calendar/lib.php

   1 <?php // $Id$
   2
   3 /////////////////////////////////////////////////////////////////////////////
   4 //                                                                         //
   5 // NOTICE OF COPYRIGHT                                                     //
   6 //                                                                         //
   7 // Moodle - Calendar extension                                             //
   8 //                                                                         //
   9 // Copyright (C) 2003-2004  Greek School Network            www.sch.gr     //
  10 //                                                                         //
  11 // Designed by:                                                            //
  12 //     Avgoustos Tsinakos (tsinakos@teikav.edu.gr)                         //
  13 //     Jon Papaioannou (pj@moodle.org)                                     //
  14 //                                                                         //
  15 // Programming and development:                                            //
  16 //     Jon Papaioannou (pj@moodle.org)                                     //
  17 //                                                                         //
  18 // For bugs, suggestions, etc contact:                                     //
  19 //     Jon Papaioannou (pj@moodle.org)                                     //
  20 //                                                                         //
  21 // The current module was developed at the University of Macedonia         //
  22 // (www.uom.gr) under the funding of the Greek School Network (www.sch.gr) //
  23 // The aim of this project is to provide additional and improved           //
  24 // functionality to the Asynchronous Distance Education service that the   //
  25 // Greek School Network deploys.                                           //
  26 //                                                                         //
  27 // This program is free software; you can redistribute it and/or modify    //
  28 // it under the terms of the GNU General Public License as published by    //
  29 // the Free Software Foundation; either version 2 of the License, or       //
  30 // (at your option) any later version.                                     //
  31 //                                                                         //
  32 // This program is distributed in the hope that it will be useful,         //
  33 // but WITHOUT ANY WARRANTY; without even the implied warranty of          //
  34 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the           //
  35 // GNU General Public License for more details:                            //
  36 //                                                                         //
  37 //          http://www.gnu.org/copyleft/gpl.html                           //
  38 //                                                                         //
  39 /////////////////////////////////////////////////////////////////////////////
  40
  41 // These are read by the administration component to provide default values
  42 define('CALENDAR_DEFAULT_UPCOMING_LOOKAHEAD', 21);
  43 define('CALENDAR_DEFAULT_UPCOMING_MAXEVENTS', 10);
  44 define('CALENDAR_DEFAULT_STARTING_WEEKDAY',   1);
  45 // This is a packed bitfield: day X is "weekend" if $field & (1 << X) is true
  46 // Default value = 65 = 64 + 1 = 2^6 + 2^0 = Saturday & Sunday
  47 define('CALENDAR_DEFAULT_WEEKEND',            65);
  48
  49 // Fetch the correct values from admin settings/lang pack
  50 // If no such settings found, use the above defaults
  51 $firstday = isset($CFG->calendar_startwday) ? $CFG->calendar_startwday : get_string('firstdayofweek');
  52 if(!is_numeric($firstday)) {
  53     define ('CALENDAR_STARTING_WEEKDAY', CALENDAR_DEFAULT_STARTING_WEEKDAY);
  54 }
  55 else {
  56     define ('CALENDAR_STARTING_WEEKDAY', intval($firstday) % 7);
  57 }
  58 define ('CALENDAR_UPCOMING_DAYS', isset($CFG->calendar_lookahead) ? intval($CFG->calendar_lookahead) : CALENDAR_DEFAULT_UPCOMING_LOOKAHEAD);
  59 define ('CALENDAR_UPCOMING_MAXEVENTS', isset($CFG->calendar_maxevents) ? intval($CFG->calendar_maxevents) : CALENDAR_DEFAULT_UPCOMING_MAXEVENTS);
  60 define ('CALENDAR_WEEKEND', isset($CFG->calendar_weekend) ? intval($CFG->calendar_weekend) : CALENDAR_DEFAULT_WEEKEND);
  61 define ('CALENDAR_URL', $CFG->wwwroot.'/calendar/');
  62 define ('CALENDAR_TF_24', '%H:%M');
  63 define ('CALENDAR_TF_12', '%I:%M %p');
  64
  65 $CALENDARDAYS = array('sunday','monday','tuesday','wednesday','thursday','friday','saturday');
  66
  67
  68
  69 function calendar_get_mini($courses, $groups, $users, $cal_month = false, $cal_year = false) {
  70     global $CFG, $USER;
  71
  72     $display = &New stdClass;
  73     $display->minwday = get_user_preferences('calendar_startwday', CALENDAR_STARTING_WEEKDAY);
  74     $display->maxwday = $display->minwday + 6;
  75
  76     $content = '';
  77
  78     if(!empty($cal_month) && !empty($cal_year)) {
  79         $thisdate = usergetdate(time()); // Date and time the user sees at his location
  80         if($cal_month == $thisdate['mon'] && $cal_year == $thisdate['year']) {
  81             // Navigated to this month
  82             $date = $thisdate;
  83             $display->thismonth = true;
  84         }
  85         else {
  86             // Navigated to other month, let's do a nice trick and save us a lot of work...
  87             if(!checkdate($cal_month, 1, $cal_year)) {
  88                 $date = array('mday' => 1, 'mon' => $thisdate['mon'], 'year' => $thisdate['year']);
  89                 $display->thismonth = true;
  90             }
  91             else {
  92                 $date = array('mday' => 1, 'mon' => $cal_month, 'year' => $cal_year);
  93                 $display->thismonth = false;
  94             }
  95         }
  96     }
  97     else {
  98         $date = usergetdate(time()); // Date and time the user sees at his location
  99         $display->thismonth = true;
 100     }
 101
 102     // Fill in the variables we 're going to use, nice and tidy
 103     list($d, $m, $y) = array($date['mday'], $date['mon'], $date['year']); // This is what we want to display
 104     $display->maxdays = calendar_days_in_month($m, $y);
 105
 106     if (get_user_timezone_offset() < 99) {
 107         // We 'll keep these values as GMT here, and offset them when the time comes to query the db
 108         $display->tstart = gmmktime(0, 0, 0, $m, 1, $y); // This is GMT
 109         $display->tend = gmmktime(23, 59, 59, $m, $display->maxdays, $y); // GMT
 110     } else {
 111         // no timezone info specified
 112         $display->tstart = mktime(0, 0, 0, $m, 1, $y);
 113         $display->tend = mktime(23, 59, 59, $m, $display->maxdays, $y);
 114     }
 115
 116     $startwday = dayofweek(1, $m, $y);
 117
 118     // Align the starting weekday to fall in our display range
 119     // This is simple, not foolproof.
 120     if($startwday < $display->minwday) {
 121         $startwday += 7;
 122     }
 123
 124     // TODO: THIS IS TEMPORARY CODE!
 125     // [pj] I was just reading through this and realized that I when writing this code I was probably
 126     // asking for trouble, as all these time manipulations seem to be unnecessary and a simple
 127     // make_timestamp would accomplish the same thing. So here goes a test:
 128     //$test_start = make_timestamp($y, $m, 1);
 129     //$test_end   = make_timestamp($y, $m, $display->maxdays, 23, 59, 59);
 130     //if($test_start != usertime($display->tstart) - dst_offset_on($display->tstart)) {
 131         //notify('Failed assertion in calendar/lib.php line 126; display->tstart = '.$display->tstart.', dst_offset = '.dst_offset_on($display->tstart).', usertime = '.usertime($display->tstart).', make_t = '.$test_start);
 132     //}
 133     //if($test_end != usertime($display->tend) - dst_offset_on($display->tend)) {
 134         //notify('Failed assertion in calendar/lib.php line 130; display->tend = '.$display->tend.', dst_offset = '.dst_offset_on($display->tend).', usertime = '.usertime($display->tend).', make_t = '.$test_end);
 135     //}
 136
 137
 138     // Get the events matching our criteria. Don't forget to offset the timestamps for the user's TZ!
 139     $whereclause = calendar_sql_where(
 140         usertime($display->tstart) - dst_offset_on($display->tstart),
 141         usertime($display->tend) - dst_offset_on($display->tend),
 142         $users, $groups, $courses);
 143
 144     if($whereclause === false) {
 145         $events = array();
 146     }
 147     else {
 148         $events = get_records_select('event', $whereclause, 'timestart');
 149     }
 150
 151     // This is either a genius idea or an idiot idea: in order to not complicate things, we use this rule: if, after
 152     // possibly removing SITEID from $courses, there is only one course left, then clicking on a day in the month
 153     // will also set the $SESSION->cal_courses_shown variable to that one course. Otherwise, we 'd need to add extra
 154     // arguments to this function.
 155
 156     $morehref = '';
 157     if(!empty($courses)) {
 158         $courses = array_diff($courses, array(SITEID));
 159         if(count($courses) == 1) {
 160             $morehref = '&amp;course='.reset($courses);
 161         }
 162     }
 163
 164     // We want to have easy access by day, since the display is on a per-day basis.
 165     // Arguments passed by reference.
 166     //calendar_events_by_day($events, $display->tstart, $eventsbyday, $durationbyday, $typesbyday);
 167     calendar_events_by_day($events, $m, $y, $eventsbyday, $durationbyday, $typesbyday);
 168
 169     //Accessibility: added summary and <abbr> elements.
 170     ///global $CALENDARDAYS; appears to be broken.
 171     $days_title = array('sunday','monday','tuesday','wednesday','thursday','friday','saturday');
 172
 173     $summary = get_string('calendarheading', 'calendar', userdate(make_timestamp($y, $m), get_string('strftimemonthyear')));
 174     $summary = get_string('tabledata', 'access', $summary);
 175     $content .= '<table class="minicalendar" summary="'.$summary.'">'; // Begin table
 176     $content .= '<tr class="weekdays">'; // Header row: day names
 177
 178     // Print out the names of the weekdays
 179     $days = array('sun', 'mon', 'tue', 'wed', 'thu', 'fri', 'sat');
 180     for($i = $display->minwday; $i <= $display->maxwday; ++$i) {
 181         // This uses the % operator to get the correct weekday no matter what shift we have
 182         // applied to the $display->minwday : $display->maxwday range from the default 0 : 6
 183         $content .= '<th scope="col"><abbr title="'. get_string($days_title[$i % 7], 'calendar') .'">'.
 184             get_string($days[$i % 7], 'calendar') ."</abbr></th>\n";
 185     }
 186
 187     $content .= '</tr><tr>'; // End of day names; prepare for day numbers
 188
 189     // For the table display. $week is the row; $dayweek is the column.
 190     $dayweek = $startwday;
 191
 192     // Paddding (the first week may have blank days in the beginning)
 193     for($i = $display->minwday; $i < $startwday; ++$i) {
 194         $content .= '<td class="day">&nbsp;</td>'."\n";
 195     }
 196
 197     // Now display all the calendar
 198     for($day = 1; $day <= $display->maxdays; ++$day, ++$dayweek) {
 199         if($dayweek > $display->maxwday) {
 200             // We need to change week (table row)
 201             $content .= '</tr><tr>';
 202             $dayweek = $display->minwday;
 203         }
 204
 205         // Reset vars
 206         $cell = '';
 207         if(CALENDAR_WEEKEND & (1 << ($dayweek % 7))) {
 208             // Weekend. This is true no matter what the exact range is.
 209             $class = 'weekend day';
 210         }
 211         else {
 212             // Normal working day.
 213             $class = 'day';
 214         }
 215
 216         // Special visual fx if an event is defined
 217         if(isset($eventsbyday[$day])) {
 218             $dayhref = calendar_get_link_href(CALENDAR_URL.'view.php?view=day'.$morehref.'&amp;', $day, $m, $y);
 219
 220             // OverLib popup
 221             $popupcontent = '';
 222             foreach($eventsbyday[$day] as $eventid) {
 223                 if (!isset($events[$eventid])) {
 224                     continue;
 225                 }
 226                 $event = $events[$eventid];
 227                 if(!empty($event->modulename)) {
 228                     $popupicon = $CFG->modpixpath.'/'.$event->modulename.'/icon.gif';
 229                     $popupalt  = $event->modulename;
 230
 231                 } else if ($event->courseid == SITEID) {                                // Site event
 232                     $popupicon = $CFG->pixpath.'/c/site.gif';
 233                     $popupalt  = '';
 234                 } else if ($event->courseid != 0 && $event->courseid != SITEID && $event->groupid == 0) {      // Course event
 235                     $popupicon = $CFG->pixpath.'/c/course.gif';
 236                     $popupalt  = '';
 237                 } else if ($event->groupid) {                                      // Group event
 238                     $popupicon = $CFG->pixpath.'/c/group.gif';
 239                     $popupalt  = '';
 240                 } else if ($event->userid) {                                       // User event
 241                     $popupicon = $CFG->pixpath.'/c/user.gif';
 242                     $popupalt  = '';
 243                 }
 244                 $popupcontent .= '<div><img class="icon" src="'.$popupicon.'" alt="'.$popupalt.'" /><a href="'.$dayhref.'#event_'.$event->id.'">'.format_string($event->name, true).'</a></div>';
 245             }
 246
 247             //Accessibility: functionality moved to calendar_get_popup.
 248             if($display->thismonth && $day == $d) {
 249                 $popup = calendar_get_popup(true, $events[$eventid]->timestart, $popupcontent);
 250             } else {
 251                 $popup = calendar_get_popup(false, $events[$eventid]->timestart, $popupcontent);
 252             }
 253
 254             // Class and cell content
 255             if(isset($typesbyday[$day]['startglobal'])) {
 256                 $class .= ' event_global';
 257             }
 258             else if(isset($typesbyday[$day]['startcourse'])) {
 259                 $class .= ' event_course';
 260             }
 261             else if(isset($typesbyday[$day]['startgroup'])) {
 262                 $class .= ' event_group';
 263             }
 264             else if(isset($typesbyday[$day]['startuser'])) {
 265                 $class .= ' event_user';
 266             }
 267             $cell = '<a href="'.$dayhref.'" '.$popup.'>'.$day.'</a>';
 268         }
 269         else {
 270             $cell = $day;
 271         }
 272
 273         if(isset($typesbyday[$day]['durationglobal'])) {
 274             $class .= ' duration_global';
 275         }
 276         else if(isset($typesbyday[$day]['durationcourse'])) {
 277             $class .= ' duration_course';
 278         }
 279         else if(isset($typesbyday[$day]['durationgroup'])) {
 280             $class .= ' duration_group';
 281         }
 282         else if(isset($typesbyday[$day]['durationuser'])) {
 283             $class .= ' duration_user';
 284         }
 285
 286         // Special visual fx for today
 287         //Accessibility: hidden text for today, and popup.
 288         if($display->thismonth && $day == $d) {
 289             $class .= ' today';
 290             $today = get_string('today', 'calendar').' '.userdate(time(), get_string('strftimedayshort'));
 291
 292             if(! isset($eventsbyday[$day])) {
 293                 $class .= ' eventnone';
 294                 $popup = calendar_get_popup(true, false);
 295                 $cell = '<a href="#" '.$popup.'>'.$day.'</a>';
 296             }
 297             $cell = get_accesshide($today.' ').$cell;
 298         }
 299
 300         // Just display it
 301         if(!empty($class)) {
 302             $class = ' class="'.$class.'"';
 303         }
 304         $content .= '<td'.$class.'>'.$cell."</td>\n";
 305     }
 306
 307     // Paddding (the last week may have blank days at the end)
 308     for($i = $dayweek; $i <= $display->maxwday; ++$i) {
 309         $content .= '<td class="day">&nbsp;</td>';
 310     }
 311     $content .= '</tr>'; // Last row ends
 312
 313     $content .= '</table>'; // Tabular display of days ends
 314
 315     return $content;
 316 }
 317
 318 /**
 319  * calendar_get_popup, called at multiple points in from calendar_get_mini.
 320  *        Copied and modified from calendar_get_mini.
 321  * @uses OverLib popup.
 322  * @param $is_today bool, false except when called on the current day.
 323  * @param $event_timestart mixed, $events[$eventid]->timestart, OR false if there are no events.
 324  * @param $popupcontent string.
 325  * @return $popup string, contains onmousover and onmouseout events.
 326  */
 327 function calendar_get_popup($is_today, $event_timestart, $popupcontent='') {
 328     $popupcaption = '';
 329     if($is_today) {
 330         $popupcaption = get_string('today', 'calendar').' ';
 331     }
 332     if (false === $event_timestart) {
 333         $popupcaption .= userdate(time(), get_string('strftimedayshort'));
 334         $popupcontent = get_string('eventnone', 'calendar');
 335
 336     } else {
 337         $popupcaption .= get_string('eventsfor', 'calendar', userdate($event_timestart, get_string('strftimedayshort')));
 338     }
 339     $popupcontent = str_replace("'", "\'", htmlspecialchars($popupcontent));
 340     $popupcaption = str_replace("'", "\'", htmlspecialchars($popupcaption));
 341     $popup = 'onmouseover="return overlib(\''.$popupcontent.'\', CAPTION, \''.$popupcaption.'\');" onmouseout="return nd();"';
 342     return $popup;
 343 }
 344
 345 function calendar_get_upcoming($courses, $groups, $users, $daysinfuture, $maxevents, $fromtime=0) {
 346     global $CFG;
 347
 348     $display = &new stdClass;
 349     $display->range = $daysinfuture; // How many days in the future we 'll look
 350     $display->maxevents = $maxevents;
 351
 352     $output = array();
 353
 354     // Prepare "course caching", since it may save us a lot of queries
 355     $coursecache = array();
 356
 357     $processed = 0;
 358     $now = time(); // We 'll need this later
 359     $usermidnighttoday = usergetmidnight($now);
 360
 361     if ($fromtime) {
 362         $display->tstart = $fromtime;
 363     } else {
 364         $display->tstart = $usermidnighttoday;
 365     }
 366
 367     // This works correctly with respect to the user's DST, but it is accurate
 368     // only because $fromtime is always the exact midnight of some day!
 369     $display->tend = usergetmidnight($display->tstart + DAYSECS * $display->range + 3 * HOURSECS) - 1;
 370
 371     // Get the events matching our criteria
 372     $whereclause = calendar_sql_where($display->tstart, $display->tend, $users, $groups, $courses);
 373     if ($whereclause === false) {
 374         $events = false;
 375     } else {
 376         $events = get_records_select('event', $whereclause, 'timestart');
 377     }
 378
 379     // This is either a genius idea or an idiot idea: in order to not complicate things, we use this rule: if, after
 380     // possibly removing SITEID from $courses, there is only one course left, then clicking on a day in the month
 381     // will also set the $SESSION->cal_courses_shown variable to that one course. Otherwise, we 'd need to add extra
 382     // arguments to this function.
 383
 384     $morehref = '';
 385     if(!empty($courses)) {
 386         $courses = array_diff($courses, array(SITEID));
 387         if(count($courses) == 1) {
 388             $morehref = '&amp;course='.reset($courses);
 389         }
 390     }
 391
 392     if($events !== false) {
 393
 394         foreach($events as $event) {
 395
 396             if($processed >= $display->maxevents) {
 397                 break;
 398             }
 399
 400             $event->time = calendar_format_event_time($event, $now, $morehref);
 401             $output[] = $event;
 402             ++$processed;
 403         }
 404     }
 405     return $output;
 406 }
 407
 408 function calendar_add_event_metadata($event) {
 409     global $CFG;
 410
 411     //Support multilang in event->name
 412     $event->name = format_string($event->name,true);
 413
 414     if(!empty($event->modulename)) {                                // Activity event
 415         // The module name is set. I will assume that it has to be displayed, and
 416         // also that it is an automatically-generated event. And of course that the
 417         // fields for get_coursemodule_from_instance are set correctly.
 418         $module = calendar_get_module_cached($coursecache, $event->modulename, $event->instance);
 419
 420         if ($module === false) {
 421             return;
 422         }
 423
 424         $modulename = get_string('modulename', $event->modulename);
 425         $eventtype = get_string($event->eventtype, $event->modulename);
 426         $icon = $CFG->modpixpath.'/'.$event->modulename.'/icon.gif';
 427
 428         $event->icon = '<img height="16" width="16" src="'.$icon.'" alt="'.$eventtype.'" title="'.$modulename.'" style="vertical-align: middle;" />';
 429         $event->referer = '<a href="'.$CFG->wwwroot.'/mod/'.$event->modulename.'/view.php?id='.$module->id.'">'.$event->name.'</a>';
 430         $event->courselink = '<a href="'.$CFG->wwwroot.'/course/view.php?id='.$module->course.'">'.$coursecache[$module->course]->fullname.'</a>';
 431         $event->cmid = $module->id;
 432
 433
 434     } else if($event->courseid == SITEID) {                              // Site event
 435         $event->icon = '<img height="16" width="16" src="'.$CFG->pixpath.'/c/site.gif" alt="'.get_string('globalevent', 'calendar').'" style="vertical-align: middle;" />';
 436         $event->cssclass = 'event_global';
 437     } else if($event->courseid != 0 && $event->courseid != SITEID && $event->groupid == 0) {          // Course event
 438         calendar_get_course_cached($coursecache, $event->courseid);
 439         $event->icon = '<img height="16" width="16" src="'.$CFG->pixpath.'/c/course.gif" alt="'.get_string('courseevent', 'calendar').'" style="vertical-align: middle;" />';
 440         $event->courselink = '<a href="'.$CFG->wwwroot.'/course/view.php?id='.$event->courseid.'">'.$coursecache[$event->courseid]->fullname.'</a>';
 441         $event->cssclass = 'event_course';
 442     } else if ($event->groupid) {                                    // Group event
 443         $event->icon = '<img height="16" width="16" src="'.$CFG->pixpath.'/c/group.gif" alt="'.get_string('groupevent', 'calendar').'" style="vertical-align: middle;" />';
 444         $event->cssclass = 'event_group';
 445     } else if($event->userid) {                                      // User event
 446         $event->icon = '<img height="16" width="16" src="'.$CFG->pixpath.'/c/user.gif" alt="'.get_string('userevent', 'calendar').'" style="vertical-align: middle;" />';
 447         $event->cssclass = 'event_user';
 448     }
 449     return $event;
 450 }
 451
 452 function calendar_print_event($event) {
 453     global $CFG, $USER;
 454
 455     static $strftimetime;
 456
 457     $event = calendar_add_event_metadata($event);
 458     echo '<a name="event_'.$event->id.'"></a><table class="event" cellspacing="0">';
 459     echo '<tr><td class="picture">';
 460     if (!empty($event->icon)) {
 461         echo $event->icon;
 462     } else {
 463         print_spacer(16,16);
 464     }
 465     echo '</td>';
 466     echo '<td class="topic">';
 467
 468     if (!empty($event->referer)) {
 469         echo '<div class="referer">'.$event->referer.'</div>';
 470     } else {
 471         echo '<div class="name">'.$event->name."</div>";
 472     }
 473     if (!empty($event->courselink)) {
 474         echo '<div class="course">'.$event->courselink.' </div>';
 475     }
 476     if (!empty($event->time)) {
 477         echo '<span class="date">'.$event->time.'</span>';
 478     } else {
 479         echo '<span class="date">'.calendar_time_representation($event->timestart).'</span>';
 480     }
 481
 482     echo '</td></tr>';
 483     echo '<tr><td class="side">&nbsp;</td>';
 484     echo '<td class="description '.$event->cssclass.'">';
 485     echo format_text($event->description, FORMAT_HTML);
 486     if (calendar_edit_event_allowed($event)) {
 487         echo '<div class="commands">';
 488
 489         $calendarcourseid = '';
 490                 if (!empty($event->calendarcourseid)) {
 491                     $calendarcourseid = '&amp;course='.$event->calendarcourseid;
 492                 }
 493
 494         if (empty($event->cmid)) {
 495             $editlink   = CALENDAR_URL.'event.php?action=edit&amp;id='.$event->id.$calendarcourseid;
 496             $deletelink = CALENDAR_URL.'event.php?action=delete&amp;id='.$event->id.$calendarcourseid;
 497         } else {
 498             $editlink   = $CFG->wwwroot.'/course/mod.php?update='.$event->cmid.'&amp;return=true&amp;sesskey='.$USER->sesskey;
 499             $deletelink = $CFG->wwwroot.'/course/mod.php?delete='.$event->cmid.'&amp;sesskey='.$USER->sesskey;;
 500         }
 501         echo ' <a href="'.$editlink.'"><img
 502                   src="'.$CFG->pixpath.'/t/edit.gif" alt="'.get_string('tt_editevent', 'calendar').'"
 503                   title="'.get_string('tt_editevent', 'calendar').'" /></a>';
 504         echo ' <a href="'.$deletelink.'"><img
 505                   src="'.$CFG->pixpath.'/t/delete.gif" alt="'.get_string('tt_deleteevent', 'calendar').'"
 506                   title="'.get_string('tt_deleteevent', 'calendar').'" /></a>';
 507         echo '</div>';
 508     }
 509     echo '</td></tr></table>';
 510
 511 }
 512
 513 function calendar_sql_where($tstart, $tend, $users, $groups, $courses, $withduration=true, $ignorehidden=true) {
 514     $whereclause = '';
 515     // Quick test
 516     if(is_bool($users) && is_bool($groups) && is_bool($courses)) {
 517         return false;
 518     }
 519
 520     if(is_array($users) && !empty($users)) {
 521         // Events from a number of users
 522         if(!empty($whereclause)) $whereclause .= ' OR';
 523         $whereclause .= ' (userid IN ('.implode(',', $users).') AND courseid = 0 AND groupid = 0)';
 524     }
 525     else if(is_numeric($users)) {
 526         // Events from one user
 527         if(!empty($whereclause)) $whereclause .= ' OR';
 528         $whereclause .= ' (userid = '.$users.' AND courseid = 0 AND groupid = 0)';
 529     }
 530     else if($users === true) {
 531         // Events from ALL users
 532         if(!empty($whereclause)) $whereclause .= ' OR';
 533         $whereclause .= ' (userid != 0 AND courseid = 0 AND groupid = 0)';
 534     }
 535     else if($users === false) {
 536         // No user at all, do nothing
 537     }
 538
 539     if(is_array($groups) && !empty($groups)) {
 540         // Events from a number of groups
 541         if(!empty($whereclause)) $whereclause .= ' OR';
 542         $whereclause .= ' groupid IN ('.implode(',', $groups).')';
 543     }
 544     else if(is_numeric($groups)) {
 545         // Events from one group
 546         if(!empty($whereclause)) $whereclause .= ' OR ';
 547         $whereclause .= ' groupid = '.$groups;
 548     }
 549     else if($groups === true) {
 550         // Events from ALL groups
 551         if(!empty($whereclause)) $whereclause .= ' OR ';
 552         $whereclause .= ' groupid != 0';
 553     }
 554     // boolean false (no groups at all): we don't need to do anything
 555
 556     if(is_array($courses)) {
 557         // A number of courses (maybe none at all!)
 558         if(!empty($courses)) {
 559             if(!empty($whereclause)) {
 560                 $whereclause .= ' OR';
 561             }
 562             $whereclause .= ' (groupid = 0 AND courseid IN ('.implode(',', $courses).'))';
 563         }
 564         else {
 565             // This means NO courses, not that we don't care!
 566             // No need to do anything
 567         }
 568     }
 569     else if(is_numeric($courses)) {
 570         // One course
 571         if(!empty($whereclause)) $whereclause .= ' OR';
 572         $whereclause .= ' (groupid = 0 AND courseid = '.$courses.')';
 573     }
 574     else if($courses === true) {
 575         // Events from ALL courses
 576         if(!empty($whereclause)) $whereclause .= ' OR';
 577         $whereclause .= ' (groupid = 0 AND courseid != 0)';
 578     }
 579
 580     // Security check: if, by now, we have NOTHING in $whereclause, then it means
 581     // that NO event-selecting clauses were defined. Thus, we won't be returning ANY
 582     // events no matter what. Allowing the code to proceed might return a completely
 583     // valid query with only time constraints, thus selecting ALL events in that time frame!
 584     if(empty($whereclause)) {
 585         return false;
 586     }
 587
 588     if($withduration) {
 589         $timeclause = 'timestart + timeduration >= '.$tstart.' AND timestart <= '.$tend;
 590     }
 591     else {
 592         $timeclause = 'timestart >= '.$tstart.' AND timestart <= '.$tend;
 593     }
 594     if(!empty($whereclause)) {
 595         // We have additional constraints
 596         $whereclause = $timeclause.' AND ('.$whereclause.')';
 597     }
 598     else {
 599         // Just basic time filtering
 600         $whereclause = $timeclause;
 601     }
 602
 603     if ($ignorehidden) {
 604         $whereclause .= ' AND visible = 1';
 605     }
 606
 607     return $whereclause;
 608 }
 609
 610 function calendar_top_controls($type, $data) {
 611     global $CFG, $CALENDARDAYS, $THEME;
 612     $content = '';
 613     if(!isset($data['d'])) {
 614         $data['d'] = 1;
 615     }
 616
 617     // Ensure course id passed if relevant
 618     // Required due to changes in view/lib.php mainly (calendar_session_vars())
 619     $courseid = '';
 620     if (!empty($data['id'])) {
 621         $courseid = '&amp;course='.$data['id'];
 622     }
 623
 624     if(!checkdate($data['m'], $data['d'], $data['y'])) {
 625         $time = time();
 626     }
 627     else {
 628         $time = make_timestamp($data['y'], $data['m'], $data['d']);
 629     }
 630     $date = usergetdate($time);
 631
 632     $data['m'] = $date['mon'];
 633     $data['y'] = $date['year'];
 634
 635     //Accessibility: calendar block controls, replaced <table> with <div>.
 636     //$nexttext = link_arrow_right(get_string('monthnext', 'access'), $url='', $accesshide=true);
 637     //$prevtext = link_arrow_left(get_string('monthprev', 'access'), $url='', $accesshide=true);
 638
 639     switch($type) {
 640         case 'frontpage':
 641             list($prevmonth, $prevyear) = calendar_sub_month($data['m'], $data['y']);
 642             list($nextmonth, $nextyear) = calendar_add_month($data['m'], $data['y']);
 643             $nextlink = calendar_get_link_next(get_string('monthnext', 'access'), 'index.php?', 0, $nextmonth, $nextyear, $accesshide=true);
 644             $prevlink = calendar_get_link_previous(get_string('monthprev', 'access'), 'index.php?', 0, $prevmonth, $prevyear, true);
 645             $content .= "\n".'<div class="calendar-controls">'. $prevlink;
 646             $content .= '<span class="hide"> | </span><span class="current"><a href="'.calendar_get_link_href(CALENDAR_URL.'view.php?view=month'.$courseid.'&amp;', 1, $data['m'], $data['y']).'">'.userdate($time, get_string('strftimemonthyear')).'</a></span>';
 647             $content .= '<span class="hide"> | </span>'. $nextlink ."\n";
 648             $content .= "<span class=\"clearer\"><!-- --></span></div>\n";
 649         break;
 650         case 'course':
 651             list($prevmonth, $prevyear) = calendar_sub_month($data['m'], $data['y']);
 652             list($nextmonth, $nextyear) = calendar_add_month($data['m'], $data['y']);
 653             $nextlink = calendar_get_link_next(get_string('monthnext', 'access'), 'view.php?id='.$data['id'].'&amp;', 0, $nextmonth, $nextyear, $accesshide=true);
 654             $prevlink = calendar_get_link_previous(get_string('monthprev', 'access'), 'view.php?id='.$data['id'].'&amp;', 0, $prevmonth, $prevyear, true);
 655             $content .= "\n".'<div class="calendar-controls">'. $prevlink;
 656             $content .= '<span class="hide"> | </span><span class="current"><a href="'.calendar_get_link_href(CALENDAR_URL.'view.php?view=month'.$courseid.'&amp;', 1, $data['m'], $data['y']).'">'.userdate($time, get_string('strftimemonthyear')).'</a></span>';
 657             $content .= '<span class="hide"> | </span>'. $nextlink ."\n";
 658             $content .= "<span class=\"clearer\"><!-- --></span></div>\n";
 659         break;
 660         case 'upcoming':
 661             $content .= '<div style="text-align: center;"><a href="'.CALENDAR_URL.'view.php?view=upcoming"'.$courseid.'>'.userdate($time, get_string('strftimemonthyear'))."</a></div>\n";
 662         break;
 663         case 'display':
 664             $content .= '<div style="text-align: center;"><a href="'.calendar_get_link_href(CALENDAR_URL.'view.php?view=month'.$courseid.'&amp;', 1, $data['m'], $data['y']).'">'.userdate($time, get_string('strftimemonthyear'))."</a></div>\n";
 665         break;
 666         case 'month':
 667             list($prevmonth, $prevyear) = calendar_sub_month($data['m'], $data['y']);
 668             list($nextmonth, $nextyear) = calendar_add_month($data['m'], $data['y']);
 669             $prevdate = make_timestamp($prevyear, $prevmonth, 1);
 670             $nextdate = make_timestamp($nextyear, $nextmonth, 1);
 671             $content .= "\n".'<div class="calendar-controls">';
 672             $content .= calendar_get_link_previous(userdate($prevdate, get_string('strftimemonthyear')), 'view.php?view=month'.$courseid.'&amp;', 1, $prevmonth, $prevyear);
 673             $content .= '<span class="hide"> | </span><span class="current">'.userdate($time, get_string('strftimemonthyear'))."</span>\n";
 674             $content .= '<span class="hide"> | </span>'.calendar_get_link_next(userdate($nextdate, get_string('strftimemonthyear')), 'view.php?view=month'.$courseid.'&amp;', 1, $nextmonth, $nextyear);
 675             $content .= "<span class=\"clearer\"><!-- --></span></div>\n";
 676         break;
 677         case 'day':
 678             $data['d'] = $date['mday']; // Just for convenience
 679             $prevdate = usergetdate(make_timestamp($data['y'], $data['m'], $data['d'] - 1));
 680             $nextdate = usergetdate(make_timestamp($data['y'], $data['m'], $data['d'] + 1));
 681             $prevname = calendar_wday_name($CALENDARDAYS[$prevdate['wday']]);
 682             $nextname = calendar_wday_name($CALENDARDAYS[$nextdate['wday']]);
 683             $content .= "\n".'<div class="calendar-controls">';
 684             $content .= calendar_get_link_previous($prevname, 'view.php?view=day'.$courseid.'&amp;', $prevdate['mday'], $prevdate['mon'], $prevdate['year']);
 685
 686             // Get the format string
 687             $text = get_string('strftimedaydate');
 688             /*
 689             // Regexp hackery to make a link out of the month/year part
 690             $text = ereg_replace('(%B.+%Y|%Y.+%B|%Y.+%m[^ ]+)', '<a href="'.calendar_get_link_href('view.php?view=month&amp;', 1, $data['m'], $data['y']).'">\\1</a>', $text);
 691             $text = ereg_replace('(F.+Y|Y.+F|Y.+m[^ ]+)', '<a href="'.calendar_get_link_href('view.php?view=month&amp;', 1, $data['m'], $data['y']).'">\\1</a>', $text);
 692             */
 693             // Replace with actual values and lose any day leading zero
 694             $text = userdate($time, $text);
 695             // Print the actual thing
 696             $content .= '<span class="hide"> | </span><span class="current">'.$text.'</span>';
 697
 698             $content .= '<span class="hide"> | </span>'. calendar_get_link_next($nextname, 'view.php?view=day'.$courseid.'&amp;', $nextdate['mday'], $nextdate['mon'], $nextdate['year']);
 699             $content .= "<span class=\"clearer\"><!-- --></span></div>\n";
 700         break;
 701     }
 702     return $content;
 703 }
 704
 705 function calendar_filter_controls($type, $vars = NULL, $course = NULL) {
 706     global $CFG, $SESSION, $USER;
 707
 708     $groupevents = true;
 709     $getvars = '';
 710
 711     $id = optional_param( 'id',0,PARAM_INT );
 712
 713     switch($type) {
 714         case 'event':
 715         case 'upcoming':
 716         case 'day':
 717         case 'month':
 718             $getvars = '&amp;from='.$type;
 719         break;
 720         case 'course':
 721             if ($id > 0) {
 722                 $getvars = '&amp;from=course&amp;id='.$id;
 723             } else {
 724                 $getvars = '&amp;from=course';
 725             }
 726             if (isset($course->groupmode) and $course->groupmode == NOGROUPS and $course->groupmodeforce) {
 727                 $groupevents = false;
 728             }
 729         break;
 730     }
 731
 732     if (!empty($vars)) {
 733         $getvars .= '&amp;'.$vars;
 734     }
 735
 736     $content = '<table>';
 737
 738     $content .= '<tr>';
 739     if($SESSION->cal_show_global) {
 740         $content .= '<td class="event_global" style="width: 11px;"><img src="'.$CFG->pixpath.'/t/hide.gif" class="iconsmall" alt="'.get_string('hide').'" /></td>';
 741         $content .= '<td><a href="'.CALENDAR_URL.'set.php?var=showglobal'.$getvars.'" title="'.get_string('tt_hideglobal', 'calendar').'">'.get_string('globalevents', 'calendar').'</a></td>'."\n";
 742     }
 743     else {
 744         $content .= '<td style="width: 11px;"><img src="'.$CFG->pixpath.'/t/show.gif" class="iconsmall" alt="'.get_string('show').'" /></td>';
 745         $content .= '<td><a href="'.CALENDAR_URL.'set.php?var=showglobal'.$getvars.'" title="'.get_string('tt_showglobal', 'calendar').'">'.get_string('globalevents', 'calendar').'</a></td>'."\n";
 746     }
 747     if($SESSION->cal_show_course) {
 748         $content .= '<td class="event_course" style="width: 11px;"><img src="'.$CFG->pixpath.'/t/hide.gif" class="iconsmall" alt="'.get_string('hide').'" /></td>';
 749         $content .= '<td><a href="'.CALENDAR_URL.'set.php?var=showcourses'.$getvars.'" title="'.get_string('tt_hidecourse', 'calendar').'">'.get_string('courseevents', 'calendar').'</a></td>'."\n";
 750     }
 751     else {
 752         $content .= '<td style="width: 11px;"><img src="'.$CFG->pixpath.'/t/show.gif" class="iconsmall" alt="'.get_string('hide').'" /></td>';
 753         $content .= '<td><a href="'.CALENDAR_URL.'set.php?var=showcourses'.$getvars.'" title="'.get_string('tt_showcourse', 'calendar').'">'.get_string('courseevents', 'calendar').'</a></td>'."\n";
 754     }
 755
 756     if(!empty($USER->id) && !isguest()) {
 757         $content .= "</tr>\n<tr>";
 758
 759         if($groupevents) {
 760             // This course MIGHT have group events defined, so show the filter
 761             if($SESSION->cal_show_groups) {
 762                 $content .= '<td class="event_group" style="width: 11px;"><img src="'.$CFG->pixpath.'/t/hide.gif" class="iconsmall" alt="'.get_string('hide').'" /></td>';
 763                 $content .= '<td><a href="'.CALENDAR_URL.'set.php?var=showgroups'.$getvars.'" title="'.get_string('tt_hidegroups', 'calendar').'">'.get_string('groupevents', 'calendar').'</a></td>'."\n";
 764             } else {
 765                 $content .= '<td style="width: 11px;"><img src="'.$CFG->pixpath.'/t/show.gif" class="iconsmall" alt="'.get_string('show').'" /></td>';
 766                 $content .= '<td><a href="'.CALENDAR_URL.'set.php?var=showgroups'.$getvars.'" title="'.get_string('tt_showgroups', 'calendar').'">'.get_string('groupevents', 'calendar').'</a></td>'."\n";
 767             }
 768             if ($SESSION->cal_show_user) {
 769                 $content .= '<td class="event_user" style="width: 11px;"><img src="'.$CFG->pixpath.'/t/hide.gif" class="iconsmall" alt="'.get_string('hide').'" /></td>';
 770                 $content .= '<td><a href="'.CALENDAR_URL.'set.php?var=showuser'.$getvars.'" title="'.get_string('tt_hideuser', 'calendar').'">'.get_string('userevents', 'calendar').'</a></td>'."\n";
 771             } else {
 772                 $content .= '<td style="width: 11px;"><img src="'.$CFG->pixpath.'/t/show.gif" class="iconsmall" alt="'.get_string('show').'" /></td>';
 773                 $content .= '<td><a href="'.CALENDAR_URL.'set.php?var=showuser'.$getvars.'" title="'.get_string('tt_showuser', 'calendar').'">'.get_string('userevents', 'calendar').'</a></td>'."\n";
 774             }
 775
 776         } else {
 777             // This course CANNOT have group events, so lose the filter
 778             $content .= '<td style="width: 11px;"></td><td>&nbsp;</td>'."\n";
 779
 780             if($SESSION->cal_show_user) {
 781                 $content .= '<td class="event_user" style="width: 11px;"><img src="'.$CFG->pixpath.'/t/hide.gif" class="iconsmall" alt="'.get_string('hide').'" /></td>';
 782                 $content .= '<td><a href="'.CALENDAR_URL.'set.php?var=showuser'.$getvars.'" title="'.get_string('tt_hideuser', 'calendar').'">'.get_string('userevents', 'calendar').'</a></td>'."\n";
 783             } else {
 784                 $content .= '<td style="width: 11px;"><img src="'.$CFG->pixpath.'/t/show.gif" class="iconsmall" alt="'.get_string('show').'" /></td>';
 785                 $content .= '<td><a href="'.CALENDAR_URL.'set.php?var=showuser'.$getvars.'" title="'.get_string('tt_showuser', 'calendar').'">'.get_string('userevents', 'calendar').'</a></td>'."\n";
 786             }
 787         }
 788     }
 789     $content .= "</tr>\n</table>\n";
 790
 791     return $content;
 792 }
 793
 794 function calendar_day_representation($tstamp, $now = false, $usecommonwords = true) {
 795
 796     static $shortformat;
 797     if(empty($shortformat)) {
 798         $shortformat = get_string('strftimedayshort');
 799     }
 800
 801     if($now === false) {
 802         $now = time();
 803     }
 804
 805     // To have it in one place, if a change is needed
 806     $formal = userdate($tstamp, $shortformat);
 807
 808     $datestamp = usergetdate($tstamp);
 809     $datenow   = usergetdate($now);
 810
 811     if($usecommonwords == false) {
 812         // We don't want words, just a date
 813         return $formal;
 814     }
 815     else if($datestamp['year'] == $datenow['year'] && $datestamp['yday'] == $datenow['yday']) {
 816         // Today
 817         return get_string('today', 'calendar');
 818     }
 819     else if(
 820         ($datestamp['year'] == $datenow['year'] && $datestamp['yday'] == $datenow['yday'] - 1 ) ||
 821         ($datestamp['year'] == $datenow['year'] - 1 && $datestamp['mday'] == 31 && $datestamp['mon'] == 12 && $datenow['yday'] == 1)
 822         ) {
 823         // Yesterday
 824         return get_string('yesterday', 'calendar');
 825     }
 826     else if(
 827         ($datestamp['year'] == $datenow['year'] && $datestamp['yday'] == $datenow['yday'] + 1 ) ||
 828         ($datestamp['year'] == $datenow['year'] + 1 && $datenow['mday'] == 31 && $datenow['mon'] == 12 && $datestamp['yday'] == 1)
 829         ) {
 830         // Tomorrow
 831         return get_string('tomorrow', 'calendar');
 832     }
 833     else {
 834         return $formal;
 835     }
 836 }
 837
 838 function calendar_time_representation($time) {
 839     static $langtimeformat = NULL;
 840     if($langtimeformat === NULL) {
 841         $langtimeformat = get_string('strftimetime');
 842     }
 843     $timeformat = get_user_preferences('calendar_timeformat');
 844     if(empty($timeformat)){
 845         $timeformat = get_config(NULL,'calendar_site_timeformat');
 846     }
 847     // The ? is needed because the preference might be present, but empty
 848     return userdate($time, empty($timeformat) ? $langtimeformat : $timeformat);
 849 }
 850
 851 function calendar_get_link_href($linkbase, $d, $m, $y) {
 852     if(empty($linkbase)) return '';
 853     $paramstr = '';
 854     if(!empty($d)) $paramstr .= '&amp;cal_d='.$d;
 855     if(!empty($m)) $paramstr .= '&amp;cal_m='.$m;
 856     if(!empty($y)) $paramstr .= '&amp;cal_y='.$y;
 857     if(!empty($paramstr)) $paramstr = substr($paramstr, 5);
 858     return $linkbase.$paramstr;
 859 }
 860
 861 function calendar_get_link_tag($text, $linkbase, $d, $m, $y) {
 862     $href = calendar_get_link_href($linkbase, $d, $m, $y);
 863     if(empty($href)) return $text;
 864     return '<a href="'.$href.'">'.$text.'</a>';
 865 }
 866
 867 /**
 868  * Build and return a previous month HTML link, with an arrow.
 869  * @param string $text The text label.
 870  * @param string $linkbase The URL stub.
 871  * @param int $d $m $y Day of month, month and year numbers.
 872  * @param bool $accesshide Default visible, or hide from all except screenreaders.
 873  * @return string HTML string.
 874  */
 875 function calendar_get_link_previous($text, $linkbase, $d, $m, $y, $accesshide=false) {
 876     $href = calendar_get_link_href($linkbase, $d, $m, $y);
 877     if(empty($href)) return $text;
 878     return link_arrow_left($text, $href, $accesshide, 'previous');
 879 }
 880
 881 /**
 882  * Build and return a next month HTML link, with an arrow.
 883  * @param string $text The text label.
 884  * @param string $linkbase The URL stub.
 885  * @param int $d $m $y Day of month, month and year numbers.
 886  * @param bool $accesshide Default visible, or hide from all except screenreaders.
 887  * @return string HTML string.
 888  */
 889 function calendar_get_link_next($text, $linkbase, $d, $m, $y, $accesshide=false) {
 890     $href = calendar_get_link_href($linkbase, $d, $m, $y);
 891     if(empty($href)) return $text;
 892     return link_arrow_right($text, $href, $accesshide, 'next');
 893 }
 894
 895 function calendar_wday_name($englishname) {
 896     return get_string(strtolower($englishname), 'calendar');
 897 }
 898
 899 function calendar_days_in_month($month, $year) {
 900    return intval(date('t', mktime(0, 0, 0, $month, 1, $year)));
 901 }
 902
 903 function calendar_get_sideblock_upcoming($events, $linkhref = NULL) {
 904     $content = '';
 905     $lines = count($events);
 906     if (!$lines) {
 907         return $content;
 908     }
 909
 910     for ($i = 0; $i < $lines; ++$i) {
 911         if (!isset($events[$i]->time)) {   // Just for robustness
 912             continue;
 913         }
 914         $events[$i] = calendar_add_event_metadata($events[$i]);
 915         $content .= '<div class="event"><span class="icon c0">'.$events[$i]->icon.'</span> ';
 916         if (!empty($events[$i]->referer)) {
 917             // That's an activity event, so let's provide the hyperlink
 918             $content .= $events[$i]->referer;
 919         } else {
 920             if(!empty($linkhref)) {
 921                 $ed = usergetdate($events[$i]->timestart);
 922                 $href = calendar_get_link_href(CALENDAR_URL.$linkhref, $ed['mday'], $ed['mon'], $ed['year']);
 923                 $content .= '<a href="'.$href.'#event_'.$events[$i]->id.'">'.$events[$i]->name.'</a>';
 924             }
 925             else {
 926                 $content .= $events[$i]->name;
 927             }
 928         }
 929         $events[$i]->time = str_replace('&raquo;', '<br />&raquo;', $events[$i]->time);
 930         $content .= '<div class="date">'.$events[$i]->time.'</div></div>';
 931         if ($i < $lines - 1) $content .= '<hr />';
 932     }
 933
 934     return $content;
 935 }
 936
 937 function calendar_add_month($month, $year) {
 938     if($month == 12) {
 939         return array(1, $year + 1);
 940     }
 941     else {
 942         return array($month + 1, $year);
 943     }
 944 }
 945
 946 function calendar_sub_month($month, $year) {
 947     if($month == 1) {
 948         return array(12, $year - 1);
 949     }
 950     else {
 951         return array($month - 1, $year);
 952     }
 953 }
 954
 955 function calendar_events_by_day($events, $month, $year, &$eventsbyday, &$durationbyday, &$typesbyday) {
 956     $eventsbyday = array();
 957     $typesbyday = array();
 958     $durationbyday = array();
 959
 960     if($events === false) {
 961         return;
 962     }
 963
 964     foreach($events as $event) {
 965
 966         $startdate = usergetdate($event->timestart);
 967         $enddate   = usergetdate($event->timestart + $event->timeduration);
 968
 969         // Simple arithmetic: $year * 13 + $month is a distinct integer for each distinct ($year, $month) pair
 970         if(!($startdate['year'] * 13 + $startdate['mon'] <= $year * 13 + $month) && ($enddate['year'] * 13 + $enddate['mon'] >= $year * 13 + $month)) {
 971             // Out of bounds
 972             continue;
 973         }
 974
 975         $eventdaystart = intval($startdate['mday']);
 976
 977         if($startdate['mon'] == $month && $startdate['year'] == $year) {
 978             // Give the event to its day
 979             $eventsbyday[$eventdaystart][] = $event->id;
 980
 981             // Mark the day as having such an event
 982             if($event->courseid == SITEID && $event->groupid == 0) {
 983                 $typesbyday[$eventdaystart]['startglobal'] = true;
 984             }
 985             else if($event->courseid != 0 && $event->courseid != SITEID && $event->groupid == 0) {
 986                 $typesbyday[$eventdaystart]['startcourse'] = true;
 987             }
 988             else if($event->groupid) {
 989                 $typesbyday[$eventdaystart]['startgroup'] = true;
 990             }
 991             else if($event->userid) {
 992                 $typesbyday[$eventdaystart]['startuser'] = true;
 993             }
 994         }
 995
 996         if($event->timeduration == 0) {
 997             // Proceed with the next
 998             continue;
 999         }
1000
1001         // The event starts on $month $year or before. So...
1002         $lowerbound = $startdate['mon'] == $month && $startdate['year'] == $year ? intval($startdate['mday']) : 0;
1003
1004         // Also, it ends on $month $year or later...
1005         $upperbound = $enddate['mon'] == $month && $enddate['year'] == $year ? intval($enddate['mday']) : calendar_days_in_month($month, $year);
1006
1007         // Mark all days between $lowerbound and $upperbound (inclusive) as duration
1008         for($i = $lowerbound + 1; $i <= $upperbound; ++$i) {
1009             $durationbyday[$i][] = $event->id;
1010             if($event->courseid == SITEID && $event->groupid == 0) {
1011                 $typesbyday[$i]['durationglobal'] = true;
1012             }
1013             else if($event->courseid != 0 && $event->courseid != SITEID && $event->groupid == 0) {
1014                 $typesbyday[$i]['durationcourse'] = true;
1015             }
1016             else if($event->groupid) {
1017                 $typesbyday[$i]['durationgroup'] = true;
1018             }
1019             else if($event->userid) {
1020                 $typesbyday[$i]['durationuser'] = true;
1021             }
1022         }
1023
1024     }
1025     return;
1026 }
1027
1028 function calendar_get_module_cached(&$coursecache, $modulename, $instance) {
1029     $module = get_coursemodule_from_instance($modulename, $instance);
1030
1031     if($module === false) return false;
1032     if(!calendar_get_course_cached($coursecache, $module->course)) {
1033         return false;
1034     }
1035     return $module;
1036 }
1037
1038 function calendar_get_course_cached(&$coursecache, $courseid) {
1039     if(!isset($coursecache[$courseid])) {
1040         $coursecache[$courseid] = get_record('course', 'id', $courseid);
1041     }
1042     return $coursecache[$courseid];
1043 }
1044
1045 function calendar_session_vars() {
1046     global $SESSION, $USER;
1047
1048     if(!empty($USER->id) && isset($USER->realuser) && !isset($SESSION->cal_loggedinas)) {
1049         // We just logged in as someone else, update the filtering
1050         unset($SESSION->cal_users_shown);
1051         unset($SESSION->cal_courses_shown);
1052         $SESSION->cal_loggedinas = true;
1053         if(intval(get_user_preferences('calendar_persistflt', 0))) {
1054             calendar_set_filters_status(get_user_preferences('calendar_savedflt', 0xff));
1055         }
1056     }
1057     else if(!empty($USER->id) && !isset($USER->realuser) && isset($SESSION->cal_loggedinas)) {
1058         // We just logged back to our real self, update again
1059         unset($SESSION->cal_users_shown);
1060         unset($SESSION->cal_courses_shown);
1061         unset($SESSION->cal_loggedinas);
1062         if(intval(get_user_preferences('calendar_persistflt', 0))) {
1063             calendar_set_filters_status(get_user_preferences('calendar_savedflt', 0xff));
1064         }
1065     }
1066
1067     if(!isset($SESSION->cal_course_referer)) {
1068         $SESSION->cal_course_referer = 0;
1069     }
1070     if(!isset($SESSION->cal_show_global)) {
1071         $SESSION->cal_show_global = true;
1072     }
1073     if(!isset($SESSION->cal_show_groups)) {
1074         $SESSION->cal_show_groups = true;
1075     }
1076     if(!isset($SESSION->cal_show_course)) {
1077         $SESSION->cal_show_course = true;
1078     }
1079     if(!isset($SESSION->cal_show_user)) {
1080         $SESSION->cal_show_user = true;
1081     }
1082    // if(empty($SESSION->cal_courses_shown)) {
1083         $SESSION->cal_courses_shown = calendar_get_default_courses(true);
1084     //}
1085     if(empty($SESSION->cal_users_shown)) {
1086         // The empty() instead of !isset() here makes a whole world of difference,
1087         // as it will automatically change to the user's id when the user first logs
1088         // in. With !isset(), it would never do that.
1089         $SESSION->cal_users_shown = !empty($USER->id) ? $USER->id : false;
1090     }
1091     else if(is_numeric($SESSION->cal_users_shown) && !empty($USER->id) && $SESSION->cal_users_shown != $USER->id) {
1092         // Follow the white rabbit, for example if a teacher logs in as a student
1093         $SESSION->cal_users_shown = $USER->id;
1094     }
1095 }
1096
1097 function calendar_overlib_html() {
1098     return '<div id="overDiv" style="position: absolute; visibility: hidden; z-index:1000;"></div>'
1099           .'<script type="text/javascript" src="'.CALENDAR_URL.'overlib.cfg.php"></script>';
1100 }
1101
1102 function calendar_set_referring_course($courseid) {
1103     global $SESSION;
1104     $SESSION->cal_course_referer = intval($courseid);
1105 }
1106
1107 function calendar_set_filters(&$courses, &$group, &$user, $courseeventsfrom = NULL, $groupeventsfrom = NULL, $ignorefilters = false) {
1108     global $SESSION, $USER, $CFG;
1109
1110     // Insidious bug-wannabe: setting $SESSION->cal_courses_shown to $course->id would cause
1111     // the code to function incorrectly UNLESS we convert it to an integer. One case where
1112     // PHP's loose type system works against us.
1113     if(is_string($SESSION->cal_courses_shown)) {
1114         $SESSION->cal_courses_shown = intval($SESSION->cal_courses_shown);
1115     }
1116
1117     if($courseeventsfrom === NULL) {
1118         $courseeventsfrom = $SESSION->cal_courses_shown;
1119     }
1120     if($groupeventsfrom === NULL) {
1121         $groupeventsfrom = $SESSION->cal_courses_shown;
1122     }
1123
1124     if(($SESSION->cal_show_course && $SESSION->cal_show_global) || $ignorefilters) {
1125         if(is_int($courseeventsfrom)) {
1126             $courses = array(SITEID, $courseeventsfrom);
1127         }
1128         else if(is_array($courseeventsfrom)) {
1129             $courses = array_keys($courseeventsfrom);
1130             $courses[] = SITEID;
1131         }
1132     }
1133     else if($SESSION->cal_show_course) {
1134         if(is_int($courseeventsfrom)) {
1135             $courses = array($courseeventsfrom);
1136         }
1137         else if(is_array($courseeventsfrom)) {
1138             $courses = array_keys($courseeventsfrom);
1139         }
1140         $courses = array_diff($courses, array(SITEID));
1141     }
1142     else if($SESSION->cal_show_global) {
1143         $courses = array(SITEID);
1144     }
1145     else {
1146         $courses = false;
1147     }
1148     //BUG 6130 clean $courses array as SESSION has bad entries.
1149     // [pj] TODO: See if this has to do with my new change in get_default_courses and can be taken out
1150     if (is_array($courses)) {
1151         foreach ($courses as $index => $value) {
1152             if (empty($value)) unset($courses[$index]);
1153         }
1154     }
1155
1156     if($SESSION->cal_show_user || $ignorefilters) {
1157         // This doesn't work for arrays yet (maybe someday it will)
1158         $user = $SESSION->cal_users_shown;
1159     }
1160     else {
1161         $user = false;
1162     }
1163     if($SESSION->cal_show_groups || $ignorefilters) {
1164         if(is_int($groupeventsfrom)) {
1165             $groupcourses = array($groupeventsfrom);
1166         }
1167         else if(is_array($groupeventsfrom)) {
1168             $groupcourses = array_keys($groupeventsfrom);
1169         }
1170
1171         // XXX TODO: not sure how to replace $CFG->calendar_adminseesall
1172         if(has_capability('moodle/calendar:manageentries', get_context_instance(CONTEXT_SYSTEM, SITEID)) && !empty($CFG->calendar_adminseesall)) {
1173             $group = true;
1174         }
1175         else {
1176             $grouparray = array();
1177
1178             // We already have the courses to examine in $courses
1179             // For each course...
1180
1181             foreach($groupcourses as $courseid) {
1182
1183                 // If the user is an editing teacher in there,
1184                 if(!empty($USER->id) && has_capability('moodle/calendar:manageentries', get_context_instance(CONTEXT_COURSE, $courseid))) {
1185                     // If this course has groups, show events from all of them
1186                     if(is_int($groupeventsfrom)) {
1187                         $courserecord = get_record('course', 'id', $courseid);
1188                         if ($courserecord->groupmode != NOGROUPS || !$courserecord->groupmodeforce) {
1189                             $groupids[] = $courseid;
1190                         }
1191                     }
1192                     else if(isset($SESSION->cal_courses_shown[$courseid]) && ($SESSION->cal_courses_shown[$courseid]->groupmode != NOGROUPS || !$SESSION->cal_courses_shown[$courseid]->groupmodeforce)) {
1193                         $groupids[] = $courseid;
1194                     }
1195                 }
1196
1197                 // Otherwise (not editing teacher) show events from the group he is a member of
1198                 else if(isset($USER->groupmember[$courseid])) {
1199                     //changed to 2D array
1200                     foreach ($USER->groupmember[$courseid] as $groupid){
1201                         $rec = get_record('groups_courses_groups', 'courseid', $courseid, 'groupid', $groupid);
1202                         //$grouparray[] = $groupid;
1203                         $grouparray[] = $rec->id;
1204                     }
1205                 }
1206             }
1207             if (!empty($groupids)) {
1208                 $sql = "SELECT groupid, groupid
1209                         FROM {$CFG->prefix}groups_courses_groups
1210                         WHERE courseid IN (".implode(',', $groupids).')';
1211
1212                 if ($grouprecords= get_records_sql($sql)) {
1213                     $grouparray = array_merge($grouparray, array_keys($grouprecords));
1214                 }
1215             }
1216
1217             if(empty($grouparray)) {
1218                 $group = false;
1219             }
1220             else {
1221                 $group = $grouparray;
1222             }
1223         }
1224
1225     }
1226     else {
1227         $group = false;
1228     }
1229 }
1230
1231 function calendar_edit_event_allowed($event) {
1232
1233     global $USER;
1234
1235     // can not be using guest account
1236     if ($USER->username == "guest") {
1237         return false;
1238     }
1239
1240     $sitecontext = get_context_instance(CONTEXT_SYSTEM, SITEID);
1241     // if user has manageentries at site level, return true
1242     if (has_capability('moodle/calendar:manageentries', $sitecontext)) {
1243         return true;
1244     }
1245
1246     // if groupid is set, it's definitely a group event
1247     if ($event->groupid) {
1248         //TODO:check.
1249         if (! groups_group_exists($event->groupid)) {
1250             return false;
1251         }
1252
1253         // this is ok because if you have this capability at course level, you should be able
1254         // to edit group calendar too
1255         // there is no need to check membership, because if you have this capability
1256         // you will have a role in this group context
1257         return has_capability('moodle/calendar:manageentries', get_context_instance(CONTEXT_GROUP, $event->groupid));
1258     } else if ($event->courseid) {
1259     // if groupid is not set, but course is set,
1260     // it's definiely a course event
1261         return has_capability('moodle/calendar:manageentries', get_context_instance(CONTEXT_COURSE, $event->courseid));
1262     } else if ($event->userid && $event->userid == $USER->id) {
1263     // if course is not set, but userid id set, it's a user event
1264         return (has_capability('moodle/calendar:manageownentries', $sitecontext));
1265     }
1266     return false;
1267 }
1268
1269 function calendar_get_default_courses($ignoreref = false) {
1270     global $USER, $CFG, $SESSION;
1271
1272     if(!empty($SESSION->cal_course_referer) && !$ignoreref) {
1273         return array($SESSION->cal_course_referer => 1);
1274     }
1275
1276     if(empty($USER->id)) {
1277         return array();
1278     }
1279
1280     $courses = array();
1281     if (has_capability('moodle/calendar:manageentries', get_context_instance(CONTEXT_SYSTEM, SITEID))) {
1282         if (!empty($CFG->calendar_adminseesall)) {
1283             $courses = get_records_sql('SELECT id, 1 FROM '.$CFG->prefix.'course');
1284             return $courses;
1285         }
1286     }
1287
1288     if (isset($CFG->adminseesall)) {
1289         $courses = get_my_courses($USER->id, null, null, $CFG->adminseesall);
1290     }
1291     else {
1292         $courses = get_my_courses($USER->id, null, null, false);
1293     }
1294
1295     return $courses;
1296 }
1297
1298 function calendar_preferences_button() {
1299     global $CFG, $USER;
1300
1301     // Guests have no preferences
1302     if (empty($USER->id) || isguest()) {
1303         return '';
1304     }
1305
1306     return "<form $CFG->frametarget method=\"get\" ".
1307            " action=\"$CFG->wwwroot/calendar/preferences.php\">".
1308            "<div><input type=\"submit\" value=\"".get_string("preferences", "calendar")." ...\" /></div></form>";
1309 }
1310
1311 function calendar_format_event_time($event, $now, $morehref, $usecommonwords = true) {
1312     $startdate = usergetdate($event->timestart);
1313     $enddate = usergetdate($event->timestart + $event->timeduration);
1314     $usermidnightstart = usergetmidnight($event->timestart);
1315
1316     if($event->timeduration) {
1317         // To avoid doing the math if one IF is enough :)
1318         $usermidnightend = usergetmidnight($event->timestart + $event->timeduration);
1319     }
1320     else {
1321         $usermidnightend = $usermidnightstart;
1322     }
1323
1324     // OK, now to get a meaningful display...
1325     // First of all we have to construct a human-readable date/time representation
1326
1327     if($event->timestart + $event->timeduration < $now) {
1328         // It has expired, so we don't care about duration
1329         $day = calendar_day_representation($event->timestart + $event->timeduration, $now, $usecommonwords);
1330         $time = calendar_time_representation($event->timestart + $event->timeduration);
1331
1332         // This var always has the printable time representation
1333         $eventtime = '<span class="dimmed_text"><a class="dimmed" href="'.calendar_get_link_href(CALENDAR_URL.'view.php?view=day'.$morehref.'&amp;', $enddate['mday'], $enddate['mon'], $enddate['year']).'">'.$day.'</a> ('.$time.')</span>';
1334
1335     }
1336     else if($event->timeduration) {
1337         // It has a duration
1338         if($usermidnightstart == $usermidnightend) {
1339             // But it's all on the same day
1340             $day = calendar_day_representation($event->timestart, $now, $usecommonwords);
1341             $timestart = calendar_time_representation($event->timestart);
1342             $timeend = calendar_time_representation($event->timestart + $event->timeduration);
1343
1344             // Set printable representation
1345             $eventtime = calendar_get_link_tag($day, CALENDAR_URL.'view.php?view=day'.$morehref.'&amp;', $enddate['mday'], $enddate['mon'], $enddate['year']).
1346                 ' ('.$timestart.' <strong>&raquo;</strong> '.$timeend.')';
1347         }
1348         else {
1349             // It spans two or more days
1350             $daystart = calendar_day_representation($event->timestart, $now, $usecommonwords);
1351             $dayend = calendar_day_representation($event->timestart + $event->timeduration, $now, $usecommonwords);
1352             $timestart = calendar_time_representation($event->timestart);
1353             $timeend = calendar_time_representation($event->timestart + $event->timeduration);
1354
1355             // Set printable representation
1356             $eventtime = calendar_get_link_tag($daystart, CALENDAR_URL.'view.php?view=day'.$morehref.'&amp;', $startdate['mday'], $startdate['mon'], $startdate['year']).
1357                 ' ('.$timestart.') <strong>&raquo;</strong> '.calendar_get_link_tag($dayend, CALENDAR_URL.'view.php?view=day'.$morehref.'&amp;', $enddate['mday'], $enddate['mon'], $enddate['year']).
1358                 ' ('.$timeend.')';
1359         }
1360     }
1361     else {
1362         // It's an "instantaneous" event
1363         $day = calendar_day_representation($event->timestart, $now, $usecommonwords);
1364         $time = calendar_time_representation($event->timestart);
1365
1366         // Set printable representation
1367         $eventtime = calendar_get_link_tag($day, CALENDAR_URL.'view.php?view=day'.$morehref.'&amp;', $startdate['mday'], $startdate['mon'], $startdate['year']).' ('.$time.')';
1368     }
1369
1370     return $eventtime;
1371 }
1372
1373 function calendar_print_month_selector($name, $selected) {
1374
1375     $months = array();
1376
1377     for ($i=1; $i<=12; $i++) {
1378         $months[$i] = userdate(gmmktime(12, 0, 0, $i, 15, 2000), '%B');
1379     }
1380
1381     choose_from_menu($months, $name, $selected, '');
1382 }
1383
1384 function calendar_get_filters_status() {
1385     global $SESSION;
1386
1387     $status = 0;
1388     if($SESSION->cal_show_global) {
1389         $status += 1;
1390     }
1391     if($SESSION->cal_show_course) {
1392         $status += 2;
1393     }
1394     if($SESSION->cal_show_groups) {
1395         $status += 4;
1396     }
1397     if($SESSION->cal_show_user) {
1398         $status += 8;
1399     }
1400     return $status;
1401 }
1402
1403 function calendar_set_filters_status($packed_bitfield) {
1404     global $SESSION, $USER;
1405
1406     if(!isset($USER) || empty($USER->id)) {
1407         return false;
1408     }
1409
1410     $SESSION->cal_show_global = ($packed_bitfield & 1);
1411     $SESSION->cal_show_course = ($packed_bitfield & 2);
1412     $SESSION->cal_show_groups = ($packed_bitfield & 4);
1413     $SESSION->cal_show_user   = ($packed_bitfield & 8);
1414
1415     return true;
1416 }
1417
1418 function calendar_get_allowed_types(&$allowed) {
1419     global $USER, $CFG, $SESSION;
1420     $sitecontext = get_context_instance(CONTEXT_SYSTEM);
1421     $allowed->user = has_capability('moodle/calendar:manageownentries', $sitecontext);
1422     $allowed->groups = false; // This may change just below
1423     $allowed->courses = false; // This may change just below
1424     $allowed->site = has_capability('moodle/calendar:manageentries', get_context_instance(CONTEXT_COURSE, SITEID));
1425
1426     if(!empty($SESSION->cal_course_referer) && $SESSION->cal_course_referer != SITEID && has_capability('moodle/calendar:manageentries', get_context_instance(CONTEXT_COURSE, $SESSION->cal_course_referer))) {
1427         $course = get_record('course', 'id', $SESSION->cal_course_referer);
1428
1429         $allowed->courses = array($course->id => 1);
1430
1431         if($course->groupmode != NOGROUPS || !$course->groupmodeforce) {
1432             $allowed->groups = get_groups($SESSION->cal_course_referer);
1433         }
1434     }
1435 }
1436
1437 /**
1438  * see if user can add calendar entries at all
1439  * used to print the "New Event" button
1440  * @return bool
1441  */
1442 function calendar_user_can_add_event() {
1443     calendar_get_allowed_types($allowed);
1444     return (bool)($allowed->user || $allowed->groups || $allowed->courses || $allowed->site);
1445 }
1446 ?>