C API: MessageFormat. More...

#include "unicode/utypes.h"
#include "unicode/localpointer.h"
#include "unicode/uloc.h"
#include "unicode/parseerr.h"
#include <stdarg.h>

Namespaces
	icu
	File coll.h.

Typedefs
typedef void *	UMessageFormat
	The message format object. More...

Functions
int32_t	u_formatMessage (const char locale, const UChar pattern, int32_t patternLength, UChar result, int32_t resultLength, UErrorCode status,...)
	Format a message for a locale. More...

int32_t	u_vformatMessage (const char locale, const UChar pattern, int32_t patternLength, UChar result, int32_t resultLength, va_list ap, UErrorCode status)
	Format a message for a locale. More...

void	u_parseMessage (const char locale, const UChar pattern, int32_t patternLength, const UChar source, int32_t sourceLength, UErrorCode status,...)
	Parse a message. More...

void	u_vparseMessage (const char locale, const UChar pattern, int32_t patternLength, const UChar source, int32_t sourceLength, va_list ap, UErrorCode status)
	Parse a message. More...

int32_t	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. More...

int32_t	u_vformatMessageWithError (const char locale, const UChar pattern, int32_t patternLength, UChar result, int32_t resultLength, UParseError parseError, va_list ap, UErrorCode *status)
	Format a message for a locale. More...

void	u_parseMessageWithError (const char locale, const UChar pattern, int32_t patternLength, const UChar source, int32_t sourceLength, UParseError parseError, UErrorCode *status,...)
	Parse a message. More...

void	u_vparseMessageWithError (const char locale, const UChar pattern, int32_t patternLength, const UChar source, int32_t sourceLength, va_list ap, UParseError parseError, UErrorCode *status)
	Parse a message. More...

UMessageFormat *	umsg_open (const UChar pattern, int32_t patternLength, const char locale, UParseError parseError, UErrorCode status)
	Open a message formatter with given pattern and for the given locale. More...

void	umsg_close (UMessageFormat *format)
	Close a UMessageFormat. More...

UMessageFormat	umsg_clone (const UMessageFormat fmt, UErrorCode status)
	Open a copy of a UMessageFormat. More...

void	umsg_setLocale (UMessageFormat fmt, const char locale)
	Sets the locale. More...

const char *	umsg_getLocale (const UMessageFormat *fmt)
	Gets the locale. More...

void	umsg_applyPattern (UMessageFormat fmt, const UChar pattern, int32_t patternLength, UParseError parseError, UErrorCode status)
	Sets the pattern. More...

int32_t	umsg_toPattern (const UMessageFormat fmt, UChar result, int32_t resultLength, UErrorCode *status)
	Gets the pattern. More...

int32_t	umsg_format (const UMessageFormat fmt, UChar result, int32_t resultLength, UErrorCode *status,...)
	Format a message for a locale. More...

int32_t	umsg_vformat (const UMessageFormat fmt, UChar result, int32_t resultLength, va_list ap, UErrorCode *status)
	Format a message for a locale. More...

void	umsg_parse (const UMessageFormat fmt, const UChar source, int32_t sourceLength, int32_t count, UErrorCode status,...)
	Parse a message. More...

void	umsg_vparse (const UMessageFormat fmt, const UChar source, int32_t sourceLength, int32_t count, va_list ap, UErrorCode status)
	Parse a message. More...

int32_t	umsg_autoQuoteApostrophe (const UChar pattern, int32_t patternLength, UChar dest, int32_t destCapacity, UErrorCode *ec)
	Convert an 'apostrophe-friendly' pattern into a standard pattern. More...

Detailed Description

C API: MessageFormat.

MessageFormat C API

MessageFormat prepares strings for display to users, with optional arguments (variables/placeholders). The arguments can occur in any order, which is necessary for translation into languages with different grammars.

The opaque UMessageFormat type is a thin C wrapper around a C++ MessageFormat. It is constructed from a pattern string with arguments in {curly braces} which will be replaced by formatted values.

Currently, the C API supports only numbered arguments.

For details about the pattern syntax and behavior, especially about the ASCII apostrophe vs. the real apostrophe (single quote) character ’ (U+2019), see the C++ MessageFormat class documentation.

Here are some examples of C API usage: Example 1:

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

Typically, the message format will come from resources, and the arguments will be dynamically set at runtime.

Example 2:

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.

Example 3:

UChar* str;
UChar* str1;
UErrorCode status = U_ZERO_ERROR;
UChar *result;
UChar pattern[100];
UChar expected[100];
int32_t resultlength,resultLengthOut;
str=(UChar*)malloc(sizeof(UChar) * 25);
u_uastrcpy(str, "Kirti");
str1=(UChar*)malloc(sizeof(UChar) * 25);
u_uastrcpy(str1, "female");
log_verbose("Testing message format with Select test #1\n:");
u_uastrcpy(pattern, "{0} est {1, select, female {all\\u00E9e} other {all\\u00E9}} \\u00E0 Paris.");
u_uastrcpy(expected, "Kirti est all\\u00E9e \\u00E0 Paris.");
resultlength=0;
resultLengthOut=u_formatMessage( "fr", pattern, u_strlen(pattern), NULL, resultlength, &status, str , str1);
if(status==U_BUFFER_OVERFLOW_ERROR)
 {
     status=U_ZERO_ERROR;
     resultlength=resultLengthOut+1;
     result=(UChar*)malloc(sizeof(UChar) * resultlength);
     u_formatMessage( "fr", pattern, u_strlen(pattern), result, resultlength, &status, str , str1);
     if(u_strcmp(result, expected)==0)
         log_verbose("PASS: MessagFormat successful on Select test#1\n");
     else{
         log_err("FAIL: Error in MessageFormat on Select test#1\n GOT %s EXPECTED %s\n", austrdup(result),
         austrdup(expected) );
     }
     free(result);
}

Definition in file umsg.h.

Typedef Documentation

◆ UMessageFormat

typedef void* UMessageFormat

The message format object.

Stable:: ICU 2.0

Definition at line 384 of file umsg.h.

Function Documentation

◆ u_formatMessage()

int32_t 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.

Parameters

locale	The locale for which the message will be formatted
pattern	The pattern specifying the message's format
patternLength	The length of pattern
result	A pointer to a buffer to receive the formatted message.
resultLength	The maximum size of result.
status	A pointer to an UErrorCode to receive any errors
...	A variable-length argument list containing the arguments specified in pattern.

Returns: The total buffer size needed; if greater than resultLength, the output was truncated.

See also: u_parseMessage

Stable:: ICU 2.0

◆ u_formatMessageWithError()

int32_t 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.

Parameters

locale	The locale for which the message will be formatted
pattern	The pattern specifying the message's format
patternLength	The length of pattern
result	A pointer to a buffer to receive the formatted message.
resultLength	The maximum size of result.
status	A pointer to an UErrorCode to receive any errors
...	A variable-length argument list containing the arguments specified in pattern.
parseError	A pointer to UParseError to receive information about errors occurred during parsing.

Returns: The total buffer size needed; if greater than resultLength, the output was truncated.

See also: u_parseMessage

Stable:: ICU 2.0

◆ u_parseMessage()

void 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 u_formatMessage.

Parameters

locale	The locale for which the message is formatted
pattern	The pattern specifying the message's format
patternLength	The length of pattern
source	The text to parse.
sourceLength	The length of source, or -1 if null-terminated.
status	A pointer to an UErrorCode to receive any errors
...	A variable-length argument list containing the arguments specified in pattern.

See also: u_formatMessage

Stable:: ICU 2.0

◆ u_parseMessageWithError()

void 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 u_formatMessage.

Parameters

locale	The locale for which the message is formatted
pattern	The pattern specifying the message's format
patternLength	The length of pattern
source	The text to parse.
sourceLength	The length of source, or -1 if null-terminated.
parseError	A pointer to UParseError to receive information about errors occurred during parsing.
status	A pointer to an UErrorCode to receive any errors
...	A variable-length argument list containing the arguments specified in pattern.

See also: u_formatMessage

Stable:: ICU 2.0

◆ u_vformatMessage()

int32_t u_vformatMessage	(	const char *	locale,
		const UChar *	pattern,
		int32_t	patternLength,
		UChar *	result,
		int32_t	resultLength,
		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.

Parameters

locale	The locale for which the message will be formatted
pattern	The pattern specifying the message's format
patternLength	The length of pattern
result	A pointer to a buffer to receive the formatted message.
resultLength	The maximum size of result.
ap	A variable-length argument list containing the arguments specified
status	A pointer to an UErrorCode to receive any errors in pattern.

Returns: The total buffer size needed; if greater than resultLength, the output was truncated.

See also: u_parseMessage

Stable:: ICU 2.0

◆ u_vformatMessageWithError()

int32_t u_vformatMessageWithError	(	const char *	locale,
		const UChar *	pattern,
		int32_t	patternLength,
		UChar *	result,
		int32_t	resultLength,
		UParseError *	parseError,
		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.

Parameters

locale	The locale for which the message will be formatted
pattern	The pattern specifying the message's format
patternLength	The length of pattern
result	A pointer to a buffer to receive the formatted message.
resultLength	The maximum size of result.
parseError	A pointer to UParseError to receive information about errors occurred during parsing.
ap	A variable-length argument list containing the arguments specified
status	A pointer to an UErrorCode to receive any errors in pattern.

Returns: The total buffer size needed; if greater than resultLength, the output was truncated.

Stable:: ICU 2.0

◆ u_vparseMessage()

void u_vparseMessage	(	const char *	locale,
		const UChar *	pattern,
		int32_t	patternLength,
		const UChar *	source,
		int32_t	sourceLength,
		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 u_formatMessage.

Parameters

locale	The locale for which the message is formatted
pattern	The pattern specifying the message's format
patternLength	The length of pattern
source	The text to parse.
sourceLength	The length of source, or -1 if null-terminated.
ap	A variable-length argument list containing the arguments
status	A pointer to an UErrorCode to receive any errors specified in pattern.

See also: u_formatMessage

Stable:: ICU 2.0

◆ u_vparseMessageWithError()

void u_vparseMessageWithError	(	const char *	locale,
		const UChar *	pattern,
		int32_t	patternLength,
		const UChar *	source,
		int32_t	sourceLength,
		va_list	ap,
		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 u_formatMessage.

Parameters

locale	The locale for which the message is formatted
pattern	The pattern specifying the message's format
patternLength	The length of pattern
source	The text to parse.
sourceLength	The length of source, or -1 if null-terminated.
ap	A variable-length argument list containing the arguments
parseError	A pointer to UParseError to receive information about errors occurred during parsing.
status	A pointer to an UErrorCode to receive any errors specified in pattern.

See also: u_formatMessage

Stable:: ICU 2.0

◆ umsg_applyPattern()

void umsg_applyPattern	(	UMessageFormat *	fmt,
		const UChar *	pattern,
		int32_t	patternLength,
		UParseError *	parseError,
		UErrorCode *	status
	)

Sets the pattern.

Parameters

fmt	The formatter to use
pattern	The pattern to be applied.
patternLength	Length of the pattern to use
parseError	Struct to receive information on position of error if an error is encountered.Can be NULL.
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

◆ umsg_autoQuoteApostrophe()

int32_t umsg_autoQuoteApostrophe	(	const UChar *	pattern,
		int32_t	patternLength,
		UChar *	dest,
		int32_t	destCapacity,
		UErrorCode *	ec
	)

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.

Note 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.

Parameters

pattern	the 'apostrophe-friendly' patttern to convert
patternLength	the length of pattern, or -1 if unknown and pattern is null-terminated
dest	the buffer for the result, or NULL if preflight only
destCapacity	the length of the buffer, or 0 if preflighting
ec	the error code

Returns: 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

◆ umsg_clone()

UMessageFormat umsg_clone	(	const UMessageFormat *	fmt,
		UErrorCode *	status
	)

Open a copy of a UMessageFormat.

This function performs a deep copy.

Parameters

fmt	The formatter to copy
status	A pointer to an UErrorCode to receive any errors.

Returns: A pointer to a UDateFormat identical to fmt.

Stable:: ICU 2.0

◆ umsg_close()

void umsg_close ( UMessageFormat * format )

Close a UMessageFormat.

Once closed, a UMessageFormat may no longer be used.

Parameters

format The formatter to close.

Stable:: ICU 2.0

◆ umsg_format()

int32_t 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.

Parameters

fmt	The formatter to use
result	A pointer to a buffer to receive the formatted message.
resultLength	The maximum size of result.
status	A pointer to an UErrorCode to receive any errors
...	A variable-length argument list containing the arguments specified in pattern.

Returns: The total buffer size needed; if greater than resultLength, the output was truncated.

Stable:: ICU 2.0

◆ umsg_getLocale()

const char* umsg_getLocale ( const UMessageFormat * fmt )

Gets the locale.

This locale is used for fetching default number or date format information.

Parameters

fmt	The formatter to querry

Returns: the locale.

Stable:: ICU 2.0

◆ umsg_open()

UMessageFormat* umsg_open	(	const UChar *	pattern,
		int32_t	patternLength,
		const char *	locale,
		UParseError *	parseError,
		UErrorCode *	status
	)

Open a message formatter with given pattern and for the given locale.

Parameters

pattern	A pattern specifying the format to use.
patternLength	Length of the pattern to use
locale	The locale for which the messages are formatted.
parseError	A pointer to UParseError struct to receive any errors occured during parsing. Can be NULL.
status	A pointer to an UErrorCode to receive any errors.

Returns: A pointer to a UMessageFormat to use for formatting messages, or 0 if an error occurred.

Stable:: ICU 2.0

◆ umsg_parse()

void 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 umsg_format.

Parameters

fmt	The formatter to use
source	The text to parse.
sourceLength	The length of source, or -1 if null-terminated.
count	Output param to receive number of elements returned.
status	A pointer to an UErrorCode to receive any errors
...	A variable-length argument list containing the arguments specified in pattern.

Stable:: ICU 2.0

◆ umsg_setLocale()

void umsg_setLocale	(	UMessageFormat *	fmt,
		const char *	locale
	)

Sets the locale.

This locale is used for fetching default number or date format information.

Parameters

fmt	The formatter to set
locale	The locale the formatter should use.

Stable:: ICU 2.0

◆ umsg_toPattern()

int32_t umsg_toPattern	(	const UMessageFormat *	fmt,
		UChar *	result,
		int32_t	resultLength,
		UErrorCode *	status
	)

Gets the pattern.

Parameters

fmt	The formatter to use
result	A pointer to a buffer to receive the pattern.
resultLength	The maximum size of result.
status	Output param set to success/failure code on exit. If the pattern is invalid, this will be set to a failure result.

Returns: the pattern of the format

Stable:: ICU 2.0

◆ umsg_vformat()

int32_t umsg_vformat	(	const UMessageFormat *	fmt,
		UChar *	result,
		int32_t	resultLength,
		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.

Parameters

fmt	The formatter to use
result	A pointer to a buffer to receive the formatted message.
resultLength	The maximum size of result.
ap	A variable-length argument list containing the arguments
status	A pointer to an UErrorCode to receive any errors specified in pattern.

Returns: The total buffer size needed; if greater than resultLength, the output was truncated.

Stable:: ICU 2.0

◆ umsg_vparse()

void umsg_vparse	(	const UMessageFormat *	fmt,
		const UChar *	source,
		int32_t	sourceLength,
		int32_t *	count,
		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 umsg_format.

Parameters

fmt	The formatter to use
source	The text to parse.
sourceLength	The length of source, or -1 if null-terminated.
count	Output param to receive number of elements returned.
ap	A variable-length argument list containing the arguments
status	A pointer to an UErrorCode to receive any errors specified in pattern.

See also: u_formatMessage

Stable:: ICU 2.0

Namespaces

Typedefs

Functions

Detailed Description

MessageFormat C API

Typedef Documentation

◆ UMessageFormat

Function Documentation

◆ u_formatMessage()

◆ u_formatMessageWithError()

◆ u_parseMessage()

◆ u_parseMessageWithError()

◆ u_vformatMessage()

◆ u_vformatMessageWithError()

◆ u_vparseMessage()

◆ u_vparseMessageWithError()

◆ umsg_applyPattern()

◆ umsg_autoQuoteApostrophe()

◆ umsg_clone()

◆ umsg_close()

◆ umsg_format()

◆ umsg_getLocale()

◆ umsg_open()

◆ umsg_parse()

◆ umsg_setLocale()

◆ umsg_toPattern()

◆ umsg_vformat()

◆ umsg_vparse()