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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   * Calendar extension
  19   *
  20   * @package    core_calendar
  21   * @copyright  2004 Greek School Network (http://www.sch.gr), Jon Papaioannou,
  22   *             Avgoustos Tsinakos
  23   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  24   */
  25  
  26  if (!defined('MOODLE_INTERNAL')) {
  27      die('Direct access to this script is forbidden.');    ///  It must be included from a Moodle page
  28  }
  29  
  30  /**
  31   *  These are read by the administration component to provide default values
  32   */
  33  
  34  /**
  35   * CALENDAR_DEFAULT_UPCOMING_LOOKAHEAD - default value of upcoming event preference
  36   */
  37  define('CALENDAR_DEFAULT_UPCOMING_LOOKAHEAD', 21);
  38  
  39  /**
  40   * CALENDAR_DEFAULT_UPCOMING_MAXEVENTS - default value to display the maximum number of upcoming event
  41   */
  42  define('CALENDAR_DEFAULT_UPCOMING_MAXEVENTS', 10);
  43  
  44  /**
  45   * CALENDAR_DEFAULT_STARTING_WEEKDAY - default value to display the starting weekday
  46   */
  47  define('CALENDAR_DEFAULT_STARTING_WEEKDAY', 1);
  48  
  49  // This is a packed bitfield: day X is "weekend" if $field & (1 << X) is true
  50  // Default value = 65 = 64 + 1 = 2^6 + 2^0 = Saturday & Sunday
  51  
  52  /**
  53   * CALENDAR_DEFAULT_WEEKEND - default value for weekend (Saturday & Sunday)
  54   */
  55  define('CALENDAR_DEFAULT_WEEKEND', 65);
  56  
  57  /**
  58   * CALENDAR_URL - path to calendar's folder
  59   */
  60  define('CALENDAR_URL', $CFG->wwwroot.'/calendar/');
  61  
  62  /**
  63   * CALENDAR_TF_24 - Calendar time in 24 hours format
  64   */
  65  define('CALENDAR_TF_24', '%H:%M');
  66  
  67  /**
  68   * CALENDAR_TF_12 - Calendar time in 12 hours format
  69   */
  70  define('CALENDAR_TF_12', '%I:%M %p');
  71  
  72  /**
  73   * CALENDAR_EVENT_GLOBAL - Global calendar event types
  74   */
  75  define('CALENDAR_EVENT_GLOBAL', 1);
  76  
  77  /**
  78   * CALENDAR_EVENT_COURSE - Course calendar event types
  79   */
  80  define('CALENDAR_EVENT_COURSE', 2);
  81  
  82  /**
  83   * CALENDAR_EVENT_GROUP - group calendar event types
  84   */
  85  define('CALENDAR_EVENT_GROUP', 4);
  86  
  87  /**
  88   * CALENDAR_EVENT_USER - user calendar event types
  89   */
  90  define('CALENDAR_EVENT_USER', 8);
  91  
  92  
  93  /**
  94   * CALENDAR_IMPORT_FROM_FILE - import the calendar from a file
  95   */
  96  define('CALENDAR_IMPORT_FROM_FILE', 0);
  97  
  98  /**
  99   * CALENDAR_IMPORT_FROM_URL - import the calendar from a URL
 100   */
 101  define('CALENDAR_IMPORT_FROM_URL',  1);
 102  
 103  /**
 104   * CALENDAR_IMPORT_EVENT_UPDATED - imported event was updated
 105   */
 106  define('CALENDAR_IMPORT_EVENT_UPDATED',  1);
 107  
 108  /**
 109   * CALENDAR_IMPORT_EVENT_INSERTED - imported event was added by insert
 110   */
 111  define('CALENDAR_IMPORT_EVENT_INSERTED', 2);
 112  
 113  /**
 114   * CALENDAR_SUBSCRIPTION_UPDATE - Used to represent update action for subscriptions in various forms.
 115   */
 116  define('CALENDAR_SUBSCRIPTION_UPDATE', 1);
 117  
 118  /**
 119   * CALENDAR_SUBSCRIPTION_REMOVE - Used to represent remove action for subscriptions in various forms.
 120   */
 121  define('CALENDAR_SUBSCRIPTION_REMOVE', 2);
 122  
 123  /**
 124   * Return the days of the week
 125   *
 126   * @return array array of days
 127   */
 128  function calendar_get_days() {
 129      $calendartype = \core_calendar\type_factory::get_calendar_instance();
 130      return $calendartype->get_weekdays();
 131  }
 132  
 133  /**
 134   * Get the subscription from a given id
 135   *
 136   * @since Moodle 2.5
 137   * @param int $id id of the subscription
 138   * @return stdClass Subscription record from DB
 139   * @throws moodle_exception for an invalid id
 140   */
 141  function calendar_get_subscription($id) {
 142      global $DB;
 143  
 144      $cache = cache::make('core', 'calendar_subscriptions');
 145      $subscription = $cache->get($id);
 146      if (empty($subscription)) {
 147          $subscription = $DB->get_record('event_subscriptions', array('id' => $id), '*', MUST_EXIST);
 148          // cache the data.
 149          $cache->set($id, $subscription);
 150      }
 151      return $subscription;
 152  }
 153  
 154  /**
 155   * Gets the first day of the week
 156   *
 157   * Used to be define('CALENDAR_STARTING_WEEKDAY', blah);
 158   *
 159   * @return int
 160   */
 161  function calendar_get_starting_weekday() {
 162      $calendartype = \core_calendar\type_factory::get_calendar_instance();
 163      return $calendartype->get_starting_weekday();
 164  }
 165  
 166  /**
 167   * Generates the HTML for a miniature calendar
 168   *
 169   * @param array $courses list of course to list events from
 170   * @param array $groups list of group
 171   * @param array $users user's info
 172   * @param int|bool $calmonth calendar month in numeric, default is set to false
 173   * @param int|bool $calyear calendar month in numeric, default is set to false
 174   * @param string|bool $placement the place/page the calendar is set to appear - passed on the the controls function
 175   * @param int|bool $courseid id of the course the calendar is displayed on - passed on the the controls function
 176   * @param int $time the unixtimestamp representing the date we want to view, this is used instead of $calmonth
 177   *     and $calyear to support multiple calendars
 178   * @return string $content return html table for mini calendar
 179   */
 180  function calendar_get_mini($courses, $groups, $users, $calmonth = false, $calyear = false, $placement = false,
 181      $courseid = false, $time = 0) {
 182      global $CFG, $OUTPUT, $PAGE;
 183  
 184      // Get the calendar type we are using.
 185      $calendartype = \core_calendar\type_factory::get_calendar_instance();
 186  
 187      $display = new stdClass;
 188  
 189      // Assume we are not displaying this month for now.
 190      $display->thismonth = false;
 191  
 192      $content = '';
 193  
 194      // Do this check for backwards compatibility. The core should be passing a timestamp rather than month and year.
 195      // If a month and year are passed they will be in Gregorian.
 196      if (!empty($calmonth) && !empty($calyear)) {
 197          // Ensure it is a valid date, else we will just set it to the current timestamp.
 198          if (checkdate($calmonth, 1, $calyear)) {
 199              $time = make_timestamp($calyear, $calmonth, 1);
 200          } else {
 201              $time = time();
 202          }
 203          $date = usergetdate($time);
 204          if ($calmonth == $date['mon'] && $calyear == $date['year']) {
 205              $display->thismonth = true;
 206          }
 207          // We can overwrite date now with the date used by the calendar type, if it is not Gregorian, otherwise
 208          // there is no need as it is already in Gregorian.
 209          if ($calendartype->get_name() != 'gregorian') {
 210              $date = $calendartype->timestamp_to_date_array($time);
 211          }
 212      } else if (!empty($time)) {
 213          // Get the specified date in the calendar type being used.
 214          $date = $calendartype->timestamp_to_date_array($time);
 215          $thisdate = $calendartype->timestamp_to_date_array(time());
 216          if ($date['month'] == $thisdate['month'] && $date['year'] == $thisdate['year']) {
 217              $display->thismonth = true;
 218              // If we are the current month we want to set the date to the current date, not the start of the month.
 219              $date = $thisdate;
 220          }
 221      } else {
 222          // Get the current date in the calendar type being used.
 223          $time = time();
 224          $date = $calendartype->timestamp_to_date_array($time);
 225          $display->thismonth = true;
 226      }
 227  
 228      list($d, $m, $y) = array($date['mday'], $date['mon'], $date['year']); // This is what we want to display.
 229  
 230      // Get Gregorian date for the start of the month.
 231      $gregoriandate = $calendartype->convert_to_gregorian($date['year'], $date['mon'], 1);
 232  
 233      // Store the gregorian date values to be used later.
 234      list($gy, $gm, $gd, $gh, $gmin) = array($gregoriandate['year'], $gregoriandate['month'], $gregoriandate['day'],
 235          $gregoriandate['hour'], $gregoriandate['minute']);
 236  
 237      // Get the max number of days in this month for this calendar type.
 238      $display->maxdays = calendar_days_in_month($m, $y);
 239      // Get the starting week day for this month.
 240      $startwday = dayofweek(1, $m, $y);
 241      // Get the days in a week.
 242      $daynames = calendar_get_days();
 243      // Store the number of days in a week.
 244      $numberofdaysinweek = $calendartype->get_num_weekdays();
 245  
 246      // Set the min and max weekday.
 247      $display->minwday = calendar_get_starting_weekday();
 248      $display->maxwday = $display->minwday + ($numberofdaysinweek - 1);
 249  
 250      // These are used for DB queries, so we want unixtime, so we need to use Gregorian dates.
 251      $display->tstart = make_timestamp($gy, $gm, $gd, $gh, $gmin, 0);
 252      $display->tend = $display->tstart + ($display->maxdays * DAYSECS) - 1;
 253  
 254      // Align the starting weekday to fall in our display range
 255      // This is simple, not foolproof.
 256      if ($startwday < $display->minwday) {
 257          $startwday += $numberofdaysinweek;
 258      }
 259  
 260      // Get the events matching our criteria. Don't forget to offset the timestamps for the user's TZ!
 261      $events = calendar_get_events($display->tstart, $display->tend, $users, $groups, $courses);
 262  
 263      // Set event course class for course events
 264      if (!empty($events)) {
 265          foreach ($events as $eventid => $event) {
 266              if (!empty($event->modulename)) {
 267                  $cm = get_coursemodule_from_instance($event->modulename, $event->instance);
 268                  if (!\core_availability\info_module::is_user_visible($cm, 0, false)) {
 269                      unset($events[$eventid]);
 270                  }
 271              }
 272          }
 273      }
 274  
 275      // This is either a genius idea or an idiot idea: in order to not complicate things, we use this rule: if, after
 276      // possibly removing SITEID from $courses, there is only one course left, then clicking on a day in the month
 277      // will also set the $SESSION->cal_courses_shown variable to that one course. Otherwise, we 'd need to add extra
 278      // arguments to this function.
 279      $hrefparams = array();
 280      if(!empty($courses)) {
 281          $courses = array_diff($courses, array(SITEID));
 282          if(count($courses) == 1) {
 283              $hrefparams['course'] = reset($courses);
 284          }
 285      }
 286  
 287      // We want to have easy access by day, since the display is on a per-day basis.
 288      calendar_events_by_day($events, $m, $y, $eventsbyday, $durationbyday, $typesbyday, $courses);
 289  
 290      // Accessibility: added summary and <abbr> elements.
 291      $summary = get_string('calendarheading', 'calendar', userdate($display->tstart, get_string('strftimemonthyear')));
 292      // Begin table.
 293      $content .= '<table class="minicalendar calendartable" summary="' . $summary . '">';
 294      if (($placement !== false) && ($courseid !== false)) {
 295          $content .= '<caption>'. calendar_top_controls($placement, array('id' => $courseid, 'time' => $time)) .'</caption>';
 296      }
 297      $content .= '<tr class="weekdays">'; // Header row: day names
 298  
 299      // Print out the names of the weekdays.
 300      for ($i = $display->minwday; $i <= $display->maxwday; ++$i) {
 301          $pos = $i % $numberofdaysinweek;
 302          $content .= '<th scope="col"><abbr title="'. $daynames[$pos]['fullname'] .'">'.
 303              $daynames[$pos]['shortname'] ."</abbr></th>\n";
 304      }
 305  
 306      $content .= '</tr><tr>'; // End of day names; prepare for day numbers
 307  
 308      // For the table display. $week is the row; $dayweek is the column.
 309      $dayweek = $startwday;
 310  
 311      // Paddding (the first week may have blank days in the beginning)
 312      for($i = $display->minwday; $i < $startwday; ++$i) {
 313          $content .= '<td class="dayblank">&nbsp;</td>'."\n";
 314      }
 315  
 316      $weekend = CALENDAR_DEFAULT_WEEKEND;
 317      if (isset($CFG->calendar_weekend)) {
 318          $weekend = intval($CFG->calendar_weekend);
 319      }
 320  
 321      // Now display all the calendar
 322      $daytime = strtotime('-1 day', $display->tstart);
 323      for($day = 1; $day <= $display->maxdays; ++$day, ++$dayweek) {
 324          $cellattributes = array();
 325          $daytime = strtotime('+1 day', $daytime);
 326          if($dayweek > $display->maxwday) {
 327              // We need to change week (table row)
 328              $content .= '</tr><tr>';
 329              $dayweek = $display->minwday;
 330          }
 331  
 332          // Reset vars.
 333          if ($weekend & (1 << ($dayweek % $numberofdaysinweek))) {
 334              // Weekend. This is true no matter what the exact range is.
 335              $class = 'weekend day';
 336          } else {
 337              // Normal working day.
 338              $class = 'day';
 339          }
 340  
 341          $eventids = array();
 342          if (!empty($eventsbyday[$day])) {
 343              $eventids = $eventsbyday[$day];
 344          }
 345  
 346          if (!empty($durationbyday[$day])) {
 347              $eventids = array_unique(array_merge($eventids, $durationbyday[$day]));
 348          }
 349  
 350          $finishclass = false;
 351  
 352          if (!empty($eventids)) {
 353              // There is at least one event on this day.
 354  
 355              $class .= ' hasevent';
 356              $hrefparams['view'] = 'day';
 357              $dayhref = calendar_get_link_href(new moodle_url(CALENDAR_URL . 'view.php', $hrefparams), 0, 0, 0, $daytime);
 358  
 359              $popupcontent = '';
 360              foreach ($eventids as $eventid) {
 361                  if (!isset($events[$eventid])) {
 362                      continue;
 363                  }
 364                  $event = new calendar_event($events[$eventid]);
 365                  $popupalt  = '';
 366                  $component = 'moodle';
 367                  if (!empty($event->modulename)) {
 368                      $popupicon = 'icon';
 369                      $popupalt  = $event->modulename;
 370                      $component = $event->modulename;
 371                  } else if ($event->courseid == SITEID) { // Site event.
 372                      $popupicon = 'i/siteevent';
 373                  } else if ($event->courseid != 0 && $event->courseid != SITEID && $event->groupid == 0) { // Course event.
 374                      $popupicon = 'i/courseevent';
 375                  } else if ($event->groupid) { // Group event.
 376                      $popupicon = 'i/groupevent';
 377                  } else { // Must be a user event.
 378                      $popupicon = 'i/userevent';
 379                  }
 380  
 381                  if ($event->timeduration) {
 382                      $startdate = $calendartype->timestamp_to_date_array($event->timestart);
 383                      $enddate = $calendartype->timestamp_to_date_array($event->timestart + $event->timeduration - 1);
 384                      if ($enddate['mon'] == $m && $enddate['year'] == $y && $enddate['mday'] == $day) {
 385                          $finishclass = true;
 386                      }
 387                  }
 388  
 389                  $dayhref->set_anchor('event_'.$event->id);
 390  
 391                  $popupcontent .= html_writer::start_tag('div');
 392                  $popupcontent .= $OUTPUT->pix_icon($popupicon, $popupalt, $component);
 393                  // Show ical source if needed.
 394                  if (!empty($event->subscription) && $CFG->calendar_showicalsource) {
 395                      $a = new stdClass();
 396                      $a->name = format_string($event->name, true);
 397                      $a->source = $event->subscription->name;
 398                      $name = get_string('namewithsource', 'calendar', $a);
 399                  } else {
 400                      if ($finishclass) {
 401                          $samedate = $startdate['mon'] == $enddate['mon'] &&
 402                                      $startdate['year'] == $enddate['year'] &&
 403                                      $startdate['mday'] == $enddate['mday'];
 404  
 405                          if ($samedate) {
 406                              $name = format_string($event->name, true);
 407                          } else {
 408                              $name = format_string($event->name, true) . ' (' . get_string('eventendtime', 'calendar') . ')';
 409                          }
 410                      } else {
 411                          $name = format_string($event->name, true);
 412                      }
 413                  }
 414                  $popupcontent .= html_writer::link($dayhref, $name);
 415                  $popupcontent .= html_writer::end_tag('div');
 416              }
 417  
 418              if ($display->thismonth && $day == $d) {
 419                  $popupdata = calendar_get_popup(true, $daytime, $popupcontent);
 420              } else {
 421                  $popupdata = calendar_get_popup(false, $daytime, $popupcontent);
 422              }
 423              $cellattributes = array_merge($cellattributes, $popupdata);
 424  
 425              // Class and cell content
 426              if(isset($typesbyday[$day]['startglobal'])) {
 427                  $class .= ' calendar_event_global';
 428              } else if(isset($typesbyday[$day]['startcourse'])) {
 429                  $class .= ' calendar_event_course';
 430              } else if(isset($typesbyday[$day]['startgroup'])) {
 431                  $class .= ' calendar_event_group';
 432              } else if(isset($typesbyday[$day]['startuser'])) {
 433                  $class .= ' calendar_event_user';
 434              }
 435              if ($finishclass) {
 436                  $class .= ' duration_finish';
 437              }
 438              $cell = html_writer::link($dayhref, $day);
 439          } else {
 440              $cell = $day;
 441          }
 442  
 443          $durationclass = false;
 444          if (isset($typesbyday[$day]['durationglobal'])) {
 445              $durationclass = ' duration_global';
 446          } else if(isset($typesbyday[$day]['durationcourse'])) {
 447              $durationclass = ' duration_course';
 448          } else if(isset($typesbyday[$day]['durationgroup'])) {
 449              $durationclass = ' duration_group';
 450          } else if(isset($typesbyday[$day]['durationuser'])) {
 451              $durationclass = ' duration_user';
 452          }
 453          if ($durationclass) {
 454              $class .= ' duration '.$durationclass;
 455          }
 456  
 457          // If event has a class set then add it to the table day <td> tag
 458          // Note: only one colour for minicalendar
 459          if(isset($eventsbyday[$day])) {
 460              foreach($eventsbyday[$day] as $eventid) {
 461                  if (!isset($events[$eventid])) {
 462                      continue;
 463                  }
 464                  $event = $events[$eventid];
 465                  if (!empty($event->class)) {
 466                      $class .= ' '.$event->class;
 467                  }
 468                  break;
 469              }
 470          }
 471  
 472          if ($display->thismonth && $day == $d) {
 473              // The current cell is for today - add appropriate classes and additional information for styling.
 474              $class .= ' today';
 475              $today = get_string('today', 'calendar').' '.userdate(time(), get_string('strftimedayshort'));
 476  
 477              if (!isset($eventsbyday[$day]) && !isset($durationbyday[$day])) {
 478                  $class .= ' eventnone';
 479                  $popupdata = calendar_get_popup(true, false);
 480                  $cellattributes = array_merge($cellattributes, $popupdata);
 481                  $cell = html_writer::link('#', $day);
 482              }
 483              $cell = get_accesshide($today . ' ') . $cell;
 484          }
 485  
 486          // Just display it
 487          $cellattributes['class'] = $class;
 488          $content .= html_writer::tag('td', $cell, $cellattributes);
 489      }
 490  
 491      // Paddding (the last week may have blank days at the end)
 492      for($i = $dayweek; $i <= $display->maxwday; ++$i) {
 493          $content .= '<td class="dayblank">&nbsp;</td>';
 494      }
 495      $content .= '</tr>'; // Last row ends
 496  
 497      $content .= '</table>'; // Tabular display of days ends
 498  
 499      static $jsincluded = false;
 500      if (!$jsincluded) {
 501          $PAGE->requires->yui_module('moodle-calendar-info', 'Y.M.core_calendar.info.init');
 502          $jsincluded = true;
 503      }
 504      return $content;
 505  }
 506  
 507  /**
 508   * Gets the calendar popup
 509   *
 510   * It called at multiple points in from calendar_get_mini.
 511   * Copied and modified from calendar_get_mini.
 512   *
 513   * @param bool $is_today false except when called on the current day.
 514   * @param mixed $event_timestart $events[$eventid]->timestart, OR false if there are no events.
 515   * @param string $popupcontent content for the popup window/layout.
 516   * @return string eventid for the calendar_tooltip popup window/layout.
 517   */
 518  function calendar_get_popup($today = false, $timestart, $popupcontent = '') {
 519      global $PAGE;
 520  
 521      $popupcaption = '';
 522      if ($today) {
 523          $popupcaption = get_string('today', 'calendar') . ' ';
 524      }
 525  
 526      if (false === $timestart) {
 527          $popupcaption .= userdate(time(), get_string('strftimedayshort'));
 528          $popupcontent = get_string('eventnone', 'calendar');
 529  
 530      } else {
 531          $popupcaption .= get_string('eventsfor', 'calendar', userdate($timestart, get_string('strftimedayshort')));
 532      }
 533  
 534      return array(
 535          'data-core_calendar-title' => $popupcaption,
 536          'data-core_calendar-popupcontent' => $popupcontent,
 537      );
 538  }
 539  
 540  /**
 541   * Gets the calendar upcoming event
 542   *
 543   * @param array $courses array of courses
 544   * @param array|int|bool $groups array of groups, group id or boolean for all/no group events
 545   * @param array|int|bool $users array of users, user id or boolean for all/no user events
 546   * @param int $daysinfuture number of days in the future we 'll look
 547   * @param int $maxevents maximum number of events
 548   * @param int $fromtime start time
 549   * @return array $output array of upcoming events
 550   */
 551  function calendar_get_upcoming($courses, $groups, $users, $daysinfuture, $maxevents, $fromtime=0) {
 552      global $CFG, $COURSE, $DB;
 553  
 554      $display = new stdClass;
 555      $display->range = $daysinfuture; // How many days in the future we 'll look
 556      $display->maxevents = $maxevents;
 557  
 558      $output = array();
 559  
 560      // Prepare "course caching", since it may save us a lot of queries
 561      $coursecache = array();
 562  
 563      $processed = 0;
 564      $now = time(); // We 'll need this later
 565      $usermidnighttoday = usergetmidnight($now);
 566  
 567      if ($fromtime) {
 568          $display->tstart = $fromtime;
 569      } else {
 570          $display->tstart = $usermidnighttoday;
 571      }
 572  
 573      // This works correctly with respect to the user's DST, but it is accurate
 574      // only because $fromtime is always the exact midnight of some day!
 575      $display->tend = usergetmidnight($display->tstart + DAYSECS * $display->range + 3 * HOURSECS) - 1;
 576  
 577      // Get the events matching our criteria
 578      $events = calendar_get_events($display->tstart, $display->tend, $users, $groups, $courses);
 579  
 580      // This is either a genius idea or an idiot idea: in order to not complicate things, we use this rule: if, after
 581      // possibly removing SITEID from $courses, there is only one course left, then clicking on a day in the month
 582      // will also set the $SESSION->cal_courses_shown variable to that one course. Otherwise, we 'd need to add extra
 583      // arguments to this function.
 584  
 585      $hrefparams = array();
 586      if(!empty($courses)) {
 587          $courses = array_diff($courses, array(SITEID));
 588          if(count($courses) == 1) {
 589              $hrefparams['course'] = reset($courses);
 590          }
 591      }
 592  
 593      if ($events !== false) {
 594  
 595          $modinfo = get_fast_modinfo($COURSE);
 596  
 597          foreach($events as $event) {
 598  
 599  
 600              if (!empty($event->modulename)) {
 601                  if ($event->courseid == $COURSE->id) {
 602                      if (isset($modinfo->instances[$event->modulename][$event->instance])) {
 603                          $cm = $modinfo->instances[$event->modulename][$event->instance];
 604                          if (!$cm->uservisible) {
 605                              continue;
 606                          }
 607                      }
 608                  } else {
 609                      if (!$cm = get_coursemodule_from_instance($event->modulename, $event->instance)) {
 610                          continue;
 611                      }
 612                      if (!\core_availability\info_module::is_user_visible($cm, 0, false)) {
 613                          continue;
 614                      }
 615                  }
 616              }
 617  
 618              if ($processed >= $display->maxevents) {
 619                  break;
 620              }
 621  
 622              $event->time = calendar_format_event_time($event, $now, $hrefparams);
 623              $output[] = $event;
 624              ++$processed;
 625          }
 626      }
 627      return $output;
 628  }
 629  
 630  
 631  /**
 632   * Get a HTML link to a course.
 633   *
 634   * @param int $courseid the course id
 635   * @return string a link to the course (as HTML); empty if the course id is invalid
 636   */
 637  function calendar_get_courselink($courseid) {
 638  
 639      if (!$courseid) {
 640          return '';
 641      }
 642  
 643      calendar_get_course_cached($coursecache, $courseid);
 644      $context = context_course::instance($courseid);
 645      $fullname = format_string($coursecache[$courseid]->fullname, true, array('context' => $context));
 646      $url = new moodle_url('/course/view.php', array('id' => $courseid));
 647      $link = html_writer::link($url, $fullname);
 648  
 649      return $link;
 650  }
 651  
 652  
 653  /**
 654   * Add calendar event metadata
 655   *
 656   * @param stdClass $event event info
 657   * @return stdClass $event metadata
 658   */
 659  function calendar_add_event_metadata($event) {
 660      global $CFG, $OUTPUT;
 661  
 662      //Support multilang in event->name
 663      $event->name = format_string($event->name,true);
 664  
 665      if(!empty($event->modulename)) {                                // Activity event
 666          // The module name is set. I will assume that it has to be displayed, and
 667          // also that it is an automatically-generated event. And of course that the
 668          // fields for get_coursemodule_from_instance are set correctly.
 669          $module = calendar_get_module_cached($coursecache, $event->modulename, $event->instance);
 670  
 671          if ($module === false) {
 672              return;
 673          }
 674  
 675          $modulename = get_string('modulename', $event->modulename);
 676          if (get_string_manager()->string_exists($event->eventtype, $event->modulename)) {
 677              // will be used as alt text if the event icon
 678              $eventtype = get_string($event->eventtype, $event->modulename);
 679          } else {
 680              $eventtype = '';
 681          }
 682          $icon = $OUTPUT->pix_url('icon', $event->modulename) . '';
 683  
 684          $event->icon = '<img src="'.$icon.'" alt="'.$eventtype.'" title="'.$modulename.'" class="icon" />';
 685          $event->referer = '<a href="'.$CFG->wwwroot.'/mod/'.$event->modulename.'/view.php?id='.$module->id.'">'.$event->name.'</a>';
 686          $event->courselink = calendar_get_courselink($module->course);
 687          $event->cmid = $module->id;
 688  
 689      } else if($event->courseid == SITEID) {                              // Site event
 690          $event->icon = '<img src="'.$OUTPUT->pix_url('i/siteevent') . '" alt="'.get_string('globalevent', 'calendar').'" class="icon" />';
 691          $event->cssclass = 'calendar_event_global';
 692      } else if($event->courseid != 0 && $event->courseid != SITEID && $event->groupid == 0) {          // Course event
 693          $event->icon = '<img src="'.$OUTPUT->pix_url('i/courseevent') . '" alt="'.get_string('courseevent', 'calendar').'" class="icon" />';
 694          $event->courselink = calendar_get_courselink($event->courseid);
 695          $event->cssclass = 'calendar_event_course';
 696      } else if ($event->groupid) {                                    // Group event
 697          if ($group = calendar_get_group_cached($event->groupid)) {
 698              $groupname = format_string($group->name, true, context_course::instance($group->courseid));
 699          } else {
 700              $groupname = '';
 701          }
 702          $event->icon = html_writer::empty_tag('image', array('src' => $OUTPUT->pix_url('i/groupevent'),
 703              'alt' => get_string('groupevent', 'calendar'), 'title' => $groupname, 'class' => 'icon'));
 704          $event->courselink = calendar_get_courselink($event->courseid) . ', ' . $groupname;
 705          $event->cssclass = 'calendar_event_group';
 706      } else if($event->userid) {                                      // User event
 707          $event->icon = '<img src="'.$OUTPUT->pix_url('i/userevent') . '" alt="'.get_string('userevent', 'calendar').'" class="icon" />';
 708          $event->cssclass = 'calendar_event_user';
 709      }
 710      return $event;
 711  }
 712  
 713  /**
 714   * Get calendar events
 715   *
 716   * @param int $tstart Start time of time range for events
 717   * @param int $tend End time of time range for events
 718   * @param array|int|boolean $users array of users, user id or boolean for all/no user events
 719   * @param array|int|boolean $groups array of groups, group id or boolean for all/no group events
 720   * @param array|int|boolean $courses array of courses, course id or boolean for all/no course events
 721   * @param boolean $withduration whether only events starting within time range selected
 722   *                              or events in progress/already started selected as well
 723   * @param boolean $ignorehidden whether to select only visible events or all events
 724   * @return array $events of selected events or an empty array if there aren't any (or there was an error)
 725   */
 726  function calendar_get_events($tstart, $tend, $users, $groups, $courses, $withduration=true, $ignorehidden=true) {
 727      global $DB;
 728  
 729      $whereclause = '';
 730      $params = array();
 731      // Quick test.
 732      if (empty($users) && empty($groups) && empty($courses)) {
 733          return array();
 734      }
 735  
 736      if ((is_array($users) && !empty($users)) or is_numeric($users)) {
 737          // Events from a number of users
 738          if(!empty($whereclause)) $whereclause .= ' OR';
 739          list($insqlusers, $inparamsusers) = $DB->get_in_or_equal($users, SQL_PARAMS_NAMED);
 740          $whereclause .= " (userid $insqlusers AND courseid = 0 AND groupid = 0)";
 741          $params = array_merge($params, $inparamsusers);
 742      } else if($users === true) {
 743          // Events from ALL users
 744          if(!empty($whereclause)) $whereclause .= ' OR';
 745          $whereclause .= ' (userid != 0 AND courseid = 0 AND groupid = 0)';
 746      } else if($users === false) {
 747          // No user at all, do nothing
 748      }
 749  
 750      if ((is_array($groups) && !empty($groups)) or is_numeric($groups)) {
 751          // Events from a number of groups
 752          if(!empty($whereclause)) $whereclause .= ' OR';
 753          list($insqlgroups, $inparamsgroups) = $DB->get_in_or_equal($groups, SQL_PARAMS_NAMED);
 754          $whereclause .= " groupid $insqlgroups ";
 755          $params = array_merge($params, $inparamsgroups);
 756      } else if($groups === true) {
 757          // Events from ALL groups
 758          if(!empty($whereclause)) $whereclause .= ' OR ';
 759          $whereclause .= ' groupid != 0';
 760      }
 761      // boolean false (no groups at all): we don't need to do anything
 762  
 763      if ((is_array($courses) && !empty($courses)) or is_numeric($courses)) {
 764          if(!empty($whereclause)) $whereclause .= ' OR';
 765          list($insqlcourses, $inparamscourses) = $DB->get_in_or_equal($courses, SQL_PARAMS_NAMED);
 766          $whereclause .= " (groupid = 0 AND courseid $insqlcourses)";
 767          $params = array_merge($params, $inparamscourses);
 768      } else if ($courses === true) {
 769          // Events from ALL courses
 770          if(!empty($whereclause)) $whereclause .= ' OR';
 771          $whereclause .= ' (groupid = 0 AND courseid != 0)';
 772      }
 773  
 774      // Security check: if, by now, we have NOTHING in $whereclause, then it means
 775      // that NO event-selecting clauses were defined. Thus, we won't be returning ANY
 776      // events no matter what. Allowing the code to proceed might return a completely
 777      // valid query with only time constraints, thus selecting ALL events in that time frame!
 778      if(empty($whereclause)) {
 779          return array();
 780      }
 781  
 782      if($withduration) {
 783          $timeclause = '(timestart >= '.$tstart.' OR timestart + timeduration > '.$tstart.') AND timestart <= '.$tend;
 784      }
 785      else {
 786          $timeclause = 'timestart >= '.$tstart.' AND timestart <= '.$tend;
 787      }
 788      if(!empty($whereclause)) {
 789          // We have additional constraints
 790          $whereclause = $timeclause.' AND ('.$whereclause.')';
 791      }
 792      else {
 793          // Just basic time filtering
 794          $whereclause = $timeclause;
 795      }
 796  
 797      if ($ignorehidden) {
 798          $whereclause .= ' AND visible = 1';
 799      }
 800  
 801      $events = $DB->get_records_select('event', $whereclause, $params, 'timestart');
 802      if ($events === false) {
 803          $events = array();
 804      }
 805      return $events;
 806  }
 807  
 808  /** Get calendar events by id
 809   *
 810   * @since Moodle 2.5
 811   * @param array $eventids list of event ids
 812   * @return array Array of event entries, empty array if nothing found
 813   */
 814  
 815  function calendar_get_events_by_id($eventids) {
 816      global $DB;
 817  
 818      if (!is_array($eventids) || empty($eventids)) {
 819          return array();
 820      }
 821      list($wheresql, $params) = $DB->get_in_or_equal($eventids);
 822      $wheresql = "id $wheresql";
 823  
 824      return $DB->get_records_select('event', $wheresql, $params);
 825  }
 826  
 827  /**
 828   * Get control options for Calendar
 829   *
 830   * @param string $type of calendar
 831   * @param array $data calendar information
 832   * @return string $content return available control for the calender in html
 833   */
 834  function calendar_top_controls($type, $data) {
 835      global $PAGE, $OUTPUT;
 836  
 837      // Get the calendar type we are using.
 838      $calendartype = \core_calendar\type_factory::get_calendar_instance();
 839  
 840      $content = '';
 841  
 842      // Ensure course id passed if relevant.
 843      $courseid = '';
 844      if (!empty($data['id'])) {
 845          $courseid = '&amp;course='.$data['id'];
 846      }
 847  
 848      // If we are passing a month and year then we need to convert this to a timestamp to
 849      // support multiple calendars. No where in core should these be passed, this logic
 850      // here is for third party plugins that may use this function.
 851      if (!empty($data['m']) && !empty($date['y'])) {
 852          if (!isset($data['d'])) {
 853              $data['d'] = 1;
 854          }
 855          if (!checkdate($data['m'], $data['d'], $data['y'])) {
 856              $time = time();
 857          } else {
 858              $time = make_timestamp($data['y'], $data['m'], $data['d']);
 859          }
 860      } else if (!empty($data['time'])) {
 861          $time = $data['time'];
 862      } else {
 863          $time = time();
 864      }
 865  
 866      // Get the date for the calendar type.
 867      $date = $calendartype->timestamp_to_date_array($time);
 868  
 869      $urlbase = $PAGE->url;
 870  
 871      // We need to get the previous and next months in certain cases.
 872      if ($type == 'frontpage' || $type == 'course' || $type == 'month') {
 873          $prevmonth = calendar_sub_month($date['mon'], $date['year']);
 874          $prevmonthtime = $calendartype->convert_to_gregorian($prevmonth[1], $prevmonth[0], 1);
 875          $prevmonthtime = make_timestamp($prevmonthtime['year'], $prevmonthtime['month'], $prevmonthtime['day'],
 876              $prevmonthtime['hour'], $prevmonthtime['minute']);
 877  
 878          $nextmonth = calendar_add_month($date['mon'], $date['year']);
 879          $nextmonthtime = $calendartype->convert_to_gregorian($nextmonth[1], $nextmonth[0], 1);
 880          $nextmonthtime = make_timestamp($nextmonthtime['year'], $nextmonthtime['month'], $nextmonthtime['day'],
 881              $nextmonthtime['hour'], $nextmonthtime['minute']);
 882      }
 883  
 884      switch ($type) {
 885          case 'frontpage':
 886              $prevlink = calendar_get_link_previous(get_string('monthprev', 'access'), $urlbase, false, false, false, true, $prevmonthtime);
 887              $nextlink = calendar_get_link_next(get_string('monthnext', 'access'), $urlbase, false, false, false, true, $nextmonthtime);
 888              $calendarlink = calendar_get_link_href(new moodle_url(CALENDAR_URL.'view.php', array('view' => 'month')), false, false, false, $time);
 889  
 890              if (!empty($data['id'])) {
 891                  $calendarlink->param('course', $data['id']);
 892              }
 893  
 894              if (right_to_left()) {
 895                  $left = $nextlink;
 896                  $right = $prevlink;
 897              } else {
 898                  $left = $prevlink;
 899                  $right = $nextlink;
 900              }
 901  
 902              $content .= html_writer::start_tag('div', array('class'=>'calendar-controls'));
 903              $content .= $left.'<span class="hide"> | </span>';
 904              $content .= html_writer::tag('span', html_writer::link($calendarlink, userdate($time, get_string('strftimemonthyear')), array('title'=>get_string('monththis','calendar'))), array('class'=>'current'));
 905              $content .= '<span class="hide"> | </span>'. $right;
 906              $content .= "<span class=\"clearer\"><!-- --></span>\n";
 907              $content .= html_writer::end_tag('div');
 908  
 909              break;
 910          case 'course':
 911              $prevlink = calendar_get_link_previous(get_string('monthprev', 'access'), $urlbase, false, false, false, true, $prevmonthtime);
 912              $nextlink = calendar_get_link_next(get_string('monthnext', 'access'), $urlbase, false, false, false, true, $nextmonthtime);
 913              $calendarlink = calendar_get_link_href(new moodle_url(CALENDAR_URL.'view.php', array('view' => 'month')), false, false, false, $time);
 914  
 915              if (!empty($data['id'])) {
 916                  $calendarlink->param('course', $data['id']);
 917              }
 918  
 919              if (right_to_left()) {
 920                  $left = $nextlink;
 921                  $right = $prevlink;
 922              } else {
 923                  $left = $prevlink;
 924                  $right = $nextlink;
 925              }
 926  
 927              $content .= html_writer::start_tag('div', array('class'=>'calendar-controls'));
 928              $content .= $left.'<span class="hide"> | </span>';
 929              $content .= html_writer::tag('span', html_writer::link($calendarlink, userdate($time, get_string('strftimemonthyear')), array('title'=>get_string('monththis','calendar'))), array('class'=>'current'));
 930              $content .= '<span class="hide"> | </span>'. $right;
 931              $content .= "<span class=\"clearer\"><!-- --></span>";
 932              $content .= html_writer::end_tag('div');
 933              break;
 934          case 'upcoming':
 935              $calendarlink = calendar_get_link_href(new moodle_url(CALENDAR_URL.'view.php', array('view' => 'upcoming')), false, false, false, $time);
 936              if (!empty($data['id'])) {
 937                  $calendarlink->param('course', $data['id']);
 938              }
 939              $calendarlink = html_writer::link($calendarlink, userdate($time, get_string('strftimemonthyear')));
 940              $content .= html_writer::tag('div', $calendarlink, array('class'=>'centered'));
 941              break;
 942          case 'display':
 943              $calendarlink = calendar_get_link_href(new moodle_url(CALENDAR_URL.'view.php', array('view' => 'month')), false, false, false, $time);
 944              if (!empty($data['id'])) {
 945                  $calendarlink->param('course', $data['id']);
 946              }
 947              $calendarlink = html_writer::link($calendarlink, userdate($time, get_string('strftimemonthyear')));
 948              $content .= html_writer::tag('h3', $calendarlink);
 949              break;
 950          case 'month':
 951              $prevlink = calendar_get_link_previous(userdate($prevmonthtime, get_string('strftimemonthyear')), 'view.php?view=month'.$courseid.'&amp;', false, false, false, false, $prevmonthtime);
 952              $nextlink = calendar_get_link_next(userdate($nextmonthtime, get_string('strftimemonthyear')), 'view.php?view=month'.$courseid.'&amp;', false, false, false, false, $nextmonthtime);
 953  
 954              if (right_to_left()) {
 955                  $left = $nextlink;
 956                  $right = $prevlink;
 957              } else {
 958                  $left = $prevlink;
 959                  $right = $nextlink;
 960              }
 961  
 962              $content .= html_writer::start_tag('div', array('class'=>'calendar-controls'));
 963              $content .= $left . '<span class="hide"> | </span>';
 964              $content .= $OUTPUT->heading(userdate($time, get_string('strftimemonthyear')), 2, 'current');
 965              $content .= '<span class="hide"> | </span>' . $right;
 966              $content .= '<span class="clearer"><!-- --></span>';
 967              $content .= html_writer::end_tag('div')."\n";
 968              break;
 969          case 'day':
 970              $days = calendar_get_days();
 971  
 972              $prevtimestamp = strtotime('-1 day', $time);
 973              $nexttimestamp = strtotime('+1 day', $time);
 974  
 975              $prevdate = $calendartype->timestamp_to_date_array($prevtimestamp);
 976              $nextdate = $calendartype->timestamp_to_date_array($nexttimestamp);
 977  
 978              $prevname = $days[$prevdate['wday']]['fullname'];
 979              $nextname = $days[$nextdate['wday']]['fullname'];
 980              $prevlink = calendar_get_link_previous($prevname, 'view.php?view=day'.$courseid.'&amp;', false, false, false, false, $prevtimestamp);
 981              $nextlink = calendar_get_link_next($nextname, 'view.php?view=day'.$courseid.'&amp;', false, false, false, false, $nexttimestamp);
 982  
 983              if (right_to_left()) {
 984                  $left = $nextlink;
 985                  $right = $prevlink;
 986              } else {
 987                  $left = $prevlink;
 988                  $right = $nextlink;
 989              }
 990  
 991              $content .= html_writer::start_tag('div', array('class'=>'calendar-controls'));
 992              $content .= $left;
 993              $content .= '<span class="hide"> | </span><span class="current">'.userdate($time, get_string('strftimedaydate')).'</span>';
 994              $content .= '<span class="hide"> | </span>'. $right;
 995              $content .= "<span class=\"clearer\"><!-- --></span>";
 996              $content .= html_writer::end_tag('div')."\n";
 997  
 998              break;
 999      }
1000      return $content;
1001  }
1002  
1003  /**
1004   * Formats a filter control element.
1005   *
1006   * @param moodle_url $url of the filter
1007   * @param int $type constant defining the type filter
1008   * @return string html content of the element
1009   */
1010  function calendar_filter_controls_element(moodle_url $url, $type) {
1011      global $OUTPUT;
1012      switch ($type) {
1013          case CALENDAR_EVENT_GLOBAL:
1014              $typeforhumans = 'global';
1015              $class = 'calendar_event_global';
1016              break;
1017          case CALENDAR_EVENT_COURSE:
1018              $typeforhumans = 'course';
1019              $class = 'calendar_event_course';
1020              break;
1021          case CALENDAR_EVENT_GROUP:
1022              $typeforhumans = 'groups';
1023              $class = 'calendar_event_group';
1024              break;
1025          case CALENDAR_EVENT_USER:
1026              $typeforhumans = 'user';
1027              $class = 'calendar_event_user';
1028              break;
1029      }
1030      if (calendar_show_event_type($type)) {
1031          $icon = $OUTPUT->pix_icon('t/hide', get_string('hide'));
1032          $str = get_string('hide'.$typeforhumans.'events', 'calendar');
1033      } else {
1034          $icon = $OUTPUT->pix_icon('t/show', get_string('show'));
1035          $str = get_string('show'.$typeforhumans.'events', 'calendar');
1036      }
1037      $content = html_writer::start_tag('li', array('class' => 'calendar_event'));
1038      $content .= html_writer::start_tag('a', array('href' => $url, 'rel' => 'nofollow'));
1039      $content .= html_writer::tag('span', $icon, array('class' => $class));
1040      $content .= html_writer::tag('span', $str, array('class' => 'eventname'));
1041      $content .= html_writer::end_tag('a');
1042      $content .= html_writer::end_tag('li');
1043      return $content;
1044  }
1045  
1046  /**
1047   * Get the controls filter for calendar.
1048   *
1049   * Filter is used to hide calendar info from the display page
1050   *
1051   * @param moodle_url $returnurl return-url for filter controls
1052   * @return string $content return filter controls in html
1053   */
1054  function calendar_filter_controls(moodle_url $returnurl) {
1055      global $CFG, $USER, $OUTPUT;
1056  
1057      $groupevents = true;
1058      $id = optional_param( 'id',0,PARAM_INT );
1059      $seturl = new moodle_url('/calendar/set.php', array('return' => base64_encode($returnurl->out_as_local_url(false)), 'sesskey'=>sesskey()));
1060      $content = html_writer::start_tag('ul');
1061  
1062      $seturl->param('var', 'showglobal');
1063      $content .= calendar_filter_controls_element($seturl, CALENDAR_EVENT_GLOBAL);
1064  
1065      $seturl->param('var', 'showcourses');
1066      $content .= calendar_filter_controls_element($seturl, CALENDAR_EVENT_COURSE);
1067  
1068      if (isloggedin() && !isguestuser()) {
1069          if ($groupevents) {
1070              // This course MIGHT have group events defined, so show the filter
1071              $seturl->param('var', 'showgroups');
1072              $content .= calendar_filter_controls_element($seturl, CALENDAR_EVENT_GROUP);
1073          } else {
1074              // This course CANNOT have group events, so lose the filter
1075          }
1076          $seturl->param('var', 'showuser');
1077          $content .= calendar_filter_controls_element($seturl, CALENDAR_EVENT_USER);
1078      }
1079      $content .= html_writer::end_tag('ul');
1080  
1081      return $content;
1082  }
1083  
1084  /**
1085   * Return the representation day
1086   *
1087   * @param int $tstamp Timestamp in GMT
1088   * @param int $now current Unix timestamp
1089   * @param bool $usecommonwords
1090   * @return string the formatted date/time
1091   */
1092  function calendar_day_representation($tstamp, $now = false, $usecommonwords = true) {
1093  
1094      static $shortformat;
1095      if(empty($shortformat)) {
1096          $shortformat = get_string('strftimedayshort');
1097      }
1098  
1099      if($now === false) {
1100          $now = time();
1101      }
1102  
1103      // To have it in one place, if a change is needed
1104      $formal = userdate($tstamp, $shortformat);
1105  
1106      $datestamp = usergetdate($tstamp);
1107      $datenow   = usergetdate($now);
1108  
1109      if($usecommonwords == false) {
1110          // We don't want words, just a date
1111          return $formal;
1112      }
1113      else if($datestamp['year'] == $datenow['year'] && $datestamp['yday'] == $datenow['yday']) {
1114          // Today
1115          return get_string('today', 'calendar');
1116      }
1117      else if(
1118          ($datestamp['year'] == $datenow['year'] && $datestamp['yday'] == $datenow['yday'] - 1 ) ||
1119          ($datestamp['year'] == $datenow['year'] - 1 && $datestamp['mday'] == 31 && $datestamp['mon'] == 12 && $datenow['yday'] == 1)
1120          ) {
1121          // Yesterday
1122          return get_string('yesterday', 'calendar');
1123      }
1124      else if(
1125          ($datestamp['year'] == $datenow['year'] && $datestamp['yday'] == $datenow['yday'] + 1 ) ||
1126          ($datestamp['year'] == $datenow['year'] + 1 && $datenow['mday'] == 31 && $datenow['mon'] == 12 && $datestamp['yday'] == 1)
1127          ) {
1128          // Tomorrow
1129          return get_string('tomorrow', 'calendar');
1130      }
1131      else {
1132          return $formal;
1133      }
1134  }
1135  
1136  /**
1137   * return the formatted representation time
1138   *
1139   * @param int $time the timestamp in UTC, as obtained from the database
1140   * @return string the formatted date/time
1141   */
1142  function calendar_time_representation($time) {
1143      static $langtimeformat = NULL;
1144      if($langtimeformat === NULL) {
1145          $langtimeformat = get_string('strftimetime');
1146      }
1147      $timeformat = get_user_preferences('calendar_timeformat');
1148      if(empty($timeformat)){
1149          $timeformat = get_config(NULL,'calendar_site_timeformat');
1150      }
1151      // The ? is needed because the preference might be present, but empty
1152      return userdate($time, empty($timeformat) ? $langtimeformat : $timeformat);
1153  }
1154  
1155  /**
1156   * Adds day, month, year arguments to a URL and returns a moodle_url object.
1157   *
1158   * @param string|moodle_url $linkbase
1159   * @param int $d The number of the day.
1160   * @param int $m The number of the month.
1161   * @param int $y The number of the year.
1162   * @param int $time the unixtime, used for multiple calendar support. The values $d,
1163   *     $m and $y are kept for backwards compatibility.
1164   * @return moodle_url|null $linkbase
1165   */
1166  function calendar_get_link_href($linkbase, $d, $m, $y, $time = 0) {
1167      if (empty($linkbase)) {
1168          return '';
1169      }
1170      if (!($linkbase instanceof moodle_url)) {
1171          $linkbase = new moodle_url($linkbase);
1172      }
1173  
1174      // If a day, month and year were passed then convert it to a timestamp. If these were passed
1175      // then we can assume the day, month and year are passed as Gregorian, as no where in core
1176      // should we be passing these values rather than the time.
1177      if (!empty($d) && !empty($m) && !empty($y)) {
1178          if (checkdate($m, $d, $y)) {
1179              $time = make_timestamp($y, $m, $d);
1180          } else {
1181              $time = time();
1182          }
1183      } else if (empty($time)) {
1184          $time = time();
1185      }
1186  
1187      $linkbase->param('time', $time);
1188  
1189      return $linkbase;
1190  }
1191  
1192  /**
1193   * Build and return a previous month HTML link, with an arrow.
1194   *
1195   * @param string $text The text label.
1196   * @param string|moodle_url $linkbase The URL stub.
1197   * @param int $d The number of the date.
1198   * @param int $m The number of the month.
1199   * @param int $y year The number of the year.
1200   * @param bool $accesshide Default visible, or hide from all except screenreaders.
1201   * @param int $time the unixtime, used for multiple calendar support. The values $d,
1202   *     $m and $y are kept for backwards compatibility.
1203   * @return string HTML string.
1204   */
1205  function calendar_get_link_previous($text, $linkbase, $d, $m, $y, $accesshide = false, $time = 0) {
1206      $href = calendar_get_link_href(new moodle_url($linkbase), $d, $m, $y, $time);
1207      if (empty($href)) {
1208          return $text;
1209      }
1210      return link_arrow_left($text, (string)$href, $accesshide, 'previous');
1211  }
1212  
1213  /**
1214   * Build and return a next month HTML link, with an arrow.
1215   *
1216   * @param string $text The text label.
1217   * @param string|moodle_url $linkbase The URL stub.
1218   * @param int $d the number of the Day
1219   * @param int $m The number of the month.
1220   * @param int $y The number of the year.
1221   * @param bool $accesshide Default visible, or hide from all except screenreaders.
1222   * @param int $time the unixtime, used for multiple calendar support. The values $d,
1223   *     $m and $y are kept for backwards compatibility.
1224   * @return string HTML string.
1225   */
1226  function calendar_get_link_next($text, $linkbase, $d, $m, $y, $accesshide = false, $time = 0) {
1227      $href = calendar_get_link_href(new moodle_url($linkbase), $d, $m, $y, $time);
1228      if (empty($href)) {
1229          return $text;
1230      }
1231      return link_arrow_right($text, (string)$href, $accesshide, 'next');
1232  }
1233  
1234  /**
1235   * Return the name of the weekday
1236   *
1237   * @param string $englishname
1238   * @return string of the weekeday
1239   */
1240  function calendar_wday_name($englishname) {
1241      return get_string(strtolower($englishname), 'calendar');
1242  }
1243  
1244  /**
1245   * Return the number of days in month
1246   *
1247   * @param int $month the number of the month.
1248   * @param int $year the number of the year
1249   * @return int
1250   */
1251  function calendar_days_in_month($month, $year) {
1252      $calendartype = \core_calendar\type_factory::get_calendar_instance();
1253      return $calendartype->get_num_days_in_month($year, $month);
1254  }
1255  
1256  /**
1257   * Get the upcoming event block
1258   *
1259   * @param array $events list of events
1260   * @param moodle_url|string $linkhref link to event referer
1261   * @param boolean $showcourselink whether links to courses should be shown
1262   * @return string|null $content html block content
1263   */
1264  function calendar_get_block_upcoming($events, $linkhref = NULL, $showcourselink = false) {
1265      $content = '';
1266      $lines = count($events);
1267      if (!$lines) {
1268          return $content;
1269      }
1270  
1271      for ($i = 0; $i < $lines; ++$i) {
1272          if (!isset($events[$i]->time)) {   // Just for robustness
1273              continue;
1274          }
1275          $events[$i] = calendar_add_event_metadata($events[$i]);
1276          $content .= '<div class="event"><span class="icon c0">'.$events[$i]->icon.'</span>';
1277          if (!empty($events[$i]->referer)) {
1278              // That's an activity event, so let's provide the hyperlink
1279              $content .= $events[$i]->referer;
1280          } else {
1281              if(!empty($linkhref)) {
1282                  $href = calendar_get_link_href(new moodle_url(CALENDAR_URL . $linkhref), 0, 0, 0, $events[$i]->timestart);
1283                  $href->set_anchor('event_'.$events[$i]->id);
1284                  $content .= html_writer::link($href, $events[$i]->name);
1285              }
1286              else {
1287                  $content .= $events[$i]->name;
1288              }
1289          }
1290          $events[$i]->time = str_replace('&raquo;', '<br />&raquo;', $events[$i]->time);
1291          if ($showcourselink && !empty($events[$i]->courselink)) {
1292              $content .= html_writer::div($events[$i]->courselink, 'course');
1293          }
1294          $content .= '<div class="date">'.$events[$i]->time.'</div></div>';
1295          if ($i < $lines - 1) $content .= '<hr />';
1296      }
1297  
1298      return $content;
1299  }
1300  
1301  /**
1302   * Get the next following month
1303   *
1304   * @param int $month the number of the month.
1305   * @param int $year the number of the year.
1306   * @return array the following month
1307   */
1308  function calendar_add_month($month, $year) {
1309      // Get the calendar type we are using.
1310      $calendartype = \core_calendar\type_factory::get_calendar_instance();
1311      return $calendartype->get_next_month($year, $month);
1312  }
1313  
1314  /**
1315   * Get the previous month.
1316   *
1317   * @param int $month the number of the month.
1318   * @param int $year the number of the year.
1319   * @return array previous month
1320   */
1321  function calendar_sub_month($month, $year) {
1322      // Get the calendar type we are using.
1323      $calendartype = \core_calendar\type_factory::get_calendar_instance();
1324      return $calendartype->get_prev_month($year, $month);
1325  }
1326  
1327  /**
1328   * Get per-day basis events
1329   *
1330   * @param array $events list of events
1331   * @param int $month the number of the month
1332   * @param int $year the number of the year
1333   * @param array $eventsbyday event on specific day
1334   * @param array $durationbyday duration of the event in days
1335   * @param array $typesbyday event type (eg: global, course, user, or group)
1336   * @param array $courses list of courses
1337   * @return void
1338   */
1339  function calendar_events_by_day($events, $month, $year, &$eventsbyday, &$durationbyday, &$typesbyday, &$courses) {
1340      // Get the calendar type we are using.
1341      $calendartype = \core_calendar\type_factory::get_calendar_instance();
1342  
1343      $eventsbyday = array();
1344      $typesbyday = array();
1345      $durationbyday = array();
1346  
1347      if($events === false) {
1348          return;
1349      }
1350  
1351      foreach ($events as $event) {
1352          $startdate = $calendartype->timestamp_to_date_array($event->timestart);
1353          // Set end date = start date if no duration
1354          if ($event->timeduration) {
1355              $enddate = $calendartype->timestamp_to_date_array($event->timestart + $event->timeduration - 1);
1356          } else {
1357              $enddate = $startdate;
1358          }
1359  
1360          // Simple arithmetic: $year * 13 + $month is a distinct integer for each distinct ($year, $month) pair
1361          if(!($startdate['year'] * 13 + $startdate['mon'] <= $year * 13 + $month) && ($enddate['year'] * 13 + $enddate['mon'] >= $year * 13 + $month)) {
1362              // Out of bounds
1363              continue;
1364          }
1365  
1366          $eventdaystart = intval($startdate['mday']);
1367  
1368          if($startdate['mon'] == $month && $startdate['year'] == $year) {
1369              // Give the event to its day
1370              $eventsbyday[$eventdaystart][] = $event->id;
1371  
1372              // Mark the day as having such an event
1373              if($event->courseid == SITEID && $event->groupid == 0) {
1374                  $typesbyday[$eventdaystart]['startglobal'] = true;
1375                  // Set event class for global event
1376                  $events[$event->id]->class = 'calendar_event_global';
1377              }
1378              else if($event->courseid != 0 && $event->courseid != SITEID && $event->groupid == 0) {
1379                  $typesbyday[$eventdaystart]['startcourse'] = true;
1380                  // Set event class for course event
1381                  $events[$event->id]->class = 'calendar_event_course';
1382              }
1383              else if($event->groupid) {
1384                  $typesbyday[$eventdaystart]['startgroup'] = true;
1385                  // Set event class for group event
1386                  $events[$event->id]->class = 'calendar_event_group';
1387              }
1388              else if($event->userid) {
1389                  $typesbyday[$eventdaystart]['startuser'] = true;
1390                  // Set event class for user event
1391                  $events[$event->id]->class = 'calendar_event_user';
1392              }
1393          }
1394  
1395          if($event->timeduration == 0) {
1396              // Proceed with the next
1397              continue;
1398          }
1399  
1400          // The event starts on $month $year or before. So...
1401          $lowerbound = $startdate['mon'] == $month && $startdate['year'] == $year ? intval($startdate['mday']) : 0;
1402  
1403          // Also, it ends on $month $year or later...
1404          $upperbound = $enddate['mon'] == $month && $enddate['year'] == $year ? intval($enddate['mday']) : calendar_days_in_month($month, $year);
1405  
1406          // Mark all days between $lowerbound and $upperbound (inclusive) as duration
1407          for($i = $lowerbound + 1; $i <= $upperbound; ++$i) {
1408              $durationbyday[$i][] = $event->id;
1409              if($event->courseid == SITEID && $event->groupid == 0) {
1410                  $typesbyday[$i]['durationglobal'] = true;
1411              }
1412              else if($event->courseid != 0 && $event->courseid != SITEID && $event->groupid == 0) {
1413                  $typesbyday[$i]['durationcourse'] = true;
1414              }
1415              else if($event->groupid) {
1416                  $typesbyday[$i]['durationgroup'] = true;
1417              }
1418              else if($event->userid) {
1419                  $typesbyday[$i]['durationuser'] = true;
1420              }
1421          }
1422  
1423      }
1424      return;
1425  }
1426  
1427  /**
1428   * Get current module cache
1429   *
1430   * @param array $coursecache list of course cache
1431   * @param string $modulename name of the module
1432   * @param int $instance module instance number
1433   * @return stdClass|bool $module information
1434   */
1435  function calendar_get_module_cached(&$coursecache, $modulename, $instance) {
1436      $module = get_coursemodule_from_instance($modulename, $instance);
1437  
1438      if($module === false) return false;
1439      if(!calendar_get_course_cached($coursecache, $module->course)) {
1440          return false;
1441      }
1442      return $module;
1443  }
1444  
1445  /**
1446   * Get current course cache
1447   *
1448   * @param array $coursecache list of course cache
1449   * @param int $courseid id of the course
1450   * @return stdClass $coursecache[$courseid] return the specific course cache
1451   */
1452  function calendar_get_course_cached(&$coursecache, $courseid) {
1453      if (!isset($coursecache[$courseid])) {
1454          $coursecache[$courseid] = get_course($courseid);
1455      }
1456      return $coursecache[$courseid];
1457  }
1458  
1459  /**
1460   * Get group from groupid for calendar display
1461   *
1462   * @param int $groupid
1463   * @return stdClass group object with fields 'id', 'name' and 'courseid'
1464   */
1465  function calendar_get_group_cached($groupid) {
1466      static $groupscache = array();
1467      if (!isset($groupscache[$groupid])) {
1468          $groupscache[$groupid] = groups_get_group($groupid, 'id,name,courseid');
1469      }
1470      return $groupscache[$groupid];
1471  }
1472  
1473  /**
1474   * Returns the courses to load events for, the
1475   *
1476   * @param array $courseeventsfrom An array of courses to load calendar events for
1477   * @param bool $ignorefilters specify the use of filters, false is set as default
1478   * @return array An array of courses, groups, and user to load calendar events for based upon filters
1479   */
1480  function calendar_set_filters(array $courseeventsfrom, $ignorefilters = false) {
1481      global $USER, $CFG, $DB;
1482  
1483      // For backwards compatability we have to check whether the courses array contains
1484      // just id's in which case we need to load course objects.
1485      $coursestoload = array();
1486      foreach ($courseeventsfrom as $id => $something) {
1487          if (!is_object($something)) {
1488              $coursestoload[] = $id;
1489              unset($courseeventsfrom[$id]);
1490          }
1491      }
1492      if (!empty($coursestoload)) {
1493          // TODO remove this in 2.2
1494          debugging('calendar_set_filters now preferes an array of course objects with preloaded contexts', DEBUG_DEVELOPER);
1495          $courseeventsfrom = array_merge($courseeventsfrom, $DB->get_records_list('course', 'id', $coursestoload));
1496      }
1497  
1498      $courses = array();
1499      $user = false;
1500      $group = false;
1501  
1502      // capabilities that allow seeing group events from all groups
1503      // TODO: rewrite so that moodle/calendar:manageentries is not necessary here
1504      $allgroupscaps = array('moodle/site:accessallgroups', 'moodle/calendar:manageentries');
1505  
1506      $isloggedin = isloggedin();
1507  
1508      if ($ignorefilters || calendar_show_event_type(CALENDAR_EVENT_COURSE)) {
1509          $courses = array_keys($courseeventsfrom);
1510      }
1511      if ($ignorefilters || calendar_show_event_type(CALENDAR_EVENT_GLOBAL)) {
1512          $courses[] = SITEID;
1513      }
1514      $courses = array_unique($courses);
1515      sort($courses);
1516  
1517      if (!empty($courses) && in_array(SITEID, $courses)) {
1518          // Sort courses for consistent colour highlighting
1519          // Effectively ignoring SITEID as setting as last course id
1520          $key = array_search(SITEID, $courses);
1521          unset($courses[$key]);
1522          $courses[] = SITEID;
1523      }
1524  
1525      if ($ignorefilters || ($isloggedin && calendar_show_event_type(CALENDAR_EVENT_USER))) {
1526          $user = $USER->id;
1527      }
1528  
1529      if (!empty($courseeventsfrom) && (calendar_show_event_type(CALENDAR_EVENT_GROUP) || $ignorefilters)) {
1530  
1531          if (count($courseeventsfrom)==1) {
1532              $course = reset($courseeventsfrom);
1533              if (has_any_capability($allgroupscaps, context_course::instance($course->id))) {
1534                  $coursegroups = groups_get_all_groups($course->id, 0, 0, 'g.id');
1535                  $group = array_keys($coursegroups);
1536              }
1537          }
1538          if ($group === false) {
1539              if (!empty($CFG->calendar_adminseesall) && has_any_capability($allgroupscaps, context_system::instance())) {
1540                  $group = true;
1541              } else if ($isloggedin) {
1542                  $groupids = array();
1543  
1544                  // We already have the courses to examine in $courses
1545                  // For each course...
1546                  foreach ($courseeventsfrom as $courseid => $course) {
1547                      // If the user is an editing teacher in there,
1548                      if (!empty($USER->groupmember[$course->id])) {
1549                          // We've already cached the users groups for this course so we can just use that
1550                          $groupids = array_merge($groupids, $USER->groupmember[$course->id]);
1551                      } else if ($course->groupmode != NOGROUPS || !$course->groupmodeforce) {
1552                          // If this course has groups, show events from all of those related to the current user
1553                          $coursegroups = groups_get_user_groups($course->id, $USER->id);
1554                          $groupids = array_merge($groupids, $coursegroups['0']);
1555                      }
1556                  }
1557                  if (!empty($groupids)) {
1558                      $group = $groupids;
1559                  }
1560              }
1561          }
1562      }
1563      if (empty($courses)) {
1564          $courses = false;
1565      }
1566  
1567      return array($courses, $group, $user);
1568  }
1569  
1570  /**
1571   * Return the capability for editing calendar event
1572   *
1573   * @param calendar_event $event event object
1574   * @return bool capability to edit event
1575   */
1576  function calendar_edit_event_allowed($event) {
1577      global $USER, $DB;
1578  
1579      // Must be logged in
1580      if (!isloggedin()) {
1581          return false;
1582      }
1583  
1584      // can not be using guest account
1585      if (isguestuser()) {
1586          return false;
1587      }
1588  
1589      // You cannot edit calendar subscription events presently.
1590      if (!empty($event->subscriptionid)) {
1591          return false;
1592      }
1593  
1594      $sitecontext = context_system::instance();
1595      // if user has manageentries at site level, return true
1596      if (has_capability('moodle/calendar:manageentries', $sitecontext)) {
1597          return true;
1598      }
1599  
1600      // if groupid is set, it's definitely a group event
1601      if (!empty($event->groupid)) {
1602          // Allow users to add/edit group events if:
1603          // 1) They have manageentries (= entries for whole course)
1604          // 2) They have managegroupentries AND are in the group
1605          $group = $DB->get_record('groups', array('id'=>$event->groupid));
1606          return $group && (
1607              has_capability('moodle/calendar:manageentries', $event->context) ||
1608              (has_capability('moodle/calendar:managegroupentries', $event->context)
1609                  && groups_is_member($event->groupid)));
1610      } else if (!empty($event->courseid)) {
1611      // if groupid is not set, but course is set,
1612      // it's definiely a course event
1613          return has_capability('moodle/calendar:manageentries', $event->context);
1614      } else if (!empty($event->userid) && $event->userid == $USER->id) {
1615      // if course is not set, but userid id set, it's a user event
1616          return (has_capability('moodle/calendar:manageownentries', $event->context));
1617      } else if (!empty($event->userid)) {
1618          return (has_capability('moodle/calendar:manageentries', $event->context));
1619      }
1620      return false;
1621  }
1622  
1623  /**
1624   * Returns the default courses to display on the calendar when there isn't a specific
1625   * course to display.
1626   *
1627   * @return array $courses Array of courses to display
1628   */
1629  function calendar_get_default_courses() {
1630      global $CFG, $DB;
1631  
1632      if (!isloggedin()) {
1633          return array();
1634      }
1635  
1636      $courses = array();
1637      if (!empty($CFG->calendar_adminseesall) && has_capability('moodle/calendar:manageentries', context_system::instance())) {
1638          $select = ', ' . context_helper::get_preload_record_columns_sql('ctx');
1639          $join = "LEFT JOIN {context} ctx ON (ctx.instanceid = c.id AND ctx.contextlevel = :contextlevel)";
1640          $sql = "SELECT c.* $select
1641                    FROM {course} c
1642                    $join
1643                    WHERE EXISTS (SELECT 1 FROM {event} e WHERE e.courseid = c.id)
1644                    ";
1645          $courses = $DB->get_records_sql($sql, array('contextlevel' => CONTEXT_COURSE), 0, 20);
1646          foreach ($courses as $course) {
1647              context_helper::preload_from_record($course);
1648          }
1649          return $courses;
1650      }
1651  
1652      $courses = enrol_get_my_courses();
1653  
1654      return $courses;
1655  }
1656  
1657  /**
1658   * Display calendar preference button
1659   *
1660   * @param stdClass $course course object
1661   * @return string return preference button in html
1662   */
1663  function calendar_preferences_button(stdClass $course) {
1664      global $OUTPUT;
1665  
1666      // Guests have no preferences
1667      if (!isloggedin() || isguestuser()) {
1668          return '';
1669      }
1670  
1671      return $OUTPUT->single_button(new moodle_url('/calendar/preferences.php', array('course' => $course->id)), get_string("preferences", "calendar"));
1672  }
1673  
1674  /**
1675   * Get event format time
1676   *
1677   * @param calendar_event $event event object
1678   * @param int $now current time in gmt
1679   * @param array $linkparams list of params for event link
1680   * @param bool $usecommonwords the words as formatted date/time.
1681   * @param int $showtime determine the show time GMT timestamp
1682   * @return string $eventtime link/string for event time
1683   */
1684  function calendar_format_event_time($event, $now, $linkparams = null, $usecommonwords = true, $showtime = 0) {
1685      $starttime = $event->timestart;
1686      $endtime = $event->timestart + $event->timeduration;
1687  
1688      if (empty($linkparams) || !is_array($linkparams)) {
1689          $linkparams = array();
1690      }
1691  
1692      $linkparams['view'] = 'day';
1693  
1694      // OK, now to get a meaningful display...
1695      // Check if there is a duration for this event.
1696      if ($event->timeduration) {
1697          // Get the midnight of the day the event will start.
1698          $usermidnightstart = usergetmidnight($starttime);
1699          // Get the midnight of the day the event will end.
1700          $usermidnightend = usergetmidnight($endtime);
1701          // Check if we will still be on the same day.
1702          if ($usermidnightstart == $usermidnightend) {
1703              // Check if we are running all day.
1704              if ($event->timeduration == DAYSECS) {
1705                  $time = get_string('allday', 'calendar');
1706              } else { // Specify the time we will be running this from.
1707                  $datestart = calendar_time_representation($starttime);
1708                  $dateend = calendar_time_representation($endtime);
1709                  $time = $datestart . ' <strong>&raquo;</strong> ' . $dateend;
1710              }
1711  
1712              // Set printable representation.
1713              if (!$showtime) {
1714                  $day = calendar_day_representation($event->timestart, $now, $usecommonwords);
1715                  $url = calendar_get_link_href(new moodle_url(CALENDAR_URL . 'view.php', $linkparams), 0, 0, 0, $endtime);
1716                  $eventtime = html_writer::link($url, $day) . ', ' . $time;
1717              } else {
1718                  $eventtime = $time;
1719              }
1720          } else { // It must spans two or more days.
1721              $daystart = calendar_day_representation($event->timestart, $now, $usecommonwords) . ', ';
1722              if ($showtime == $usermidnightstart) {
1723                  $daystart = '';
1724              }
1725              $timestart = calendar_time_representation($event->timestart);
1726              $dayend = calendar_day_representation($event->timestart + $event->timeduration, $now, $usecommonwords) . ', ';
1727              if ($showtime == $usermidnightend) {
1728                  $dayend = '';
1729              }
1730              $timeend = calendar_time_representation($event->timestart + $event->timeduration);
1731  
1732              // Set printable representation.
1733              if ($now >= $usermidnightstart && $now < strtotime('+1 day', $usermidnightstart)) {
1734                  $url = calendar_get_link_href(new moodle_url(CALENDAR_URL . 'view.php', $linkparams), 0, 0, 0, $endtime);
1735                  $eventtime = $timestart . ' <strong>&raquo;</strong> ' . html_writer::link($url, $dayend) . $timeend;
1736              } else {
1737                  $url = calendar_get_link_href(new moodle_url(CALENDAR_URL . 'view.php', $linkparams), 0, 0, 0, $endtime);
1738                  $eventtime  = html_writer::link($url, $daystart) . $timestart . ' <strong>&raquo;</strong> ';
1739  
1740                  $url = calendar_get_link_href(new moodle_url(CALENDAR_URL . 'view.php', $linkparams),  0, 0, 0, $starttime);
1741                  $eventtime .= html_writer::link($url, $dayend) . $timeend;
1742              }
1743          }
1744      } else { // There is no time duration.
1745          $time = calendar_time_representation($event->timestart);
1746          // Set printable representation.
1747          if (!$showtime) {
1748              $day = calendar_day_representation($event->timestart, $now, $usecommonwords);
1749              $url = calendar_get_link_href(new moodle_url(CALENDAR_URL . 'view.php', $linkparams),  0, 0, 0, $starttime);
1750              $eventtime = html_writer::link($url, $day) . ', ' . trim($time);
1751          } else {
1752              $eventtime = $time;
1753          }
1754      }
1755  
1756      // Check if It has expired.
1757      if ($event->timestart + $event->timeduration < $now) {
1758          $eventtime = '<span class="dimmed_text">' . str_replace(' href=', ' class="dimmed" href=', $eventtime) . '</span>';
1759      }
1760  
1761      return $eventtime;
1762  }
1763  
1764  /**
1765   * Display month selector options
1766   *
1767   * @param string $name for the select element
1768   * @param string|array $selected options for select elements
1769   */
1770  function calendar_print_month_selector($name, $selected) {
1771      $months = array();
1772      for ($i=1; $i<=12; $i++) {
1773          $months[$i] = userdate(gmmktime(12, 0, 0, $i, 15, 2000), '%B');
1774      }
1775      echo html_writer::label(get_string('months'), 'menu'. $name, false, array('class' => 'accesshide'));
1776      echo html_writer::select($months, $name, $selected, false);
1777  }
1778  
1779  /**
1780   * Checks to see if the requested type of event should be shown for the given user.
1781   *
1782   * @param CALENDAR_EVENT_GLOBAL|CALENDAR_EVENT_COURSE|CALENDAR_EVENT_GROUP|CALENDAR_EVENT_USER $type
1783   *          The type to check the display for (default is to display all)
1784   * @param stdClass|int|null $user The user to check for - by default the current user
1785   * @return bool True if the tyep should be displayed false otherwise
1786   */
1787  function calendar_show_event_type($type, $user = null) {
1788      $default = CALENDAR_EVENT_GLOBAL + CALENDAR_EVENT_COURSE + CALENDAR_EVENT_GROUP + CALENDAR_EVENT_USER;
1789      if (get_user_preferences('calendar_persistflt', 0, $user) === 0) {
1790          global $SESSION;
1791          if (!isset($SESSION->calendarshoweventtype)) {
1792              $SESSION->calendarshoweventtype = $default;
1793          }
1794          return $SESSION->calendarshoweventtype & $type;
1795      } else {
1796          return get_user_preferences('calendar_savedflt', $default, $user) & $type;
1797      }
1798  }
1799  
1800  /**
1801   * Sets the display of the event type given $display.
1802   *
1803   * If $display = true the event type will be shown.
1804   * If $display = false the event type will NOT be shown.
1805   * If $display = null the current value will be toggled and saved.
1806   *
1807   * @param CALENDAR_EVENT_GLOBAL|CALENDAR_EVENT_COURSE|CALENDAR_EVENT_GROUP|CALENDAR_EVENT_USER $type object of CALENDAR_EVENT_XXX
1808   * @param bool $display option to display event type
1809   * @param stdClass|int $user moodle user object or id, null means current user
1810   */
1811  function calendar_set_event_type_display($type, $display = null, $user = null) {
1812      $persist = get_user_preferences('calendar_persistflt', 0, $user);
1813      $default = CALENDAR_EVENT_GLOBAL + CALENDAR_EVENT_COURSE + CALENDAR_EVENT_GROUP + CALENDAR_EVENT_USER;
1814      if ($persist === 0) {
1815          global $SESSION;
1816          if (!isset($SESSION->calendarshoweventtype)) {
1817              $SESSION->calendarshoweventtype = $default;
1818          }
1819          $preference = $SESSION->calendarshoweventtype;
1820      } else {
1821          $preference = get_user_preferences('calendar_savedflt', $default, $user);
1822      }
1823      $current = $preference & $type;
1824      if ($display === null) {
1825          $display = !$current;
1826      }
1827      if ($display && !$current) {
1828          $preference += $type;
1829      } else if (!$display && $current) {
1830          $preference -= $type;
1831      }
1832      if ($persist === 0) {
1833          $SESSION->calendarshoweventtype = $preference;
1834      } else {
1835          if ($preference == $default) {
1836              unset_user_preference('calendar_savedflt', $user);
1837          } else {
1838              set_user_preference('calendar_savedflt', $preference, $user);
1839          }
1840      }
1841  }
1842  
1843  /**
1844   * Get calendar's allowed types
1845   *
1846   * @param stdClass $allowed list of allowed edit for event  type
1847   * @param stdClass|int $course object of a course or course id
1848   */
1849  function calendar_get_allowed_types(&$allowed, $course = null) {
1850      global $USER, $CFG, $DB;
1851      $allowed = new stdClass();
1852      $allowed->user = has_capability('moodle/calendar:manageownentries', context_system::instance());
1853      $allowed->groups = false; // This may change just below
1854      $allowed->courses = false; // This may change just below
1855      $allowed->site = has_capability('moodle/calendar:manageentries', context_course::instance(SITEID));
1856  
1857      if (!empty($course)) {
1858          if (!is_object($course)) {
1859              $course = $DB->get_record('course', array('id' => $course), '*', MUST_EXIST);
1860          }
1861          if ($course->id != SITEID) {
1862              $coursecontext = context_course::instance($course->id);
1863              $allowed->user = has_capability('moodle/calendar:manageownentries', $coursecontext);
1864  
1865              if (has_capability('moodle/calendar:manageentries', $coursecontext)) {
1866                  $allowed->courses = array($course->id => 1);
1867  
1868                  if ($course->groupmode != NOGROUPS || !$course->groupmodeforce) {
1869                      if (has_capability('moodle/site:accessallgroups', $coursecontext)) {
1870                          $allowed->groups = groups_get_all_groups($course->id);
1871                      } else {
1872                          $allowed->groups = groups_get_all_groups($course->id, $USER->id);
1873                      }
1874                  }
1875              } else if (has_capability('moodle/calendar:managegroupentries', $coursecontext)) {
1876                  if($course->groupmode != NOGROUPS || !$course->groupmodeforce) {
1877                      if (has_capability('moodle/site:accessallgroups', $coursecontext)) {
1878                          $allowed->groups = groups_get_all_groups($course->id);
1879                      } else {
1880                          $allowed->groups = groups_get_all_groups($course->id, $USER->id);
1881                      }
1882                  }
1883              }
1884          }
1885      }
1886  }
1887  
1888  /**
1889   * See if user can add calendar entries at all
1890   * used to print the "New Event" button
1891   *
1892   * @param stdClass $course object of a course or course id
1893   * @return bool has the capability to add at least one event type
1894   */
1895  function calendar_user_can_add_event($course) {
1896      if (!isloggedin() || isguestuser()) {
1897          return false;
1898      }
1899      calendar_get_allowed_types($allowed, $course);
1900      return (bool)($allowed->user || $allowed->groups || $allowed->courses || $allowed->site);
1901  }
1902  
1903  /**
1904   * Check wether the current user is permitted to add events
1905   *
1906   * @param stdClass $event object of event
1907   * @return bool has the capability to add event
1908   */
1909  function calendar_add_event_allowed($event) {
1910      global $USER, $DB;
1911  
1912      // can not be using guest account
1913      if (!isloggedin() or isguestuser()) {
1914          return false;
1915      }
1916  
1917      $sitecontext = context_system::instance();
1918      // if user has manageentries at site level, always return true
1919      if (has_capability('moodle/calendar:manageentries', $sitecontext)) {
1920          return true;
1921      }
1922  
1923      switch ($event->eventtype) {
1924          case 'course':
1925              return has_capability('moodle/calendar:manageentries', $event->context);
1926  
1927          case 'group':
1928              // Allow users to add/edit group events if:
1929              // 1) They have manageentries (= entries for whole course)
1930              // 2) They have managegroupentries AND are in the group
1931              $group = $DB->get_record('groups', array('id'=>$event->groupid));
1932              return $group && (
1933                  has_capability('moodle/calendar:manageentries', $event->context) ||
1934                  (has_capability('moodle/calendar:managegroupentries', $event->context)
1935                      && groups_is_member($event->groupid)));
1936  
1937          case 'user':
1938              if ($event->userid == $USER->id) {
1939                  return (has_capability('moodle/calendar:manageownentries', $event->context));
1940              }
1941              //there is no 'break;' intentionally
1942  
1943          case 'site':
1944              return has_capability('moodle/calendar:manageentries', $event->context);
1945  
1946          default:
1947              return has_capability('moodle/calendar:manageentries', $event->context);
1948      }
1949  }
1950  
1951  /**
1952   * Manage calendar events
1953   *
1954   * This class provides the required functionality in order to manage calendar events.
1955   * It was introduced as part of Moodle 2.0 and was created in order to provide a
1956   * better framework for dealing with calendar events in particular regard to file
1957   * handling through the new file API
1958   *
1959   * @package    core_calendar
1960   * @category   calendar
1961   * @copyright  2009 Sam Hemelryk
1962   * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
1963   *
1964   * @property int $id The id within the event table
1965   * @property string $name The name of the event
1966   * @property string $description The description of the event
1967   * @property int $format The format of the description FORMAT_?
1968   * @property int $courseid The course the event is associated with (0 if none)
1969   * @property int $groupid The group the event is associated with (0 if none)
1970   * @property int $userid The user the event is associated with (0 if none)
1971   * @property int $repeatid If this is a repeated event this will be set to the
1972   *                          id of the original
1973   * @property string $modulename If added by a module this will be the module name
1974   * @property int $instance If added by a module this will be the module instance
1975   * @property string $eventtype The event type
1976   * @property int $timestart The start time as a timestamp
1977   * @property int $timeduration The duration of the event in seconds
1978   * @property int $visible 1 if the event is visible
1979   * @property int $uuid ?
1980   * @property int $sequence ?
1981   * @property int $timemodified The time last modified as a timestamp
1982   */
1983  class calendar_event {
1984  
1985      /** @var array An object containing the event properties can be accessed via the magic __get/set methods */
1986      protected $properties = null;
1987  
1988      /**
1989       * @var string The converted event discription with file paths resolved. This gets populated when someone requests description for the first time */
1990      protected $_description = null;
1991  
1992      /** @var array The options to use with this description editor */
1993      protected $editoroptions = array(
1994              'subdirs'=>false,
1995              'forcehttps'=>false,
1996              'maxfiles'=>-1,
1997              'maxbytes'=>null,
1998              'trusttext'=>false);
1999  
2000      /** @var object The context to use with the description editor */
2001      protected $editorcontext = null;
2002  
2003      /**
2004       * Instantiates a new event and optionally populates its properties with the
2005       * data provided
2006       *
2007       * @param stdClass $data Optional. An object containing the properties to for
2008       *                  an event
2009       */
2010      public function __construct($data=null) {
2011          global $CFG, $USER;
2012  
2013          // First convert to object if it is not already (should either be object or assoc array)
2014          if (!is_object($data)) {
2015              $data = (object)$data;
2016          }
2017  
2018          $this->editoroptions['maxbytes'] = $CFG->maxbytes;
2019  
2020          $data->eventrepeats = 0;
2021  
2022          if (empty($data->id)) {
2023              $data->id = null;
2024          }
2025  
2026          if (!empty($data->subscriptionid)) {
2027              $data->subscription = calendar_get_subscription($data->subscriptionid);
2028          }
2029  
2030          // Default to a user event
2031          if (empty($data->eventtype)) {
2032              $data->eventtype = 'user';
2033          }
2034  
2035          // Default to the current user
2036          if (empty($data->userid)) {
2037              $data->userid = $USER->id;
2038          }
2039  
2040          if (!empty($data->timeduration) && is_array($data->timeduration)) {
2041              $data->timeduration = make_timestamp($data->timeduration['year'], $data->timeduration['month'], $data->timeduration['day'], $data->timeduration['hour'], $data->timeduration['minute']) - $data->timestart;
2042          }
2043          if (!empty($data->description) && is_array($data->description)) {
2044              $data->format = $data->description['format'];
2045              $data->description = $data->description['text'];
2046          } else if (empty($data->description)) {
2047              $data->description = '';
2048              $data->format = editors_get_preferred_format();
2049          }
2050          // Ensure form is defaulted correctly
2051          if (empty($data->format)) {
2052              $data->format = editors_get_preferred_format();
2053          }
2054  
2055          if (empty($data->context)) {
2056              $data->context = $this->calculate_context($data);
2057          }
2058          $this->properties = $data;
2059      }
2060  
2061      /**
2062       * Magic property method
2063       *
2064       * Attempts to call a set_$key method if one exists otherwise falls back
2065       * to simply set the property
2066       *
2067       * @param string $key property name
2068       * @param mixed $value value of the property
2069       */
2070      public function __set($key, $value) {
2071          if (method_exists($this, 'set_'.$key)) {
2072              $this->{'set_'.$key}($value);
2073          }
2074          $this->properties->{$key} = $value;
2075      }
2076  
2077      /**
2078       * Magic get method
2079       *
2080       * Attempts to call a get_$key method to return the property and ralls over
2081       * to return the raw property
2082       *
2083       * @param string $key property name
2084       * @return mixed property value
2085       */
2086      public function __get($key) {
2087          if (method_exists($this, 'get_'.$key)) {
2088              return $this->{'get_'.$key}();
2089          }
2090          if (!isset($this->properties->{$key})) {
2091              throw new coding_exception('Undefined property requested');
2092          }
2093          return $this->properties->{$key};
2094      }
2095  
2096      /**
2097       * Stupid PHP needs an isset magic method if you use the get magic method and
2098       * still want empty calls to work.... blah ~!
2099       *
2100       * @param string $key $key property name
2101       * @return bool|mixed property value, false if property is not exist
2102       */
2103      public function __isset($key) {
2104          return !empty($this->properties->{$key});
2105      }
2106  
2107      /**
2108       * Calculate the context value needed for calendar_event.
2109       * Event's type can be determine by the available value store in $data
2110       * It is important to check for the existence of course/courseid to determine
2111       * the course event.
2112       * Default value is set to CONTEXT_USER
2113       *
2114       * @param stdClass $data information about event
2115       * @return stdClass The context object.
2116       */
2117      protected function calculate_context(stdClass $data) {
2118          global $USER, $DB;
2119  
2120          $context = null;
2121          if (isset($data->courseid) && $data->courseid > 0) {
2122              $context =  context_course::instance($data->courseid);
2123          } else if (isset($data->course) && $data->course > 0) {
2124              $context =  context_course::instance($data->course);
2125          } else if (isset($data->groupid) && $data->groupid > 0) {
2126              $group = $DB->get_record('groups', array('id'=>$data->groupid));
2127              $context = context_course::instance($group->courseid);
2128          } else if (isset($data->userid) && $data->userid > 0 && $data->userid == $USER->id) {
2129              $context =  context_user::instance($data->userid);
2130          } else if (isset($data->userid) && $data->userid > 0 && $data->userid != $USER->id &&
2131                     isset($data->instance) && $data->instance > 0) {
2132              $cm = get_coursemodule_from_instance($data->modulename, $data->instance, 0, false, MUST_EXIST);
2133              $context =  context_course::instance($cm->course);
2134          } else {
2135              $context =  context_user::instance($data->userid);
2136          }
2137  
2138          return $context;
2139      }
2140  
2141      /**
2142       * Returns an array of editoroptions for this event: Called by __get
2143       * Please use $blah = $event->editoroptions;
2144       *
2145       * @return array event editor options
2146       */
2147      protected function get_editoroptions() {
2148          return $this->editoroptions;
2149      }
2150  
2151      /**
2152       * Returns an event description: Called by __get
2153       * Please use $blah = $event->description;
2154       *
2155       * @return string event description
2156       */
2157      protected function get_description() {
2158          global $CFG;
2159  
2160          require_once($CFG->libdir . '/filelib.php');
2161  
2162          if ($this->_description === null) {
2163              // Check if we have already resolved the context for this event
2164              if ($this->editorcontext === null) {
2165                  // Switch on the event type to decide upon the appropriate context
2166                  // to use for this event
2167                  $this->editorcontext = $this->properties->context;
2168                  if ($this->properties->eventtype != 'user' && $this->properties->eventtype != 'course'
2169                          && $this->properties->eventtype != 'site' && $this->properties->eventtype != 'group') {
2170                      return clean_text($this->properties->description, $this->properties->format);
2171                  }
2172              }
2173  
2174              // Work out the item id for the editor, if this is a repeated event then the files will
2175              // be associated with the original
2176              if (!empty($this->properties->repeatid) && $this->properties->repeatid > 0) {
2177                  $itemid = $this->properties->repeatid;
2178              } else {
2179                  $itemid = $this->properties->id;
2180              }
2181  
2182              // Convert file paths in the description so that things display correctly
2183              $this->_description = file_rewrite_pluginfile_urls($this->properties->description, 'pluginfile.php', $this->editorcontext->id, 'calendar', 'event_description', $itemid);
2184              // Clean the text so no nasties get through
2185              $this->_description = clean_text($this->_description, $this->properties->format);
2186          }
2187          // Finally return the description
2188          return $this->_description;
2189      }
2190  
2191      /**
2192       * Return the number of repeat events there are in this events series
2193       *
2194       * @return int number of event repeated
2195       */
2196      public function count_repeats() {
2197          global $DB;
2198          if (!empty($this->properties->repeatid)) {
2199              $this->properties->eventrepeats = $DB->count_records('event', array('repeatid'=>$this->properties->repeatid));
2200              // We don't want to count ourselves
2201              $this->properties->eventrepeats--;
2202          }
2203          return $this->properties->eventrepeats;
2204      }
2205  
2206      /**
2207       * Update or create an event within the database
2208       *
2209       * Pass in a object containing the event properties and this function will
2210       * insert it into the database and deal with any associated files
2211       *
2212       * @see self::create()
2213       * @see self::update()
2214       *
2215       * @param stdClass $data object of event
2216       * @param bool $checkcapability if moodle should check calendar managing capability or not
2217       * @return bool event updated
2218       */
2219      public function update($data, $checkcapability=true) {
2220          global $DB, $USER;
2221  
2222          foreach ($data as $key=>$value) {
2223              $this->properties->$key = $value;
2224          }
2225  
2226          $this->properties->timemodified = time();
2227          $usingeditor = (!empty($this->properties->description) && is_array($this->properties->description));
2228  
2229          // Prepare event data.
2230          $eventargs = array(
2231              'context' => $this->properties->context,
2232              'objectid' => $this->properties->id,
2233              'other' => array(
2234                  'repeatid' => empty($this->properties->repeatid) ? 0 : $this->properties->repeatid,
2235                  'timestart' => $this->properties->timestart,
2236                  'name' => $this->properties->name
2237              )
2238          );
2239  
2240          if (empty($this->properties->id) || $this->properties->id < 1) {
2241  
2242              if ($checkcapability) {
2243                  if (!calendar_add_event_allowed($this->properties)) {
2244                      print_error('nopermissiontoupdatecalendar');
2245                  }
2246              }
2247  
2248              if ($usingeditor) {
2249                  switch ($this->properties->eventtype) {
2250                      case 'user':
2251                          $this->properties->courseid = 0;
2252                          $this->properties->course = 0;
2253                          $this->properties->groupid = 0;
2254                          $this->properties->userid = $USER->id;
2255                          break;
2256                      case 'site':
2257                          $this->properties->courseid = SITEID;
2258                          $this->properties->course = SITEID;
2259                          $this->properties->groupid = 0;
2260                          $this->properties->userid = $USER->id;
2261                          break;
2262                      case 'course':
2263                          $this->properties->groupid = 0;
2264                          $this->properties->userid = $USER->id;
2265                          break;
2266                      case 'group':
2267                          $this->properties->userid = $USER->id;
2268                          break;
2269                      default:
2270                          // Ewww we should NEVER get here, but just incase we do lets
2271                          // fail gracefully
2272                          $usingeditor = false;
2273                          break;
2274                  }
2275  
2276                  // If we are actually using the editor, we recalculate the context because some default values
2277                  // were set when calculate_context() was called from the constructor.
2278                  if ($usingeditor) {
2279                      $this->properties->context = $this->calculate_context($this->properties);
2280                      $this->editorcontext = $this->properties->context;
2281                  }
2282  
2283                  $editor = $this->properties->description;
2284                  $this->properties->format = $this->properties->description['format'];
2285                  $this->properties->description = $this->properties->description['text'];
2286              }
2287  
2288              // Insert the event into the database
2289              $this->properties->id = $DB->insert_record('event', $this->properties);
2290  
2291              if ($usingeditor) {
2292                  $this->properties->description = file_save_draft_area_files(
2293                                                  $editor['itemid'],
2294                                                  $this->editorcontext->id,
2295                                                  'calendar',
2296                                                  'event_description',
2297                                                  $this->properties->id,
2298                                                  $this->editoroptions,
2299                                                  $editor['text'],
2300                                                  $this->editoroptions['forcehttps']);
2301                  $DB->set_field('event', 'description', $this->properties->description, array('id'=>$this->properties->id));
2302              }
2303  
2304              // Log the event entry.
2305              $eventargs['objectid'] = $this->properties->id;
2306              $eventargs['context'] = $this->properties->context;
2307              $event = \core\event\calendar_event_created::create($eventargs);
2308              $event->trigger();
2309  
2310              $repeatedids = array();
2311  
2312              if (!empty($this->properties->repeat)) {
2313                  $this->properties->repeatid = $this->properties->id;
2314                  $DB->set_field('event', 'repeatid', $this->properties->repeatid, array('id'=>$this->properties->id));
2315  
2316                  $eventcopy = clone($this->properties);
2317                  unset($eventcopy->id);
2318  
2319                  $timestart = new DateTime('@' . $eventcopy->timestart);
2320                  $timestart->setTimezone(core_date::get_user_timezone_object());
2321  
2322                  for($i = 1; $i < $eventcopy->repeats; $i++) {
2323  
2324                      $timestart->add(new DateInterval('P7D'));
2325                      $eventcopy->timestart = $timestart->getTimestamp();
2326  
2327                      // Get the event id for the log record.
2328                      $eventcopyid = $DB->insert_record('event', $eventcopy);
2329  
2330                      // If the context has been set delete all associated files
2331                      if ($usingeditor) {
2332                          $fs = get_file_storage();
2333                          $files = $fs->get_area_files($this->editorcontext->id, 'calendar', 'event_description', $this->properties->id);
2334                          foreach ($files as $file) {
2335                              $fs->create_file_from_storedfile(array('itemid'=>$eventcopyid), $file);
2336                          }
2337                      }
2338  
2339                      $repeatedids[] = $eventcopyid;
2340  
2341                      // Trigger an event.
2342                      $eventargs['objectid'] = $eventcopyid;
2343                      $eventargs['other']['timestart'] = $eventcopy->timestart;
2344                      $event = \core\event\calendar_event_created::create($eventargs);
2345                      $event->trigger();
2346                  }
2347              }
2348  
2349              // Hook for tracking added events
2350              self::calendar_event_hook('add_event', array($this->properties, $repeatedids));
2351              return true;
2352          } else {
2353  
2354              if ($checkcapability) {
2355                  if(!calendar_edit_event_allowed($this->properties)) {
2356                      print_error('nopermissiontoupdatecalendar');
2357                  }
2358              }
2359  
2360              if ($usingeditor) {
2361                  if ($this->editorcontext !== null) {
2362                      $this->properties->description = file_save_draft_area_files(
2363                                                      $this->properties->description['itemid'],
2364                                                      $this->editorcontext->id,
2365                                                      'calendar',
2366                                                      'event_description',
2367                                                      $this->properties->id,
2368                                                      $this->editoroptions,
2369                                                      $this->properties->description['text'],
2370                                                      $this->editoroptions['forcehttps']);
2371                  } else {
2372                      $this->properties->format = $this->properties->description['format'];
2373                      $this->properties->description = $this->properties->description['text'];
2374                  }
2375              }
2376  
2377              $event = $DB->get_record('event', array('id'=>$this->properties->id));
2378  
2379              $updaterepeated = (!empty($this->properties->repeatid) && !empty($this->properties->repeateditall));
2380  
2381              if ($updaterepeated) {
2382                  // Update all
2383                  if ($this->properties->timestart != $event->timestart) {
2384                      $timestartoffset = $this->properties->timestart - $event->timestart;
2385                      $sql = "UPDATE {event}
2386                                 SET name = ?,
2387                                     description = ?,
2388                                     timestart = timestart + ?,
2389                                     timeduration = ?,
2390                                     timemodified = ?
2391                               WHERE repeatid = ?";
2392                      $params = array($this->properties->name, $this->properties->description, $timestartoffset, $this->properties->timeduration, time(), $event->repeatid);
2393                  } else {
2394                      $sql = "UPDATE {event} SET name = ?, description = ?, timeduration = ?, timemodified = ? WHERE repeatid = ?";
2395                      $params = array($this->properties->name, $this->properties->description, $this->properties->timeduration, time(), $event->repeatid);
2396                  }
2397                  $DB->execute($sql, $params);
2398  
2399                  // Trigger an update event for each of the calendar event.
2400                  $events = $DB->get_records('event', array('repeatid' => $event->repeatid), '', 'id,timestart');
2401                  foreach ($events as $event) {
2402                      $eventargs['objectid'] = $event->id;
2403                      $eventargs['other']['timestart'] = $event->timestart;
2404                      $event = \core\event\calendar_event_updated::create($eventargs);
2405                      $event->trigger();
2406                  }
2407              } else {
2408                  $DB->update_record('event', $this->properties);
2409                  $event = calendar_event::load($this->properties->id);
2410                  $this->properties = $event->properties();
2411  
2412                  // Trigger an update event.
2413                  $event = \core\event\calendar_event_updated::create($eventargs);
2414                  $event->trigger();
2415              }
2416  
2417              // Hook for tracking event updates
2418              self::calendar_event_hook('update_event', array($this->properties, $updaterepeated));
2419              return true;
2420          }
2421      }
2422  
2423      /**
2424       * Deletes an event and if selected an repeated events in the same series
2425       *
2426       * This function deletes an event, any associated events if $deleterepeated=true,
2427       * and cleans up any files associated with the events.
2428       *
2429       * @see self::delete()
2430       *
2431       * @param bool $deleterepeated  delete event repeatedly
2432       * @return bool succession of deleting event
2433       */
2434      public function delete($deleterepeated=false) {
2435          global $DB;
2436  
2437          // If $this->properties->id is not set then something is wrong
2438          if (empty($this->properties->id)) {
2439              debugging('Attempting to delete an event before it has been loaded', DEBUG_DEVELOPER);
2440              return false;
2441          }
2442          $calevent = $DB->get_record('event',  array('id' => $this->properties->id), '*', MUST_EXIST);
2443          // Delete the event
2444          $DB->delete_records('event', array('id'=>$this->properties->id));
2445  
2446          // Trigger an event for the delete action.
2447          $eventargs = array(
2448              'context' => $this->properties->context,
2449              'objectid' => $this->properties->id,
2450              'other' => array(
2451                  'repeatid' => empty($this->properties->repeatid) ? 0 : $this->properties->repeatid,
2452                  'timestart' => $this->properties->timestart,
2453                  'name' => $this->properties->name
2454              ));
2455          $event = \core\event\calendar_event_deleted::create($eventargs);
2456          $event->add_record_snapshot('event', $calevent);
2457          $event->trigger();
2458  
2459          // If we are deleting parent of a repeated event series, promote the next event in the series as parent
2460          if (($this->properties->id == $this->properties->repeatid) && !$deleterepeated) {
2461              $newparent = $DB->get_field_sql("SELECT id from {event} where repeatid = ? order by id ASC", array($this->properties->id), IGNORE_MULTIPLE);
2462              if (!empty($newparent)) {
2463                  $DB->execute("UPDATE {event} SET repeatid = ? WHERE repeatid = ?", array($newparent, $this->properties->id));
2464                  // Get all records where the repeatid is the same as the event being removed
2465                  $events = $DB->get_records('event', array('repeatid' => $newparent));
2466                  // For each of the returned events trigger the event_update hook and an update event.
2467                  foreach ($events as $event) {
2468                      // Trigger an event for the update.
2469                      $eventargs['objectid'] = $event->id;
2470                      $eventargs['other']['timestart'] = $event->timestart;
2471                      $event = \core\event\calendar_event_updated::create($eventargs);
2472                      $event->trigger();
2473  
2474                      self::calendar_event_hook('update_event', array($event, false));
2475                  }
2476              }
2477          }
2478  
2479          // If the editor context hasn't already been set then set it now
2480          if ($this->editorcontext === null) {
2481              $this->editorcontext = $this->properties->context;
2482          }
2483  
2484          // If the context has been set delete all associated files
2485          if ($this->editorcontext !== null) {
2486              $fs = get_file_storage();
2487              $files = $fs->get_area_files($this->editorcontext->id, 'calendar', 'event_description', $this->properties->id);
2488              foreach ($files as $file) {
2489                  $file->delete();
2490              }
2491          }
2492  
2493          // Fire the event deleted hook
2494          self::calendar_event_hook('delete_event', array($this->properties->id, $deleterepeated));
2495  
2496          // If we need to delete repeated events then we will fetch them all and delete one by one
2497          if ($deleterepeated && !empty($this->properties->repeatid) && $this->properties->repeatid > 0) {
2498              // Get all records where the repeatid is the same as the event being removed
2499              $events = $DB->get_records('event', array('repeatid'=>$this->properties->repeatid));
2500              // For each of the returned events populate a calendar_event object and call delete
2501              // make sure the arg passed is false as we are already deleting all repeats
2502              foreach ($events as $event) {
2503                  $event = new calendar_event($event);
2504                  $event->delete(false);
2505              }
2506          }
2507  
2508          return true;
2509      }
2510  
2511      /**
2512       * Fetch all event properties
2513       *
2514       * This function returns all of the events properties as an object and optionally
2515       * can prepare an editor for the description field at the same time. This is
2516       * designed to work when the properties are going to be used to set the default
2517       * values of a moodle forms form.
2518       *
2519       * @param bool $prepareeditor If set to true a editor is prepared for use with
2520       *              the mforms editor element. (for description)
2521       * @return stdClass Object containing event properties
2522       */
2523      public function properties($prepareeditor=false) {
2524          global $USER, $CFG, $DB;
2525  
2526          // First take a copy of the properties. We don't want to actually change the
2527          // properties or we'd forever be converting back and forwards between an
2528          // editor formatted description and not
2529          $properties = clone($this->properties);
2530          // Clean the description here
2531          $properties->description = clean_text($properties->description, $properties->format);
2532  
2533          // If set to true we need to prepare the properties for use with an editor
2534          // and prepare the file area
2535          if ($prepareeditor) {
2536  
2537              // We may or may not have a property id. If we do then we need to work
2538              // out the context so we can copy the existing files to the draft area
2539              if (!empty($properties->id)) {
2540  
2541                  if ($properties->eventtype === 'site') {
2542                      // Site context
2543                      $this->editorcontext = $this->properties->context;
2544                  } else if ($properties->eventtype === 'user') {
2545                      // User context
2546                      $this->editorcontext = $this->properties->context;
2547                  } else if ($properties->eventtype === 'group' || $properties->eventtype === 'course') {
2548                      // First check the course is valid
2549                      $course = $DB->get_record('course', array('id'=>$properties->courseid));
2550                      if (!$course) {
2551                          print_error('invalidcourse');
2552                      }
2553                      // Course context
2554                      $this->editorcontext = $this->properties->context;
2555                      // We have a course and are within the course context so we had
2556                      // better use the courses max bytes value
2557                      $this->editoroptions['maxbytes'] = $course->maxbytes;
2558                  } else {
2559                      // If we get here we have a custom event type as used by some
2560                      // modules. In this case the event will have been added by
2561                      // code and we won't need the editor
2562                      $this->editoroptions['maxbytes'] = 0;
2563                      $this->editoroptions['maxfiles'] = 0;
2564                  }
2565  
2566                  if (empty($this->editorcontext) || empty($this->editorcontext->id)) {
2567                      $contextid = false;
2568                  } else {
2569                      // Get the context id that is what we really want
2570                      $contextid = $this->editorcontext->id;
2571                  }
2572              } else {
2573  
2574                  // If we get here then this is a new event in which case we don't need a
2575                  // context as there is no existing files to copy to the draft area.
2576                  $contextid = null;
2577              }
2578  
2579              // If the contextid === false we don't support files so no preparing
2580              // a draft area
2581              if ($contextid !== false) {
2582                  // Just encase it has already been submitted
2583                  $draftiddescription = file_get_submitted_draft_itemid('description');
2584                  // Prepare the draft area, this copies existing files to the draft area as well
2585                  $properties->description = file_prepare_draft_area($draftiddescription, $contextid, 'calendar', 'event_description', $properties->id, $this->editoroptions, $properties->description);
2586              } else {
2587                  $draftiddescription = 0;
2588              }
2589  
2590              // Structure the description field as the editor requires
2591              $properties->description = array('text'=>$properties->description, 'format'=>$properties->format, 'itemid'=>$draftiddescription);
2592          }
2593  
2594          // Finally return the properties
2595          return $properties;
2596      }
2597  
2598      /**
2599       * Toggles the visibility of an event
2600       *
2601       * @param null|bool $force If it is left null the events visibility is flipped,
2602       *                   If it is false the event is made hidden, if it is true it
2603       *                   is made visible.
2604       * @return bool if event is successfully updated, toggle will be visible
2605       */
2606      public function toggle_visibility($force=null) {
2607          global $CFG, $DB;
2608  
2609          // Set visible to the default if it is not already set
2610          if (empty($this->properties->visible)) {
2611              $this->properties->visible = 1;
2612          }
2613  
2614          if ($force === true || ($force !== false && $this->properties->visible == 0)) {
2615              // Make this event visible
2616              $this->properties->visible = 1;
2617              // Fire the hook
2618              self::calendar_event_hook('show_event', array($this->properties));
2619          } else {
2620              // Make this event hidden
2621              $this->properties->visible = 0;
2622              // Fire the hook
2623              self::calendar_event_hook('hide_event', array($this->properties));
2624          }
2625  
2626          // Update the database to reflect this change
2627          return $DB->set_field('event', 'visible', $this->properties->visible, array('id'=>$this->properties->id));
2628      }
2629  
2630      /**
2631       * Attempts to call the hook for the specified action should a calendar type
2632       * by set $CFG->calendar, and the appopriate function defined
2633       *
2634       * @param string $action One of `update_event`, `add_event`, `delete_event`, `show_event`, `hide_event`
2635       * @param array $args The args to pass to the hook, usually the event is the first element
2636       * @return bool attempts to call event hook
2637       */
2638      public static function calendar_event_hook($action, array $args) {
2639          global $CFG;
2640          static $extcalendarinc;
2641          if ($extcalendarinc === null) {
2642              if (!empty($CFG->calendar)) {
2643                  if (is_readable($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php')) {
2644                      include_once($CFG->dirroot .'/calendar/'. $CFG->calendar .'/lib.php');
2645                      $extcalendarinc = true;
2646                  } else {
2647                      debugging("Calendar lib file missing or not readable at /calendar/{$CFG->calendar}/lib.php.",
2648                          DEBUG_DEVELOPER);
2649                      $extcalendarinc = false;
2650                  }
2651              } else {
2652                  $extcalendarinc = false;
2653              }
2654          }
2655          if($extcalendarinc === false) {
2656              return false;
2657          }
2658          $hook = $CFG->calendar .'_'.$action;
2659          if (function_exists($hook)) {
2660              call_user_func_array($hook, $args);
2661              return true;
2662          }
2663          return false;
2664      }
2665  
2666      /**
2667       * Returns a calendar_event object when provided with an event id
2668       *
2669       * This function makes use of MUST_EXIST, if the event id passed in is invalid
2670       * it will result in an exception being thrown
2671       *
2672       * @param int|object $param event object or event id
2673       * @return calendar_event|false status for loading calendar_event
2674       */
2675      public static function load($param) {
2676          global $DB;
2677          if (is_object($param)) {
2678              $event = new calendar_event($param);
2679          } else {
2680              $event = $DB->get_record('event', array('id'=>(int)$param), '*', MUST_EXIST);
2681              $event = new calendar_event($event);
2682          }
2683          return $event;
2684      }
2685  
2686      /**
2687       * Creates a new event and returns a calendar_event object
2688       *
2689       * @param stdClass|array $properties An object containing event properties
2690       * @param bool $checkcapability Check caps or not
2691       * @throws coding_exception
2692       *
2693       * @return calendar_event|bool The event object or false if it failed
2694       */
2695      public static function create($properties, $checkcapability = true) {
2696          if (is_array($properties)) {
2697              $properties = (object)$properties;
2698          }
2699          if (!is_object($properties)) {
2700              throw new coding_exception('When creating an event properties should be either an object or an assoc array');
2701          }
2702          $event = new calendar_event($properties);
2703          if ($event->update($properties, $checkcapability)) {
2704              return $event;
2705          } else {
2706              return false;
2707          }
2708      }
2709  
2710      /**
2711       * Format the text using the external API.
2712       * This function should we used when text formatting is required in external functions.
2713       *
2714       * @return array an array containing the text formatted and the text format
2715       */
2716      public function format_external_text() {
2717  
2718          if ($this->editorcontext === null) {
2719              // Switch on the event type to decide upon the appropriate context to use for this event.
2720              $this->editorcontext = $this->properties->context;
2721  
2722              if ($this->properties->eventtype != 'user' && $this->properties->eventtype != 'course'
2723                      && $this->properties->eventtype != 'site' && $this->properties->eventtype != 'group') {
2724                  // We don't have a context here, do a normal format_text.
2725                  return external_format_text($this->properties->description, $this->properties->format, $this->editorcontext->id);
2726              }
2727          }
2728  
2729          // Work out the item id for the editor, if this is a repeated event then the files will be associated with the original.
2730          if (!empty($this->properties->repeatid) && $this->properties->repeatid > 0) {
2731              $itemid = $this->properties->repeatid;
2732          } else {
2733              $itemid = $this->properties->id;
2734          }
2735  
2736          return external_format_text($this->properties->description, $this->properties->format, $this->editorcontext->id,
2737                                      'calendar', 'event_description', $itemid);
2738      }
2739  }
2740  
2741  /**
2742   * Calendar information class
2743   *
2744   * This class is used simply to organise the information pertaining to a calendar
2745   * and is used primarily to make information easily available.
2746   *
2747   * @package core_calendar
2748   * @category calendar
2749   * @copyright 2010 Sam Hemelryk
2750   * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
2751   */
2752  class calendar_information {
2753  
2754      /**
2755       * @var int The timestamp
2756       *
2757       * Rather than setting the day, month and year we will set a timestamp which will be able
2758       * to be used by multiple calendars.
2759       */
2760      public $time;
2761  
2762      /** @var int A course id */
2763      public $courseid = null;
2764  
2765      /** @var array An array of courses */
2766      public $courses = array();
2767  
2768      /** @var array An array of groups */
2769      public $groups = array();
2770  
2771      /** @var array An array of users */
2772      public $users = array();
2773  
2774      /**
2775       * Creates a new instance
2776       *
2777       * @param int $day the number of the day
2778       * @param int $month the number of the month
2779       * @param int $year the number of the year
2780       * @param int $time the unixtimestamp representing the date we want to view, this is used instead of $calmonth
2781       *     and $calyear to support multiple calendars
2782       */
2783      public function __construct($day = 0, $month = 0, $year = 0, $time = 0) {
2784          // If a day, month and year were passed then convert it to a timestamp. If these were passed
2785          // then we can assume the day, month and year are passed as Gregorian, as no where in core
2786          // should we be passing these values rather than the time. This is done for BC.
2787          if (!empty($day) || !empty($month) || !empty($year)) {
2788              $date = usergetdate(time());
2789              if (empty($day)) {
2790                  $day = $date['mday'];
2791              }
2792              if (empty($month)) {
2793                  $month = $date['mon'];
2794              }
2795              if (empty($year)) {
2796                  $year =  $date['year'];
2797              }
2798              if (checkdate($month, $day, $year)) {
2799                  $this->time = make_timestamp($year, $month, $day);
2800              } else {
2801                  $this->time = time();
2802              }
2803          } else if (!empty($time)) {
2804              $this->time = $time;
2805          } else {
2806              $this->time = time();
2807          }
2808      }
2809  
2810      /**
2811       * Initialize calendar information
2812       *
2813       * @param stdClass $course object
2814       * @param array $coursestoload An array of courses [$course->id => $course]
2815       * @param bool $ignorefilters options to use filter
2816       */
2817      public function prepare_for_view(stdClass $course, array $coursestoload, $ignorefilters = false) {
2818          $this->courseid = $course->id;
2819          $this->course = $course;
2820          list($courses, $group, $user) = calendar_set_filters($coursestoload, $ignorefilters);
2821          $this->courses = $courses;
2822          $this->groups = $group;
2823          $this->users = $user;
2824      }
2825  
2826      /**
2827       * Ensures the date for the calendar is correct and either sets it to now
2828       * or throws a moodle_exception if not
2829       *
2830       * @param bool $defaultonow use current time
2831       * @throws moodle_exception
2832       * @return bool validation of checkdate
2833       */
2834      public function checkdate($defaultonow = true) {
2835          if (!checkdate($this->month, $this->day, $this->year)) {
2836              if ($defaultonow) {
2837                  $now = usergetdate(time());
2838                  $this->day = intval($now['mday']);
2839                  $this->month = intval($now['mon']);
2840                  $this->year = intval($now['year']);
2841                  return true;
2842              } else {
2843                  throw new moodle_exception('invaliddate');
2844              }
2845          }
2846          return true;
2847      }
2848  
2849      /**
2850       * Gets todays timestamp for the calendar
2851       *
2852       * @return int today timestamp
2853       */
2854      public function timestamp_today() {
2855          return $this->time;
2856      }
2857      /**
2858       * Gets tomorrows timestamp for the calendar
2859       *
2860       * @return int tomorrow timestamp
2861       */
2862      public function timestamp_tomorrow() {
2863          return strtotime('+1 day', $this->time);
2864      }
2865      /**
2866       * Adds the pretend blocks for the calendar
2867       *
2868       * @param core_calendar_renderer $renderer
2869       * @param bool $showfilters display filters, false is set as default
2870       * @param string|null $view preference view options (eg: day, month, upcoming)
2871       */
2872      public function add_sidecalendar_blocks(core_calendar_renderer $renderer, $showfilters=false, $view=null) {
2873          if ($showfilters) {
2874              $filters = new block_contents();
2875              $filters->content = $renderer->fake_block_filters($this->courseid, 0, 0, 0, $view, $this->courses);
2876              $filters->footer = '';
2877              $filters->title = get_string('eventskey', 'calendar');
2878              $renderer->add_pretend_calendar_block($filters, BLOCK_POS_RIGHT);
2879          }
2880          $block = new block_contents;
2881          $block->content = $renderer->fake_block_threemonths($this);
2882          $block->footer = '';
2883          $block->title = get_string('monthlyview', 'calendar');
2884          $renderer->add_pretend_calendar_block($block, BLOCK_POS_RIGHT);
2885      }
2886  }
2887  
2888  /**
2889   * Returns option list for the poll interval setting.
2890   *
2891   * @return array An array of poll interval options. Interval => description.
2892   */
2893  function calendar_get_pollinterval_choices() {
2894      return array(
2895          '0' => new lang_string('never', 'calendar'),
2896          HOURSECS => new lang_string('hourly', 'calendar'),
2897          DAYSECS => new lang_string('daily', 'calendar'),
2898          WEEKSECS => new lang_string('weekly', 'calendar'),
2899          '2628000' => new lang_string('monthly', 'calendar'),
2900          YEARSECS => new lang_string('annually', 'calendar')
2901      );
2902  }
2903  
2904  /**
2905   * Returns option list of available options for the calendar event type, given the current user and course.
2906   *
2907   * @param int $courseid The id of the course
2908   * @return array An array containing the event types the user can create.
2909   */
2910  function calendar_get_eventtype_choices($courseid) {
2911      $choices = array();
2912      $allowed = new stdClass;
2913      calendar_get_allowed_types($allowed, $courseid);
2914  
2915      if ($allowed->user) {
2916          $choices['user'] = get_string('userevents', 'calendar');
2917      }
2918      if ($allowed->site) {
2919          $choices['site'] = get_string('siteevents', 'calendar');
2920      }
2921      if (!empty($allowed->courses)) {
2922          $choices['course'] = get_string('courseevents', 'calendar');
2923      }
2924      if (!empty($allowed->groups) and is_array($allowed->groups)) {
2925          $choices['group'] = get_string('group');
2926      }
2927  
2928      return array($choices, $allowed->groups);
2929  }
2930  
2931  /**
2932   * Add an iCalendar subscription to the database.
2933   *
2934   * @param stdClass $sub The subscription object (e.g. from the form)
2935   * @return int The insert ID, if any.
2936   */
2937  function calendar_add_subscription($sub) {
2938      global $DB, $USER, $SITE;
2939  
2940      if ($sub->eventtype === 'site') {
2941          $sub->courseid = $SITE->id;
2942      } else if ($sub->eventtype === 'group' || $sub->eventtype === 'course') {
2943          $sub->courseid = $sub->course;
2944      } else {
2945          // User events.
2946          $sub->courseid = 0;
2947      }
2948      $sub->userid = $USER->id;
2949  
2950      // File subscriptions never update.
2951      if (empty($sub->url)) {
2952          $sub->pollinterval = 0;
2953      }
2954  
2955      if (!empty($sub->name)) {
2956          if (empty($sub->id)) {
2957              $id = $DB->insert_record('event_subscriptions', $sub);
2958              // we cannot cache the data here because $sub is not complete.
2959              $sub->id = $id;
2960              // Trigger event, calendar subscription added.
2961              $eventparams = array('objectid' => $sub->id,
2962                  'context' => calendar_get_calendar_context($sub),
2963                  'other' => array('eventtype' => $sub->eventtype, 'courseid' => $sub->courseid)
2964              );
2965              $event = \core\event\calendar_subscription_created::create($eventparams);
2966              $event->trigger();
2967              return $id;
2968          } else {
2969              // Why are we doing an update here?
2970              calendar_update_subscription($sub);
2971              return $sub->id;
2972          }
2973      } else {
2974          print_error('errorbadsubscription', 'importcalendar');
2975      }
2976  }
2977  
2978  /**
2979   * Add an iCalendar event to the Moodle calendar.
2980   *
2981   * @param stdClass $event The RFC-2445 iCalendar event
2982   * @param int $courseid The course ID
2983   * @param int $subscriptionid The iCalendar subscription ID
2984   * @param string $timezone The X-WR-TIMEZONE iCalendar property if provided
2985   * @throws dml_exception A DML specific exception is thrown for invalid subscriptionids.
2986   * @return int Code: CALENDAR_IMPORT_EVENT_UPDATED = updated,  CALENDAR_IMPORT_EVENT_INSERTED = inserted, 0 = error
2987   */
2988  function calendar_add_icalendar_event($event, $courseid, $subscriptionid, $timezone='UTC') {
2989      global $DB;
2990  
2991      // Probably an unsupported X-MICROSOFT-CDO-BUSYSTATUS event.
2992      if (empty($event->properties['SUMMARY'])) {
2993          return 0;
2994      }
2995  
2996      $name = $event->properties['SUMMARY'][0]->value;
2997      $name = str_replace('\n', '<br />', $name);
2998      $name = str_replace('\\', '', $name);
2999      $name = preg_replace('/\s+/u', ' ', $name);
3000  
3001      $eventrecord = new stdClass;
3002      $eventrecord->name = clean_param($name, PARAM_NOTAGS);
3003  
3004      if (empty($event->properties['DESCRIPTION'][0]->value)) {
3005          $description = '';
3006      } else {
3007          $description = $event->properties['DESCRIPTION'][0]->value;
3008          $description = clean_param($description, PARAM_NOTAGS);
3009          $description = str_replace('\n', '<br />', $description);
3010          $description = str_replace('\\', '', $description);
3011          $description = preg_replace('/\s+/u', ' ', $description);
3012      }
3013      $eventrecord->description = $description;
3014  
3015      // Probably a repeating event with RRULE etc. TODO: skip for now.
3016      if (empty($event->properties['DTSTART'][0]->value)) {
3017          return 0;
3018      }
3019  
3020      $tz = isset($event->properties['DTSTART'][0]->parameters['TZID']) ? $event->properties['DTSTART'][0]->parameters['TZID'] :
3021              $timezone;
3022      $tz = core_date::normalise_timezone($tz);
3023      $eventrecord->timestart = strtotime($event->properties['DTSTART'][0]->value . ' ' . $tz);
3024      if (empty($event->properties['DTEND'])) {
3025          $eventrecord->timeduration = 0; // no duration if no end time specified
3026      } else {
3027          $endtz = isset($event->properties['DTEND'][0]->parameters['TZID']) ? $event->properties['DTEND'][0]->parameters['TZID'] :
3028                  $timezone;
3029          $endtz = core_date::normalise_timezone($endtz);
3030          $eventrecord->timeduration = strtotime($event->properties['DTEND'][0]->value . ' ' . $endtz) - $eventrecord->timestart;
3031      }
3032  
3033      // Check to see if it should be treated as an all day event.
3034      if ($eventrecord->timeduration == DAYSECS) {
3035          // Check to see if the event started at Midnight on the imported calendar.
3036          date_default_timezone_set($timezone);
3037          if (date('H:i:s', $eventrecord->timestart) === "00:00:00") {
3038              // This event should be an all day event.
3039              $eventrecord->timeduration = 0;
3040          }
3041          core_date::set_default_server_timezone();
3042      }
3043  
3044      $eventrecord->uuid = $event->properties['UID'][0]->value;
3045      $eventrecord->timemodified = time();
3046  
3047      // Add the iCal subscription details if required.
3048      // We should never do anything with an event without a subscription reference.
3049      $sub = calendar_get_subscription($subscriptionid);
3050      $eventrecord->subscriptionid = $subscriptionid;
3051      $eventrecord->userid = $sub->userid;
3052      $eventrecord->groupid = $sub->groupid;
3053      $eventrecord->courseid = $sub->courseid;
3054      $eventrecord->eventtype = $sub->eventtype;
3055  
3056      if ($updaterecord = $DB->get_record('event', array('uuid' => $eventrecord->uuid))) {
3057          $eventrecord->id = $updaterecord->id;
3058          $return = CALENDAR_IMPORT_EVENT_UPDATED; // Update.
3059      } else {
3060          $return = CALENDAR_IMPORT_EVENT_INSERTED; // Insert.
3061      }
3062      if ($createdevent = calendar_event::create($eventrecord, false)) {
3063          if (!empty($event->properties['RRULE'])) {
3064              // Repeating events.
3065              date_default_timezone_set($tz); // Change time zone to parse all events.
3066              $rrule = new \core_calendar\rrule_manager($event->properties['RRULE'][0]->value);
3067              $rrule->parse_rrule();
3068              $rrule->create_events($createdevent);
3069              core_date::set_default_server_timezone(); // Change time zone back to what it was.
3070          }
3071          return $return;
3072      } else {
3073          return 0;
3074      }
3075  }
3076  
3077  /**
3078   * Update a subscription from the form data in one of the rows in the existing subscriptions table.
3079   *
3080   * @param int $subscriptionid The ID of the subscription we are acting upon.
3081   * @param int $pollinterval The poll interval to use.
3082   * @param int $action The action to be performed. One of update or remove.
3083   * @throws dml_exception if invalid subscriptionid is provided
3084   * @return string A log of the import progress, including errors
3085   */
3086  function calendar_process_subscription_row($subscriptionid, $pollinterval, $action) {
3087  
3088      // Fetch the subscription from the database making sure it exists.
3089      $sub = calendar_get_subscription($subscriptionid);
3090  
3091      // Update or remove the subscription, based on action.
3092      switch ($action) {
3093          case CALENDAR_SUBSCRIPTION_UPDATE:
3094              // Skip updating file subscriptions.
3095              if (empty($sub->url)) {
3096                  break;
3097              }
3098              $sub->pollinterval = $pollinterval;
3099              calendar_update_subscription($sub);
3100  
3101              // Update the events.
3102              return "<p>".get_string('subscriptionupdated', 'calendar', $sub->name)."</p>" . calendar_update_subscription_events($subscriptionid);
3103  
3104          case CALENDAR_SUBSCRIPTION_REMOVE:
3105              calendar_delete_subscription($subscriptionid);
3106              return get_string('subscriptionremoved', 'calendar', $sub->name);
3107              break;
3108  
3109          default:
3110              break;
3111      }
3112      return '';
3113  }
3114  
3115  /**
3116   * Delete subscription and all related events.
3117   *
3118   * @param int|stdClass $subscription subscription or it's id, which needs to be deleted.
3119   */
3120  function calendar_delete_subscription($subscription) {
3121      global $DB;
3122  
3123      if (!is_object($subscription)) {
3124          $subscription = $DB->get_record('event_subscriptions', array('id' => $subscription), '*', MUST_EXIST);
3125      }
3126      // Delete subscription and related events.
3127      $DB->delete_records('event', array('subscriptionid' => $subscription->id));
3128      $DB->delete_records('event_subscriptions', array('id' => $subscription->id));
3129      cache_helper::invalidate_by_definition('core', 'calendar_subscriptions', array(), array($subscription->id));
3130  
3131      // Trigger event, calendar subscription deleted.
3132      $eventparams = array('objectid' => $subscription->id,
3133          'context' => calendar_get_calendar_context($subscription),
3134          'other' => array('courseid' => $subscription->courseid)
3135      );
3136      $event = \core\event\calendar_subscription_deleted::create($eventparams);
3137      $event->trigger();
3138  }
3139  /**
3140   * From a URL, fetch the calendar and return an iCalendar object.
3141   *
3142   * @param string $url The iCalendar URL
3143   * @return stdClass The iCalendar object
3144   */
3145  function calendar_get_icalendar($url) {
3146      global $CFG;
3147  
3148      require_once($CFG->libdir.'/filelib.php');
3149  
3150      $curl = new curl();
3151      $curl->setopt(array('CURLOPT_FOLLOWLOCATION' => 1, 'CURLOPT_MAXREDIRS' => 5));
3152      $calendar = $curl->get($url);
3153      // Http code validation should actually be the job of curl class.
3154      if (!$calendar || $curl->info['http_code'] != 200 || !empty($curl->errorno)) {
3155          throw new moodle_exception('errorinvalidicalurl', 'calendar');
3156      }
3157  
3158      $ical = new iCalendar();
3159      $ical->unserialize($calendar);
3160      return $ical;
3161  }
3162  
3163  /**
3164   * Import events from an iCalendar object into a course calendar.
3165   *
3166   * @param stdClass $ical The iCalendar object.
3167   * @param int $courseid The course ID for the calendar.
3168   * @param int $subscriptionid The subscription ID.
3169   * @return string A log of the import progress, including errors.
3170   */
3171  function calendar_import_icalendar_events($ical, $courseid, $subscriptionid = null) {
3172      global $DB;
3173      $return = '';
3174      $eventcount = 0;
3175      $updatecount = 0;
3176  
3177      // Large calendars take a while...
3178      if (!CLI_SCRIPT) {
3179          core_php_time_limit::raise(300);
3180      }
3181  
3182      // Mark all events in a subscription with a zero timestamp.
3183      if (!empty($subscriptionid)) {
3184          $sql = "UPDATE {event} SET timemodified = :time WHERE subscriptionid = :id";
3185          $DB->execute($sql, array('time' => 0, 'id' => $subscriptionid));
3186      }
3187      // Grab the timezone from the iCalendar file to be used later.
3188      if (isset($ical->properties['X-WR-TIMEZONE'][0]->value)) {
3189          $timezone = $ical->properties['X-WR-TIMEZONE'][0]->value;
3190      } else {
3191          $timezone = 'UTC';
3192      }
3193      foreach ($ical->components['VEVENT'] as $event) {
3194          $res = calendar_add_icalendar_event($event, $courseid, $subscriptionid, $timezone);
3195          switch ($res) {
3196            case CALENDAR_IMPORT_EVENT_UPDATED:
3197              $updatecount++;
3198              break;
3199            case CALENDAR_IMPORT_EVENT_INSERTED:
3200              $eventcount++;
3201              break;
3202            case 0:
3203              $return .= '<p>'.get_string('erroraddingevent', 'calendar').': '.(empty($event->properties['SUMMARY'])?'('.get_string('notitle', 'calendar').')':$event->properties['SUMMARY'][0]->value)." </p>\n";
3204              break;
3205          }
3206      }
3207      $return .= "<p> ".get_string('eventsimported', 'calendar', $eventcount)."</p>";
3208      $return .= "<p> ".get_string('eventsupdated', 'calendar', $updatecount)."</p>";
3209  
3210      // Delete remaining zero-marked events since they're not in remote calendar.
3211      if (!empty($subscriptionid)) {
3212          $deletecount = $DB->count_records('event', array('timemodified' => 0, 'subscriptionid' => $subscriptionid));
3213          if (!empty($deletecount)) {
3214              $sql = "DELETE FROM {event} WHERE timemodified = :time AND subscriptionid = :id";
3215              $DB->execute($sql, array('time' => 0, 'id' => $subscriptionid));
3216              $return .= "<p> ".get_string('eventsdeleted', 'calendar').": {$deletecount} </p>\n";
3217          }
3218      }
3219  
3220      return $return;
3221  }
3222  
3223  /**
3224   * Fetch a calendar subscription and update the events in the calendar.
3225   *
3226   * @param int $subscriptionid The course ID for the calendar.
3227   * @return string A log of the import progress, including errors.
3228   */
3229  function calendar_update_subscription_events($subscriptionid) {
3230      global $DB;
3231  
3232      $sub = calendar_get_subscription($subscriptionid);
3233      // Don't update a file subscription. TODO: Update from a new uploaded file.
3234      if (empty($sub->url)) {
3235          return 'File subscription not updated.';
3236      }
3237      $ical = calendar_get_icalendar($sub->url);
3238      $return = calendar_import_icalendar_events($ical, $sub->courseid, $subscriptionid);
3239      $sub->lastupdated = time();
3240      calendar_update_subscription($sub);
3241      return $return;
3242  }
3243  
3244  /**
3245   * Update a calendar subscription. Also updates the associated cache.
3246   *
3247   * @param stdClass|array $subscription Subscription record.
3248   * @throws coding_exception If something goes wrong
3249   * @since Moodle 2.5
3250   */
3251  function calendar_update_subscription($subscription) {
3252      global $DB;
3253  
3254      if (is_array($subscription)) {
3255          $subscription = (object)$subscription;
3256      }
3257      if (empty($subscription->id) || !$DB->record_exists('event_subscriptions', array('id' => $subscription->id))) {
3258          throw new coding_exception('Cannot update a subscription without a valid id');
3259      }
3260  
3261      $DB->update_record('event_subscriptions', $subscription);
3262      // Update cache.
3263      $cache = cache::make('core', 'calendar_subscriptions');
3264      $cache->set($subscription->id, $subscription);
3265      // Trigger event, calendar subscription updated.
3266      $eventparams = array('userid' => $subscription->userid,
3267          'objectid' => $subscription->id,
3268          'context' => calendar_get_calendar_context($subscription),
3269          'other' => array('eventtype' => $subscription->eventtype, 'courseid' => $subscription->courseid)
3270          );
3271      $event = \core\event\calendar_subscription_updated::create($eventparams);
3272      $event->trigger();
3273  }
3274  
3275  /**
3276   * Checks to see if the user can edit a given subscription feed.
3277   *
3278   * @param mixed $subscriptionorid Subscription object or id
3279   * @return bool true if current user can edit the subscription else false
3280   */
3281  function calendar_can_edit_subscription($subscriptionorid) {
3282      global $DB;
3283  
3284      if (is_array($subscriptionorid)) {
3285          $subscription = (object)$subscriptionorid;
3286      } else if (is_object($subscriptionorid)) {
3287          $subscription = $subscriptionorid;
3288      } else {
3289          $subscription = calendar_get_subscription($subscriptionorid);
3290      }
3291      $allowed = new stdClass;
3292      $courseid = $subscription->courseid;
3293      $groupid = $subscription->groupid;
3294      calendar_get_allowed_types($allowed, $courseid);
3295      switch ($subscription->eventtype) {
3296          case 'user':
3297              return $allowed->user;
3298          case 'course':
3299              if (isset($allowed->courses[$courseid])) {
3300                  return $allowed->courses[$courseid];
3301              } else {
3302                  return false;
3303              }
3304          case 'site':
3305              return $allowed->site;
3306          case 'group':
3307              if (isset($allowed->groups[$groupid])) {
3308                  return $allowed->groups[$groupid];
3309              } else {
3310                  return false;
3311              }
3312          default:
3313              return false;
3314      }
3315  }
3316  
3317  /**
3318   * Update calendar subscriptions.
3319   *
3320   * @return bool
3321   */
3322  function calendar_cron() {
3323      global $CFG, $DB;
3324  
3325      // In order to execute this we need bennu.
3326      require_once($CFG->libdir.'/bennu/bennu.inc.php');
3327  
3328      mtrace('Updating calendar subscriptions:');
3329      cron_trace_time_and_memory();
3330  
3331      $time = time();
3332      $subscriptions = $DB->get_records_sql('SELECT * FROM {event_subscriptions} WHERE pollinterval > 0 AND lastupdated + pollinterval < ?', array($time));
3333      foreach ($subscriptions as $sub) {
3334          mtrace("Updating calendar subscription {$sub->name} in course {$sub->courseid}");
3335          try {
3336              $log = calendar_update_subscription_events($sub->id);
3337              mtrace(trim(strip_tags($log)));
3338          } catch (moodle_exception $ex) {
3339              mtrace('Error updating calendar subscription: ' . $ex->getMessage());
3340          }
3341      }
3342  
3343      mtrace('Finished updating calendar subscriptions.');
3344  
3345      return true;
3346  }
3347  
3348  /**
3349   * Helper function to determine the context of a calendar subscription.
3350   * Subscriptions can be created in two contexts COURSE, or USER.
3351   *
3352   * @param stdClass $subscription
3353   * @return context instance
3354   */
3355  function calendar_get_calendar_context($subscription) {
3356  
3357      // Determine context based on calendar type.
3358      if ($subscription->eventtype === 'site') {
3359          $context = context_course::instance(SITEID);
3360      } else if ($subscription->eventtype === 'group' || $subscription->eventtype === 'course') {
3361          $context = context_course::instance($subscription->courseid);
3362      } else {
3363          $context = context_user::instance($subscription->userid);
3364      }
3365      return $context;
3366  }