com.vaadin.data.provider

Class DataCommunicator.ActiveDataHandler

java.lang.Object

com.vaadin.data.provider.DataCommunicator.ActiveDataHandler

All Implemented Interfaces:

DataGenerator<T>, Serializable

Enclosing class:

DataCommunicator<T>

protected class DataCommunicator.ActiveDataHandler
extends Object
implements DataGenerator<T>

A class for handling currently active data and dropping data that is no longer needed. Data tracking is based on key string provided by DataKeyMapper.

When the DataCommunicator is pushing new data to the client-side via DataCommunicator.pushData(int, List), addActiveData(Stream) and cleanUp(Stream) are called with the same parameter. In the clean up method any dropped data objects that are not in the given collection will be cleaned up and DataGenerator.destroyData(Object) will be called for them.

See Also:

Serialized Form

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ActiveDataHandler()

Method Summary

Modifier and Type	Method and Description
void	addActiveData(Stream<T> dataObjects) Adds given objects as currently active objects.
void	cleanUp(Stream<T> dataObjects) Executes the data destruction for dropped data that is not sent to the client.
void	destroyAllData() Informs the DataGenerator that all data has been dropped.
void	destroyData(T data) Informs the DataGenerator that the given data item has been dropped and is no longer needed.
void	dropActiveData(String key) Marks a data object identified by given key string to be dropped.
void	dropAllActiveData() Marks all currently active data objects to be dropped.
void	generateData(T data, elemental.json.JsonObject jsonObject) Adds custom data for the given item to its serialized JsonObject representation.
Map<Object,T>	getActiveData() Returns all currently active data mapped by their id from DataProvider.
protected Map<Object,T>	getDroppedData() Returns all dropped data mapped by their id from DataProvider.

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.vaadin.data.provider.DataGenerator

refreshData

Constructor Detail

ActiveDataHandler

protected ActiveDataHandler()

Method Detail

addActiveData

public void addActiveData(Stream<T> dataObjects)

Adds given objects as currently active objects.

Parameters:

dataObjects - collection of new active data objects

cleanUp

public void cleanUp(Stream<T> dataObjects)

Executes the data destruction for dropped data that is not sent to the client. This method takes most recently sent data objects in a collection. Doing the clean up like this prevents the DataCommunicator.ActiveDataHandler from creating new keys for rows that were dropped but got re-requested by the client-side. In the case of having all data at the client, the collection should be all the data in the back end.

Parameters:

dataObjects - collection of most recently sent data to the client

dropAllActiveData

public void dropAllActiveData()

Marks all currently active data objects to be dropped.

Since:

8.6.0

dropActiveData

public void dropActiveData(String key)

Marks a data object identified by given key string to be dropped.

Parameters:

key - key string

getDroppedData

protected Map<Object,T> getDroppedData()

Returns all dropped data mapped by their id from DataProvider.

Returns:

map of ids to dropped data objects

Since:

8.6.0

getActiveData

public Map<Object,T> getActiveData()

Returns all currently active data mapped by their id from DataProvider.

Returns:

map of ids to active data objects

generateData

public void generateData(T data,
                         elemental.json.JsonObject jsonObject)

Description copied from interface: DataGenerator

Adds custom data for the given item to its serialized JsonObject representation. This JSON object will be sent to client-side DataProvider.

Specified by:

generateData in interface DataGenerator<T>

Parameters:

data - the data item being serialized

jsonObject - the JSON object being sent to the client

destroyData

public void destroyData(T data)

Description copied from interface: DataGenerator

Informs the DataGenerator that the given data item has been dropped and is no longer needed. This method should clean up any unneeded information stored for this item.

Specified by:

destroyData in interface DataGenerator<T>

Parameters:

data - the dropped data item

destroyAllData

public void destroyAllData()

Description copied from interface: DataGenerator

Informs the DataGenerator that all data has been dropped. This method should clean up any unneeded information stored for items.

Specified by:

destroyAllData in interface DataGenerator<T>