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.
SelectFormat for Gender AgreementNote: Typically, select formatting is done via MessageFormat
with a select argument type,
rather than using a stand-alone SelectFormat.
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:
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.
Note:For the gender of a person in a given sentence, we usually need to distinguish only between female, male and other/unknown.
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:
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}.
Note: The entire sentence should be included (and partially repeated) inside each phrase. Otherwise translators would have to be trained on how to move bits of the sentence in and out of the select argument of a message. (The examples below do not follow this recommendation!)
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 {allée} other {allé}} à {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 {allée} other {allé}}}
other {sont {2, select, female {allées} other {allés}}}
}à {3}.
The SelectFormat pattern string defines the phrase output
for each user-defined keyword.
The pattern is a sequence of (keyword, message) pairs.
A keyword is a "pattern identifier": [^[[:Pattern_Syntax:][:Pattern_White_Space:]]]+
Each message is a MessageFormat pattern string enclosed in {curly braces}.
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.
Pattern_White_Space between keywords and messages is ignored.
Pattern_White_Space within a message is preserved and output.
Example:
MessageFormat msgFmt = new MessageFormat("{0} est " +
"{1, select, female {allée} other {allé}} à Paris.",
new ULocale("fr"));
Object args[] = {"Kirti","female"};
System.out.println(msgFmt.format(args));
Produces the output:
Kirti est allée à Paris.
Format.Field| Constructor and Description |
|---|
SelectFormat(String pattern)
Creates a new
SelectFormat for a given pattern string. |
| Modifier and Type | Method and Description |
|---|---|
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() |
clone, format, formatToCharacterIterator, parseObjectpublic SelectFormat(String pattern)
SelectFormat for a given pattern string.pattern - the pattern for this SelectFormat.public void applyPattern(String pattern)
pattern - the pattern for this select format.IllegalArgumentException - when the pattern is not a valid select format pattern.public String toPattern()
SelectFormatpublic final String format(String keyword)
keyword - a phrase selection keyword.IllegalArgumentException - when the given keyword is not a "pattern identifier"public StringBuffer format(Object keyword, StringBuffer toAppendTo, FieldPosition pos)
StringBuffer.format in class Formatkeyword - a phrase selection keyword.toAppendTo - the selected phrase will be appended to this
StringBuffer.pos - will be ignored by this method.IllegalArgumentException - when the given keyword is not a String
or not a "pattern identifier"public Object parseObject(String source, ParsePosition pos)
SelectFormat.parseObject in class Formatsource - 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.UnsupportedOperationException - thrown always.Copyright © 2016 Unicode, Inc. and others.