ICU 75.1 75.1
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DateIntervalFormat is a class for formatting and parsing date intervals in a language-independent manner. More...
#include <dtitvfmt.h>
Static Public Member Functions | |
static DateIntervalFormat * | createInstance (const UnicodeString &skeleton, UErrorCode &status) |
Construct a DateIntervalFormat from skeleton and the default locale. | |
static DateIntervalFormat * | createInstance (const UnicodeString &skeleton, const Locale &locale, UErrorCode &status) |
Construct a DateIntervalFormat from skeleton and a given locale. | |
static DateIntervalFormat * | createInstance (const UnicodeString &skeleton, const DateIntervalInfo &dtitvinf, UErrorCode &status) |
Construct a DateIntervalFormat from skeleton DateIntervalInfo, and default locale. | |
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. | |
static UClassID | getStaticClassID () |
Return the class ID for this class. | |
Protected Member Functions | |
DateIntervalFormat (const DateIntervalFormat &) | |
Copy constructor. | |
DateIntervalFormat & | operator= (const DateIntervalFormat &) |
Assignment operator. | |
Protected Member Functions inherited from icu::Format | |
void | setLocaleIDs (const char *valid, const char *actual) |
Format () | |
Default constructor for subclass use only. | |
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. | |
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
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, second, and millisecond. (though we do not currently have specific intervalFormat date for skeletons with seconds and millisecond). Those calendar fields can be defined in the following order: year > month > date > hour (in day) > minute > second > millisecond
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:
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:
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 intoFieldPosition pos = 0;// formattingdelete dtIntervalFmt;DateIntervalFormat is a class for formatting and parsing date intervals in a language-independent man...Definition dtitvfmt.h:300static DateIntervalFormat * createInstance(const UnicodeString &skeleton, UErrorCode &status)Construct a DateIntervalFormat from skeleton and the default locale.FieldPosition is a simple class used by Format and its subclasses to identify fields in formatted out...Definition fieldpos.h:110"Smart pointer" base class; do not use directly: use LocalPointer etc.Definition localpointer.h:68A Locale object represents a specific geographical, political, or cultural region.Definition locid.h:195#define UDAT_YEAR_MONTH_DAYConstant for date skeleton with year, month, and day.Definition udat.h:269
Definition at line 300 of file dtitvfmt.h.
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protected |
Copy constructor.
Sets the time zone for the calendar used by this DateIntervalFormat object.
The caller no longer owns the TimeZone object and should not delete it after this call.
zoneToAdopt | the TimeZone to be adopted. |
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overridevirtual |
Clone this Format object polymorphically.
The caller owns the result and should delete it when done.
Implements icu::Format.
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static |
Construct a DateIntervalFormat from skeleton DateIntervalInfo, and default locale.
This is a convenient override of createInstance(const UnicodeString& skeleton, const Locale& locale, const DateIntervalInfo& dtitvinf, UErrorCode&) with the locale value as default locale.
skeleton | the skeleton on which interval format based. |
dtitvinf | the DateIntervalInfo object. |
status | output param set to success/failure code on exit |
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static |
Construct a DateIntervalFormat from skeleton a DateIntervalInfo, and the given locale.
In this factory method, user provides its own date interval pattern information, instead of using those pre-defined data in resource file. This factory method is for powerful users who want to provide their own interval patterns.
There are pre-defined skeletons (defined in udate.h) having predefined interval patterns in resource files. Users are encouraged to use those macros. For example: DateIntervalFormat::createInstance(UDAT_MONTH_DAY, status)
The DateIntervalInfo provides the interval patterns. and the DateIntervalInfo ownership remains to the caller.
User are encouraged to set default interval pattern in DateIntervalInfo as well, if they want to set other interval patterns ( instead of reading the interval patterns from resource files). When the corresponding interval pattern for a largest calendar different field is not found ( if user not set it ), interval format fallback to the default interval pattern. If user does not provide default interval pattern, it fallback to "{date0} - {date1}"
skeleton | the skeleton on which interval format based. |
locale | the given locale |
dtitvinf | the DateIntervalInfo object. |
status | output param set to success/failure code on exit |
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static |
Construct a DateIntervalFormat from skeleton and a given locale.
In this factory method, the date interval pattern information is load from resource files. Users are encouraged to created date interval formatter this way and to use the pre-defined skeleton macros.
There are pre-defined skeletons (defined in udate.h) having predefined interval patterns in resource files. Users are encouraged to use those macros. For example: DateIntervalFormat::createInstance(UDAT_MONTH_DAY, status)
The given Locale provides the interval patterns. For example, for en_GB, if skeleton is UDAT_YEAR_ABBR_MONTH_WEEKDAY_DAY, which is "yMMMEEEd", the interval patterns defined in resource file to above skeleton are: "EEE, d MMM, yyyy - EEE, d MMM, yyyy" for year differs, "EEE, d MMM - EEE, d MMM, yyyy" for month differs, "EEE, d - EEE, d MMM, yyyy" for day differs,
skeleton | the skeleton on which the interval format is based. |
locale | the given locale |
status | output param set to success/failure code on exit |
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static |
Construct a DateIntervalFormat from skeleton and the default locale.
This is a convenient override of createInstance(const UnicodeString& skeleton, const Locale& locale, UErrorCode&) with the value of locale as default locale.
skeleton | the skeleton on which interval format based. |
status | output param set to success/failure code on exit |
UnicodeString & icu::DateIntervalFormat::format | ( | Calendar & | fromCalendar, |
Calendar & | toCalendar, | ||
UnicodeString & | appendTo, | ||
FieldPosition & | fieldPosition, | ||
UErrorCode & | status | ||
) | const |
Format 2 Calendars to produce a string.
Note: "fromCalendar" and "toCalendar" are not const, since calendar is not const in SimpleDateFormat::format(Calendar&),
fromCalendar | calendar set to the from date in date interval to be formatted into date interval string |
toCalendar | calendar set to the to date in date interval to be formatted into date interval string |
appendTo | Output parameter to receive result. Result is appended to existing contents. |
fieldPosition | On input: an alignment field, if desired. On output: the offsets of the alignment field. There may be multiple instances of a given field type in an interval format; in this case the fieldPosition offsets refer to the first instance. |
status | Output param filled with success/failure status. Caller needs to make sure it is SUCCESS at the function entrance |
UnicodeString & icu::DateIntervalFormat::format | ( | const DateInterval * | dtInterval, |
UnicodeString & | appendTo, | ||
FieldPosition & | fieldPosition, | ||
UErrorCode & | status | ||
) | const |
Format a DateInterval to produce a string.
dtInterval | DateInterval to be formatted. |
appendTo | Output parameter to receive result. Result is appended to existing contents. |
fieldPosition | On input: an alignment field, if desired. On output: the offsets of the alignment field. There may be multiple instances of a given field type in an interval format; in this case the fieldPosition offsets refer to the first instance. |
status | Output param filled with success/failure status. |
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overridevirtual |
Format an object to produce a string.
This method handles Formattable objects with a DateInterval type. If a the Formattable object type is not a DateInterval, then it returns a failing UErrorCode.
obj | The object to format. Must be a DateInterval. |
appendTo | Output parameter to receive result. Result is appended to existing contents. |
fieldPosition | On input: an alignment field, if desired. On output: the offsets of the alignment field. There may be multiple instances of a given field type in an interval format; in this case the fieldPosition offsets refer to the first instance. |
status | Output param filled with success/failure status. |
Implements icu::Format.
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virtual |
Format an object to produce a string.
This is a pure virtual method which subclasses must implement. This method allows polymorphic formatting of Formattable objects. If a subclass of Format receives a Formattable object type it doesn't handle (e.g., if a numeric Formattable is passed to a DateFormat object) then it returns a failing UErrorCode.
obj | The object to format. |
appendTo | Output parameter to receive result. Result is appended to existing contents. |
pos | On input: an alignment field, if desired. On output: the offsets of the alignment field. |
status | Output param filled with success/failure status. |
Implements icu::Format.
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virtual |
Format an object to produce a string.
Subclasses should override this method. This method allows polymorphic formatting of Formattable objects. If a subclass of Format receives a Formattable object type it doesn't handle (e.g., if a numeric Formattable is passed to a DateFormat object) then it returns a failing UErrorCode.
obj | The object to format. |
appendTo | Output parameter to receive result. Result is appended to existing contents. |
posIter | On return, can be used to iterate over positions of fields generated by this format call. |
status | Output param filled with success/failure status. |
Reimplemented from icu::Format.
UnicodeString & icu::Format::format | ( | const Formattable & | obj, |
UnicodeString & | appendTo, | ||
UErrorCode & | status | ||
) | const |
Formats an object to produce a string.
obj | The object to format. |
appendTo | Output parameter to receive result. Result is appended to existing contents. |
status | Output parameter filled in with success or failure status. |
FormattedDateInterval icu::DateIntervalFormat::formatToValue | ( | Calendar & | fromCalendar, |
Calendar & | toCalendar, | ||
UErrorCode & | status | ||
) | const |
Format 2 Calendars to produce a FormattedDateInterval.
The FormattedDateInterval exposes field information about the formatted string.
Note: "fromCalendar" and "toCalendar" are not const, since calendar is not const in SimpleDateFormat::format(Calendar&),
fromCalendar | calendar set to the from date in date interval to be formatted into date interval string |
toCalendar | calendar set to the to date in date interval to be formatted into date interval string |
status | Set if an error occurs. |
FormattedDateInterval icu::DateIntervalFormat::formatToValue | ( | const DateInterval & | dtInterval, |
UErrorCode & | status | ||
) | const |
Format a DateInterval to produce a FormattedDateInterval.
The FormattedDateInterval exposes field information about the formatted string.
dtInterval | DateInterval to be formatted. |
status | Set if an error occurs. |
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virtual |
Get the formatter's UDisplayContext value for the specified UDisplayContextType, such as UDISPCTX_TYPE_CAPITALIZATION.
type | The UDisplayContextType whose value to return |
status | Input/output status. If at entry this indicates a failure status, the function will do nothing; otherwise this will be updated with any new status from the function. |
const DateFormat * icu::DateIntervalFormat::getDateFormat | ( | ) | const |
Gets the date formatter.
The DateIntervalFormat instance continues to own the returned DateFormatter object, and will use and possibly modify it during format operations. In a multi-threaded environment, the returned DateFormat can only be used if it is certain that no other threads are concurrently using this DateIntervalFormatter, even for nominally const functions.
const DateIntervalInfo * icu::DateIntervalFormat::getDateIntervalInfo | ( | ) | const |
Gets the date time interval patterns.
Returns a unique class ID POLYMORPHICALLY.
Pure virtual override. This method is to implement a simple version of RTTI, since not all C++ compilers support genuine RTTI. Polymorphic operator==() and clone() methods call this method.
Reimplemented from icu::UObject.
Return the class ID for this class.
This is useful only for comparing to a return value from getDynamicClassID(). For example:
. Base* polymorphic_pointer = createPolymorphicObject(); . if (polymorphic_pointer->getDynamicClassID() == . erived::getStaticClassID()) ...
Returns a reference to the TimeZone used by this DateIntervalFormat's calendar.
Return true if the given Format objects are not semantically equal.
Objects of different subclasses are considered unequal.
other | the object to be compared with. |
Definition at line 1190 of file dtitvfmt.h.
References icu::operator==().
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protected |
Assignment operator.
Return true if the given Format objects are semantically equal.
Objects of different subclasses are considered unequal.
other | the object to be compared with. |
Implements icu::Format.
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overridevirtual |
Date interval parsing is not supported.
Please do not use.
This method should handle parsing of date time interval strings into Formattable objects with DateInterval type, which is a pair of UDate.
Before calling, set parse_pos.index to the offset you want to start parsing at in the source. After calling, parse_pos.index is the end of the text you parsed. If error occurs, index is unchanged.
When parsing, leading whitespace is discarded (with a successful parse), while trailing whitespace is left as is.
See Format::parseObject() for more.
source | The string to be parsed into an object. |
result | Formattable to be set to the parse result. If parse fails, return contents are undefined. |
parse_pos | The position to start parsing at. Since no parsing is supported, upon return this param is unchanged. |
Implements icu::Format.
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virtual |
Set a particular UDisplayContext value in the formatter, such as UDISPCTX_CAPITALIZATION_FOR_STANDALONE.
This causes the formatted result to be capitalized appropriately for the context in which it is intended to be used, considering both the locale and the type of field at the beginning of the formatted result.
value | The UDisplayContext value to set. |
status | Input/output status. If at entry this indicates a failure status, the function will do nothing; otherwise this will be updated with any new status from the function. |
void icu::DateIntervalFormat::setDateIntervalInfo | ( | const DateIntervalInfo & | newIntervalPatterns, |
UErrorCode & | status | ||
) |
Set the date time interval patterns.
newIntervalPatterns | the given interval patterns to copy. |
status | output param set to success/failure code on exit |
Sets the time zone for the calendar used by this DateIntervalFormat object.
zone | the new time zone. |