Package org.drools.mvel.evaluators

Class StartedByEvaluatorDefinition

java.lang.Object

org.drools.mvel.evaluators.StartedByEvaluatorDefinition

All Implemented Interfaces:

Externalizable, Serializable, org.drools.compiler.rule.builder.EvaluatorDefinition, org.kie.api.runtime.rule.EvaluatorDefinition

public class StartedByEvaluatorDefinition
extends Object
implements org.drools.compiler.rule.builder.EvaluatorDefinition

The implementation of the startedby evaluator definition.

The startedby evaluator correlates two events and matches when the correlating event's end timestamp happens before the current event's end timestamp, but both start timestamps occur at the same time.

Lets look at an example:

$eventA : EventA( this startedby $eventB )

The previous pattern will match if and only if the $eventB finishes before $eventA finishes and starts at the same time $eventB starts. In other words:

 
 $eventA.startTimestamp == $eventB.startTimestamp &&
 $eventA.endTimestamp > $eventB.endTimestamp 
 

The startedby evaluator accepts one optional parameter. If it is defined, it determines the maximum distance between the start timestamp of both events in order for the operator to match. Example:

$eventA : EventA( this startedby[ 5s ] $eventB )

Will match if and only if:

 
 abs( $eventA.startTimestamp - $eventB.startTimestamp ) <= 5s &&
 $eventA.endTimestamp > $eventB.endTimestamp 
 

NOTE: it makes no sense to use a negative interval value for the parameter and the engine will raise an exception if that happens.

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	StartedByEvaluatorDefinition.StartedByEvaluator	Implements the 'startedby' evaluator itself

Nested classes/interfaces inherited from interface org.drools.compiler.rule.builder.EvaluatorDefinition

org.drools.compiler.rule.builder.EvaluatorDefinition.Target

Field Summary

Fields

Modifier and Type	Field	Description
static org.drools.drl.parser.impl.Operator	NOT_STARTED_BY
static org.drools.drl.parser.impl.Operator	STARTED_BY
protected static String	startedByOp

Constructor Summary

Constructors

Constructor	Description
StartedByEvaluatorDefinition()

Method Summary

Modifier and Type	Method	Description
org.drools.core.rule.accessor.Evaluator	getEvaluator(org.drools.core.base.ValueType type, String operatorId, boolean isNegated, String parameterText)
org.drools.core.rule.accessor.Evaluator	getEvaluator(org.drools.core.base.ValueType type, String operatorId, boolean isNegated, String parameterText, org.drools.compiler.rule.builder.EvaluatorDefinition.Target left, org.drools.compiler.rule.builder.EvaluatorDefinition.Target right)
org.drools.core.rule.accessor.Evaluator	getEvaluator(org.drools.core.base.ValueType type, org.drools.drl.parser.impl.Operator operator)
org.drools.core.rule.accessor.Evaluator	getEvaluator(org.drools.core.base.ValueType type, org.drools.drl.parser.impl.Operator operator, String parameterText)
String[]	getEvaluatorIds()
org.drools.compiler.rule.builder.EvaluatorDefinition.Target	getTarget()
boolean	isNegatable()
void	readExternal(ObjectInput in)
boolean	supportsType(org.drools.core.base.ValueType type)
void	writeExternal(ObjectOutput out)

Methods inherited from class java.lang.Object

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

Field Detail

startedByOp

protected static final String startedByOp

STARTED_BY

public static final org.drools.drl.parser.impl.Operator STARTED_BY

NOT_STARTED_BY

public static final org.drools.drl.parser.impl.Operator NOT_STARTED_BY

Constructor Detail

StartedByEvaluatorDefinition

public StartedByEvaluatorDefinition()

Method Detail

readExternal

public void readExternal(ObjectInput in)
                  throws IOException,
                         ClassNotFoundException

Specified by:

readExternal in interface Externalizable

Throws:

IOException

ClassNotFoundException

writeExternal

public void writeExternal(ObjectOutput out)
                   throws IOException

Specified by:

writeExternal in interface Externalizable

Throws:

IOException

getEvaluator

public org.drools.core.rule.accessor.Evaluator getEvaluator(org.drools.core.base.ValueType type,
                                                            org.drools.drl.parser.impl.Operator operator)

Specified by:

getEvaluator in interface org.drools.compiler.rule.builder.EvaluatorDefinition

getEvaluator

public org.drools.core.rule.accessor.Evaluator getEvaluator(org.drools.core.base.ValueType type,
                                                            org.drools.drl.parser.impl.Operator operator,
                                                            String parameterText)

Specified by:

getEvaluator in interface org.drools.compiler.rule.builder.EvaluatorDefinition

getEvaluator

public org.drools.core.rule.accessor.Evaluator getEvaluator(org.drools.core.base.ValueType type,
                                                            String operatorId,
                                                            boolean isNegated,
                                                            String parameterText)

Specified by:

getEvaluator in interface org.drools.compiler.rule.builder.EvaluatorDefinition

getEvaluator

public org.drools.core.rule.accessor.Evaluator getEvaluator(org.drools.core.base.ValueType type,
                                                            String operatorId,
                                                            boolean isNegated,
                                                            String parameterText,
                                                            org.drools.compiler.rule.builder.EvaluatorDefinition.Target left,
                                                            org.drools.compiler.rule.builder.EvaluatorDefinition.Target right)

Specified by:

getEvaluator in interface org.drools.compiler.rule.builder.EvaluatorDefinition

getEvaluatorIds

public String[] getEvaluatorIds()

Specified by:

getEvaluatorIds in interface org.drools.compiler.rule.builder.EvaluatorDefinition

isNegatable

public boolean isNegatable()

Specified by:

isNegatable in interface org.drools.compiler.rule.builder.EvaluatorDefinition

getTarget

public org.drools.compiler.rule.builder.EvaluatorDefinition.Target getTarget()

Specified by:

getTarget in interface org.drools.compiler.rule.builder.EvaluatorDefinition

supportsType

public boolean supportsType(org.drools.core.base.ValueType type)

Specified by:

supportsType in interface org.drools.compiler.rule.builder.EvaluatorDefinition