| Current File : /home/bwalansa/www/wp-content/plugins/the-events-calendar/src/Tribe/Timezones.php |
<?php
/**
* Helpers for handling timezone based event datetimes.
*
* In our timezone logic, the term "local" refers to the locality of an event
* rather than the local WordPress timezone.
*/
class Tribe__Events__Timezones {
const SITE_TIMEZONE = 'site';
const EVENT_TIMEZONE = 'event';
/**
* Container for reusable DateTimeZone objects.
*
* @var array
*/
protected static $timezones = array();
public static function init() {
self::display_timezones();
self::invalidate_caches();
}
/**
* Takes care of appending timezone information to the display of
* event date/times.
*/
protected static function display_timezones() {
if ( tribe_get_option( 'tribe_events_timezones_show_zone' ) ) {
add_filter( 'tribe_events_event_schedule_details_inner', array( __CLASS__, 'append_timezone' ), 10, 2 );
}
}
/**
* Adds the timezone to the event schedule information.
*
* @param string $schedule_text
* @param int|null $event_id
*
* @return string
*/
public static function append_timezone( $schedule_text, $event_id = null ) {
static $hide_for_all_day;
if ( ! isset( $hide_for_all_day ) ) {
$hide_for_all_day = apply_filters( 'tribe_events_hide_timezone_for_all_day_events', true );
}
if ( tribe_event_is_all_day( $event_id ) && $hide_for_all_day ) {
return $schedule_text;
}
$timezone = Tribe__Events__Timezones::is_mode( 'site' )
? self::wp_timezone_abbr( tribe_get_start_date( $event_id, true, Tribe__Events__Date_Utils::DBDATETIMEFORMAT ) )
: self::get_event_timezone_abbr( $event_id );
if ( ! empty( $timezone ) ) {
$timezone_text = " <span class='timezone'> $timezone </span>";
$schedule_text = $schedule_text . $timezone_text;
}
return $schedule_text;
}
/**
* Clear any cached timezone-related values when appropriate.
*
* Currently we are concerned only with the site timezone abbreviation.
*/
protected static function invalidate_caches() {
add_filter( 'pre_update_option_gmt_offset', array( __CLASS__, 'clear_site_timezone_abbr' ) );
add_filter( 'pre_update_option_timezone_string', array( __CLASS__, 'clear_site_timezone_abbr' ) );
}
/**
* Wipe the cached site timezone abbreviation, if set.
*
* @param mixed $option_val (passed through without modification)
*
* @return mixed
*/
public static function clear_site_timezone_abbr( $option_val ) {
delete_transient( 'tribe_events_wp_timezone_abbr' );
return $option_val;
}
/**
* Returns the timezone string for the specified event (if null it assumes the
* current event where that can be determined).
*
* If no timezone has explicitly been set for the event, it returns the global
* WordPress timezone string.
*
* @param int|null $event_id
*
* @return string
*/
public static function get_event_timezone_string( $event_id = null ) {
$event_id = Tribe__Events__Main::postIdHelper( $event_id );
$tzstring = get_post_meta( $event_id, '_EventTimezone', true );
return $tzstring ? $tzstring : self::wp_timezone_string();
}
/**
* Returns the event's timezone abbreviation if it can be determined, or else
* falls back on the full timezone string/offset text (again, if known - if it
* is not it will assume the global WP timezone setting).
*
* @param int|null $event_id
*
* @return string
*/
public static function get_event_timezone_abbr( $event_id = null ) {
$abbr = get_post_meta( $event_id, '_EventTimezoneAbbr', true );
if ( empty( $abbr ) ) {
$timezone_string = self::get_event_timezone_string( $event_id );
$date = tribe_get_start_date( $event_id, true, Tribe__Events__Date_Utils::DBDATETIMEFORMAT );
$abbr = self::abbr( $date, $timezone_string );
}
return empty( $abbr )
? $timezone_string
: $abbr;
}
/**
* Returns the current site-wide timezone string.
*
* Based on the core WP code found in wp-admin/options-general.php.
*
* @return string
*/
public static function wp_timezone_string() {
$current_offset = get_option( 'gmt_offset' );
$tzstring = get_option( 'timezone_string' );
// Return the timezone string if already set
if ( ! empty( $tzstring ) ) {
return $tzstring;
}
// Otherwise return the UTC offset
if ( 0 == $current_offset ) {
return 'UTC+0';
} elseif ($current_offset < 0) {
return 'UTC' . $current_offset;
}
return 'UTC+' . $current_offset;
}
/**
* Returns the current site-wide timezone string abbreviation, if it can be
* determined or falls back on the full timezone string/offset text.
*
* @param string $date
*
* @return string
*/
public static function wp_timezone_abbr( $date ) {
$abbr = get_transient( 'tribe_events_wp_timezone_abbr' );
if ( empty( $abbr ) ) {
$timezone_string = self::wp_timezone_string();
$abbr = self::abbr( $date, $timezone_string );
set_transient( 'tribe_events_wp_timezone_abbr', $abbr );
}
return empty( $abbr )
? $timezone_string
: $abbr;
}
/**
* Tried to convert the provided $datetime to UTC from the timezone represented by $tzstring.
*
* Though the usual range of formats are allowed, $datetime ordinarily ought to be something
* like the "Y-m-d H:i:s" format (ie, no timezone information). If it itself contains timezone
* data, the results may be unexpected.
*
* In those cases where the conversion fails to take place, the $datetime string will be
* returned untouched.
*
* @param string $datetime
* @param string $tzstring
*
* @return string
*/
public static function to_utc( $datetime, $tzstring ) {
if ( self::is_utc_offset( $tzstring ) ) {
return self::apply_offset( $datetime, $tzstring, true );
}
$local = self::get_timezone( $tzstring );
$utc = self::get_timezone( 'UTC' );
$new_datetime = date_create( $datetime, $local );
if ( $new_datetime && $new_datetime->setTimezone( $utc ) ) {
return $new_datetime->format( Tribe__Events__Date_Utils::DBDATETIMEFORMAT );
}
// Fallback to the unmodified datetime if there was a failure during conversion
return $datetime;
}
/**
* Tries to convert the provided $datetime to the timezone represented by $tzstring.
*
* This is the sister function of self::to_utc() - please review the docs for that method
* for more information.
*
* @param string $datetime
* @param string $tzstring
*
* @return string
*/
public static function to_tz( $datetime, $tzstring ) {
if ( self::is_utc_offset( $tzstring ) ) {
return self::apply_offset( $datetime, $tzstring );
}
$local = self::get_timezone( $tzstring );
$utc = self::get_timezone( 'UTC' );
$new_datetime = date_create( $datetime, $utc );
if ( $new_datetime && $new_datetime->setTimezone( $local ) ) {
return $new_datetime->format( Tribe__Events__Date_Utils::DBDATETIMEFORMAT );
}
// Fallback to the unmodified datetime if there was a failure during conversion
return $datetime;
}
/**
* Tests to see if the timezone string is a UTC offset, ie "UTC+2".
*
* @param string $timezone
*
* @return bool
*/
public static function is_utc_offset( $timezone ) {
$timezone = trim( $timezone );
return ( 0 === strpos( $timezone, 'UTC' ) && strlen( $timezone ) > 3 );
}
/**
* @param string $datetime
* @param mixed $offset (string or numeric offset)
* @param bool $invert = false
*
* @return string
*/
public static function apply_offset( $datetime, $offset, $invert = false ) {
// Normalize
$offset = strtolower( trim( $offset ) );
// Strip any leading "utc" text if set
if ( 0 === strpos( $offset, 'utc' ) ) {
$offset = substr( $offset, 3 );
}
// It's possible no adjustment will be needed
if ( 0 === $offset ) {
return $datetime;
}
// Convert the offset to minutes for easier handling of fractional offsets
$offset = (int) ( $offset * 60 );
// Invert the offset? Useful for stripping an offset that has already been applied
if ( $invert ) {
$offset *= -1;
}
if ( $offset > 0 ) {
$offset = '+' . $offset;
}
$offset = $offset . ' minutes';
$offset_datetime = date_create( $datetime );
if ( $offset_datetime && $offset_datetime->modify( $offset ) ) {
return $offset_datetime->format( Tribe__Events__Date_Utils::DBDATETIMEFORMAT );
}
return $datetime;
}
/**
* Returns a timestamp for the event start date that can be passed to tribe_event_format_date()
* in order to produce the time in the correct timezone.
*
* @param int $event_id
* @param string $timezone
*
* @return int
*/
public static function event_start_timestamp( $event_id, $timezone = null ) {
return self::get_event_timestamp( $event_id, 'Start', $timezone );
}
/**
* Returns a timestamp for the event end date that can be passed to tribe_event_format_date()
* in order to produce the time in the correct timezone.
*
* @param int $event_id
* @param string $timezone
*
* @return int
*/
public static function event_end_timestamp( $event_id, $timezone = null ) {
return self::get_event_timestamp( $event_id, 'End', $timezone );
}
/**
* Returns a timestamp for the event date that can be passed to tribe_event_format_date()
* in order to produce the time in the correct timezone.
*
* @param int $event_id
* @param string $type (expected to be 'Start' or 'End')
* @param string $timezone
*
* @return int
*/
protected static function get_event_timestamp( $event_id, $type = 'Start', $timezone = null ) {
$event = get_post( Tribe__Events__Main::postIdHelper( $event_id ) );
$event_tz = get_post_meta( $event->ID, '_EventTimezone', true );
$site_tz = self::wp_timezone_string();
if ( null === $timezone ) {
$timezone = self::mode();
}
// Should we use the event specific timezone or the site-wide timezone?
$use_event_tz = self::EVENT_TIMEZONE === $timezone;
$use_site_tz = self::SITE_TIMEZONE === $timezone;
// Determine if the event timezone and site timezone the same *or* if the event does not have timezone
// information (in which case, we'll assume the event time inherits the site timezone)
$site_zone_is_event_zone = ( $event_tz === $site_tz || empty( $event_tz ) );
// If the event-specific timezone is suitable, we can obtain it without any conversion work
if ( $use_event_tz || ( $use_site_tz && $site_zone_is_event_zone ) ) {
$datetime = isset( $event->{"Event{$type}StartDate"} )
? $event->{"Event{$type}StartDate"}
: get_post_meta( $event->ID, "_Event{$type}Date", true );
return strtotime( $datetime );
}
// Otherwise lets load the event's UTC time and convert it
$datetime = isset( $event->{"Event{$type}StartDateUTC"} )
? $event->{"Event{$type}StartDateUTC"}
: get_post_meta( $event->ID, "_Event{$type}DateUTC", true );
$tzstring = ( self::SITE_TIMEZONE === $timezone )
? self::wp_timezone_string()
: $timezone;
$localized = self::to_tz( $datetime, $tzstring );
return strtotime( $localized );
}
/**
* Accepts a unix timestamp and adjusts it so that when it is used to consitute
* a new datetime string, that string reflects the designated timezone.
*
* @param string $unix_timestamp
* @param string $tzstring
*
* @return string
*/
public static function adjust_timestamp( $unix_timestamp, $tzstring ) {
try {
$local = self::get_timezone( $tzstring );
$datetime = date_create_from_format( 'U', $unix_timestamp )->format( Tribe__Events__Date_Utils::DBDATETIMEFORMAT );
return date_create_from_format( 'Y-m-d H:i:s', $datetime, $local )->getTimestamp();
}
catch( Exception $e ) {
return $unix_timestamp;
}
}
/**
* Returns a DateTimeZone object matching the representation in $tzstring where
* possible, or else representing UTC (or, in the worst case, false).
*
* If optional parameter $with_fallback is true, which is the default, then in
* the event it cannot find/create the desired timezone it will try to return the
* UTC DateTimeZone before bailing.
*
* @param string $tzstring
* @param bool $with_fallback = true
*
* @return DateTimeZone|false
*/
public static function get_timezone( $tzstring, $with_fallback = true ) {
if ( isset( self::$timezones[$tzstring] ) ) {
return self::$timezones[$tzstring];
}
try {
self::$timezones[$tzstring] = new DateTimeZone( $tzstring );
return self::$timezones[$tzstring];
}
catch ( Exception $e ) {
if ( $with_fallback ) {
return self::get_timezone( 'UTC', true );
}
}
return false;
}
/**
* Returns a string representing the timezone/offset currently desired for
* the display of dates and times.
*
* @return string
*/
public static function mode() {
$mode = self::EVENT_TIMEZONE;
if ( 'site' === tribe_get_option( 'tribe_events_timezone_mode' ) ) {
$mode = self::SITE_TIMEZONE;
}
return apply_filters( 'tribe_events_current_display_timezone', $mode );
}
/**
* Confirms if the current timezone mode matches the $possible_mode.
*
* @param string $possible_mode
*
* @return bool
*/
public static function is_mode( $possible_mode ) {
return $possible_mode === self::mode();
}
/**
* Attempts to provide the correct timezone abbreviation for the provided timezone string
* on the date given (and so should account for daylight saving time, etc).
*
* @param string $date
* @param string $timezone_string
*
* @return string
*/
public static function abbr( $date, $timezone_string ) {
try {
return date_create( $date, new DateTimeZone( $timezone_string ) )->format( 'T' );
}
catch ( Exception $e ) {
return '';
}
}
}