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