DateIntervalFormat is a class for formatting and parsing date intervals in a language-independent manner. More...

#include <dtitvfmt.h>

Inheritance diagram for icu::DateIntervalFormat:

Public Member Functions
virtual	~DateIntervalFormat ()
	Destructor. More...

virtual Format *	clone (void) const
	Clone this Format object polymorphically. More...

virtual UBool	operator== (const Format &other) const
	Return true if the given Format objects are semantically equal. More...

UBool	operator!= (const Format &other) const
	Return true if the given Format objects are not semantically equal. More...

virtual UnicodeString &	format (const Formattable &obj, UnicodeString &appendTo, FieldPosition &fieldPosition, UErrorCode &status) const
	Format an object to produce a string. More...

UnicodeString &	format (const DateInterval *dtInterval, UnicodeString &appendTo, FieldPosition &fieldPosition, UErrorCode &status) const
	Format a DateInterval to produce a string. More...

UnicodeString &	format (Calendar &fromCalendar, Calendar &toCalendar, UnicodeString &appendTo, FieldPosition &fieldPosition, UErrorCode &status) const
	Format 2 Calendars to produce a string. More...

virtual void	parseObject (const UnicodeString &source, Formattable &result, ParsePosition &parse_pos) const
	Date interval parsing is not supported. More...

const DateIntervalInfo *	getDateIntervalInfo (void) const
	Gets the date time interval patterns. More...

void	setDateIntervalInfo (const DateIntervalInfo &newIntervalPatterns, UErrorCode &status)
	Set the date time interval patterns. More...

const DateFormat *	getDateFormat (void) const
	Gets the date formatter. More...

virtual const TimeZone &	getTimeZone (void) const
	Returns a reference to the TimeZone used by this DateIntervalFormat's calendar. More...

virtual void	adoptTimeZone (TimeZone *zoneToAdopt)
	Sets the time zone for the calendar used by this DateIntervalFormat object. More...

virtual void	setTimeZone (const TimeZone &zone)
	Sets the time zone for the calendar used by this DateIntervalFormat object. More...

virtual UClassID	getDynamicClassID (void) const
	Returns a unique class ID POLYMORPHICALLY. More...

Public Member Functions inherited from icu::Format
virtual	~Format ()
	Destructor. More...

UBool	operator!= (const Format &other) const
	Return true if the given Format objects are not semantically equal. More...

UnicodeString &	format (const Formattable &obj, UnicodeString &appendTo, UErrorCode &status) const
	Formats an object to produce a string. More...

virtual UnicodeString &	format (const Formattable &obj, UnicodeString &appendTo, FieldPositionIterator *posIter, UErrorCode &status) const
	Format an object to produce a string. More...

void	parseObject (const UnicodeString &source, Formattable &result, UErrorCode &status) const
	Parses a string to produce an object. More...

Locale	getLocale (ULocDataLocaleType type, UErrorCode &status) const
	Get the locale for this format object. More...

const char *	getLocaleID (ULocDataLocaleType type, UErrorCode &status) const
	Get the locale for this format object. More...

Public Member Functions inherited from icu::UObject
virtual	~UObject ()
	Destructor. More...

Static Public Member Functions
static DateIntervalFormat *	createInstance (const UnicodeString &skeleton, UErrorCode &status)
	Construct a DateIntervalFormat from skeleton and the default locale. More...

static DateIntervalFormat *	createInstance (const UnicodeString &skeleton, const Locale &locale, UErrorCode &status)
	Construct a DateIntervalFormat from skeleton and a given locale. More...

static DateIntervalFormat *	createInstance (const UnicodeString &skeleton, const DateIntervalInfo &dtitvinf, UErrorCode &status)
	Construct a DateIntervalFormat from skeleton DateIntervalInfo, and default locale. More...

static DateIntervalFormat *	createInstance (const UnicodeString &skeleton, const Locale &locale, const DateIntervalInfo &dtitvinf, UErrorCode &status)
	Construct a DateIntervalFormat from skeleton a DateIntervalInfo, and the given locale. More...

static UClassID	getStaticClassID (void)
	Return the class ID for this class. More...

Protected Member Functions
	DateIntervalFormat (const DateIntervalFormat &)
	Copy constructor. More...

DateIntervalFormat &	operator= (const DateIntervalFormat &)
	Assignment operator. More...

Protected Member Functions inherited from icu::Format
void	setLocaleIDs (const char valid, const char actual)

	Format ()
	Default constructor for subclass use only. More...

	Format (const Format &)

Format &	operator= (const Format &)

Additional Inherited Members
Static Protected Member Functions inherited from icu::Format
static void	syntaxError (const UnicodeString &pattern, int32_t pos, UParseError &parseError)
	Simple function for initializing a UParseError from a UnicodeString. More...

Detailed Description

DateIntervalFormat is a class for formatting and parsing date intervals in a language-independent manner.

Only formatting is supported, parsing is not supported.

Date interval means from one date to another date, for example, from "Jan 11, 2008" to "Jan 18, 2008". We introduced class DateInterval to represent it. DateInterval is a pair of UDate, which is the standard milliseconds since 24:00 GMT, Jan 1, 1970.

DateIntervalFormat formats a DateInterval into text as compactly as possible. For example, the date interval format from "Jan 11, 2008" to "Jan 18,. 2008" is "Jan 11-18, 2008" for English. And it parses text into DateInterval, although initially, parsing is not supported.

There is no structural information in date time patterns. For any punctuations and string literals inside a date time pattern, we do not know whether it is just a separator, or a prefix, or a suffix. Without such information, so, it is difficult to generate a sub-pattern (or super-pattern) by algorithm. So, formatting a DateInterval is pattern-driven. It is very similar to formatting in SimpleDateFormat. We introduce class DateIntervalInfo to save date interval patterns, similar to date time pattern in SimpleDateFormat.

Logically, the interval patterns are mappings from (skeleton, the_largest_different_calendar_field) to (date_interval_pattern).

A skeleton

only keeps the field pattern letter and ignores all other parts in a pattern, such as space, punctuations, and string literals.
hides the order of fields.
might hide a field's pattern letter length.

For those non-digit calendar fields, the pattern letter length is important, such as MMM, MMMM, and MMMMM; EEE and EEEE, and the field's pattern letter length is honored.

For the digit calendar fields, such as M or MM, d or dd, yy or yyyy, the field pattern length is ignored and the best match, which is defined in date time patterns, will be returned without honor the field pattern letter length in skeleton.

The calendar fields we support for interval formatting are: year, month, date, day-of-week, am-pm, hour, hour-of-day, minute, and second (though we do not currently have specific intervalFormat date for skeletons with seconds). Those calendar fields can be defined in the following order: year > month > date > hour (in day) > minute > second

The largest different calendar fields between 2 calendars is the first different calendar field in above order.

For example: the largest different calendar fields between "Jan 10, 2007" and "Feb 20, 2008" is year.

For other calendar fields, the compact interval formatting is not supported. And the interval format will be fall back to fall-back patterns, which is mostly "{date0} - {date1}".

There is a set of pre-defined static skeleton strings. There are pre-defined interval patterns for those pre-defined skeletons in locales' resource files. For example, for a skeleton UDAT_YEAR_ABBR_MONTH_DAY, which is "yMMMd", in en_US, if the largest different calendar field between date1 and date2 is "year", the date interval pattern is "MMM d, yyyy - MMM d, yyyy", such as "Jan 10, 2007 - Jan 10, 2008". If the largest different calendar field between date1 and date2 is "month", the date interval pattern is "MMM d - MMM d, yyyy", such as "Jan 10 - Feb 10, 2007". If the largest different calendar field between date1 and date2 is "day", the date interval pattern is "MMM d-d, yyyy", such as "Jan 10-20, 2007".

For date skeleton, the interval patterns when year, or month, or date is different are defined in resource files. For time skeleton, the interval patterns when am/pm, or hour, or minute is different are defined in resource files.

If a skeleton is not found in a locale's DateIntervalInfo, which means the interval patterns for the skeleton is not defined in resource file, the interval pattern will falls back to the interval "fallback" pattern defined in resource file. If the interval "fallback" pattern is not defined, the default fall-back is "{date0} - {data1}".

For the combination of date and time, The rule to generate interval patterns are:

when the year, month, or day differs, falls back to fall-back interval pattern, which mostly is the concatenate the two original expressions with a separator between, For example, interval pattern from "Jan 10, 2007 10:10 am" to "Jan 11, 2007 10:10am" is "Jan 10, 2007 10:10 am - Jan 11, 2007 10:10am"
otherwise, present the date followed by the range expression for the time. For example, interval pattern from "Jan 10, 2007 10:10 am" to "Jan 10, 2007 11:10am" is "Jan 10, 2007 10:10 am - 11:10am"

If two dates are the same, the interval pattern is the single date pattern. For example, interval pattern from "Jan 10, 2007" to "Jan 10, 2007" is "Jan 10, 2007".

Or if the presenting fields between 2 dates have the exact same values, the interval pattern is the single date pattern. For example, if user only requests year and month, the interval pattern from "Jan 10, 2007" to "Jan 20, 2007" is "Jan 2007".

DateIntervalFormat needs the following information for correct formatting: time zone, calendar type, pattern, date format symbols, and date interval patterns. It can be instantiated in 2 ways:

create an instance using default or given locale plus given skeleton. Users are encouraged to created date interval formatter this way and to use the pre-defined skeleton macros, such as UDAT_YEAR_NUM_MONTH, which consists the calendar fields and the format style.
create an instance using default or given locale plus given skeleton plus a given DateIntervalInfo. This factory method is for powerful users who want to provide their own interval patterns. Locale provides the timezone, calendar, and format symbols information. Local plus skeleton provides full pattern information. DateIntervalInfo provides the date interval patterns.

For the calendar field pattern letter, such as G, y, M, d, a, h, H, m, s etc. DateIntervalFormat uses the same syntax as that of DateTime format.

Code Sample: general usage

// the date interval object which the DateIntervalFormat formats on
// and parses into
DateInterval*  dtInterval = new DateInterval(1000*3600*24, 1000*3600*24*2);
UErrorCode status = U_ZERO_ERROR;
DateIntervalFormat* dtIntervalFmt = DateIntervalFormat::createInstance(
                        UDAT_YEAR_MONTH_DAY,
                        Locale("en", "GB", ""), status);
UnicodeUnicodeString dateIntervalString;
FieldPosition pos = 0;
// formatting
dtIntervalFmt->format(dtInterval, dateIntervalUnicodeString, pos, status);
delete dtIntervalFmt;

Definition at line 220 of file dtitvfmt.h.

Constructor & Destructor Documentation

◆ ~DateIntervalFormat()

virtual icu::DateIntervalFormat::~DateIntervalFormat ( )

virtual

Destructor.

Stable:: ICU 4.0

◆ DateIntervalFormat()

icu::DateIntervalFormat::DateIntervalFormat ( const DateIntervalFormat & )

protected

Copy constructor.

Stable:: ICU 4.0

Member Function Documentation

◆ adoptTimeZone()

virtual void icu::DateIntervalFormat::adoptTimeZone (

Public Member Functions

Static Public Member Functions