jfxtras.icalendarfx.components.VTimeZone Maven / Gradle / Ivy
package jfxtras.icalendarfx.components;
import java.lang.reflect.Method;
import java.net.URI;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.stream.Collectors;
import jfxtras.icalendarfx.VCalendar;
import jfxtras.icalendarfx.VChild;
import jfxtras.icalendarfx.components.DaylightSavingTime;
import jfxtras.icalendarfx.components.StandardOrDaylight;
import jfxtras.icalendarfx.components.StandardTime;
import jfxtras.icalendarfx.components.VCommon;
import jfxtras.icalendarfx.components.VComponent;
import jfxtras.icalendarfx.components.VComponentElement;
import jfxtras.icalendarfx.components.VLastModified;
import jfxtras.icalendarfx.components.VTimeZone;
import jfxtras.icalendarfx.properties.component.change.LastModified;
import jfxtras.icalendarfx.properties.component.timezone.TimeZoneIdentifier;
import jfxtras.icalendarfx.properties.component.timezone.TimeZoneURL;
/**
* VTIMEZONE
* Time Zone Component
* RFC 5545 iCalendar 3.6.5. page 62
*
* A time zone is unambiguously defined by the set of time
measurement rules determined by the governing body for a given
geographic area. These rules describe, at a minimum, the base
offset from UTC for the time zone, often referred to as the
Standard Time offset. Many locations adjust their Standard Time
forward or backward by one hour, in order to accommodate seasonal
changes in number of daylight hours, often referred to as Daylight
Saving Time. Some locations adjust their time by a fraction of an
hour. Standard Time is also known as Winter Time. Daylight
Saving Time is also known as Advanced Time, Summer Time, or Legal
Time in certain countries. The following table shows the changes
in time zone rules in effect for New York City starting from 1967.
Each line represents a description or rule for a particular
observance.
Effective Observance Rule
+-----------+--------------------------+--------+--------------+
| Date | (Date-Time) | Offset | Abbreviation |
+-----------+--------------------------+--------+--------------+
| 1967-1973 | last Sun in Apr, 02:00 | -0400 | EDT |
| | | | |
| 1967-2006 | last Sun in Oct, 02:00 | -0500 | EST |
| | | | |
| 1974-1974 | Jan 6, 02:00 | -0400 | EDT |
| | | | |
| 1975-1975 | Feb 23, 02:00 | -0400 | EDT |
| | | | |
| 1976-1986 | last Sun in Apr, 02:00 | -0400 | EDT |
| | | | |
| 1987-2006 | first Sun in Apr, 02:00 | -0400 | EDT |
| | | | |
| 2007-* | second Sun in Mar, 02:00 | -0400 | EDT |
| | | | |
| 2007-* | first Sun in Nov, 02:00 | -0500 | EST |
+-----------+--------------------------+--------+--------------+
Note: The specification of a global time zone registry is not
addressed by this document and is left for future study.
However, implementers may find the TZ database [TZDB] a useful
reference. It is an informal, public-domain collection of time
zone information, which is currently being maintained by
volunteer Internet participants, and is used in several
operating systems. This database contains current and
historical time zone information for a wide variety of
locations around the globe; it provides a time zone identifier
for every unique time zone rule set in actual use since 1970,
with historical data going back to the introduction of standard
time.
Interoperability between two calendaring and scheduling
applications, especially for recurring events, to-dos or journal
entries, is dependent on the ability to capture and convey date
and time information in an unambiguous format. The specification
of current time zone information is integral to this behavior.
If present, the "VTIMEZONE" calendar component defines the set of
Standard Time and Daylight Saving Time observances (or rules) for
a particular time zone for a given interval of time. The
"VTIMEZONE" calendar component cannot be nested within other
calendar components. Multiple "VTIMEZONE" calendar components can
exist in an iCalendar object. In this situation, each "VTIMEZONE"
MUST represent a unique time zone definition. This is necessary
for some classes of events, such as airline flights, that start in
one time zone and end in another.
The "VTIMEZONE" calendar component MUST include the "TZID"
property and at least one definition of a "STANDARD" or "DAYLIGHT"
sub-component. The "STANDARD" or "DAYLIGHT" sub-component MUST
include the "DTSTART", "TZOFFSETFROM", and "TZOFFSETTO"
properties.
An individual "VTIMEZONE" calendar component MUST be specified for
each unique "TZID" parameter value specified in the iCalendar
object. In addition, a "VTIMEZONE" calendar component, referred
to by a recurring calendar component, MUST provide valid time zone
information for all recurrence instances.
Each "VTIMEZONE" calendar component consists of a collection of
one or more sub-components that describe the rule for a particular
observance (either a Standard Time or a Daylight Saving Time
observance). The "STANDARD" sub-component consists of a
collection of properties that describe Standard Time. The
"DAYLIGHT" sub-component consists of a collection of properties
that describe Daylight Saving Time. In general, this collection
of properties consists of:
* the first onset DATE-TIME for the observance;
* the last onset DATE-TIME for the observance, if a last onset is
known;
* the offset to be applied for the observance;
* a rule that describes the day and time when the observance
takes effect;
* an optional name for the observance.
For a given time zone, there may be multiple unique definitions of
the observances over a period of time. Each observance is
described using either a "STANDARD" or "DAYLIGHT" sub-component.
The collection of these sub-components is used to describe the
time zone for a given period of time. The offset to apply at any
given time is found by locating the observance that has the last
onset date and time before the time in question, and using the
offset value from that observance.
The top-level properties in a "VTIMEZONE" calendar component are:
The mandatory "TZID" property is a text value that uniquely
identifies the "VTIMEZONE" calendar component within the scope of
an iCalendar object.
The optional "LAST-MODIFIED" property is a UTC value that
specifies the date and time that this time zone definition was
last updated.
The optional "TZURL" property is a url value that points to a
published "VTIMEZONE" definition. "TZURL" SHOULD refer to a
resource that is accessible by anyone who might need to interpret
the object. This SHOULD NOT normally be a "file" URL or other URL
that is not widely accessible.
The collection of properties that are used to define the
"STANDARD" and "DAYLIGHT" sub-components include:
The mandatory "DTSTART" property gives the effective onset date
and local time for the time zone sub-component definition.
"DTSTART" in this usage MUST be specified as a date with a local
time value.
The mandatory "TZOFFSETFROM" property gives the UTC offset that is
in use when the onset of this time zone observance begins.
"TZOFFSETFROM" is combined with "DTSTART" to define the effective
onset for the time zone sub-component definition. For example,
the following represents the time at which the observance of
Standard Time took effect in Fall 1967 for New York City:
DTSTART:19671029T020000
TZOFFSETFROM:-0400
The mandatory "TZOFFSETTO" property gives the UTC offset for the
time zone sub-component (Standard Time or Daylight Saving Time)
when this observance is in use.
The optional "TZNAME" property is the customary name for the time
zone. This could be used for displaying dates.
The onset DATE-TIME values for the observance defined by the time
zone sub-component is defined by the "DTSTART", "RRULE", and
"RDATE" properties.
The "RRULE" property defines the recurrence rule for the onset of
the observance defined by this time zone sub-component. Some
specific requirements for the usage of "RRULE" for this purpose
include:
* If observance is known to have an effective end date, the
"UNTIL" recurrence rule parameter MUST be used to specify the
last valid onset of this observance (i.e., the UNTIL DATE-TIME
will be equal to the last instance generated by the recurrence
pattern). It MUST be specified in UTC time.
* The "DTSTART" and the "TZOFFSETFROM" properties MUST be used
when generating the onset DATE-TIME values (instances) from the
"RRULE".
The "RDATE" property can also be used to define the onset of the
observance by giving the individual onset date and times. "RDATE"
in this usage MUST be specified as a date with local time value,
relative to the UTC offset specified in the "TZOFFSETFROM"
property.
The optional "COMMENT" property is also allowed for descriptive
explanatory text.
Example: The following are examples of the "VTIMEZONE" calendar
component:
This is an example showing all the time zone rules for New York
City since April 30, 1967 at 03:00:00 EDT.
BEGIN:VTIMEZONE
TZID:America/New_York
LAST-MODIFIED:20050809T050000Z
BEGIN:DAYLIGHT
DTSTART:19670430T020000
RRULE:FREQ=YEARLY;BYMONTH=4;BYDAY=-1SU;UNTIL=19730429T070000Z
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:EDT
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:19671029T020000
RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU;UNTIL=20061029T060000Z
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:EST
END:STANDARD
BEGIN:DAYLIGHT
DTSTART:19740106T020000
RDATE:19750223T020000
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:EDT
END:DAYLIGHT
BEGIN:DAYLIGHT
DTSTART:19760425T020000
RRULE:FREQ=YEARLY;BYMONTH=4;BYDAY=-1SU;UNTIL=19860427T070000Z
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:EDT
END:DAYLIGHT
BEGIN:DAYLIGHT
DTSTART:19870405T020000
RRULE:FREQ=YEARLY;BYMONTH=4;BYDAY=1SU;UNTIL=20060402T070000Z
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:EDT
END:DAYLIGHT
BEGIN:DAYLIGHT
DTSTART:20070311T020000
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
TZNAME:EDT
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20071104T020000
RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
TZNAME:EST
END:STANDARD
END:VTIMEZONE
*
* @author David Bal
*
*/
public class VTimeZone extends VCommon implements VLastModified
{
/**
* STANDARD or DAYLIGHT
* Subcomponent of VTimeZone
* Either StandardTime or DaylightSavingsTime.
* Both classes have identical methods.
*
* @author David Bal
* @see DaylightSavingTime
* @see StandardTime
*
*/
public List> getStandardOrDaylight() { return standardOrDaylight; }
private List> standardOrDaylight;
public void setStandardOrDaylight(List> standardOrDaylight)
{
if (this.standardOrDaylight != null)
{
this.standardOrDaylight.forEach(e -> orderChild(e, null)); // remove old elements
}
this.standardOrDaylight = standardOrDaylight;
if (standardOrDaylight != null)
{
standardOrDaylight.forEach(c -> orderChild(c)); // order new elements
}
}
public VTimeZone withStandardOrDaylight(List> standardOrDaylight)
{
if (getStandardOrDaylight() == null)
{
setStandardOrDaylight(new ArrayList<>());
}
getStandardOrDaylight().addAll(standardOrDaylight);
if (standardOrDaylight != null)
{
standardOrDaylight.forEach(c -> orderChild(c));
}
return this;
}
public VTimeZone withStandardOrDaylight(StandardOrDaylight...standardOrDaylight)
{
return withStandardOrDaylight(Arrays.asList(standardOrDaylight));
}
public VTimeZone withStandardOrDaylight(String...standardOrDaylight)
{
List> newElements = Arrays.stream(standardOrDaylight)
.map(c ->
{
final StandardOrDaylight v;
if (c.startsWith(BEGIN + VComponentElement.DAYLIGHT_SAVING_TIME.toString()))
{
v = DaylightSavingTime.parse(c);
} else if (c.startsWith(BEGIN + VComponentElement.STANDARD_TIME.toString()))
{
v = StandardTime.parse(c);
} else
{
throw new IllegalArgumentException("Invalid calendar content text. Must start with BEGIN:DAYLIGHT or BEGIN:STANDARD");
}
v.addChild(c);
return v;
})
.collect(Collectors.toList());
return withStandardOrDaylight(newElements);
}
/**
* LAST-MODIFIED
* RFC 5545, 3.8.7.3, page 138
*
* This property specifies the date and time that the
* information associated with the calendar component was last
* revised in the calendar store.
*
* Note: This is analogous to the modification date and time for a
* file in the file system.
*
* The value MUST be specified as a date with UTC time.
*
* Example:
* LAST-MODIFIED:19960817T133000Z
*/
private LastModified lastModified;
@Override
public LastModified getDateTimeLastModified() { return lastModified; }
@Override
public void setDateTimeLastModified(LastModified lastModified)
{
orderChild(this.lastModified, lastModified);
this.lastModified = lastModified;
}
/**
* TZID
* Time Zone Identifier
* RFC 5545, 3.8.3.1, page 102
*
* To specify the identifier for the time zone definition for
* a time component in the property value
*
* LIMITATION: globally unique time zones are stored as strings and the ZoneID is null.
* Only the toString and toContentLine methods will display the original string. Another
* method to convert the unique time zone string into a ZoneId is required.
*
* EXAMPLE:
* TZID:America/Los_Angeles
*/
private TimeZoneIdentifier timeZoneIdentifier;
public TimeZoneIdentifier getTimeZoneIdentifier() { return timeZoneIdentifier; }
public void setTimeZoneIdentifier(TimeZoneIdentifier timeZoneIdentifier)
{
orderChild(this.timeZoneIdentifier, timeZoneIdentifier);
this.timeZoneIdentifier = timeZoneIdentifier;
}
public void setTimeZoneIdentifier(String timeZoneIdentifier) { setTimeZoneIdentifier(TimeZoneIdentifier.parse(timeZoneIdentifier)); }
public VTimeZone withTimeZoneIdentifier(TimeZoneIdentifier timeZoneIdentifier)
{
setTimeZoneIdentifier(timeZoneIdentifier);
return this;
}
public VTimeZone withTimeZoneIdentifier(String timeZoneIdentifier)
{
setTimeZoneIdentifier(timeZoneIdentifier);
return this;
}
/**
* TZURL
* Time Zone URL
* RFC 5545, 3.8.3.5, page 106
*
* This property provides a means for a "VTIMEZONE" component
* to point to a network location that can be used to retrieve an up-
* to-date version of itself
*
* EXAMPLES:
* TZURL:http://timezones.example.org/tz/America-Los_Angeles.ics
*/
private TimeZoneURL timeZoneURL;
public TimeZoneURL getTimeZoneURL() { return timeZoneURL; }
public void setTimeZoneURL(TimeZoneURL timeZoneURL)
{
orderChild(this.timeZoneURL, timeZoneURL);
this.timeZoneURL = timeZoneURL;
}
public void setTimeZoneURL(String timeZoneURL) { setTimeZoneURL(TimeZoneURL.parse(timeZoneURL)); }
public void setTimeZoneURL(URI timeZoneURL) { setTimeZoneURL(new TimeZoneURL(timeZoneURL)); }
public VTimeZone withTimeZoneURL(TimeZoneURL timeZoneURL)
{
setTimeZoneURL(timeZoneURL);
return this;
}
public VTimeZone withTimeZoneURL(URI timeZoneURL)
{
setTimeZoneURL(new TimeZoneURL(timeZoneURL));
return this;
}
public VTimeZone withTimeZoneURL(String timeZoneURL)
{
setTimeZoneURL(timeZoneURL);
return this;
}
/*
* CONSTRUCTORS
*/
public VTimeZone() { super(); }
public VTimeZone(VTimeZone source)
{
super(source);
}
@Override
protected Method getSetter(VChild child)
{
Method setter = getSetters().get(child.getClass());
if ((setter == null) && (StandardOrDaylight.class.isAssignableFrom(child.getClass())))
{
setter = getSetters().get(StandardOrDaylight.class);
}
return setter;
}
@Override
protected Method getGetter(VChild child)
{
Method getter = getGetters().get(child.getClass());
if ((getter == null) && (StandardOrDaylight.class.isAssignableFrom(child.getClass())))
{
getter = getGetters().get(StandardOrDaylight.class);
}
return getter;
}
@Override
public List errors()
{
List errors = new ArrayList<>();
if (getTimeZoneIdentifier() == null)
{
errors.add("TZID is REQUIRED and MUST NOT occur more than once");
}
if (getStandardOrDaylight() != null && (getStandardOrDaylight().size() > 0))
{
getStandardOrDaylight().forEach(c -> errors.addAll(c.errors()));
} else
{
errors.add("No STANDARD or DAYLIGHT subcomponents exist. At least one STANDARD or DAYLIGHT subcomponent MUST occur");
}
return Collections.unmodifiableList(errors);
}
@Override
void addSubcomponent(VComponent subcomponent)
{
if (subcomponent instanceof StandardOrDaylight)
{
final List> list;
if (getStandardOrDaylight() == null)
{
list = new ArrayList<>();
setStandardOrDaylight(list);
} else
{
list = getStandardOrDaylight();
}
list.add((StandardOrDaylight) subcomponent);
} else
{
throw new IllegalArgumentException("Unsuported subcomponent type:" + subcomponent.getClass().getSimpleName() +
" found inside " + name() + " component");
}
}
@Override
public List calendarList()
{
if (getParent() != null)
{
VCalendar cal = (VCalendar) getParent();
return cal.getVTimeZones();
}
return null;
}
// @Override // include STANDARD or DAYLIGHT Subcomponents
// public int hashCode()
// {
// int hash = super.hashCode();
// if (getStandardOrDaylight() != null)
// {
// Iterator> i = getStandardOrDaylight().iterator();
// while (i.hasNext())
// {
// Object property = i.next();
// hash = (31 * hash) + property.hashCode();
// }
// }
// return hash;
// }
/**
* Creates a new VTimeZone calendar component by parsing a String of iCalendar content lines
*
* @param content the text to parse, not null
* @return the parsed VTimeZone
*/
public static VTimeZone parse(String content)
{
return VTimeZone.parse(new VTimeZone(), content);
}
}
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