datefmt.h | Explore in Territory

// © 2016 and later: Unicode, Inc. and others.
// License & terms of use: http://www.unicode.org/copyright.html
/*
 ********************************************************************************
 *   Copyright (C) 1997-2016, International Business Machines
 *   Corporation and others.  All Rights Reserved.
 ********************************************************************************
 *
 * File DATEFMT.H
 *
 * Modification History:
 *
 *   Date        Name        Description
 *   02/19/97    aliu        Converted from java.
 *   04/01/97    aliu        Added support for centuries.
 *   07/23/98    stephen     JDK 1.2 sync
 *   11/15/99    weiv        Added support for week of year/day of week formatting
 ********************************************************************************
 */

#ifndef DATEFMT_H
#define DATEFMT_H

#include "unicode/utypes.h"

#if U_SHOW_CPLUSPLUS_API

#if !UCONFIG_NO_FORMATTING

#include "unicode/udat.h"
#include "unicode/calendar.h"
#include "unicode/numfmt.h"
#include "unicode/format.h"
#include "unicode/locid.h"
#include "unicode/enumset.h"
#include "unicode/udisplaycontext.h"

/**
 * \file
 * \brief C++ API: Abstract class for converting dates.
 */

U_NAMESPACE_BEGIN

class TimeZone;
class DateTimePatternGenerator;

/**
 * \cond
 * Export an explicit template instantiation. (See digitlst.h, datefmt.h, and others.)
 * (When building DLLs for Windows this is required.)
 */
#if U_PF_WINDOWS <= U_PLATFORM && U_PLATFORM <= U_PF_CYGWIN && !defined(U_IN_DOXYGEN)
template class U_I18N_API EnumSet<UDateFormatBooleanAttribute,
            0, 
            UDAT_BOOLEAN_ATTRIBUTE_COUNT>;
#endif
/** \endcond */

/**
 * 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.
 * <P>
 * 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.
 * <P>
 * To format a date for the current Locale, use one of the static factory
 * methods:
 * <pre>
 * \code
 *      DateFormat* dfmt = DateFormat::createDateInstance();
 *      UDate myDate = Calendar::getNow();
 *      UnicodeString myString;
 *      myString = dfmt->format( myDate, myString );
 * \endcode
 * </pre>
 * 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.
 * <pre>
 * \code
 *      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;
 *      }
 * \endcode
 * </pre>
 * To get specific fields of a date, you can use UFieldPosition to
 * get specific fields.
 * <pre>
 * \code
 *      DateFormat* dfmt = DateFormat::createDateInstance();
 *      FieldPosition pos(DateFormat::YEAR_FIELD);
 *      UnicodeString myString;
 *      myString = dfmt->format( myDate, myString );
 *      cout << myString << endl;
 *      cout << pos.getBeginIndex() << "," << pos. getEndIndex() << endl;
 * \endcode
 * </pre>
 * To format a date for a different Locale, specify it in the call to
 * createDateInstance().
 * <pre>
 * \code
 *       DateFormat* df =
 *           DateFormat::createDateInstance( DateFormat::SHORT, Locale::getFrance());
 * \endcode
 * </pre>
 * You can use a DateFormat to parse also.
 * <pre>
 * \code
 *       UErrorCode status = U_ZERO_ERROR;
 *       UDate myDate = df->parse(myString, status);
 * \endcode
 * </pre>
 * 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:
 * <ul type=round>
 *   <li>   SHORT is completely numeric, such as 12/13/52 or 3:30pm
 *   <li>   MEDIUM is longer, such as Jan 12, 1952
 *   <li>   LONG is longer, such as January 12, 1952 or 3:30:32pm
 *   <li>   FULL is pretty completely specified, such as
 *          Tuesday, April 12, 1952 AD or 3:30:42pm PST.
 * </ul>
 * 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 check getDynamicClassID() before carrying out the cast.
 * <P>
 * You can also use forms of the parse and format methods with ParsePosition and
 * FieldPosition to allow you to
 * <ul type=round>
 *   <li>   Progressively parse through pieces of a string.
 *   <li>   Align any particular field, or find out where it is for selection
 *          on the screen.
 * </ul>
 *
 * <p><em>User subclasses are not supported.</em> While clients may write
 * subclasses, such code will not necessarily work and will not be
 * guaranteed to work stably from release to release.
 */
class U_I18N_API DateFormat : public Format { … };

U_NAMESPACE_END

#endif /* #if !UCONFIG_NO_FORMATTING */

#endif /* U_SHOW_CPLUSPLUS_API */

#endif // _DATEFMT
//eof
chromium/third_party/icu/source/i18n/unicode/datefmt.h
