Message Formatting Examples

Contents

1. MessageFormat Class
   1. C++
   2. C
   3. Java
2. ChoiceFormat Class
   1. C++
   2. C
   3. Java

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MessageFormat Class

ICU’s MessageFormat class can be used to format messages in a locale-independent manner to localize the user interface (UI) strings.

C++

/* The strings below can be isolated into a resource bundle
* and retrieved dynamically
*/
#define LANGUAGE_NAMES "{0}<{1}languages {2}>\n"
#define LANG_ATTRIB "{0}<language id=\"{1}\" >{2}</language>\n"
#define MONTH_NAMES "{0}<monthNames>\n"
#define END_MONTH_NAMES "{0}</monthNames>\n"
#define MONTH "{0}<month id=\"{1}\">{2}</month>\n"
#define MONTH_ABBR "{0}<monthAbbr>\n"
#define END_MONTH_ABBR "{0}</monthAbbr>\n"

UnicodeString CXMLGenerator::formatString(UnicodeString& str,UnicodeString&
argument){
Formattable args[] ={ argument};
UnicodeString result;
MessageFormat format(str,mError);
FieldPosition fpos=0;
format.format(args,1, result,fpos,mError);
if(U_FAILURE(mError)) {
 return UnicodeString("Illegal argument");
}
return result;
}
void CXMLGenerator::writeLanguage(UnicodeString& xmlString){
UnicodeString *itemTags, *items;
char* key="Languages";
int32_t numItems;
if(U_FAILURE(mError)) {
 return;
}
mRBundle.getTaggedArray(key,itemTags, items, numItems, mError);
if(mError!=U_USING_DEFAULT_ERROR && U_SUCCESS(mError) &&
mError!=U_ERROR_INFO_START){
 Formattable args[]={indentOffset,"",""};
 xmlString= formatString(UnicodeString(LANGUAGE_NAMES),args,3);
 indentOffset.append("\t");
 for(int32_t i=0;i<numItems;i++){
 args[0] = indentOffset;
 args[1] =itemTags[i] ;
 args[2] = items[i] ;
 xmlString.append(formatString(UnicodeString(LANG_ATTRIB),args,3));
 }
 chopIndent();
 args[0]=indentOffset;
 args[1] =(UnicodeString(XML_END_SLASH));
 args[2] = "";
 xmlString.append(formatString(UnicodeString(LANGUAGE_NAMES),args,3));
 return;
}
mError=U_ZERO_ERROR;
xmlString.remove();
}
void CXMLGenerator::writeMonthNames(UnicodeString& xmlString){
int32_t lNum;
const UnicodeString* longMonths=
mRBundle.getStringArray("MonthNames",lNum,mError);
if(mError!=U_USING_DEFAULT_ERROR && mError!=U_ERROR_INFO_START && mError !=
U_MISSING_RESOURCE_ERROR){
 xmlString.append(formatString(UnicodeString(MONTH_NAMES),indentOffset));
 indentOffset.append("\t");
 for(int i=0;i<lNum;i++){
 char c;
 itoa(i+1,&c,10);
 Formattable args[]={indentOffset,UnicodeString(&c),longMonths[i]};
 xmlString.append(formatString(UnicodeString(MONTH),args,3));
 }
 chopIndent();
 xmlString.append(formatString(UnicodeString(END_MONTH_NAMES),indentOffset));
 mError=U_ZERO_ERROR;
 return;
}
xmlString.remove();
mError= U_ZERO_ERROR;
}

C

void msgSample1(){
 UChar *result, *tzID, *str;
 UChar pattern[100];
 int32_t resultLengthOut, resultlength;
 UCalendar *cal;
 UDate d1;
 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*)
 free(tzID);
 free(str);
 free(result);
}
char *austrdup(const UChar* unichars)
{
 int length;
 char *newString;
 length = u_strlen ( unichars );
 newString = (char*)malloc ( sizeof( char ) * 4 * ( length + 1 ) );
 if ( newString == NULL )
 return NULL;
 u_austrcpy ( newString, unichars );
 return newString;
}
This is a more practical sample which retrieves data from a resource bundle
and
feeds the data
to u_formatMessage to produce a formatted string
void msgSample3(){
char* key="Languages";
int32_t numItems;
 /* This constant string can also be in the resouce bundle and retrieved at
the time
 * of formatting
 * eg:
 * UResouceBundle* myResB = ures_open("myResources",currentLocale,&err);
 * UChar* Lang_Attrib = ures_getString(myResb,"LANG_ATTRIB",&err);
 */
 UChar* LANG_ATTRIB =(UChar*) "{0}<language id=\"{1}\">{2}</language>\n";
 UChar *result;
 UResourceBundle* pResB,*pDeltaResB=NULL;
 UErrorCode err=U_ZERO_ERROR;
 UChar* indentOffset = (UChar*)"\t\t\t";
 pResB = ures_open("","en",&err);
if(U_FAILURE(err)) {
 return;
}
 ures_getByKey(pResB, key, pDeltaResB, &err);
 if(U_SUCCESS(err)) {
 const UChar *value = 0;
 const char *key = 0;
 int32_t len = 0;
 int16_t indexR = -1;
 int32_t resultLength=0,resultLengthOut=0;
 numItems = ures_getSize(pDeltaResB);
 for(;numItems-->0;){
 key= ures_getKey(pDeltaResB);
 value = ures_get(pDeltaResB,key,&err);
 resultLength=0;
 resultLengthOut=u_formatMessage( "en_US", LANG_ATTRIB,
u_strlen(LANG_ATTRIB),
 NULL, resultLength, &err,
indentOffset, value, key);
 if(err==U_BUFFER_OVERFLOW_ERROR){
 err=U_ZERO_ERROR;
 resultLength=resultLengthOut+1;
 result=(UChar*)realloc(result, sizeof(UChar) * resultLength);
 u_formatMessage("en_US",LANG_ATTRIB,u_strlen(LANG_ATTRIB),
 result,resultLength,&err,indentOffset,
 value,key);
 printf("%s\n", austrdup(result) );
 }
 }
 return;
}
err=U_ZERO_ERROR;
}

Java

import com.ibm.icu.text.*;
import java.util.Date;
import java.text.FieldPosition;
public class TestMessageFormat{
 public void runTest() {
 String format = "At {1,time,::jmm} on {1,date,::dMMMM}, there was {2} on planet {3,number,integer}.";
 MessageFormat mf = new MessageFormat(format);
 Object objectsToFormat[] = { new Date(System.currentTimeMillis()), new Date(System.currentTimeMillis()), "a Disturbance in the Force", new Integer(5)};
 FieldPosition fp = new FieldPosition(1);
 StringBuffer sb = new StringBuffer();
 try{
 sb = mf.format(objectsToFormat, sb, fp);
 System.out.println(sb.toString());
 }catch(IllegalArgumentException e){
 System.out.println("Exception during formatting of type :" +e);
 }
 }
 public static void main(String args[]){
 try{
 new TestMessageFormat().runTest();
 }catch(Exception e){
 System.out.println("Exception of type: "+e);
 }
 }
}

ChoiceFormat Class

Important: The following documentation is outdated. ChoiceFormat is probably not what you need. Please use MessageFormat with plural arguments for proper plural selection, and select arguments for simple selection among a fixed set of choices!

ICU’s ChoiceFormat class provides more flexibility than the printf() and scanf() style functions for formatting UI strings. This interface can be useful if you would like a message to change according to the number of items you are displaying.

Note: Some Asian languages do not have plural words or phrases.

C++

void msgSample1(){
 UChar *result, *tzID, *str;
 UChar pattern[100];
 int32_t resultLengthOut, resultlength;
 UCalendar *cal;
 UDate d1;
 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*)
 free(tzID);
 free(str);
double filelimits[] = {0,1,2};
UErrorCode err;
UnicodeString filepart[] = {"are no files","is one file","are {2} files"};
ChoiceFormat fileform(filelimits, filepart,err);
Format testFormats[] = {fileform, null, NumberFormat.getInstance()};
MessageFormat pattform("There {0} on {1}",err);
pattform.setFormats(testFormats);
Formattable testArgs[] = {null, "ADisk", null};
for (int i = 0; i < 4; ++i) {
 testArgs[0] = i;
 testArgs[2] = testArgs[0];
 FieldPosition fpos=0;
 format.format(args,1, result,fpos,mError);
 UnicodeString result = pattform.format(testArgs);
}

C

void msgSample2(){
 UChar* str;
 UErrorCode status = U_ZERO_ERROR;
 UChar *result;
 UChar pattern[100];
 int32_t resultlength,resultLengthOut, i;
 double testArgs[3]= { 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#onefile|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);
}

Java

import java.text.ChoiceFormat;
import com.ibm.icu.text.*;
import java.text.Format;
public class TestChoiceFormat{
 public void run(){
 double[] filelimits = {0,1,2};
 String[] filepart = {"are no files","is one file","are {2} files"};
 ChoiceFormat fileform = new ChoiceFormat(filelimits,filepart);
 Format[] testFormats = {fileform,null,NumberFormat.getInstance()};
 MessageFormat pattform = new MessageFormat("There {0} on {1}");
 Object[] testArgs = {null,"ADisk",null};
 for(int i=0;i<4;++i) {
 testArgs[0] = new Integer(i);
 testArgs[2] = testArgs[0];
 System.out.println(pattform.format(testArgs));
 }
 }
 public static void main(String args[]){
 new TestChoiceFormat().run();
 }
}