com.ibm.icu.text
Class SelectFormat

java.lang.Object
  java.text.Format
      com.ibm.icu.text.SelectFormat

All Implemented Interfaces:

Serializable, Cloneable

public class SelectFormat
extends Format

SelectFormat supports the creation of internationalized messages by selecting phrases based on keywords. The pattern specifies how to map keywords to phrases and provides a default phrase. The object provided to the format method is a string that's matched against the keywords. If there is a match, the corresponding phrase is selected; otherwise, the default phrase is used.

Using SelectFormat for Gender Agreement

The main use case for the select format is gender based inflection. When names or nouns are inserted into sentences, their gender can affect pronouns, verb forms, articles, and adjectives. Special care needs to be taken for the case where the gender cannot be determined. The impact varies between languages:

• English has three genders, and unknown gender is handled as a special case. Names use the gender of the named person (if known), nouns referring to people use natural gender, and inanimate objects are usually neutral. The gender only affects pronouns: "he", "she", "it", "they".
• German differs from English in that the gender of nouns is rather arbitrary, even for nouns referring to people ("M&#u00E4;dchen", girl, is neutral). The gender affects pronouns ("er", "sie", "es"), articles ("der", "die", "das"), and adjective forms ("guter Mann", "gute Frau", "gutes M&#u00E4;dchen").
• French has only two genders; as in German the gender of nouns is rather arbitrary - for sun and moon, the genders are the opposite of those in German. The gender affects pronouns ("il", "elle"), articles ("le", "la"), adjective forms ("bon", "bonne"), and sometimes verb forms ("all&#u00E9;", "all&#u00E9e;").
• Polish distinguishes five genders (or noun classes), human masculine, animate non-human masculine, inanimate masculine, feminine, and neuter.

Some other languages have noun classes that are not related to gender, but similar in grammatical use. Some African languages have around 20 noun classes.

To enable localizers to create sentence patterns that take their language's gender dependencies into consideration, software has to provide information about the gender associated with a noun or name to MessageFormat. Two main cases can be distinguished:

• For people, natural gender information should be maintained for each person. The keywords "male", "female", "mixed" (for groups of people) and "unknown" are used.
• For nouns, grammatical gender information should be maintained for each noun and per language, e.g., in resource bundles. The keywords "masculine", "feminine", and "neuter" are commonly used, but some languages may require other keywords.

The resulting keyword is provided to MessageFormat as a parameter separate from the name or noun it's associated with. For example, to generate a message such as "Jean went to Paris", three separate arguments would be provided: The name of the person as argument 0, the gender of the person as argument 1, and the name of the city as argument 2. The sentence pattern for English, where the gender of the person has no impact on this simple sentence, would not refer to argument 1 at all:

{0} went to {2}.

The sentence pattern for French, where the gender of the person affects the form of the participle, uses a select format based on argument 1:

{0} est {1, select, female {all&#u00E9;e} other {all&#u00E9;}} &#u00E0; {2}.

Patterns can be nested, so that it's possible to handle interactions of number and gender where necessary. For example, if the above sentence should allow for the names of several people to be inserted, the following sentence pattern can be used (with argument 0 the list of people's names, argument 1 the number of people, argument 2 their combined gender, and argument 3 the city name):

{0} {1, plural, 
 one {est {2, select, female {all&#u00E9;e} other  {all&#u00E9;}}}
 other {sont {2, select, female {all&#u00E9;es} other {all&#u00E9;s}}}
 }&#u00E0; {3}.

Patterns and Their Interpretation

The SelectFormat pattern text defines the phrase output for each user-defined keyword. The pattern is a sequence of keyword{phrase} clauses, separated by white space characters. Each clause assigns the phrase phrase to the user-defined keyword.

Keywords must match the pattern [a-zA-Z][a-zA-Z0-9_-]*; keywords that don't match this pattern result in the error code U_ILLEGAL_CHARACTER. You always have to define a phrase for the default keyword other; this phrase is returned when the keyword provided to the format method matches no other keyword. If a pattern does not provide a phrase for other, the method it's provided to returns the error U_DEFAULT_KEYWORD_MISSING. If a pattern provides more than one phrase for the same keyword, the error U_DUPLICATE_KEYWORD is returned.
Spaces between keyword and {phrase} will be ignored; spaces within {phrase} will be preserved.

The phrase for a particular select case may contain other message format patterns. SelectFormat preserves these so that you can use the strings produced by SelectFormat with other formatters. If you are using SelectFormat inside a MessageFormat pattern, MessageFormat will automatically evaluate the resulting format pattern. Thus, curly braces ({, }) are only allowed in phrases to define a nested format pattern.

Example:
 MessageFormat msgFmt = new MessageFormat("{0} est " +
     "{1, select, female {all&#u00E9;e} other {all&#u00E9;}} &#u00E0; Paris.",
     new ULocale("fr"));
 Object args[] = {"Kirti","female"};
 System.out.println(msgFmt.format(args));
 

Produces the output:
Kirti est all&#u00E9;e &#u00E0; Paris.

See Also:

Serialized Form

Status:

Stable ICU 4.4.

Nested Class Summary

Nested classes/interfaces inherited from class java.text.Format

Format.Field

Constructor Summary

SelectFormat(String pattern)
Creates a new SelectFormat for a given pattern string.

Method Summary

void	applyPattern(String pattern) Sets the pattern used by this select format.
boolean	equals(Object obj)
StringBuffer	format(Object keyword, StringBuffer toAppendTo, FieldPosition pos) Selects the phrase for the given keyword.
String	format(String keyword) Selects the phrase for the given keyword.
int	hashCode()
Object	parseObject(String source, ParsePosition pos) This method is not supported by SelectFormat.
String	toPattern() Returns the pattern for this SelectFormat
String	toString() Returns a string representation of the object

Methods inherited from class java.text.Format

clone, format, formatToCharacterIterator, parseObject

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

SelectFormat

public SelectFormat(String pattern)

Creates a new SelectFormat for a given pattern string.

Parameters:

pattern - the pattern for this SelectFormat.

Status:

Stable ICU 4.4.

Method Detail

applyPattern

public void applyPattern(String pattern)

Sets the pattern used by this select format. Patterns and their interpretation are specified in the class description.

Parameters:

pattern - the pattern for this select format.

Throws:

IllegalArgumentException - when the pattern is not a valid select format pattern.

Status:

Stable ICU 4.4.

toPattern

public String toPattern()

Returns the pattern for this SelectFormat

Returns:

the pattern string

Status:

Stable ICU 4.4.

format

public final String format(String keyword)

Selects the phrase for the given keyword.

Parameters:

keyword - a keyword for which the select message should be formatted.

Returns:

the string containing the formatted select message.

Throws:

IllegalArgumentException - when the given keyword is not available in the select format pattern

Status:

Stable ICU 4.4.

format

public StringBuffer format(Object keyword,
                           StringBuffer toAppendTo,
                           FieldPosition pos)

Selects the phrase for the given keyword. and appends the formatted message to the given StringBuffer.

Specified by:

format in class Format

Parameters:

keyword - a keyword for which the select message should be formatted.

toAppendTo - the formatted message will be appended to this StringBuffer.

pos - will be ignored by this method.

Returns:

the string buffer passed in as toAppendTo, with formatted text appended.

Throws:

IllegalArgumentException - when the given keyword is not available in the select format pattern

Status:

Stable ICU 4.4.

parseObject

public Object parseObject(String source,
                          ParsePosition pos)

This method is not supported by SelectFormat.

Specified by:

parseObject in class Format

Parameters:

source - the string to be parsed.

pos - defines the position where parsing is to begin, and upon return, the position where parsing left off. If the position has not changed upon return, then parsing failed.

Returns:

nothing because this method is not supported.

Throws:

UnsupportedOperationException - thrown always.

Status:

Stable ICU 4.4.

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

Status:

Stable ICU 4.4.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

Status:

Stable ICU 4.4.

toString

public String toString()

Returns a string representation of the object

Overrides:

toString in class Object

Returns:

a text representation of the format object. The result string includes the class name and the pattern string returned by toPattern().

Status:

Stable ICU 4.4.