Move classes for recurring events/tasks computation to libkolab

plugins/calendar/drivers/kolab/kolab_calendar.php

@@ -360,7 +360,7 @@ class kolab_calendar
         raise_error(array(
           'code' => 600, 'type' => 'php',
           'file' => __FILE__, 'line' => __LINE__,
-          'message' => "Error undeleting a contact object $uid from the Kolab server"),
+          'message' => "Error undeleting the event object $uid from the Kolab server"),
         true, false);
     }
 
@@ -373,10 +373,7 @@ class kolab_calendar
    */
   public function _get_recurring_events($event, $start, $end, $event_id = null)
   {
-    // include library class
-    require_once($this->cal->home . '/lib/calendar_recurrence.php');
-    
-    $recurrence = new calendar_recurrence($this->cal, $event);
+    $recurrence = new kolab_date_recurrence($event);
     
     $events = array();
     $duration = $event['end'] - $event['start'];

plugins/calendar/lib/Horde_Date_Recurrence.php

@@ -5,7 +5,8 @@
  *   PEAR/Date/Calc.php, Horde/Date/Recurrence.php
  */
 
-require_once(dirname(__FILE__) . '/Horde_Date.php');
+if (!class_exists('Horde_Date'))
+    require_once(dirname(__FILE__) . '/Horde_Date.php');
 
 // {{{ Header
 

plugins/calendar/lib/Horde_iCalendar.php

@@ -5,7 +5,8 @@
  *   Horde/String.php, Horde/iCalendar.php, Horde/iCalendar/*.php
  */
 
-require_once(dirname(__FILE__) . '/Horde_Date.php');
+if (!class_exists('Horde_Date'))
+    require_once(dirname(__FILE__) . '/Horde_Date.php');
 
 
 $GLOBALS['_HORDE_STRING_CHARSET'] = 'iso-8859-1';

plugins/libkolab/bin/get_horde_date.sh

@@ -0,0 +1,38 @@
+#!/bin/sh
+
+# Copy Horde_Date_Recurrence classes and dependencies to stdout.
+# This will create a standalone copy of the classes requried for date recurrence computation.
+
+SRCDIR=$1
+
+if [ ! -d "$SRCDIR" ]; then
+  echo "Usage: get_horde_date.sh SRCDIR"
+  echo "Please enter a valid source directory of the Horde libs"
+  exit 1
+fi
+
+echo "<?php
+
+/**
+ * This is a concatenated copy of the following files:
+ *   Horde/Date/Utils.php, Horde/Date/Recurrence.php
+ * Pull the latest version of these files from the PEAR channel of the Horde
+ * project at http://pear.horde.org by installing the Horde_Date package.
+ */
+
+if (!class_exists('Horde_Date'))
+	require_once(dirname(__FILE__) . '/Horde_Date.php');
+
+// minimal required implementation of Horde_Date_Translation to avoid a huge dependency nightmare
+class Horde_Date_Translation
+{
+	function t(\$arg) { return \$arg; }
+	function ngettext(\$sing, \$plur, \$num) { return (\$num > 1 ? \$plur : \$sing); }
+}
+"
+
+sed 's/<?php//; s/?>//' $SRCDIR/Date/Utils.php
+echo "\n"
+sed 's/<?php//; s/?>//' $SRCDIR/Date/Recurrence.php | sed -E "s/Horde_String::/strto/"
+echo "\n"
+

plugins/libkolab/lib/kolab_date_recurrence.php

@@ -0,0 +1,105 @@
+<?php
+
+/**
+ * Recurrence computation class for xcal-based Kolab format objects
+ *
+ * Uitility class to compute instances of recurring events.
+ *
+ * @version @package_version@
+ * @author Thomas Bruederli <bruederli@kolabsys.com>
+ *
+ * Copyright (C) 2012, Kolab Systems AG <contact@kolabsys.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+class kolab_date_recurrence
+{
+  private $engine;
+  private $tz_offset = 0;
+  private $allday = false;
+  private $hour = 0;
+
+  /**
+   * Default constructor
+   *
+   * @param array The Kolab object to operate on
+   */
+  function __construct($object)
+  {
+      // use (copied) Horde classes to compute recurring instances
+      // TODO: replace with something that has less than 6'000 lines of code
+      $this->engine = new Horde_Date_Recurrence($object['start']);
+      $this->engine->fromRRule20($this->to_rrule($object['recurrence']));  // TODO: get that string directly from libkolabxml
+
+      foreach ((array)$object['recurrence']['EXDATE'] as $exdate)
+          $this->engine->addException(date('Y', $exdate), date('n', $exdate), date('j', $exdate));
+
+      $now = new DateTime('now', kolab_format::$timezone);
+      $this->tz_offset = $object['allday'] ? $now->getOffset() - date('Z') : 0;
+      $this->next = new Horde_Date($object['start'] + $this->tz_offset);  # shift all-day times to server timezone because computation operates in local TZ
+      $this->dst_start = $this->next->format('I');
+      $this->allday = $object['allday'];
+      $this->hour = $this->next->hour;
+  }
+
+  /**
+   * Get timestamp of the next occurence of this event
+   *
+   * @return mixed Unix timestamp or False if recurrence ended
+   */
+  public function next_start()
+  {
+    $time = false;
+    if ($this->next && ($next = $this->engine->nextActiveRecurrence(array('year' => $this->next->year, 'month' => $this->next->month, 'mday' => $this->next->mday + 1, 'hour' => $this->next->hour, 'min' => $this->next->min, 'sec' => $this->next->sec)))) {
+      if ($this->allday) {
+        $next->hour = $this->hour;  # fix time for all-day events
+        $next->min = 0;
+      }
+      # consider difference in daylight saving between base event and recurring instance
+      $dst_diff = ($this->dst_start - $next->format('I')) * 3600;
+      $time = $next->timestamp() - $this->tz_offset - $dst_diff;
+      $this->next = $next;
+    }
+
+    return $time;
+  }
+
+  /**
+   * Convert the internal structured data into a vcalendar RRULE 2.0 string
+   */
+  private function to_rrule($recurrence)
+  {
+    if (is_string($recurrence))
+        return $recurrence;
+
+      $rrule = '';
+      foreach ((array)$recurrence as $k => $val) {
+          $k = strtoupper($k);
+          switch ($k) {
+          case 'UNTIL':
+              $val = gmdate('Ymd\THis', $val);
+              break;
+          case 'EXDATE':
+              foreach ((array)$val as $i => $ex)
+                  $val[$i] = gmdate('Ymd\THis', $ex);
+              $val = join(',', (array)$val);
+              break;
+          }
+          $rrule .= $k . '=' . $val . ';';
+      }
+
+    return $rrule;
+  }
+
+}