org.eclipse.scada.da.server.common.chain

Class DataItemOutputChained

java.lang.Object

org.eclipse.scada.da.server.common.DataItemBase

org.eclipse.scada.da.server.common.chain.DataItemBaseChained

org.eclipse.scada.da.server.common.chain.DataItemOutputChained

All Implemented Interfaces:

DataItem, SuspendableDataItem

public abstract class DataItemOutputChained
extends DataItemBaseChained
implements SuspendableDataItem

Field Summary

Fields inherited from class org.eclipse.scada.da.server.common.chain.DataItemBaseChained

chain, executor, primaryAttributes, secondaryAttributes

Fields inherited from class org.eclipse.scada.da.server.common.DataItemBase

listener

Constructor Summary

Constructors

Constructor and Description
DataItemOutputChained(DataItemInformation dataItemInformation, Executor executor)
DataItemOutputChained(String id, Executor executor)

Method Summary

Modifier and Type	Method and Description
protected void	process()
protected Variant	process(Variant value)
NotifyFuture<Variant>	readValue() The read operation of a data item.
void	suspend() Called when the listener is set from a valid listener to null
void	wakeup() Called when the listener is set from null to a valid listener
protected abstract void	writeCalculatedValue(Variant value)
void	writeValue(Variant value)

Methods inherited from class org.eclipse.scada.da.server.common.chain.DataItemBaseChained

addChainElement, addChainElement, getAttributes, getChainCopy, handleUnhandledAttributes, processSetAttributes, removeChainElement, setChain, startSetAttributes

Methods inherited from class org.eclipse.scada.da.server.common.DataItemBase

getCacheAttributes, getCacheValue, getInformation, handleListenerChange, notifyData, notifyData, setListener

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.scada.da.server.common.DataItem

startWriteValue

Constructor Detail

DataItemOutputChained

public DataItemOutputChained(DataItemInformation dataItemInformation,
                             Executor executor)

DataItemOutputChained

public DataItemOutputChained(String id,
                             Executor executor)

Method Detail

readValue

public NotifyFuture<Variant> readValue()
                                throws InvalidOperationException

Description copied from interface: DataItem

The read operation of a data item.

Specified by:

readValue in interface DataItem

Returns:

The value read from the subsystem.

Throws:

InvalidOperationException - Raised if "read" is not a valid operation for this item

writeValue

public void writeValue(Variant value)
                throws InvalidOperationException,
                       NullValueException,
                       NotConvertableException

Throws:

InvalidOperationException

NullValueException

NotConvertableException

process

protected void process()

Specified by:

process in class DataItemBaseChained

process

protected Variant process(Variant value)

suspend

public void suspend()

Description copied from interface: SuspendableDataItem

Called when the listener is set from a valid listener to null

Specified by:

suspend in interface SuspendableDataItem

wakeup

public void wakeup()

Description copied from interface: SuspendableDataItem

Called when the listener is set from null to a valid listener

Specified by:

wakeup in interface SuspendableDataItem

writeCalculatedValue

protected abstract void writeCalculatedValue(Variant value)
                                      throws NullValueException,
                                             NotConvertableException

Throws:

NullValueException

NotConvertableException