/**
* create (very simple) timezone and standard/daylight components
*
* Result when 'Europe/Stockholm' is used as timezone:
*
* BEGIN:VTIMEZONE
* TZID:Europe/Stockholm
* BEGIN:STANDARD
* DTSTART:20101031T020000
* TZOFFSETFROM:+0200
* TZOFFSETTO:+0100
* RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
* TZNAME:CET
* END:STANDARD
* BEGIN:DAYLIGHT
* DTSTART:20100328T030000
* TZOFFSETFROM:+0100
* TZOFFSETTO:+0200
* RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=3
* TZNAME:CEST
* END:DAYLIGHT
* END:VTIMEZONE
*
* @author Kjell-Inge Gustafsson, kigkonsult <*****@*****.**>
* @since 2.10.3 - 2011-08-01
* @param object $calendar, reference to an iCalcreator calendar instance
* @param string $timezone, a PHP5 (DateTimeZone) valid timezone
* @param array $xProp, *[x-propName => x-propValue], optional
* @return bool
*/
public static function createTimezone(&$calendar, $timezone, $xProp = array())
{
if (!class_exists('DateTimeZone')) {
return FALSE;
}
if (empty($timezone)) {
return FALSE;
}
try {
$dtz = new DateTimeZone($timezone);
} catch (Exception $e) {
return FALSE;
}
$stdDTSTART = $stdTZOFFSETTO = $stdTZOFFSETFROM = $stdTZNAME = $dlghtDTSTART = $dlghtTZOFFSETTO = $dlghtTZOFFSETFROM = $dlghtTZNAME = FALSE;
$dateNow = new DateTime();
$transitions = $dtz->getTransitions();
foreach ($transitions as $trans) {
if (FALSE === ($date = DateTime::createFromFormat('Y-m-d', substr($trans['time'], 0, 10)))) {
continue;
}
if ($date > $dateNow) {
break;
}
if (TRUE !== $trans['isdst']) {
$stdDTSTART = $trans['time'];
$stdTZOFFSETTO = $dlghtTZOFFSETFROM = iCal_UtilityFunctions::offsetSec2His($trans['offset']);
$stdTZNAME = $trans['abbr'];
} else {
$dlghtDTSTART = $trans['time'];
$dlghtTZOFFSETTO = $stdTZOFFSETFROM = iCal_UtilityFunctions::offsetSec2His($trans['offset']);
$dlghtTZNAME = $trans['abbr'];
}
}
if (!$stdDTSTART || !$stdTZOFFSETTO || !$stdTZOFFSETFROM) {
return FALSE;
}
$tz =& $calendar->newComponent('vtimezone');
$tz->setproperty('tzid', $timezone);
if (!empty($xProp)) {
foreach ($xProp as $xPropName => $xPropValue) {
if ('x-' == strtolower(substr($xPropName, 0, 2))) {
$tz->setproperty($xPropName, $xPropValue);
}
}
}
$std =& $tz->newComponent('standard');
$std->setProperty('dtstart', $stdDTSTART);
if ($stdTZNAME) {
$std->setProperty('tzname', $stdTZNAME);
}
$std->setProperty('tzoffsetto', $stdTZOFFSETTO);
$std->setProperty('tzoffsetfrom', $stdTZOFFSETFROM);
if ($stdTZOFFSETTO != $stdTZOFFSETFROM && FALSE === iCal_UtilityFunctions::_setTZrrule($std)) {
$std->setProperty('RRULE', array('FREQ' => 'YEARLY', 'BYDAY' => array('-1', 'DAY' => 'SU'), 'BYMONTH' => 10));
}
if (!$dlghtDTSTART || !$dlghtTZOFFSETTO || !$dlghtTZOFFSETFROM || $dlghtTZOFFSETTO == $dlghtTZOFFSETFROM) {
return TRUE;
}
$dlght =& $tz->newComponent('daylight');
$dlght->setProperty('dtstart', $dlghtDTSTART);
if ($dlghtTZNAME) {
$dlght->setProperty('tzname', $dlghtTZNAME);
}
$dlght->setProperty('tzoffsetto', $dlghtTZOFFSETTO);
$dlght->setProperty('tzoffsetfrom', $dlghtTZOFFSETFROM);
if (FALSE === iCal_UtilityFunctions::_setTZrrule($dlght)) {
$dlght->setProperty('RRULE', array('FREQ' => 'YEARLY', 'BYDAY' => array('-1', 'DAY' => 'SU'), 'BYMONTH' => 3));
}
return TRUE;
}