com.vaadin.data.provider.

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 Description

protected ActiveDataHandler()

Method Summary

All Methods
Modifier and Type	Method	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>

com.vaadin.data.provider.

Class DataCommunicator.ActiveDataHandler

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

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

Constructor Detail

ActiveDataHandler

Method Detail

addActiveData

cleanUp

dropAllActiveData

dropActiveData

getDroppedData

getActiveData

generateData

destroyData

destroyAllData