/*
***************************************************************************************
* Copyright (C) 2006 EsperTech, Inc. All rights reserved. *
* http://www.espertech.com/esper *
* http://www.espertech.com *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the GPL license *
* a copy of which has been included with this distribution in the license.txt file. *
***************************************************************************************
*/
package com.espertech.esper.pattern;
/**
* Interface for observing when an event expression needs to start (by adding the first listener).
* The publishing event expression supplies the callback used for indicating matches. The implementation supplies
* as a return value the callback to use to stop the event expression.
*/
public interface PatternStarter {
/**
* An event expression was started and supplies the callback to use when matching events appear.
* Returns the callback to use to stop the event expression.
*
* @param matchCallback must be supplied to indicate what to call when the expression turns true
* @param context is the context for handles to services required for evaluation.
* @param isRecoveringResilient true for recovering
* @return a callback to stop the expression again
*/
public PatternStopCallback start(PatternMatchCallback matchCallback,
PatternContext context,
boolean isRecoveringResilient);
}