package bboss.org.apache.velocity.app.event;
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
/**
* Strategy object used to execute event handler method. Will be called
* while looping through all the chained event handler implementations.
* Each EventHandler method call should have a parallel executor object
* defined.
*
* @author <a href="mailto:wglass@forio.com">Will Glass-Husain</a>
* @version $Id: EventHandlerMethodExecutor.java 685685 2008-08-13 21:43:27Z nbubna $
* @since 1.5
*/
public interface EventHandlerMethodExecutor
{
/**
* Execute the event handler method. If Object is not null, do not
* iterate further through the handler chain.
* If appropriate, the returned Object will be the return value.
*
* @param handler call the appropriate method on this handler
* @exception Exception generic exception potentially thrown by event handlers
*/
public void execute(EventHandler handler) throws Exception;
/**
* Called after execute() to see if iterating should stop. Should
* always return false before method execute() is run.
*
* @return true if no more event handlers for this method should be called.
*/
public boolean isDone();
/**
* Get return value at end of all the iterations
*
* @return null if no return value is required
*/
public Object getReturnValue();
}