org.apache.wicket.markup.html.form

Interface IChoiceRenderer<T>

Type Parameters:

T - The model object type

All Superinterfaces:

IClusterable, IDetachable, Serializable

All Known Implementing Classes:

ChoiceRenderer, EnumChoiceRenderer, LambdaChoiceRenderer

public interface IChoiceRenderer<T>
extends IDetachable

Renders one choice. Separates the 'id' values used for internal representation from 'display values' which are the values shown to the user of components that use this renderer.

Author:

jcompagner

Method Summary

Modifier and Type	Method and Description
default void	detach() Override when needed.
Object	getDisplayValue(T object) Get the value for displaying to an end user.
default String	getIdValue(T object, int index) This method is called to get the id value of an object (used as the value attribute of a choice element) The id can be extracted from the object like a primary key, or if the list is stable you could just return a toString of the index.
default T	getObject(String id, IModel<? extends List<? extends T>> choices) This method is called to get an object back from its id representation.

Method Detail

getDisplayValue

Object getDisplayValue(T object)

Get the value for displaying to an end user.

Parameters:

object - the actual object

Returns:

the value meant for displaying to an end user

getIdValue

default String getIdValue(T object,
                          int index)

This method is called to get the id value of an object (used as the value attribute of a choice element) The id can be extracted from the object like a primary key, or if the list is stable you could just return a toString of the index.

Note that the given index can be -1 if the object in question is not contained in the available choices.

Parameters:

object - The object for which the id should be generated

index - The index of the object in the choices list.

Returns:

String

getObject

default T getObject(String id,
                    IModel<? extends List<? extends T>> choices)

This method is called to get an object back from its id representation. The id may be used to find/load the object in a more efficient way than loading all choices and find the one with the same id in the list

Parameters:

id - The id representation of the object

choices - The list of all rendered choices

Returns:

A choice from the list that has this id

detach

default void detach()

Override when needed.

Specified by:

detach in interface IDetachable