/*
============================================================================
The Apache Software License, Version 1.1
============================================================================
Copyright (C) 1999-2003 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.generation;
import java.io.IOException;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import org.apache.avalon.excalibur.pool.Recyclable;
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.configuration.Configurable;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.parameters.ParameterException;
import org.apache.avalon.framework.parameters.Parameters;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.caching.CacheableProcessingComponent;
import org.apache.cocoon.caching.validity.Event;
import org.apache.cocoon.caching.validity.EventFactory;
import org.apache.cocoon.caching.validity.EventValidity;
import org.apache.cocoon.caching.validity.NameValueEventFactory;
import org.apache.cocoon.caching.validity.NamedEventFactory;
import org.apache.cocoon.environment.SourceResolver;
import org.apache.cocoon.xml.XMLConsumer;
import org.apache.excalibur.source.SourceUtil;
import org.apache.excalibur.source.SourceValidity;
import org.xml.sax.SAXException;
/**
* Generator wrapper that forwards generation to
* to its delegate but overides its caching strategy
* by replacing it with an event-cache aware implementation.
*
* <p>
* Sitemap configuration is as follows:<br>
* <map:generator name="event-cache" src="org.apache.cocoon.generation.EventCacheGenerator" ><br>
* <factory name="my-event" value="com.my.EventFactoryImpl" /><br>
* <factory name="my-other-event" value="com.myother.EventFactoryImpl" /><br>
* </map:generator><br>
* </p>
*
* Two event types are preconfigured: NamedEvent (name="named") and NameValueEvent
* (name="name-value").
*
* <p>
* Pipeline usage is as follows:<br>
* <map:generate type="event-cache" src="delegate-src"><br>
* <map:parameter name="delegate" value="delegate-type" /><br>
* <map:parameter name="event-type" value="my-event" /><br>
* <!-- my event parameters --><br>
* <map:parameter name="event-name" value="some name" /><br>
* <map:parameter name="event-value" value="some value" /><br>
* </map:generate>
* </p>
*
* The two preconfigured event types take the following parameters:<br>
* - event-type 'named': parameter 'event-name'<br>
* - event-type 'name-value': parameter 'event-name' and parameter 'event-value'<br>
*
* <p>
* The src attribute and all parameters are passed as is to delegate generator.
* </p>
*
* TODO: share common code with EventCacheTransformer
* @author Unico Hommes
*/
public class EventCacheGenerator extends ComposerGenerator
implements Configurable, Generator, CacheableProcessingComponent, Recyclable {
// ---------------------------------------------------- constants
public static final String NAME_VALUE_EVENT_TYPE = "name-value";
public static final String EVENT_TYPE_DEFAULT = "named";
public static final String NAMED_EVENT_TYPE = EVENT_TYPE_DEFAULT;
public static final String FACTORY_CONF = "factory";
public static final String FACTORY_NAME_CONF = "name";
public static final String FACTORY_NAME_TYPE = "src";
public static final String DELEGATE_PARAM = "delegate";
public static final String EVENT_TYPE_PARAM = "event-type";
// ---------------------------------------------------- member variables
private ComponentSelector m_generatorSelector;
private Generator m_delegate;
private Serializable m_key;
private Event m_event;
private Map m_types = new HashMap();
// ---------------------------------------------------- lifecycle methods
public void compose(ComponentManager manager) throws ComponentException {
super.compose(manager);
m_generatorSelector = (ComponentSelector)
manager.lookup(Generator.ROLE + "Selector");
}
public void configure(Configuration configuration) throws ConfigurationException {
Configuration[] factories = configuration.getChildren(FACTORY_CONF);
for (int i = 0; i < factories.length; i++) {
Configuration child = factories[i];
String name = child.getAttribute(FACTORY_NAME_CONF);
String src = child.getAttribute(FACTORY_NAME_TYPE);
try {
EventFactory factory = (EventFactory) Class.forName(src).newInstance();
m_types.put(name,factory);
} catch (Exception e) {
final String message =
"Unable to create EventFactory of type " + src;
throw new ConfigurationException(message, e);
}
}
if (!m_types.containsKey(NAMED_EVENT_TYPE)) {
m_types.put(NAMED_EVENT_TYPE,new NamedEventFactory());
}
if (!m_types.containsKey(NAME_VALUE_EVENT_TYPE)) {
m_types.put(NAME_VALUE_EVENT_TYPE,new NameValueEventFactory());
}
}
public void setup(
SourceResolver resolver,
Map objectModel,
String src,
Parameters par)
throws ProcessingException, SAXException, IOException {
// delegate
String delegate = par.getParameter(DELEGATE_PARAM, null);
if (delegate == null) {
String message =
"Required parameter 'delegate' is missing";
throw new ProcessingException(message);
}
try {
m_delegate = (Generator) m_generatorSelector.select(delegate);
} catch (ComponentException e) {
final String message =
"Transformer '" + delegate + "' could not be found.";
throw new ProcessingException(message);
}
m_delegate.setup(resolver, objectModel, src, par);
// event
String eventType = par.getParameter(EVENT_TYPE_PARAM, EVENT_TYPE_DEFAULT);
EventFactory factory = (EventFactory) m_types.get(eventType);
if (factory == null) {
throw new ProcessingException("No such type of event: " + eventType);
}
try {
m_event = factory.createEvent(par);
} catch (ParameterException e) {
final String message = "Failure creating Event";
throw new ProcessingException(message,e);
}
// key - TODO: use delegates key?
m_key = SourceUtil.appendParameters(src,par);
}
public void setConsumer(XMLConsumer consumer) {
m_delegate.setConsumer(consumer);
}
public void generate() throws IOException, SAXException, ProcessingException {
m_delegate.generate();
}
public void recycle() {
if ( m_delegate != null ) {
m_generatorSelector.release(m_delegate);
}
m_delegate = null;
m_key = null;
m_event = null;
}
// ---------------------------------------------------- caching strategy
public Serializable getKey() {
return m_key;
}
public SourceValidity getValidity() {
return new EventValidity(m_event);
}
}