net.time4j.engine

Interface ChronoExtension

public interface ChronoExtension

Defines a configuration-dependent extension of the chronological elements of a Chronology used in formatting and parsing.

Author:

Meno Hochschild

Method Summary

Modifier and Type	Method and Description
boolean	accept(Class<?> chronoType) Will be called by a java.util.ServiceLoader in order to determine if the given chronological type should register this extension or not.
default boolean	canResolve(ChronoElement<?> element) Gives a hint to the parser if the element in question can be resolved by resolve().
Set<ChronoElement<?>>	getElements(Locale locale, AttributeQuery attributes) Returns the element set for given configuration.
ChronoEntity<?>	resolve(ChronoEntity<?> entity, Locale locale, AttributeQuery attributes) Updates the given value source if necessary in order to resolve the values of extension elements to values of standard elements.

Method Detail

accept

boolean accept(Class<?> chronoType)

Will be called by a java.util.ServiceLoader in order to determine if the given chronological type should register this extension or not.

Parameters:

chronoType - chronological type

Returns:

true if given type should register this extension else false

Since:

3.0

getElements

Set<ChronoElement<?>> getElements(Locale locale,
                                  AttributeQuery attributes)

Returns the element set for given configuration.

An empty Set indicates that this extension is not relevant for the given configuration.

Parameters:

locale - language and country setting

attributes - global configuration attributes of formatter

Returns:

extended element model

resolve

ChronoEntity<?> resolve(ChronoEntity<?> entity,
                        Locale locale,
                        AttributeQuery attributes)

Updates the given value source if necessary in order to resolve the values of extension elements to values of standard elements.

Implementations are allowed to use null as pseudo-value in order to delete an element from given source via the expression entity.with(element, null). Note: The argument has exceptionally no chronology.

Parameters:

entity - any kind of map from chronological elements to their values (note that the main use case of parsed data has no chronology and allows the virtual value null to be set as indication for removing associated element)

locale - language and country setting

attributes - global configuration attributes of parser

Returns:

eventually changed entity

Throws:

IllegalArgumentException - if resolving fails due to inconsistencies

Since:

3.0

See Also:

ChronoEntity.with(ChronoElement, V)

canResolve

default boolean canResolve(ChronoElement<?> element)

Gives a hint to the parser if the element in question can be resolved by resolve().

This method serves for optimization purpose and helps the parser to decide if chronological extensions are needed at all during parsing. Subclasses should override this method in most cases.

Parameters:

element - the element to be checked

Returns:

true if this extension can resolve given element else false

Since:

3.40/4.35

See Also:

resolve(ChronoEntity, Locale, AttributeQuery)