class U_I18N_API DateFormat : public Format

DateFormat is an abstract class for a family of classes that convert dates and times from their internal representations to textual form and back again in a language-independent manner

Inheritance:

Public Classes

enum EField
The following enum values are used in FieldPosition with date/time formatting
ERA_FIELD
These constants are provided for backwards compatibility only, and are deprecated
enum EStyle
Constants for various style patterns
FULL
These constants are provided for backwards compatibility only, and are deprecated

Public Methods

virtual ~DateFormat()
Destructor
virtual bool_t operator==(const Format&) const
Equality operator
virtual UnicodeString& format(const Formattable& obj, UnicodeString& toAppendTo, FieldPosition& pos, UErrorCode& status) const
Format an object to produce a string
virtual UnicodeString& format( UDate date, UnicodeString& toAppendTo, FieldPosition& fieldPosition) const
Formats a UDate into a date/time string
UnicodeString& format(UDate date, UnicodeString& result) const
Formats a UDate into a date/time string
UnicodeString& format(const Formattable& obj, UnicodeString& result, UErrorCode& status) const
Redeclared Format method
virtual UDate parse( const UnicodeString& text, UErrorCode& status) const
Parse a date/time string
virtual UDate parse( const UnicodeString& text, ParsePosition& pos) const
Parse a date/time string beginning at the given parse position
virtual void parseObject(const UnicodeString& source, Formattable& result, ParsePosition& parse_pos) const
Parse a string to produce an object
static DateFormat* createInstance(void)
Create a default date/time formatter that uses the SHORT style for both the date and the time
static DateFormat* createTimeInstance(EStyle style = kDefault, const Locale& aLocale = Locale::getDefault())
Creates a time formatter with the given formatting style for the given locale
static DateFormat* createDateInstance(EStyle style = kDefault, const Locale& aLocale = Locale::getDefault())
Creates a date formatter with the given formatting style for the given const locale
static DateFormat* createDateTimeInstance(EStyle dateStyle = kDefault, EStyle timeStyle = kDefault, const Locale& aLocale = Locale::getDefault())
Creates a date/time formatter with the given formatting styles for the given locale
static const Locale* getAvailableLocales(int32_t& count)
Gets the set of locales for which DateFormats are installed
virtual bool_t isLenient(void) const
Returns true if the formatter is set for lenient parsing
virtual void setLenient(bool_t lenient)
Specify whether or not date/time parsing is to be lenient
virtual const Calendar* getCalendar(void) const
Gets the calendar associated with this date/time formatter
virtual void adoptCalendar(Calendar* calendarToAdopt)
Set the calendar to be used by this date format
virtual void setCalendar(const Calendar& newCalendar)
Set the calendar to be used by this date format
virtual const NumberFormat* getNumberFormat(void) const
Gets the number formatter which this date/time formatter uses to format and parse the numeric portions of the pattern
virtual void adoptNumberFormat(NumberFormat* formatToAdopt)
Allows you to set the number formatter
virtual void setNumberFormat(const NumberFormat& newNumberFormat)
Allows you to set the number formatter
virtual const TimeZone& getTimeZone(void) const
Returns a reference to the TimeZone used by this DateFormat's calendar
virtual void adoptTimeZone(TimeZone* zoneToAdopt)
Sets the time zone for the calendar of this DateFormat object
virtual void setTimeZone(const TimeZone& zone)
Sets the time zone for the calendar of this DateFormat object

Protected Fields

Calendar* fCalendar
The calendar that DateFormat uses to produce the time field values needed to implement date/time formatting
NumberFormat* fNumberFormat
The number formatter that DateFormat uses to format numbers in dates and times

Protected Methods

DateFormat()
Default constructor
DateFormat(const DateFormat&)
Copy constructor
DateFormat& operator=(const DateFormat&)
Default assignment operator

Inherited from Format:

Public Methods

bool_t operator!=(const Format& other) const
virtual Format* clone() const
virtual UClassID getDynamicClassID() const

Documentation

DateFormat is an abstract class for a family of classes that convert dates and times from their internal representations to textual form and back again in a language-independent manner. Converting from the internal representation (milliseconds since midnight, January 1, 1970) to text is known as "formatting," and converting from text to millis is known as "parsing." We currently define only one concrete subclass of DateFormat: SimpleDateFormat, which can handle pretty much all normal date formatting and parsing actions.

DateFormat helps you to format and parse dates for any locale. Your code can be completely independent of the locale conventions for months, days of the week, or even the calendar format: lunar vs. solar.

To format a date for the current Locale, use one of the static factory methods: 

.    DateFormat* dfmt = DateFormat::createDateInstance();
.    UnicodeString myString;
.    myString = dfmt->format( myDate, myString );
If you are formatting multiple numbers, it is more efficient to get the format and use it multiple times so that the system doesn't have to fetch the information about the local language and country conventions multiple times. 
.    DateFormat* df = DateFormat::createDateInstance();
.    UnicodeString myString;
.    UDate myDateArr[] = { 0.0, 100000000.0, 2000000000.0 }; // test values
.    for (int32_t i = 0; i < 3; ++i) {
.        myString.remove();
.        cout << df->format( myDateArr[i], myString ) << endl;
.    }
To format a date for a different Locale, specify it in the call to getDateInstance(). 
.       DateFormat* df =
.          DateFormat::createDateInstance( DateFormat::SHORT, Locale::FRANCE);
You can use a DateFormat to parse also. 
.       UErrorCode status = U_ZERO_ERROR;
.       UDate myDate = df->parse(myString, status);
Use createDateInstance() to produce the normal date format for that country. There are other static factory methods available. Use createTimeInstance() to produce the normal time format for that country. Use createDateTimeInstance() to produce a DateFormat that formats both date and time. You can pass in different options to these factory methods to control the length of the result; from SHORT to MEDIUM to LONG to FULL. The exact result depends on the locale, but generally: You can also set the time zone on the format if you wish. If you want even more control over the format or parsing, (or want to give your users more control), you can try casting the DateFormat you get from the factory methods to a SimpleDateFormat. This will work for the majority of countries; just remember to chck getDynamicClassID() before carrying out the cast.

You can also use forms of the parse and format methods with ParsePosition and FieldPosition to allow you to

enum EField
The following enum values are used in FieldPosition with date/time formatting. They are also used to index into DateFormatSymbols::fgPatternChars, which is the list of standard internal-representation pattern characters, and the resource bundle localPatternChars data. For this reason, this enum should be treated with care; don't change the order or contents of it unless you really know what you are doing. You'll probably have to change the code in DateFormatSymbols, SimpleDateFormat, and all the locale resource bundle data files.

ERA_FIELD
These constants are provided for backwards compatibility only, and are deprecated. Please use the C++ style constants defined above.

enum EStyle
Constants for various style patterns. These reflect the order of items in the DateTimePatterns resource. There are 4 time patterns, 4 date patterns, and then the date-time pattern. Each block of 4 values in the resource occurs in the order full, long, medium, short.

FULL
These constants are provided for backwards compatibility only, and are deprecated. Please use the C++ style constants defined above.

virtual ~DateFormat()
Destructor

virtual bool_t operator==(const Format&) const
Equality operator. Returns true if the two formats have the same behavior.

virtual UnicodeString& format(const Formattable& obj, UnicodeString& toAppendTo, FieldPosition& pos, UErrorCode& status) const
Format an object to produce a string. This method handles Formattable objects with a UDate type. If a the Formattable object type is not a Date, then it returns a failing UErrorCode.
Returns:
The value passed in as toAppendTo (this allows chaining, as with UnicodeString::append())
Parameters:
obj - The object to format. Must be a Date.
toAppendTo - The result of the formatting operation is appended to this string.
pos - On input: an alignment field, if desired. On output: the offsets of the alignment field.
status - Output param filled with success/failure status.

virtual UnicodeString& format( UDate date, UnicodeString& toAppendTo, FieldPosition& fieldPosition) const
Formats a UDate into a date/time string. This is an abstract method which concrete subclasses must implement.

On input, the FieldPosition parameter may have its "field" member filled with an enum value specifying a field. On output, the FieldPosition will be filled in with the text offsets for that field.

For example, given a time text "1996.07.10 AD at 15:08:56 PDT", if the given fieldPosition.field is DateFormat::kYearField, the offsets fieldPosition.beginIndex and statfieldPositionus.getEndIndex will be set to 0 and 4, respectively.

Notice that if the same time field appears more than once in a pattern, the status will be set for the first occurence of that time field. For instance, formatting a UDate to the time string "1 PM PDT (Pacific Daylight Time)" using the pattern "h a z (zzzz)" and the alignment field DateFormat::TIMEZONE_FIELD, the offsets fieldPosition.beginIndex and fieldPosition.getEndIndex will be set to 5 and 8, respectively, for the first occurence of the timezone pattern character 'z'.

Returns:
A reference to 'toAppendTo'.
Parameters:
date - a UDate to be formatted into a date/time string.
toAppendTo - the result of the formatting operation is appended to the end of this string.
fieldPosition - On input: an alignment field, if desired (see examples above) On output: the offsets of the alignment field (see examples above)

UnicodeString& format(UDate date, UnicodeString& result) const
Formats a UDate into a date/time string. If there is a problem, you won't know, using this method. Use the overloaded format() method which takes a FieldPosition& to detect formatting problems.
Returns:
A reference to 'result'.
Parameters:
date - The UDate value to be formatted into a string.
result - Output param which will receive the formatted date.

UnicodeString& format(const Formattable& obj, UnicodeString& result, UErrorCode& status) const
Redeclared Format method

virtual UDate parse( const UnicodeString& text, UErrorCode& status) const
Parse a date/time string.
Parameters:
text - The string to be parsed into a UDate value.
status - Output param to be set to success/failure code. If 'text' cannot be parsed, it will be set to a failure code. @result The parsed UDate value, if successful.

virtual UDate parse( const UnicodeString& text, ParsePosition& pos) const
Parse a date/time string beginning at the given parse position. For example, a time text "07/10/96 4:5 PM, PDT" will be parsed into a Date that is equivalent to Date(837039928046).

By default, parsing is lenient: If the input is not in the form used by this object's format method but can still be parsed as a date, then the parse succeeds. Clients may insist on strict adherence to the format by calling setLenient(false).

Returns:
A valid UDate if the input could be parsed.
Parameters:
text - The date/time string to be parsed
pos - On input, the position at which to start parsing; on output, the position at which parsing terminated, or the start position if the parse failed.
See Also:
DateFormat::setLenient(boolean)

virtual void parseObject(const UnicodeString& source, Formattable& result, ParsePosition& parse_pos) const
Parse a string to produce an object. This methods handles parsing of date/time strings into Formattable objects with UDate types.

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.

Returns:
A newly created Formattable* object, or NULL on failure. The caller owns this and should delete it when done.
Parameters:
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. Upon return this param is set to the position after the last character successfully parsed. If the source is not parsed successfully, this param will remain unchanged.

static DateFormat* createInstance(void)
Create a default date/time formatter that uses the SHORT style for both the date and the time.
Returns:
A date/time formatter which the caller owns.

static DateFormat* createTimeInstance(EStyle style = kDefault, const Locale& aLocale = Locale::getDefault())
Creates a time formatter with the given formatting style for the given locale.
Returns:
A time formatter which the caller owns.
Parameters:
style - The given formatting style. For example, SHORT for "h:mm a" in the US locale.
aLocale - The given locale.

static DateFormat* createDateInstance(EStyle style = kDefault, const Locale& aLocale = Locale::getDefault())
Creates a date formatter with the given formatting style for the given const locale.
Returns:
A date formatter which the caller owns.
Parameters:
style - The given formatting style. For example, SHORT for "M/d/yy" in the US locale.
aLocale - The given locale.

static DateFormat* createDateTimeInstance(EStyle dateStyle = kDefault, EStyle timeStyle = kDefault, const Locale& aLocale = Locale::getDefault())
Creates a date/time formatter with the given formatting styles for the given locale.
Returns:
A date/time formatter which the caller owns.
Parameters:
dateStyle - The given formatting style for the date portion of the result. For example, SHORT for "M/d/yy" in the US locale.
timeStyle - The given formatting style for the time portion of the result. For example, SHORT for "h:mm a" in the US locale.
aLocale - The given locale.

static const Locale* getAvailableLocales(int32_t& count)
Gets the set of locales for which DateFormats are installed
Returns:
the set of locales for which DateFormats are installed. The caller does NOT own this list and must not delete it.
Parameters:
count - Filled in with the number of locales in the list that is returned.

virtual bool_t isLenient(void) const
Returns true if the formatter is set for lenient parsing

virtual void setLenient(bool_t lenient)
Specify whether or not date/time parsing is to be lenient. With lenient parsing, the parser may use heuristics to interpret inputs that do not precisely match this object's format. With strict parsing, inputs must match this object's format.
See Also:
Calendar::setLenient

virtual const Calendar* getCalendar(void) const
Gets the calendar associated with this date/time formatter
Returns:
the calendar associated with this date/time formatter.

virtual void adoptCalendar(Calendar* calendarToAdopt)
Set the calendar to be used by this date format. Initially, the default calendar for the specified or default locale is used. The caller should not delete the Calendar object after it is adopted by this call.

virtual void setCalendar(const Calendar& newCalendar)
Set the calendar to be used by this date format. Initially, the default calendar for the specified or default locale is used.

virtual const NumberFormat* getNumberFormat(void) const
Gets the number formatter which this date/time formatter uses to format and parse the numeric portions of the pattern
Returns:
the number formatter which this date/time formatter uses.

virtual void adoptNumberFormat(NumberFormat* formatToAdopt)
Allows you to set the number formatter. The caller should not delete the NumberFormat object after it is adopted by this call.
Parameters:
formatToAdopt - NumberFormat object to be adopted.

virtual void setNumberFormat(const NumberFormat& newNumberFormat)
Allows you to set the number formatter
Parameters:
formatToAdopt - NumberFormat object to be adopted.

virtual const TimeZone& getTimeZone(void) const
Returns a reference to the TimeZone used by this DateFormat's calendar
Returns:
the time zone associated with the calendar of DateFormat.

virtual void adoptTimeZone(TimeZone* zoneToAdopt)
Sets the time zone for the calendar of this DateFormat object. The caller no longer owns the TimeZone object and should not delete it after this call.
Parameters:
zone - the new time zone.

virtual void setTimeZone(const TimeZone& zone)
Sets the time zone for the calendar of this DateFormat object
Parameters:
zone - the new time zone.

DateFormat()
Default constructor. Creates a DateFormat with no Calendar or NumberFormat associated with it. This constructor depends on the subclasses to fill in the calendar and numberFormat fields.

DateFormat(const DateFormat&)
Copy constructor

DateFormat& operator=(const DateFormat&)
Default assignment operator

Calendar* fCalendar
The calendar that DateFormat uses to produce the time field values needed to implement date/time formatting. Subclasses should generally initialize this to the default calendar for the locale associated with this DateFormat.

NumberFormat* fNumberFormat
The number formatter that DateFormat uses to format numbers in dates and times. Subclasses should generally initialize this to the default number format for the locale associated with this DateFormat.

Direct child classes:
SimpleDateFormat

alphabetic index hierarchy of classes

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