com.vaadin.data.provider

Class DataCommunicator<T>

java.lang.Object

com.vaadin.server.AbstractClientConnector

com.vaadin.server.AbstractExtension

com.vaadin.data.provider.DataCommunicator<T>

Type Parameters:

T - the bean type

All Implemented Interfaces:

MethodEventSource, ClientConnector, Extension, Connector, Serializable

Direct Known Subclasses:

HierarchicalDataCommunicator

public class DataCommunicator<T>
extends AbstractExtension

DataProvider base class. This class is the base for all DataProvider communication implementations. It uses DataGenerators to write JsonObjects representing each data object to be sent to the client-side.

Since:

8.0

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	DataCommunicator.ActiveDataHandler A class for handling currently active data and dropping data that is no longer needed.
protected class	DataCommunicator.SimpleDataRequestRpc Simple implementation of collection data provider communication.

Nested classes/interfaces inherited from interface com.vaadin.server.ClientConnector

ClientConnector.AttachEvent, ClientConnector.AttachListener, ClientConnector.ConnectorErrorEvent, ClientConnector.DetachEvent, ClientConnector.DetachListener

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	reset Boolean for pending hard reset.

Constructor Summary

Constructors

Constructor and Description
DataCommunicator()

Method Summary

Modifier and Type	Method and Description
void	addDataGenerator(DataGenerator<T> generator) Adds a data generator to this data communicator.
void	attach() Notifies the connector that it is connected to a VaadinSession (and therefore also to a UI).
void	beforeClientResponse(boolean initial) Initially and in the case of a reset all data should be pushed to the client.
protected DataKeyMapper<T>	createKeyMapper(ValueProvider<T,Object> identifierGetter) Creates a DataKeyMapper to use with this DataCommunicator.
protected DataRequestRpc	createRpc() Creates a DataRequestRpc used with this DataCommunicator.
void	detach() Notifies the connector that it is detached from its VaadinSession.
protected void	dropAllData() Drops all data associated with this data communicator.
List<T>	fetchItemsWithRange(int offset, int limit) Fetches a list of items from the DataProvider.
protected DataCommunicator.ActiveDataHandler	getActiveDataHandler() Returns the active data handler.
List<QuerySortOrder>	getBackEndSorting() Returns the QuerySortOrder to use with backend sorting.
protected DataCommunicatorClientRpc	getClientRpc() Get the client rpc interface for this data communicator.
protected JsonObject	getDataObject(T data) Creates the JsonObject for given data object.
DataProvider<T,?>	getDataProvider() Gets the current data provider from this DataCommunicator.
int	getDataProviderSize() Getter method for finding the size of DataProvider.
protected Object	getFilter() Get the object used for filtering in this data communicator.
Comparator<T>	getInMemorySorting() Returns the Comparator to use with in-memory sorting.
DataKeyMapper<T>	getKeyMapper() Gets the DataKeyMapper used by this DataCommunicator.
int	getMinPushSize() Get minimum size of data which will be sent to the client when data source is set.
protected Range	getPushRows() Get the current range of rows to push in the next response.
protected DataCommunicatorState	getState() Returns the shared state for this connector.
protected DataCommunicatorState	getState(boolean markAsDirty) Returns the shared state for this connector.
protected Set<T>	getUpdatedData() Returns the currently set updated data.
protected void	onDropRows(JsonArray keys) Triggered when rows have been dropped from the client side cache.
protected void	onRequestRows(int firstRowIndex, int numberOfRows, int firstCachedRowIndex, int cacheSize) Request the given rows to be available on the client side.
protected void	pushData(int firstIndex, List<T> data) Sends given collection of data objects to the client-side.
void	refresh(T data) Informs the DataProvider that a data object has been updated.
void	removeDataGenerator(DataGenerator<T> generator) Removes a data generator from this data communicator.
void	reset() Method for internal reset from a change in the component, requiring a full data update.
protected void	sendDataToClient(boolean initial) Send the needed data and updates to the client side.
void	setBackEndSorting(List<QuerySortOrder> sortOrder) Sets the QuerySortOrders to use with backend sorting.
protected void	setDataProvider(DataProvider<T,?> dataProvider) Sets a new DataProvider and refreshes all the internal structures.
<F> SerializableConsumer<F>	setDataProvider(DataProvider<T,F> dataProvider, F initialFilter) Sets the current data provider for this DataCommunicator.
protected <F> void	setFilter(F filter) Sets the filter for this DataCommunicator.
void	setInMemorySorting(Comparator<T> comparator) Sets the Comparator to use with in-memory sorting.
void	setMinPushSize(int size) Set minimum size of data which will be sent to the client when data source is set.
protected void	setPushRows(Range pushRows) Set the range of rows to push for next response.

Methods inherited from class com.vaadin.server.AbstractExtension

extend, getParent, getSupportedParentType, remove, setParent

Methods inherited from class com.vaadin.server.AbstractClientConnector

addAttachListener, addDetachListener, addExtension, addListener, addListener, addListener, addMethodInvocationToQueue, createState, encodeState, equals, fireEvent, getAllChildrenIterable, getConnectorId, getErrorHandler, getExtensions, getListeners, getResource, getRpcManager, getRpcProxy, getSession, getStateType, getUI, handleConnectorRequest, hashCode, hasListeners, isAttached, isConnectorEnabled, isThis, markAsDirty, markAsDirtyRecursive, registerRpc, registerRpc, removeAttachListener, removeDetachListener, removeExtension, removeListener, removeListener, removeListener, removeListener, requestRepaint, requestRepaintAll, retrievePendingRpcCalls, setErrorHandler, setResource, updateDiffstate

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.vaadin.server.ClientConnector

addAttachListener, addDetachListener, encodeState, getErrorHandler, getExtensions, getRpcManager, getStateType, getUI, handleConnectorRequest, isAttached, isConnectorEnabled, markAsDirty, markAsDirtyRecursive, removeAttachListener, removeDetachListener, removeExtension, requestRepaint, requestRepaintAll, retrievePendingRpcCalls, setErrorHandler

Methods inherited from interface com.vaadin.shared.Connector

getConnectorId

Field Detail

reset

protected boolean reset

Boolean for pending hard reset.

Constructor Detail

DataCommunicator

public DataCommunicator()

Method Detail

attach

public void attach()

Description copied from interface: ClientConnector

Notifies the connector that it is connected to a VaadinSession (and therefore also to a UI).

The caller of this method is Connector#setParent(ClientConnector) if the parent is itself already attached to the session. If not, the parent will call the ClientConnector.attach() for all its children when it is attached to the session. This method is always called before the connector's data is sent to the client-side for the first time.

The attachment logic is implemented in AbstractClientConnector.

Specified by:

attach in interface ClientConnector

Overrides:

attach in class AbstractClientConnector

detach

public void detach()

Description copied from class: AbstractClientConnector

Notifies the connector that it is detached from its VaadinSession.

The caller of this method is #setParent(ClientConnector) if the parent is in the session. When the parent is detached from the session it is its responsibility to call ClientConnector.detach() for each of its children.

The AbstractClientConnector.getSession() and AbstractClientConnector.getUI() methods might return null after this method is called.

Specified by:

detach in interface ClientConnector

Overrides:

detach in class AbstractClientConnector

setPushRows

protected void setPushRows(Range pushRows)

Set the range of rows to push for next response.

Parameters:

pushRows -

Since:

8.0.6

getPushRows

protected Range getPushRows()

Get the current range of rows to push in the next response.

Returns:

the range of rows to push

Since:

8.0.6

getFilter

protected Object getFilter()

Get the object used for filtering in this data communicator.

Returns:

the filter object of this data communicator

Since:

8.0.6

getClientRpc

protected DataCommunicatorClientRpc getClientRpc()

Get the client rpc interface for this data communicator.

Returns:

the client rpc interface for this data communicator

Since:

8.0.6

onRequestRows

protected void onRequestRows(int firstRowIndex,
                             int numberOfRows,
                             int firstCachedRowIndex,
                             int cacheSize)

Request the given rows to be available on the client side.

Parameters:

firstRowIndex - the index of the first requested row

numberOfRows - the number of requested rows

firstCachedRowIndex - the index of the first cached row

cacheSize - the number of cached rows

Since:

8.0.6

onDropRows

protected void onDropRows(JsonArray keys)

Triggered when rows have been dropped from the client side cache.

Parameters:

keys - the keys of the rows that have been dropped

Since:

8.0.6

beforeClientResponse

public void beforeClientResponse(boolean initial)

Initially and in the case of a reset all data should be pushed to the client.

Specified by:

beforeClientResponse in interface ClientConnector

Overrides:

beforeClientResponse in class AbstractClientConnector

Parameters:

initial - true if the client-side connector will be created and initialized after this method has been invoked. false if there is already an initialized client-side connector.

sendDataToClient

protected void sendDataToClient(boolean initial)

Send the needed data and updates to the client side.

Parameters:

initial - true if initial data load, false if not

Since:

8.0.6

fetchItemsWithRange

public List<T> fetchItemsWithRange(int offset,
                                   int limit)

Fetches a list of items from the DataProvider.

Parameters:

offset - the starting index of the range

limit - the max number of results

Returns:

the list of items in given range

Since:

8.1

addDataGenerator

public void addDataGenerator(DataGenerator<T> generator)

Adds a data generator to this data communicator. Data generators can be used to insert custom data to the rows sent to the client. If the data generator is already added, does nothing.

Parameters:

generator - the data generator to add, not null

removeDataGenerator

public void removeDataGenerator(DataGenerator<T> generator)

Removes a data generator from this data communicator. If there is no such data generator, does nothing.

Parameters:

generator - the data generator to remove, not null

getKeyMapper

public DataKeyMapper<T> getKeyMapper()

Gets the DataKeyMapper used by this DataCommunicator. Key mapper can be used to map keys sent to the client-side back to their respective data objects.

Returns:

key mapper

pushData

protected void pushData(int firstIndex,
                        List<T> data)

Sends given collection of data objects to the client-side.

Parameters:

firstIndex - first index of pushed data

data - data objects to send as an iterable

getDataObject

protected JsonObject getDataObject(T data)

Creates the JsonObject for given data object. This method calls all data generators for it.

Parameters:

data - data object to be made into a json object

Returns:

json object representing the data object

getActiveDataHandler

protected DataCommunicator.ActiveDataHandler getActiveDataHandler()

Returns the active data handler.

Returns:

the active data handler

Since:

8.0.6

dropAllData

protected void dropAllData()

Drops all data associated with this data communicator.

reset

public void reset()

Method for internal reset from a change in the component, requiring a full data update.

refresh

public void refresh(T data)

Informs the DataProvider that a data object has been updated.

Parameters:

data - updated data object; not null

getUpdatedData

protected Set<T> getUpdatedData()

Returns the currently set updated data.

Returns:

the set of data that should be updated on the next response

Since:

8.0.6

setInMemorySorting

public void setInMemorySorting(Comparator<T> comparator)

Sets the Comparator to use with in-memory sorting.

Parameters:

comparator - comparator used to sort data

getInMemorySorting

public Comparator<T> getInMemorySorting()

Returns the Comparator to use with in-memory sorting.

Returns:

comparator used to sort data

Since:

8.0.6

setBackEndSorting

public void setBackEndSorting(List<QuerySortOrder> sortOrder)

Sets the QuerySortOrders to use with backend sorting.

Parameters:

sortOrder - list of sort order information to pass to a query

getBackEndSorting

public List<QuerySortOrder> getBackEndSorting()

Returns the QuerySortOrder to use with backend sorting.

Returns:

an unmodifiable list of sort order information to pass to a query

Since:

8.0.6

createKeyMapper

protected DataKeyMapper<T> createKeyMapper(ValueProvider<T,Object> identifierGetter)

Creates a DataKeyMapper to use with this DataCommunicator.

This method is called from the constructor.

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.

Returns:

key mapper

Since:

8.1

createRpc

protected DataRequestRpc createRpc()

Creates a DataRequestRpc used with this DataCommunicator.

This method is called from the constructor.

Returns:

data request rpc implementation

getDataProvider

public DataProvider<T,?> getDataProvider()

Gets the current data provider from this DataCommunicator.

Returns:

the data provider

setDataProvider

public <F> SerializableConsumer<F> setDataProvider(DataProvider<T,F> dataProvider,
                                                   F initialFilter)

Sets the current data provider for this DataCommunicator.

The returned consumer can be used to set some other filter value that should be included in queries sent to the data provider. It is only valid until another data provider is set.

Type Parameters:

F - the filter type

Parameters:

dataProvider - the data provider to set, not null

initialFilter - the initial filter value to use, or null to not use any initial filter value

Returns:

a consumer that accepts a new filter value to use

setFilter

protected <F> void setFilter(F filter)

Sets the filter for this DataCommunicator. This method is used by user through the consumer method from setDataProvider(com.vaadin.data.provider.DataProvider<T, F>, F) and should not be called elsewhere.

Type Parameters:

F - the filter type

Parameters:

filter - the filter

Since:

8.1

setMinPushSize

public void setMinPushSize(int size)

Set minimum size of data which will be sent to the client when data source is set.

Server doesn't send all data from data source to the client. It sends some initial chunk of data (whose size is determined as minimum between size parameter of this method and data size). Client decides whether it is able to show more data and request server to send more data (next chunk).

When component is disabled then client cannot communicate to the server side (by design, because of security reasons). It means that client will get only initial chunk of data whose size is set here.

Parameters:

size - the size of initial data to send to the client

getMinPushSize

public int getMinPushSize()

Get minimum size of data which will be sent to the client when data source is set.

Returns:

current minimum push size of initial data chunk which is sent to the client when data source is set

See Also:

setMinPushSize(int)

getDataProviderSize

public int getDataProviderSize()

Getter method for finding the size of DataProvider. Can be overridden by a subclass that uses a specific type of DataProvider and/or query.

Returns:

the size of data provider with current filter

getState

protected DataCommunicatorState getState(boolean markAsDirty)

Description copied from class: AbstractClientConnector

Returns the shared state for this connector.

Overrides:

getState in class AbstractClientConnector

Parameters:

markAsDirty - true if the connector should automatically be marked dirty, false otherwise

Returns:

The shared state for this connector. Never null.

See Also:

AbstractClientConnector.getState()

getState

protected DataCommunicatorState getState()

Description copied from class: AbstractClientConnector

Returns the shared state for this connector. The shared state object is shared between the server connector and the client connector. Changes are only communicated from the server to the client and not in the other direction.

As a side effect, marks the connector dirty so any changes done to the state will be sent to the client. Use getState(false) to avoid marking the connector as dirty.

Overrides:

getState in class AbstractClientConnector

Returns:

The shared state for this connector. Never null.

setDataProvider

protected void setDataProvider(DataProvider<T,?> dataProvider)

Sets a new DataProvider and refreshes all the internal structures.

Parameters:

dataProvider -

Since:

8.1