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