com.espertech.esper.pattern
Class EvalObserverStateNode

java.lang.Object
  extended by com.espertech.esper.pattern.EvalStateNode
      extended by com.espertech.esper.pattern.EvalObserverStateNode
All Implemented Interfaces:
ObserverEventEvaluator

public class EvalObserverStateNode
extends EvalStateNode
implements ObserverEventEvaluator

This class represents the state of an eventObserver sub-expression in the evaluation state tree.


Field Summary
protected  EvalObserverNode evalObserverNode
           
protected  EventObserver eventObserver
           
 
Constructor Summary
EvalObserverStateNode(Evaluator parentNode, EvalObserverNode evalObserverNode)
          Constructor.
 
Method Summary
 java.lang.Object accept(EvalStateNodeVisitor visitor, java.lang.Object data)
          Accept a visitor.
 java.lang.Object childrenAccept(EvalStateNodeVisitor visitor, java.lang.Object data)
          Pass the visitor to all child nodes.
 PatternAgentInstanceContext getContext()
           
 EvalNode getFactoryNode()
          Returns the factory node for the state node.
 boolean isFilterStateNode()
           
 boolean isNotOperator()
           
 void observerEvaluateFalse()
          Indicate that the observer turned permanently false.
 void observerEvaluateTrue(MatchedEventMap matchEvent)
          Indicate an event for evaluation (sub-expression the observer represents has turned true).
 void quit()
          Stops the event expression or an instance of it.
 void start(MatchedEventMap beginState)
          Starts the event expression or an instance of it.
 java.lang.String toString()
           
 
Methods inherited from class com.espertech.esper.pattern.EvalStateNode
getParentEvaluator, setParentEvaluator
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

evalObserverNode

protected final EvalObserverNode evalObserverNode

eventObserver

protected EventObserver eventObserver
Constructor Detail

EvalObserverStateNode

public EvalObserverStateNode(Evaluator parentNode,
                             EvalObserverNode evalObserverNode)
Constructor.

Parameters:
parentNode - is the parent evaluator to call to indicate truth value
evalObserverNode - is the factory node associated to the state
Method Detail

getFactoryNode

public EvalNode getFactoryNode()
Description copied from class: EvalStateNode
Returns the factory node for the state node.

Specified by:
getFactoryNode in class EvalStateNode
Returns:
factory node

getContext

public PatternAgentInstanceContext getContext()
Specified by:
getContext in interface ObserverEventEvaluator

observerEvaluateTrue

public void observerEvaluateTrue(MatchedEventMap matchEvent)
Description copied from interface: ObserverEventEvaluator
Indicate an event for evaluation (sub-expression the observer represents has turned true).

Specified by:
observerEvaluateTrue in interface ObserverEventEvaluator
Parameters:
matchEvent - is the matched events so far

observerEvaluateFalse

public void observerEvaluateFalse()
Description copied from interface: ObserverEventEvaluator
Indicate that the observer turned permanently false.

Specified by:
observerEvaluateFalse in interface ObserverEventEvaluator

start

public void start(MatchedEventMap beginState)
Description copied from class: EvalStateNode
Starts the event expression or an instance of it. Child classes are expected to initialize and start any event listeners or schedule any time-based callbacks as needed.

Specified by:
start in class EvalStateNode

quit

public final void quit()
Description copied from class: EvalStateNode
Stops the event expression or an instance of it. Child classes are expected to free resources and stop any event listeners or remove any time-based callbacks.

Specified by:
quit in class EvalStateNode

accept

public final java.lang.Object accept(EvalStateNodeVisitor visitor,
                                     java.lang.Object data)
Description copied from class: EvalStateNode
Accept a visitor. Child classes are expected to invoke the visit method on the visitor instance passed in.

Specified by:
accept in class EvalStateNode
Parameters:
visitor - on which the visit method is invoked by each node
data - any additional data the visitor may need is passed in this parameter
Returns:
any additional data the visitor may need or null

childrenAccept

public final java.lang.Object childrenAccept(EvalStateNodeVisitor visitor,
                                             java.lang.Object data)
Description copied from class: EvalStateNode
Pass the visitor to all child nodes.

Specified by:
childrenAccept in class EvalStateNode
Parameters:
visitor - is the instance to be passed to all child nodes
data - any additional data the visitor may need is passed in this parameter
Returns:
any additional data the visitor may need or null

isNotOperator

public boolean isNotOperator()
Specified by:
isNotOperator in class EvalStateNode

isFilterStateNode

public boolean isFilterStateNode()
Specified by:
isFilterStateNode in class EvalStateNode

toString

public final java.lang.String toString()
Overrides:
toString in class java.lang.Object

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