/*
============================================================================
The Apache Software License, Version 1.1
============================================================================
Copyright (C) 1999-2002 The Apache Software Foundation. All rights reserved.
Redistribution and use in source and binary forms, with or without modifica-
tion, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
3. The end-user documentation included with the redistribution, if any, must
include the following acknowledgment: "This product includes software
developed by the Apache Software Foundation (http://www.apache.org/)."
Alternately, this acknowledgment may appear in the software itself, if
and wherever such third-party acknowledgments normally appear.
4. The names "Apache Cocoon" and "Apache Software Foundation" must not be
used to endorse or promote products derived from this software without
prior written permission. For written permission, please contact
apache@apache.org.
5. Products derived from this software may not be called "Apache", nor may
"Apache" appear in their name, without prior written permission of the
Apache Software Foundation.
THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
APACHE SOFTWARE FOUNDATION OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLU-
DING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
This software consists of voluntary contributions made by many individuals
on behalf of the Apache Software Foundation and was originally created by
Stefano Mazzocchi <stefano@apache.org>. For more information on the Apache
Software Foundation, please see <http://www.apache.org/>.
*/
package org.apache.cocoon.portal.event.impl;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.apache.avalon.framework.activity.Disposable;
import org.apache.avalon.framework.activity.Initializable;
import org.apache.avalon.framework.component.ComponentException;
import org.apache.avalon.framework.component.ComponentManager;
import org.apache.avalon.framework.component.ComponentSelector;
import org.apache.avalon.framework.component.Composable;
import org.apache.avalon.framework.configuration.Configurable;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.logger.AbstractLogEnabled;
import org.apache.avalon.framework.thread.ThreadSafe;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.components.CocoonComponentManager;
import org.apache.cocoon.portal.PortalService;
import org.apache.cocoon.portal.event.Event;
import org.apache.cocoon.portal.event.EventConverter;
import org.apache.cocoon.portal.event.EventManager;
import org.apache.cocoon.portal.event.Publisher;
import org.apache.cocoon.portal.event.Register;
import org.apache.cocoon.portal.event.Subscriber;
import org.apache.cocoon.portal.event.aspect.DefaultEventAspectContext;
import org.apache.cocoon.portal.event.aspect.EventAspect;
import org.apache.cocoon.portal.event.aspect.EventAspectChain;
import org.apache.cocoon.portal.event.aspect.impl.SizingEventSubscriber;
import org.apache.cocoon.portal.event.subscriber.impl.DefaultLayoutAspectDataEventSubscriber;
import org.apache.cocoon.portal.event.subscriber.impl.DefaultLayoutEventSubscriber;
/**
*
* @author <a href="mailto:cziegeler@s-und-n.de">Carsten Ziegeler</a>
* @author <a href="mailto:volker.schmitt@basf-it-services.com">Volker Schmitt</a>
*
* @version CVS $Id: DefaultEventManager.java,v 1.3 2003/05/19 14:10:12 cziegeler Exp $
*/
public class DefaultEventManager
extends AbstractLogEnabled
implements EventManager,
Composable,
Initializable,
ThreadSafe,
Configurable,
Disposable,
Publisher, Register {
private final String rootEventType = Event.class.getName();
private Class eventClass;
private List subscribers = new ArrayList();
private ComponentManager manager;
private Configuration configuration;
protected EventAspectChain chain;
protected ComponentSelector aspectSelector;
public Publisher getPublisher() {
return this;
}
public Register getRegister() {
return this;
}
/* (non-Javadoc)
* @see org.apache.avalon.framework.configuration.Configurable#configure(org.apache.avalon.framework.configuration.Configuration)
*/
public void configure(Configuration conf)
throws ConfigurationException {
this.configuration = conf;
}
/* (non-Javadoc)
* @see org.apache.avalon.framework.activity.Disposable#dispose()
*/
public void dispose() {
if (this.manager != null) {
if ( this.chain != null) {
this.chain.dispose( this.aspectSelector );
}
this.manager.release( this.aspectSelector );
this.aspectSelector = null;
this.manager = null;
}
}
public void initialize()
throws Exception {
this.eventClass = Class.forName( rootEventType );
if ( this.getLogger().isDebugEnabled() ) {
this.getLogger().debug("Initialising eventClass " + eventClass);
}
// FIXME (CZ,HIGH) : Make this configurable
this.subscribe(new DefaultLayoutEventSubscriber(this.manager));
this.subscribe(new DefaultLayoutAspectDataEventSubscriber(this.manager));
this.subscribe(new SizingEventSubscriber(this.manager));
}
public void publish( final Event event ) {
if ( getLogger().isDebugEnabled() ) {
getLogger().debug("Publishing event " + event.getClass());
}
for ( Iterator e = subscribers.iterator(); e.hasNext(); ){
Subscriber subscriber = (Subscriber)e.next();
if (subscriber.getEventType().isAssignableFrom(event.getClass())
&& (subscriber.getFilter() == null || subscriber.getFilter().filter(event))) {
if ( getLogger().isDebugEnabled() ) {
getLogger().info("Informing subscriber "+subscriber+" of event "+event.getClass());
}
subscriber.inform(event);
}
}
}
public void subscribe( final Subscriber subscriber )
throws InvalidEventTypeException {
if ( !eventClass.isAssignableFrom( subscriber.getEventType() ) ) {
throw new InvalidEventTypeException();
}
if ( getLogger().isDebugEnabled() ) {
getLogger().debug( "Subscribing event " + subscriber.getEventType().getName() );
}
// Add to list but prevent duplicate subscriptions
if ( !subscribers.contains( subscriber ) ) {
subscribers.add( subscriber );
if ( getLogger().isDebugEnabled() ) {
getLogger().debug( "Subscribed Event " + subscriber.getEventType().getName() );
getLogger().debug( "Subscribers now active: " + subscribers.size() );
}
}
}
public void unsubscribe( Subscriber subscriber )
throws InvalidEventTypeException {
if ( !eventClass.isAssignableFrom( subscriber.getEventType() ) ) {
throw new InvalidEventTypeException();
}
if ( subscribers.contains( subscriber ) ) {
subscribers.remove( subscriber );
if ( getLogger().isDebugEnabled() ) {
getLogger().debug( "Unsubscribed Event " + subscriber.getEventType().getName() );
getLogger().debug( "Subscribers now active: " + subscribers.size() );
}
} else {
getLogger().warn( "Subscriber " + subscriber + " not found" );
}
}
/* (non-Javadoc)
* @see org.apache.avalon.framework.component.Composable#compose(org.apache.avalon.framework.component.ComponentManager)
*/
public void compose(ComponentManager manager)
throws ComponentException {
this.manager = manager;
}
/**
* Process the events
*/
public void processEvents()
throws ProcessingException {
if ( this.configuration != null ) {
try {
this.aspectSelector = (ComponentSelector) this.manager.lookup( EventAspect.ROLE+"Selector");
this.chain = new EventAspectChain();
this.chain.configure(this.aspectSelector, this.configuration.getChild("event-aspects"));
} catch (ConfigurationException ce) {
throw new ProcessingException("Unable configure component.", ce);
} catch (ComponentException ce) {
throw new ProcessingException("Unable to lookup component.", ce);
}
this.configuration = null;
}
DefaultEventAspectContext context = new DefaultEventAspectContext(this.chain);
EventConverter converter = null;
PortalService service = null;
try {
service = (PortalService)this.manager.lookup(PortalService.ROLE);
converter = (EventConverter) this.manager.lookup(EventConverter.ROLE);
Publisher publisher = this.getPublisher();
converter.start();
// Invoke aspects
context.setEventPublisher( publisher );
context.setObjectModel(CocoonComponentManager.getCurrentEnvironment().getObjectModel());
context.setEventConverter(converter);
context.invokeNext( service );
converter.finish();
} catch (ComponentException ce) {
throw new ProcessingException("Unable to lookup component.", ce);
} finally {
this.manager.release(converter);
this.manager.release(service);
}
}
}