Package com.vaadin.flow.data.provider

Class KeyMapper<V>

java.lang.Object

com.vaadin.flow.data.provider.KeyMapper<V>

Type Parameters:

V - the type of mapped objects

All Implemented Interfaces:

DataKeyMapper<V>, Serializable

Direct Known Subclasses:

ComboBoxDataCommunicator.SelectionPreservingKeyMapper

public class KeyMapper<V>
extends Object
implements DataKeyMapper<V>

KeyMapper is the simple two-way map for generating textual keys for objects and retrieving the objects later with the key.

Since:

1.0.

Author:

Vaadin Ltd

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor	Description
KeyMapper()	Constructs a new mapper with trivial identifierGetter
KeyMapper(ValueProvider<V,Object> identifierGetter)	Constructs a new mapper.

Method Summary

Modifier and Type	Method	Description
boolean	containsKey(String key)	Checks if the given key is mapped to an object.
protected String	createKey()	Creates a key for a new item.
V	get(String key)	Retrieves object with the key.
boolean	has(V o)	Check whether this key mapper contains the given data object.
String	key(V o)	Gets key for an object.
void	refresh(V dataObject)	Updates any existing mappings of given data object.
void	remove(V removeobj)	Removes object from the mapper.
void	removeAll()	Removes all objects from the mapper.
void	setIdentifierGetter(ValueProvider<V,Object> identifierGetter)	Takes identifier getter into use and updates existing mappings

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

KeyMapper

public KeyMapper(ValueProvider<V,Object> identifierGetter)

Constructs a new mapper.

Parameters:

identifierGetter - has to return a unique key for every bean, and the returned key has to follow general hashCode() and equals() contract, see Object.hashCode() for details.

KeyMapper

public KeyMapper()

Constructs a new mapper with trivial identifierGetter

Method Detail

key

public String key(V o)

Gets key for an object.

Specified by:

key in interface DataKeyMapper<V>

Parameters:

o - the object.

Returns:

key for given data object

createKey

protected String createKey()

Creates a key for a new item. This method can be overridden to customize the keys used.

Returns:

new key

has

public boolean has(V o)

Description copied from interface: DataKeyMapper

Check whether this key mapper contains the given data object.

Specified by:

has in interface DataKeyMapper<V>

Parameters:

o - the data object to check

Returns:

true if the given data object is contained in this key mapper, false otherwise

get

public V get(String key)

Retrieves object with the key.

Specified by:

get in interface DataKeyMapper<V>

Parameters:

key - the name with the desired value.

Returns:

the object with the key.

remove

public void remove(V removeobj)

Removes object from the mapper.

Specified by:

remove in interface DataKeyMapper<V>

Parameters:

removeobj - the object to be removed.

removeAll

public void removeAll()

Removes all objects from the mapper.

Specified by:

removeAll in interface DataKeyMapper<V>

containsKey

public boolean containsKey(String key)

Checks if the given key is mapped to an object.

Parameters:

key - the key to check

Returns:

true if the key is currently mapped, false otherwise

refresh

public void refresh(V dataObject)

Description copied from interface: DataKeyMapper

Updates any existing mappings of given data object. The equality of two data objects is determined by the equality of their identifiers provided by the given value provider.

Specified by:

refresh in interface DataKeyMapper<V>

Parameters:

dataObject - the data object to update

setIdentifierGetter

public void setIdentifierGetter(ValueProvider<V,Object> identifierGetter)

Description copied from interface: DataKeyMapper

Takes identifier getter into use and updates existing mappings

Specified by:

setIdentifierGetter in interface DataKeyMapper<V>

Parameters:

identifierGetter - has to return a unique key for every bean, and the returned key has to follow general hashCode() and equals() contract, see Object.hashCode() for details.