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

Interface ChainItem

All Known Implementing Classes:

AutoTimestampChainItem, BaseChainItemCommon, SumAlarmChainItem, SumErrorChainItem, SummarizeChainItem, SumPatternAttributesChainItem

public interface ChainItem

A chain element

An instance of chain element may only be added to one data item

Method Summary

Methods

Modifier and Type	Method and Description
org.eclipse.scada.core.Variant	process(org.eclipse.scada.core.Variant value, Map<String,org.eclipse.scada.core.Variant> attributes) Process the chain item
WriteAttributeResults	setAttributes(Map<String,org.eclipse.scada.core.Variant> attributes) Request to set attributes

Method Detail

setAttributes

WriteAttributeResults setAttributes(Map<String,org.eclipse.scada.core.Variant> attributes)

Request to set attributes

Parameters:

attributes - the attributes update set

Returns:

result for processed attributes

process

org.eclipse.scada.core.Variant process(org.eclipse.scada.core.Variant value,
                                     Map<String,org.eclipse.scada.core.Variant> attributes)

Process the chain item

Parameters:

value - the value to process or null if a output item changed only the attributes

attributes - The current primary attributes

Returns:

the new result or null if the chain item does not change the input value