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   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  }