30
  31
  32 /**
  33  * Settings form for the preview options.
  34  *
  35  * @copyright  2009 The Open University
  36  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  37  */
  38 class preview_options_form extends moodleform {
  39     public function definition() {
  40         $mform = $this->_form;
  41
  42         $hiddenofvisible = array(
  43             question_display_options::HIDDEN => get_string('notshown', 'question'),
  44             question_display_options::VISIBLE => get_string('shown', 'question'),
  45         );
  46
  47         $mform->addElement('header', 'optionsheader', get_string('changeoptions', 'question'));
  48
  49         $behaviours = question_engine::get_behaviour_options(
  50                 $this->_customdata['quba']->get_preferred_behaviour());
  51         $mform->addElement('select', 'behaviour',
  52                 get_string('howquestionsbehave', 'question'), $behaviours);
  53         $mform->addHelpButton('behaviour', 'howquestionsbehave', 'question');
  54
  55         $mform->addElement('text', 'maxmark', get_string('markedoutof', 'question'),
  56                 array('size' => '5'));
  57         $mform->setType('maxmark', PARAM_FLOAT);
  58
  59         if ($this->_customdata['maxvariant'] > 1) {
  60             $variants = range(1, $this->_customdata['maxvariant']);
  61             $mform->addElement('select', 'variant', get_string('questionvariant', 'question'),
  62                     array_combine($variants, $variants));
  63         }
  64         $mform->setType('variant', PARAM_INT);
  65
  66         $mform->addElement('select', 'correctness', get_string('whethercorrect', 'question'),
  67                 $hiddenofvisible);
  68
  69         $marksoptions = array(
  70             question_display_options::HIDDEN => get_string('notshown', 'question'),
  71             question_display_options::MAX_ONLY => get_string('showmaxmarkonly', 'question'),
  72             question_display_options::MARK_AND_MAX => get_string('showmarkandmax', 'question'),
  73         );
  74         $mform->addElement('select', 'marks', get_string('marks', 'question'), $marksoptions);
  75
  76         $mform->addElement('select', 'markdp', get_string('decimalplacesingrades', 'question'),
  77                 question_engine::get_dp_options());
  78
  79         $mform->addElement('select', 'feedback',
  80                 get_string('specificfeedback', 'question'), $hiddenofvisible);
  81
  82         $mform->addElement('select', 'generalfeedback',
  83                 get_string('generalfeedback', 'question'), $hiddenofvisible);
  84
  85         $mform->addElement('select', 'rightanswer',
  86                 get_string('rightanswer', 'question'), $hiddenofvisible);
  87
  88         $mform->addElement('select', 'history',
  89                 get_string('responsehistory', 'question'), $hiddenofvisible);
  90
  91         $mform->addElement('submit', 'submit',
  92                 get_string('restartwiththeseoptions', 'question'));
  93     }
  94 }
  95
  96
  97 /**
  98  * Displays question preview options as default and set the options
  99  * Setting default, getting and setting user preferences in question preview options.
 100  *
 101  * @copyright  2010 The Open University
 102  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 103  */
 104 class question_preview_options extends question_display_options {
 105     /** @var string the behaviour to use for this preview. */
 106     public $behaviour;
 107
 108     /** @var number the maximum mark to use for this preview. */
 109     public $maxmark;
 110
 111     /** @var int the variant of the question to preview. */
 112     public $variant;
 113
 114     /** @var string prefix to append to field names to get user_preference names. */
 115     const OPTIONPREFIX = 'question_preview_options_';
 116
 117     /**
 118      * Constructor.
 119      */
 120     public function __construct($question) {
 121         global $CFG;
 122         $this->behaviour = 'deferredfeedback';
 123         $this->maxmark = $question->defaultmark;
 124         $this->variant = null;
 125         $this->correctness = self::VISIBLE;
 126         $this->marks = self::MARK_AND_MAX;
 127         $this->markdp = get_config('quiz', 'decimalpoints');
 128         $this->feedback = self::VISIBLE;
 129         $this->numpartscorrect = $this->feedback;
 130         $this->generalfeedback = self::VISIBLE;
 131         $this->rightanswer = self::VISIBLE;
 132         $this->history = self::HIDDEN;
 133         $this->flags = self::HIDDEN;
 134         $this->manualcomment = self::HIDDEN;
 135     }
 136
 137     /**
 138      * @return array names of the options we store in the user preferences table.
 139      */
 140     protected function get_user_pref_fields() {
 141         return array('behaviour', 'correctness', 'marks', 'markdp', 'feedback',
 142                 'generalfeedback', 'rightanswer', 'history');
 143     }
 144
 145     /**
 146      * @return array names and param types of the options we read from the request.
 147      */
 148     protected function get_field_types() {
 149         return array(
 150             'behaviour' => PARAM_ALPHA,
 151             'maxmark' => PARAM_NUMBER,
 152             'variant' => PARAM_INT,
 153             'correctness' => PARAM_BOOL,
 154             'marks' => PARAM_INT,
 155             'markdp' => PARAM_INT,
 156             'feedback' => PARAM_BOOL,
 157             'generalfeedback' => PARAM_BOOL,
 158             'rightanswer' => PARAM_BOOL,
 159             'history' => PARAM_BOOL,
 160         );
 161     }
 162
 163     /**
 164      * Load the value of the options from the user_preferences table.
 165      */
 166     public function load_user_defaults() {
 167         foreach ($this->get_user_pref_fields() as $field) {
 168             $this->$field = get_user_preferences(
 169                     self::OPTIONPREFIX . $field, $this->$field);
 170         }
 171         $this->numpartscorrect = $this->feedback;
 172     }
 173
 174     /**
 175      * Save a change to the user's preview options to the database.
 176      * @param object $newoptions
 177      */
 178     public function save_user_preview_options($newoptions) {
 179         foreach ($this->get_user_pref_fields() as $field) {
 180             if (isset($newoptions->$field)) {
 181                 set_user_preference(self::OPTIONPREFIX . $field, $newoptions->$field);
 182             }
 183         }
 184     }
 185
 186     /**
 187      * Set the value of any fields included in the request.
 188      */
 189     public function set_from_request() {
 190         foreach ($this->get_field_types() as $field => $type) {
 191             $this->$field = optional_param($field, $this->$field, $type);
 192         }
 193         $this->numpartscorrect = $this->feedback;
 194     }
 195
 196     /**
 197      * @return string URL fragment. Parameters needed in the URL when continuing
 198      * this preview.
 199      */
 200     public function get_url_params() {
 201         $params = array();
 202         foreach ($this->get_field_types() as $field => $notused) {
 203             if ($field == 'behaviour' || $field == 'maxmark' || is_null($this->$field)) {
 204                 continue;
 205             }
 206             $params[$field] = $this->$field;
 207         }
 208         return $params;
 209     }
 210 }
 211
 212
 213 /**
 214  * Called via pluginfile.php -> question_pluginfile to serve files belonging to
 215  * a question in a question_attempt when that attempt is a preview.
 216  *
 217  * @param object $course course settings object
 218  * @param object $context context object
 219  * @param string $component the name of the component we are serving files for.
 220  * @param string $filearea the name of the file area.
 221  * @param int $qubaid the question_usage this image belongs to.
 222  * @param int $slot the relevant slot within the usage.
 223  * @param array $args the remaining bits of the file path.
 224  * @param bool $forcedownload whether the user must be forced to download the file.
 225  * @return bool false if file not found, does not return if found - justsend the file
 226  */
 227 function question_preview_question_pluginfile($course, $context, $component,
 228         $filearea, $qubaid, $slot, $args, $forcedownload) {
 229     global $USER, $DB, $CFG;
 230
 231     $quba = question_engine::load_questions_usage_by_activity($qubaid);
 232
 233     if (!question_has_capability_on($quba->get_question($slot), 'use')) {
 234         send_file_not_found();
 235     }
 236
 237     $options = new question_display_options();
 238     $options->feedback = question_display_options::VISIBLE;
 239     $options->numpartscorrect = question_display_options::VISIBLE;
 240     $options->generalfeedback = question_display_options::VISIBLE;
 241     $options->rightanswer = question_display_options::VISIBLE;
 242     $options->manualcomment = question_display_options::VISIBLE;
 243     $options->history = question_display_options::VISIBLE;
 244     if (!$quba->check_file_access($slot, $options, $component,
 245             $filearea, $args, $forcedownload)) {
 246         send_file_not_found();
 247     }
 248
 249     $fs = get_file_storage();
 250     $relativepath = implode('/', $args);
 251     $fullpath = "/$context->id/$component/$filearea/$relativepath";
 252     if (!$file = $fs->get_file_by_hash(sha1($fullpath)) or $file->is_directory()) {
 253         send_file_not_found();
 254     }
 255
 256     send_stored_file($file, 0, 0, $forcedownload);
 257 }
 258
 259 /**
 260  * The the URL to use for actions relating to this preview.
 261  * @param int $questionid the question being previewed.
 262  * @param int $qubaid the id of the question usage for this preview.
 263  * @param question_preview_options $options the options in use.
 264  */
 265 function question_preview_action_url($questionid, $qubaid,
 266         question_preview_options $options, $context) {
 267     $params = array(
 268         'id' => $questionid,
 269         'previewid' => $qubaid,
 270     );
 271     if ($context->contextlevel == CONTEXT_MODULE) {
 272         $params['cmid'] = $context->instanceid;
 273     } else if ($context->contextlevel == CONTEXT_COURSE) {
 274         $params['courseid'] = $context->instanceid;
 275     }
 276     $params = array_merge($params, $options->get_url_params());
 277     return new moodle_url('/question/preview.php', $params);
 278 }
 279
 280 /**
 281  * The the URL to use for actions relating to this preview.
 282  * @param int $questionid the question being previewed.
 283  * @param int $qubaid the id of the question usage for this preview.
 284  * @param question_preview_options $options the options in use.
 285  */
 286 function question_preview_form_url($questionid, $context) {
 287     $params = array(
 288         'id' => $questionid,
 289     );
 290     if ($context->contextlevel == CONTEXT_MODULE) {
 291         $params['cmid'] = $context->instanceid;
 292     } else if ($context->contextlevel == CONTEXT_COURSE) {
 293         $params['courseid'] = $context->instanceid;
 294     }
 295     return new moodle_url('/question/preview.php', $params);
 296 }
 297
 298 /**
 299  * Delete the current preview, if any, and redirect to start a new preview.
 300  * @param int $previewid
 301  * @param int $questionid
 302  * @param object $displayoptions
 303  * @param object $context
 304  */
 305 function restart_preview($previewid, $questionid, $displayoptions, $context) {
 306     global $DB;
 307
 308     if ($previewid) {
 309         $transaction = $DB->start_delegated_transaction();
 310         question_engine::delete_questions_usage_by_activity($previewid);
 311         $transaction->allow_commit();
 312     }
 313     redirect(question_preview_url($questionid, $displayoptions->behaviour,
 314             $displayoptions->maxmark, $displayoptions, $displayoptions->variant, $context));
 315 }
 316
 317 /**
 318  * Scheduled tasks relating to question preview. Specifically, delete any old
 319  * previews that are left over in the database.
 320  */
 321 function question_preview_cron() {
 322     $maxage = 24*60*60; // We delete previews that have not been touched for 24 hours.
 323     $lastmodifiedcutoff = time() - $maxage;
 324
 325     mtrace("\n  Cleaning up old question previews...", '');
 326     $oldpreviews = new qubaid_join('{question_usages} quba', 'quba.id',
 327             'quba.component = :qubacomponent
 328                     AND NOT EXISTS (
 329                         SELECT 1
 330                           FROM {question_attempts} qa
 331                           JOIN {question_attempt_steps} qas ON qas.questionattemptid = qa.id
 332                          WHERE qa.questionusageid = quba.id
 333                            AND (qa.timemodified > :qamodifiedcutoff
 334                                     OR qas.timecreated > :stepcreatedcutoff)
 335                     )
 336             ',
 337             array('qubacomponent' => 'core_question_preview',
 338                 'qamodifiedcutoff' => $lastmodifiedcutoff, 'stepcreatedcutoff' => $lastmodifiedcutoff));
 339
 340     question_engine::delete_questions_usage_by_activities($oldpreviews);
 341     mtrace('done.');
 342 }