org.kie.api.runtime.rule

Interface AccumulateFunction<C extends Serializable>

All Superinterfaces:

Externalizable, Serializable

public interface AccumulateFunction<C extends Serializable>
extends Externalizable

An interface for accumulate external function implementations

Method Summary

Modifier and Type	Method and Description
void	accumulate(C context, Object value) Executes the accumulation action
default Object	accumulateValue(C context, Object value) Executes the accumulation action returning the accumulated object that will be passed back to the reverse method when this value will be eventually removed from acccumulation.
C	createContext() Creates and returns a new context object
Object	getResult(C context)
Class<?>	getResultType()
void	init(C context) Initializes the accumulator
default C	initContext(C context) Initializes the accumulator, possibly returning a new accumulation context instead of the original one
void	reverse(C context, Object value) Reverses the accumulation action
boolean	supportsReverse()
default boolean	tryReverse(C context, Object value) Reverses the accumulation action

Methods inherited from interface java.io.Externalizable

readExternal, writeExternal

Method Detail

createContext

C createContext()

Creates and returns a new context object

Returns:

new context object

init

void init(C context)
   throws Exception

Initializes the accumulator

Parameters:

context - never null

Throws:

Exception

initContext

default C initContext(C context)

Initializes the accumulator, possibly returning a new accumulation context instead of the original one

Parameters:

context -

Returns:

new context object

accumulate

void accumulate(C context,
                Object value)

Executes the accumulation action

Parameters:

context - never null

value -

accumulateValue

default Object accumulateValue(C context,
                               Object value)

Executes the accumulation action returning the accumulated object that will be passed back to the reverse method when this value will be eventually removed from acccumulation.

Parameters:

context -

value -

Returns:

the accumulated object

reverse

void reverse(C context,
             Object value)
      throws Exception

Reverses the accumulation action

Parameters:

context - never null

value -

Throws:

Exception

getResult

Object getResult(C context)
          throws Exception

Returns:

the current value in this accumulation session

Throws:

Exception

supportsReverse

boolean supportsReverse()

Returns:

true if the function supports reverse, otherwise false

getResultType

Class<?> getResultType()

Returns:

the class type of the result of this function

tryReverse

default boolean tryReverse(C context,
                           Object value)

Reverses the accumulation action

Parameters:

context -

value -

Returns:

true if this accumulate function was able to remove this value, false otherwise. In this last case the engine will have to retrigger a full reaccumulation.