T
- The model object typepublic class ChoiceRenderer<T> extends Object implements IChoiceRenderer<T>, org.apache.wicket.util.io.IClusterable
new DropDownChoice<User>("users", new Model<User>(selectedUser), listOfUsers)creates a DropDownChoice of users and the display value will be toString() and the id the index of the object in the ListOfUsers.
new DropDownChoice<User>("users", new Model<User>(selectedUser), listOfUsers, new ChoiceRenderer<User>("name"))creates a DropDownChoice of users and the display value will be looked up by property expression ("name") and the id the index of the object in the ListOfUsers
new DropDownChoice<User>("users", new Model<User>(selectedUser), listOfUsers, new ChoiceRenderer<User>("name", "id"))creates a DropDownChoice of users and the display value will be looked up by property expression ("name") and the id will be looked up by the property expression "id"
Constructor and Description |
---|
ChoiceRenderer()
Constructor.
|
ChoiceRenderer(String displayExpression)
Constructor.
|
ChoiceRenderer(String displayExpression,
String idExpression)
Constructor.
|
Modifier and Type | Method and Description |
---|---|
Object |
getDisplayValue(T object)
Get the value for displaying to an end user.
|
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.
|
T |
getObject(String id,
IModel<? extends List<? extends T>> choices)
This method is called to get an object back from its id representation.
|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
detach
public ChoiceRenderer()
public ChoiceRenderer(String displayExpression)
displayExpression
- A property expression to get the display valuepublic ChoiceRenderer(String displayExpression, String idExpression)
displayExpression
- A property expression to get the display valueidExpression
- A property expression to get the id valuepublic Object getDisplayValue(T object)
IChoiceRenderer
getDisplayValue
in interface IChoiceRenderer<T>
object
- the actual objectpublic String getIdValue(T object, int index)
IChoiceRenderer
Note that the given index can be -1
if the object in question is not contained in the
available choices.
getIdValue
in interface IChoiceRenderer<T>
object
- The object for which the id should be generatedindex
- The index of the object in the choices list.public T getObject(String id, IModel<? extends List<? extends T>> choices)
IChoiceRenderer
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 listgetObject
in interface IChoiceRenderer<T>
id
- The id representation of the objectchoices
- The list of all rendered choicesid
Copyright © 2006–2019 Apache Software Foundation. All rights reserved.