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('attemptoptions', '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('submit', 'saverestart',
  67                 get_string('restartwiththeseoptions', 'question'));
  68
  69         $mform->addElement('header', 'optionsheader', get_string('displayoptions', 'question'));
  70
  71         $mform->addElement('select', 'correctness', get_string('whethercorrect', 'question'),
  72                 $hiddenofvisible);
  73
  74         $marksoptions = array(
  75             question_display_options::HIDDEN => get_string('notshown', 'question'),
  76             question_display_options::MAX_ONLY => get_string('showmaxmarkonly', 'question'),
  77             question_display_options::MARK_AND_MAX => get_string('showmarkandmax', 'question'),
  78         );
  79         $mform->addElement('select', 'marks', get_string('marks', 'question'), $marksoptions);
  80
  81         $mform->addElement('select', 'markdp', get_string('decimalplacesingrades', 'question'),
  82                 question_engine::get_dp_options());
  83
  84         $mform->addElement('select', 'feedback',
  85                 get_string('specificfeedback', 'question'), $hiddenofvisible);
  86
  87         $mform->addElement('select', 'generalfeedback',
  88                 get_string('generalfeedback', 'question'), $hiddenofvisible);
  89
  90         $mform->addElement('select', 'rightanswer',
  91                 get_string('rightanswer', 'question'), $hiddenofvisible);
  92
  93         $mform->addElement('select', 'history',
  94                 get_string('responsehistory', 'question'), $hiddenofvisible);
  95
  96         $mform->addElement('submit', 'saveupdate',
  97                 get_string('updatedisplayoptions', 'question'));
  98     }
  99 }
 100
 101
 102 /**
 103  * Displays question preview options as default and set the options
 104  * Setting default, getting and setting user preferences in question preview options.
 105  *
 106  * @copyright  2010 The Open University
 107  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 108  */
 109 class question_preview_options extends question_display_options {
 110     /** @var string the behaviour to use for this preview. */
 111     public $behaviour;
 112
 113     /** @var number the maximum mark to use for this preview. */
 114     public $maxmark;
 115
 116     /** @var int the variant of the question to preview. */
 117     public $variant;
 118
 119     /** @var string prefix to append to field names to get user_preference names. */
 120     const OPTIONPREFIX = 'question_preview_options_';
 121
 122     /**
 123      * Constructor.
 124      */
 125     public function __construct($question) {
 126         $this->behaviour = 'deferredfeedback';
 127         $this->maxmark = $question->defaultmark;
 128         $this->variant = null;
 129         $this->correctness = self::VISIBLE;
 130         $this->marks = self::MARK_AND_MAX;
 131         $this->markdp = get_config('quiz', 'decimalpoints');
 132         $this->feedback = self::VISIBLE;
 133         $this->numpartscorrect = $this->feedback;
 134         $this->generalfeedback = self::VISIBLE;
 135         $this->rightanswer = self::VISIBLE;
 136         $this->history = self::HIDDEN;
 137         $this->flags = self::HIDDEN;
 138         $this->manualcomment = self::HIDDEN;
 139     }
 140
 141     /**
 142      * @return array names of the options we store in the user preferences table.
 143      */
 144     protected function get_user_pref_fields() {
 145         return array('behaviour', 'correctness', 'marks', 'markdp', 'feedback',
 146                 'generalfeedback', 'rightanswer', 'history');
 147     }
 148
 149     /**
 150      * @return array names and param types of the options we read from the request.
 151      */
 152     protected function get_field_types() {
 153         return array(
 154             'behaviour' => PARAM_ALPHA,
 155             'maxmark' => PARAM_FLOAT,
 156             'variant' => PARAM_INT,
 157             'correctness' => PARAM_BOOL,
 158             'marks' => PARAM_INT,
 159             'markdp' => PARAM_INT,
 160             'feedback' => PARAM_BOOL,
 161             'generalfeedback' => PARAM_BOOL,
 162             'rightanswer' => PARAM_BOOL,
 163             'history' => PARAM_BOOL,
 164         );
 165     }
 166
 167     /**
 168      * Load the value of the options from the user_preferences table.
 169      */
 170     public function load_user_defaults() {
 171         $defaults = get_config('question_preview');
 172         foreach ($this->get_user_pref_fields() as $field) {
 173             $this->$field = get_user_preferences(
 174                     self::OPTIONPREFIX . $field, $defaults->$field);
 175         }
 176         $this->numpartscorrect = $this->feedback;
 177     }
 178
 179     /**
 180      * Save a change to the user's preview options to the database.
 181      * @param object $newoptions
 182      */
 183     public function save_user_preview_options($newoptions) {
 184         foreach ($this->get_user_pref_fields() as $field) {
 185             if (isset($newoptions->$field)) {
 186                 set_user_preference(self::OPTIONPREFIX . $field, $newoptions->$field);
 187             }
 188         }
 189     }
 190
 191     /**
 192      * Set the value of any fields included in the request.
 193      */
 194     public function set_from_request() {
 195         foreach ($this->get_field_types() as $field => $type) {
 196             $this->$field = optional_param($field, $this->$field, $type);
 197         }
 198         $this->numpartscorrect = $this->feedback;
 199     }
 200
 201     /**
 202      * @return string URL fragment. Parameters needed in the URL when continuing
 203      * this preview.
 204      */
 205     public function get_url_params() {
 206         $params = array();
 207         foreach ($this->get_field_types() as $field => $notused) {
 208             if ($field == 'behaviour' || $field == 'maxmark' || is_null($this->$field)) {
 209                 continue;
 210             }
 211             $params[$field] = $this->$field;
 212         }
 213         return $params;
 214     }
 215 }
 216
 217
 218 /**
 219  * Called via pluginfile.php -> question_pluginfile to serve files belonging to
 220  * a question in a question_attempt when that attempt is a preview.
 221  *
 222  * @package  core_question
 223  * @category files
 224  * @param stdClass $course course settings object
 225  * @param stdClass $context context object
 226  * @param string $component the name of the component we are serving files for.
 227  * @param string $filearea the name of the file area.
 228  * @param int $qubaid the question_usage this image belongs to.
 229  * @param int $slot the relevant slot within the usage.
 230  * @param array $args the remaining bits of the file path.
 231  * @param bool $forcedownload whether the user must be forced to download the file.
 232  * @param array $options additional options affecting the file serving
 233  * @return bool false if file not found, does not return if found - justsend the file
 234  */
 235 function question_preview_question_pluginfile($course, $context, $component,
 236         $filearea, $qubaid, $slot, $args, $forcedownload, $fileoptions) {
 237     global $USER, $DB, $CFG;
 238
 239     list($context, $course, $cm) = get_context_info_array($context->id);
 240     require_login($course, false, $cm);
 241
 242     $quba = question_engine::load_questions_usage_by_activity($qubaid);
 243
 244     if (!question_has_capability_on($quba->get_question($slot), 'use')) {
 245         send_file_not_found();
 246     }
 247
 248     $options = new question_display_options();
 249     $options->feedback = question_display_options::VISIBLE;
 250     $options->numpartscorrect = question_display_options::VISIBLE;
 251     $options->generalfeedback = question_display_options::VISIBLE;
 252     $options->rightanswer = question_display_options::VISIBLE;
 253     $options->manualcomment = question_display_options::VISIBLE;
 254     $options->history = question_display_options::VISIBLE;
 255     if (!$quba->check_file_access($slot, $options, $component,
 256             $filearea, $args, $forcedownload)) {
 257         send_file_not_found();
 258     }
 259
 260     $fs = get_file_storage();
 261     $relativepath = implode('/', $args);
 262     $fullpath = "/{$context->id}/{$component}/{$filearea}/{$relativepath}";
 263     if (!$file = $fs->get_file_by_hash(sha1($fullpath)) or $file->is_directory()) {
 264         send_file_not_found();
 265     }
 266
 267     send_stored_file($file, 0, 0, $forcedownload, $fileoptions);
 268 }
 269
 270 /**
 271  * The the URL to use for actions relating to this preview.
 272  * @param int $questionid the question being previewed.
 273  * @param int $qubaid the id of the question usage for this preview.
 274  * @param question_preview_options $options the options in use.
 275  */
 276 function question_preview_action_url($questionid, $qubaid,
 277         question_preview_options $options, $context) {
 278     $params = array(
 279         'id' => $questionid,
 280         'previewid' => $qubaid,
 281     );
 282     if ($context->contextlevel == CONTEXT_MODULE) {
 283         $params['cmid'] = $context->instanceid;
 284     } else if ($context->contextlevel == CONTEXT_COURSE) {
 285         $params['courseid'] = $context->instanceid;
 286     }
 287     $params = array_merge($params, $options->get_url_params());
 288     return new moodle_url('/question/preview.php', $params);
 289 }
 290
 291 /**
 292  * The the URL to use for actions relating to this preview.
 293  * @param int $questionid the question being previewed.
 294  * @param context $context the current moodle context.
 295  * @param int $previewid optional previewid to sign post saved previewed answers.
 296  */
 297 function question_preview_form_url($questionid, $context, $previewid = null) {
 298     $params = array(
 299         'id' => $questionid,
 300     );
 301     if ($context->contextlevel == CONTEXT_MODULE) {
 302         $params['cmid'] = $context->instanceid;
 303     } else if ($context->contextlevel == CONTEXT_COURSE) {
 304         $params['courseid'] = $context->instanceid;
 305     }
 306     if ($previewid) {
 307         $params['previewid'] = $previewid;
 308     }
 309     return new moodle_url('/question/preview.php', $params);
 310 }
 311
 312 /**
 313  * Delete the current preview, if any, and redirect to start a new preview.
 314  * @param int $previewid
 315  * @param int $questionid
 316  * @param object $displayoptions
 317  * @param object $context
 318  */
 319 function restart_preview($previewid, $questionid, $displayoptions, $context) {
 320     global $DB;
 321
 322     if ($previewid) {
 323         $transaction = $DB->start_delegated_transaction();
 324         question_engine::delete_questions_usage_by_activity($previewid);
 325         $transaction->allow_commit();
 326     }
 327     redirect(question_preview_url($questionid, $displayoptions->behaviour,
 328             $displayoptions->maxmark, $displayoptions, $displayoptions->variant, $context));
 329 }
 330
 331 /**
 332  * Scheduled tasks relating to question preview. Specifically, delete any old
 333  * previews that are left over in the database.
 334  */
 335 function question_preview_cron() {
 336     $maxage = 24*60*60; // We delete previews that have not been touched for 24 hours.
 337     $lastmodifiedcutoff = time() - $maxage;
 338
 339     mtrace("\n  Cleaning up old question previews...", '');
 340     $oldpreviews = new qubaid_join('{question_usages} quba', 'quba.id',
 341             'quba.component = :qubacomponent
 342                     AND NOT EXISTS (
 343                         SELECT 1
 344                           FROM {question_attempts}      subq_qa
 345                           JOIN {question_attempt_steps} subq_qas ON subq_qas.questionattemptid = subq_qa.id
 346                           JOIN {question_usages}        subq_qu  ON subq_qu.id = subq_qa.questionusageid
 347                          WHERE subq_qa.questionusageid = quba.id
 348                            AND subq_qu.component = :qubacomponent2
 349                            AND (subq_qa.timemodified > :qamodifiedcutoff
 350                                     OR subq_qas.timecreated > :stepcreatedcutoff)
 351                     )
 352             ',
 353             array('qubacomponent' => 'core_question_preview', 'qubacomponent2' => 'core_question_preview',
 354                 'qamodifiedcutoff' => $lastmodifiedcutoff, 'stepcreatedcutoff' => $lastmodifiedcutoff));
 355
 356     question_engine::delete_questions_usage_by_activities($oldpreviews);
 357     mtrace('done.');
 358 }