[apple/icu.git] / icuSources / i18n / unicode / umsg.h

/*
*******************************************************************************
* Copyright (C) 1996-2006, International Business Machines Corporation
* and others. All Rights Reserved.
*******************************************************************************
*
*   file name:  umsg.h
*   encoding:   US-ASCII
*   tab size:   8 (not used)
*   indentation:4
*
*   Change history:
*
*   08/5/2001  Ram         Added C wrappers for C++ API.
*                          
*
*/

#ifndef UMSG_H
#define UMSG_H

#include "unicode/utypes.h"

#if !UCONFIG_NO_FORMATTING

#include "unicode/uloc.h"
#include "unicode/parseerr.h"
#include <stdarg.h>
/**
 * \file
 * \brief C API: MessageFormat
 *
 * <h2>Message Format C API </h2>
 *
 * Provides means to produce concatenated messages in language-neutral way.
 * Use this for all concatenations that show up to end users.
 * <P>
 * Takes a set of objects, formats them, then inserts the formatted
 * strings into the pattern at the appropriate places.
 * <P>
 * Here are some examples of usage:
 * Example 1:
 * <pre>
 * \code
 *     UChar *result, *tzID, *str;
 *     UChar pattern[100];
 *     int32_t resultLengthOut, resultlength;
 *     UCalendar *cal;
 *     UDate d1;
 *     UDateFormat *def1;
 *     UErrorCode status = U_ZERO_ERROR;
 *
 *     str=(UChar*)malloc(sizeof(UChar) * (strlen("disturbance in force") +1));
 *     u_uastrcpy(str, "disturbance in force");
 *     tzID=(UChar*)malloc(sizeof(UChar) * 4);
 *     u_uastrcpy(tzID, "PST");
 *     cal=ucal_open(tzID, u_strlen(tzID), "en_US", UCAL_TRADITIONAL, &status);
 *     ucal_setDateTime(cal, 1999, UCAL_MARCH, 18, 0, 0, 0, &status);
 *     d1=ucal_getMillis(cal, &status);
 *     u_uastrcpy(pattern, "On {0, date, long}, there was a {1} on planet {2,number,integer}");
 *     resultlength=0;
 *     resultLengthOut=u_formatMessage( "en_US", pattern, u_strlen(pattern), NULL, resultlength, &status, d1, str, 7);
 *     if(status==U_BUFFER_OVERFLOW_ERROR){
 *         status=U_ZERO_ERROR;
 *         resultlength=resultLengthOut+1;
 *         result=(UChar*)realloc(result, sizeof(UChar) * resultlength);
 *         u_formatMessage( "en_US", pattern, u_strlen(pattern), result, resultlength, &status, d1, str, 7);
 *     }
 *     printf("%s\n", austrdup(result) );//austrdup( a function used to convert UChar* to char*)
 *     //output>: "On March 18, 1999, there was a disturbance in force on planet 7
 * \endcode
 * </pre>
 * Typically, the message format will come from resources, and the
 * arguments will be dynamically set at runtime.
 * <P>
 * Example 2:
 * <pre>
 * \code
 *     UChar* str;
 *     UErrorCode status = U_ZERO_ERROR;
 *     UChar *result;
 *     UChar pattern[100];
 *     int32_t resultlength, resultLengthOut, i;
 *     double testArgs= { 100.0, 1.0, 0.0};
 *
 *     str=(UChar*)malloc(sizeof(UChar) * 10);
 *     u_uastrcpy(str, "MyDisk");
 *     u_uastrcpy(pattern, "The disk {1} contains {0,choice,0#no files|1#one file|1<{0,number,integer} files}");
 *     for(i=0; i<3; i++){
 *       resultlength=0;
 *       resultLengthOut=u_formatMessage( "en_US", pattern, u_strlen(pattern), NULL, resultlength, &status, testArgs[i], str);
 *       if(status==U_BUFFER_OVERFLOW_ERROR){
 *         status=U_ZERO_ERROR;
 *         resultlength=resultLengthOut+1;
 *         result=(UChar*)malloc(sizeof(UChar) * resultlength);
 *         u_formatMessage( "en_US", pattern, u_strlen(pattern), result, resultlength, &status, testArgs[i], str);
 *       }
 *       printf("%s\n", austrdup(result) );  //austrdup( a function used to convert UChar* to char*)
 *       free(result);
 *     }
 *     // output, with different testArgs:
 *     // output: The disk "MyDisk" contains 100 files.
 *     // output: The disk "MyDisk" contains one file.
 *     // output: The disk "MyDisk" contains no files.
 * \endcode
 *  </pre>
 *
 *  The pattern is of the following form.  Legend:
 *  <pre>
 * \code
 *       {optional item}
 *       (group that may be repeated)*
 * \endcode
 *  </pre>
 *  Do not confuse optional items with items inside quotes braces, such
 *  as this: "{".  Quoted braces are literals.
 *  <pre>
 * \code
 *       messageFormatPattern := string ( "{" messageFormatElement "}" string )*
 *
 *       messageFormatElement := argument { "," elementFormat }
 *
 *       elementFormat := "time" { "," datetimeStyle }
 *                      | "date" { "," datetimeStyle }
 *                      | "number" { "," numberStyle }
 *                      | "choice" "," choiceStyle
 *
 *       datetimeStyle := "short"
 *                      | "medium"
 *                      | "long"
 *                      | "full"
 *                      | dateFormatPattern
 *
 *       numberStyle :=   "currency"
 *                      | "percent"
 *                      | "integer"
 *                      | numberFormatPattern
 *
 *       choiceStyle :=   choiceFormatPattern
 * \endcode
 * </pre>
 * If there is no elementFormat, then the argument must be a string,
 * which is substituted. If there is no dateTimeStyle or numberStyle,
 * then the default format is used (e.g.  NumberFormat.getInstance(),
 * DateFormat.getDefaultTime() or DateFormat.getDefaultDate(). For
 * a ChoiceFormat, the pattern must always be specified, since there
 * is no default.
 * <P>
 * In strings, single quotes can be used to quote the "{" sign if
 * necessary. A real single quote is represented by ''.  Inside a
 * messageFormatElement, quotes are [not] removed. For example,
 * {1,number,$'#',##} will produce a number format with the pound-sign
 * quoted, with a result such as: "$#31,45".
 * <P>
 * If a pattern is used, then unquoted braces in the pattern, if any,
 * must match: that is, "ab {0} de" and "ab '}' de" are ok, but "ab
 * {0'}' de" and "ab } de" are not.
 * <p>
 * <dl><dt><b>Warning:</b><dd>The rules for using quotes within message
 * format patterns unfortunately have shown to be somewhat confusing.
 * In particular, it isn't always obvious to localizers whether single
 * quotes need to be doubled or not. Make sure to inform localizers about
 * the rules, and tell them (for example, by using comments in resource
 * bundle source files) which strings will be processed by MessageFormat.
 * Note that localizers may need to use single quotes in translated
 * strings where the original version doesn't have them.
 * <br>Note also that the simplest way to avoid the problem is to
 * use the real apostrophe (single quote) character U+2019 (') for
 * human-readable text, and to use the ASCII apostrophe (U+0027 ' )
 * only in program syntax, like quoting in MessageFormat.
 * See the annotations for U+0027 Apostrophe in The Unicode Standard.</p>
 * </dl>
 * <P>
 * The argument is a number from 0 to 9, which corresponds to the
 * arguments presented in an array to be formatted.
 * <P>
 * It is ok to have unused arguments in the array.  With missing
 * arguments or arguments that are not of the right class for the
 * specified format, a failing UErrorCode result is set.
 * <P>

 * <P>
 * [Note:] As we see above, the string produced by a choice Format in
 * MessageFormat is treated specially; occurances of '{' are used to
 * indicated subformats.
 * <P>
 * [Note:] Formats are numbered by order of variable in the string.
 * This is [not] the same as the argument numbering!
 * <pre>
 * \code
 *    For example: with "abc{2}def{3}ghi{0}...",
 *
 *    format0 affects the first variable {2}
 *    format1 affects the second variable {3}
 *    format2 affects the second variable {0}
 * \endcode
 * </pre>
 * and so on.
 */

/**
 * Format a message for a locale.
 * This function may perform re-ordering of the arguments depending on the
 * locale. For all numeric arguments, double is assumed unless the type is
 * explicitly integer.  All choice format arguments must be of type double.
 * @param locale The locale for which the message will be formatted
 * @param pattern The pattern specifying the message's format
 * @param patternLength The length of pattern
 * @param result A pointer to a buffer to receive the formatted message.
 * @param resultLength The maximum size of result.
 * @param status A pointer to an UErrorCode to receive any errors
 * @param ... A variable-length argument list containing the arguments specified
 * in pattern.
 * @return The total buffer size needed; if greater than resultLength, the
 * output was truncated.
 * @see u_parseMessage
 * @stable ICU 2.0
 */
U_STABLE int32_t U_EXPORT2 
u_formatMessage(const char  *locale,
                 const UChar *pattern,
                int32_t     patternLength,
                UChar       *result,
                int32_t     resultLength,
                UErrorCode  *status,
                ...);

/**
 * Format a message for a locale.
 * This function may perform re-ordering of the arguments depending on the
 * locale. For all numeric arguments, double is assumed unless the type is
 * explicitly integer.  All choice format arguments must be of type double.
 * @param locale The locale for which the message will be formatted
 * @param pattern The pattern specifying the message's format
 * @param patternLength The length of pattern
 * @param result A pointer to a buffer to receive the formatted message.
 * @param resultLength The maximum size of result.
 * @param ap A variable-length argument list containing the arguments specified
 * @param status A pointer to an UErrorCode to receive any errors
 * in pattern.
 * @return The total buffer size needed; if greater than resultLength, the
 * output was truncated.
 * @see u_parseMessage
 * @stable ICU 2.0
 */
U_STABLE int32_t U_EXPORT2 
u_vformatMessage(   const char  *locale,
                    const UChar *pattern,
                    int32_t     patternLength,
                    UChar       *result,
                    int32_t     resultLength,
                    va_list     ap,
                    UErrorCode  *status);

/**
 * Parse a message.
 * For numeric arguments, this function will always use doubles.  Integer types
 * should not be passed.
 * This function is not able to parse all output from {@link #u_formatMessage }.
 * @param locale The locale for which the message is formatted
 * @param pattern The pattern specifying the message's format
 * @param patternLength The length of pattern
 * @param source The text to parse.
 * @param sourceLength The length of source, or -1 if null-terminated.
 * @param status A pointer to an UErrorCode to receive any errors
 * @param ... A variable-length argument list containing the arguments
 * specified in pattern.
 * @see u_formatMessage
 * @stable ICU 2.0
 */
U_STABLE void U_EXPORT2 
u_parseMessage( const char   *locale,
                const UChar  *pattern,
                int32_t      patternLength,
                const UChar  *source,
                int32_t      sourceLength,
                UErrorCode   *status,
                ...);

/**
 * Parse a message.
 * For numeric arguments, this function will always use doubles.  Integer types
 * should not be passed.
 * This function is not able to parse all output from {@link #u_formatMessage }.
 * @param locale The locale for which the message is formatted
 * @param pattern The pattern specifying the message's format
 * @param patternLength The length of pattern
 * @param source The text to parse.
 * @param sourceLength The length of source, or -1 if null-terminated.
 * @param ap A variable-length argument list containing the arguments
 * @param status A pointer to an UErrorCode to receive any errors
 * specified in pattern.
 * @see u_formatMessage
 * @stable ICU 2.0
 */
U_STABLE void U_EXPORT2 
u_vparseMessage(const char  *locale,
                const UChar *pattern,
                int32_t     patternLength,
                const UChar *source,
                int32_t     sourceLength,
                va_list     ap,
                UErrorCode  *status);

/**
 * Format a message for a locale.
 * This function may perform re-ordering of the arguments depending on the
 * locale. For all numeric arguments, double is assumed unless the type is
 * explicitly integer.  All choice format arguments must be of type double.
 * @param locale The locale for which the message will be formatted
 * @param pattern The pattern specifying the message's format
 * @param patternLength The length of pattern
 * @param result A pointer to a buffer to receive the formatted message.
 * @param resultLength The maximum size of result.
 * @param status A pointer to an UErrorCode to receive any errors
 * @param ... A variable-length argument list containing the arguments specified
 * in pattern.
 * @param parseError  A pointer to UParseError to receive information about errors
 *                     occurred during parsing.
 * @return The total buffer size needed; if greater than resultLength, the
 * output was truncated.
 * @see u_parseMessage
 * @stable ICU 2.0
 */
U_STABLE int32_t U_EXPORT2 
u_formatMessageWithError(   const char    *locale,
                            const UChar   *pattern,
                            int32_t       patternLength,
                            UChar         *result,
                            int32_t       resultLength,
                            UParseError   *parseError,
                            UErrorCode    *status,
                            ...);

/**
 * Format a message for a locale.
 * This function may perform re-ordering of the arguments depending on the
 * locale. For all numeric arguments, double is assumed unless the type is
 * explicitly integer.  All choice format arguments must be of type double.
 * @param locale The locale for which the message will be formatted
 * @param pattern The pattern specifying the message's format
 * @param patternLength The length of pattern
 * @param result A pointer to a buffer to receive the formatted message.
 * @param resultLength The maximum size of result.
 * @param parseError  A pointer to UParseError to receive information about errors
 *                    occurred during parsing.
 * @param ap A variable-length argument list containing the arguments specified
 * @param status A pointer to an UErrorCode to receive any errors
 * in pattern.
 * @return The total buffer size needed; if greater than resultLength, the
 * output was truncated.
 * @stable ICU 2.0
 */
U_STABLE int32_t U_EXPORT2 
u_vformatMessageWithError(  const char   *locale,
                            const UChar  *pattern,
                            int32_t      patternLength,
                            UChar        *result,
                            int32_t      resultLength,
                            UParseError* parseError,
                            va_list      ap,
                            UErrorCode   *status);

/**
 * Parse a message.
 * For numeric arguments, this function will always use doubles.  Integer types
 * should not be passed.
 * This function is not able to parse all output from {@link #u_formatMessage }.
 * @param locale The locale for which the message is formatted
 * @param pattern The pattern specifying the message's format
 * @param patternLength The length of pattern
 * @param source The text to parse.
 * @param sourceLength The length of source, or -1 if null-terminated.
 * @param parseError  A pointer to UParseError to receive information about errors
 *                     occurred during parsing.
 * @param status A pointer to an UErrorCode to receive any errors
 * @param ... A variable-length argument list containing the arguments
 * specified in pattern.
 * @see u_formatMessage
 * @stable ICU 2.0
 */
U_STABLE void U_EXPORT2 
u_parseMessageWithError(const char  *locale,
                        const UChar *pattern,
                        int32_t     patternLength,
                        const UChar *source,
                        int32_t     sourceLength,
                        UParseError *parseError,
                        UErrorCode  *status,
                        ...);

/**
 * Parse a message.
 * For numeric arguments, this function will always use doubles.  Integer types
 * should not be passed.
 * This function is not able to parse all output from {@link #u_formatMessage }.
 * @param locale The locale for which the message is formatted
 * @param pattern The pattern specifying the message's format
 * @param patternLength The length of pattern
 * @param source The text to parse.
 * @param sourceLength The length of source, or -1 if null-terminated.
 * @param ap A variable-length argument list containing the arguments
 * @param parseError  A pointer to UParseError to receive information about errors
 *                     occurred during parsing.
 * @param status A pointer to an UErrorCode to receive any errors
 * specified in pattern.
 * @see u_formatMessage
 * @stable ICU 2.0
 */
U_STABLE void U_EXPORT2 
u_vparseMessageWithError(const char  *locale,
                         const UChar *pattern,
                         int32_t     patternLength,
                         const UChar *source,
                         int32_t     sourceLength,
                         va_list     ap,
                         UParseError *parseError,
                         UErrorCode* status);

/*----------------------- New experimental API --------------------------- */
/** 
 * The message format object
 * @stable ICU 2.0
 */
typedef void* UMessageFormat;


/**
 * Open a message formatter with given pattern and for the given locale.
 * @param pattern       A pattern specifying the format to use.
 * @param patternLength Length of the pattern to use
 * @param locale        The locale for which the messages are formatted.
 * @param parseError    A pointer to UParseError struct to receive any errors 
 *                      occured during parsing. Can be NULL.
 * @param status        A pointer to an UErrorCode to receive any errors.
 * @return              A pointer to a UMessageFormat to use for formatting 
 *                      messages, or 0 if an error occurred. 
 * @stable ICU 2.0
 */
U_STABLE UMessageFormat* U_EXPORT2 
umsg_open(  const UChar     *pattern,
            int32_t         patternLength,
            const  char     *locale,
            UParseError     *parseError,
            UErrorCode      *status);

/**
 * Close a UMessageFormat.
 * Once closed, a UMessageFormat may no longer be used.
 * @param format The formatter to close.
 * @stable ICU 2.0
 */
U_STABLE void U_EXPORT2 
umsg_close(UMessageFormat* format);

/**
 * Open a copy of a UMessageFormat.
 * This function performs a deep copy.
 * @param fmt The formatter to copy
 * @param status A pointer to an UErrorCode to receive any errors.
 * @return A pointer to a UDateFormat identical to fmt.
 * @stable ICU 2.0
 */
U_STABLE UMessageFormat U_EXPORT2 
umsg_clone(const UMessageFormat *fmt,
           UErrorCode *status);

/**
 * Sets the locale. This locale is used for fetching default number or date
 * format information.
 * @param fmt The formatter to set
 * @param locale The locale the formatter should use.
 * @stable ICU 2.0
 */
U_STABLE void  U_EXPORT2 
umsg_setLocale(UMessageFormat *fmt,
               const char* locale);

/**
 * Gets the locale. This locale is used for fetching default number or date
 * format information.
 * @param fmt The formatter to querry
 * @return the locale.
 * @stable ICU 2.0
 */
U_STABLE const char*  U_EXPORT2 
umsg_getLocale(const UMessageFormat *fmt);

/**
 * Sets the pattern.
 * @param fmt           The formatter to use
 * @param pattern       The pattern to be applied.
 * @param patternLength Length of the pattern to use
 * @param parseError    Struct to receive information on position 
 *                      of error if an error is encountered.Can be NULL.
 * @param status        Output param set to success/failure code on
 *                      exit. If the pattern is invalid, this will be
 *                      set to a failure result.
 * @stable ICU 2.0
 */
U_STABLE void  U_EXPORT2 
umsg_applyPattern( UMessageFormat *fmt,
                   const UChar* pattern,
                   int32_t patternLength,
                   UParseError* parseError,
                   UErrorCode* status);

/**
 * Gets the pattern.
 * @param fmt          The formatter to use
 * @param result       A pointer to a buffer to receive the pattern.
 * @param resultLength The maximum size of result.
 * @param status       Output param set to success/failure code on
 *                     exit. If the pattern is invalid, this will be
 *                     set to a failure result.  
 * @return the pattern of the format
 * @stable ICU 2.0
 */
U_STABLE int32_t  U_EXPORT2 
umsg_toPattern(const UMessageFormat *fmt,
               UChar* result, 
               int32_t resultLength,
               UErrorCode* status);

/**
 * Format a message for a locale.
 * This function may perform re-ordering of the arguments depending on the
 * locale. For all numeric arguments, double is assumed unless the type is
 * explicitly integer.  All choice format arguments must be of type double.
 * @param fmt           The formatter to use
 * @param result        A pointer to a buffer to receive the formatted message.
 * @param resultLength  The maximum size of result.
 * @param status        A pointer to an UErrorCode to receive any errors
 * @param ...           A variable-length argument list containing the arguments 
 *                      specified in pattern.
 * @return              The total buffer size needed; if greater than resultLength, 
 *                      the output was truncated.
 * @stable ICU 2.0
 */
U_STABLE int32_t U_EXPORT2 
umsg_format(    const UMessageFormat *fmt,
                UChar          *result,
                int32_t        resultLength,
                UErrorCode     *status,
                ...);

/**
 * Format a message for a locale.
 * This function may perform re-ordering of the arguments depending on the
 * locale. For all numeric arguments, double is assumed unless the type is
 * explicitly integer.  All choice format arguments must be of type double.
 * @param fmt          The formatter to use 
 * @param result       A pointer to a buffer to receive the formatted message.
 * @param resultLength The maximum size of result.
 * @param ap           A variable-length argument list containing the arguments 
 * @param status       A pointer to an UErrorCode to receive any errors
 *                     specified in pattern.
 * @return             The total buffer size needed; if greater than resultLength, 
 *                     the output was truncated.
 * @stable ICU 2.0
 */
U_STABLE int32_t U_EXPORT2 
umsg_vformat(   const UMessageFormat *fmt,
                UChar          *result,
                int32_t        resultLength,
                va_list        ap,
                UErrorCode     *status);

/**
 * Parse a message.
 * For numeric arguments, this function will always use doubles.  Integer types
 * should not be passed.
 * This function is not able to parse all output from {@link #umsg_format }.
 * @param fmt           The formatter to use 
 * @param source        The text to parse.
 * @param sourceLength  The length of source, or -1 if null-terminated.
 * @param count         Output param to receive number of elements returned.
 * @param status        A pointer to an UErrorCode to receive any errors
 * @param ...           A variable-length argument list containing the arguments
 *                      specified in pattern.
 * @stable ICU 2.0
 */
U_STABLE void U_EXPORT2 
umsg_parse( const UMessageFormat *fmt,
            const UChar    *source,
            int32_t        sourceLength,
            int32_t        *count,
            UErrorCode     *status,
            ...);

/**
 * Parse a message.
 * For numeric arguments, this function will always use doubles.  Integer types
 * should not be passed.
 * This function is not able to parse all output from {@link #umsg_format }.
 * @param fmt           The formatter to use 
 * @param source        The text to parse.
 * @param sourceLength  The length of source, or -1 if null-terminated.
 * @param count         Output param to receive number of elements returned.
 * @param ap            A variable-length argument list containing the arguments
 * @param status        A pointer to an UErrorCode to receive any errors
 *                      specified in pattern.
 * @see u_formatMessage
 * @stable ICU 2.0
 */
U_STABLE void U_EXPORT2 
umsg_vparse(const UMessageFormat *fmt,
            const UChar    *source,
            int32_t        sourceLength,
            int32_t        *count,
            va_list        ap,
            UErrorCode     *status);


/**
 * Convert an 'apostrophe-friendly' pattern into a standard
 * pattern.  Standard patterns treat all apostrophes as
 * quotes, which is problematic in some languages, e.g. 
 * French, where apostrophe is commonly used.  This utility
 * assumes that only an unpaired apostrophe immediately before
 * a brace is a true quote.  Other unpaired apostrophes are paired,
 * and the resulting standard pattern string is returned.
 *
 * <p><b>Note</b> it is not guaranteed that the returned pattern
 * is indeed a valid pattern.  The only effect is to convert
 * between patterns having different quoting semantics.
 *
 * @param pattern the 'apostrophe-friendly' patttern to convert
 * @param patternLength the length of pattern, or -1 if unknown and pattern is null-terminated
 * @param dest the buffer for the result, or NULL if preflight only
 * @param destCapacity the length of the buffer, or 0 if preflighting
 * @param ec the error code
 * @return the length of the resulting text, not including trailing null
 *        if buffer has room for the trailing null, it is provided, otherwise
 *        not
 * @stable ICU 3.4
 */
U_STABLE int32_t U_EXPORT2 
umsg_autoQuoteApostrophe(const UChar* pattern, 
                         int32_t patternLength,
                         UChar* dest,
                         int32_t destCapacity,
                         UErrorCode* ec);

#endif /* #if !UCONFIG_NO_FORMATTING */

#endif