/*
* 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.
*/
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.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.avalon.framework.service.ServiceException;
import org.apache.avalon.framework.service.ServiceManager;
import org.apache.avalon.framework.service.ServiceSelector;
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 ServiceableGenerator
implements Configurable, CacheableProcessingComponent {
// ---------------------------------------------------- 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 ServiceSelector m_generatorSelector;
private Generator m_delegate;
private Serializable m_key;
private Event m_event;
private Map m_types = new HashMap();
/* (non-Javadoc)
* @see org.apache.avalon.framework.service.Serviceable#service(org.apache.avalon.framework.service.ServiceManager)
*/
public void service(ServiceManager manager) throws ServiceException {
super.service(manager);
m_generatorSelector = (ServiceSelector)
manager.lookup(Generator.ROLE + "Selector");
}
/* (non-Javadoc)
* @see org.apache.avalon.framework.configuration.Configurable#configure(org.apache.avalon.framework.configuration.Configuration)
*/
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());
}
}
/* (non-Javadoc)
* @see org.apache.cocoon.sitemap.SitemapModelComponent#setup(org.apache.cocoon.environment.SourceResolver, java.util.Map, java.lang.String, org.apache.avalon.framework.parameters.Parameters)
*/
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 (ServiceException e) {
final String message =
"Generator '" + 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);
}
/* (non-Javadoc)
* @see org.apache.cocoon.xml.XMLProducer#setConsumer(org.apache.cocoon.xml.XMLConsumer)
*/
public void setConsumer(XMLConsumer consumer) {
m_delegate.setConsumer(consumer);
}
/* (non-Javadoc)
* @see org.apache.cocoon.generation.Generator#generate()
*/
public void generate() throws IOException, SAXException, ProcessingException {
m_delegate.generate();
}
/* (non-Javadoc)
* @see org.apache.avalon.excalibur.pool.Recyclable#recycle()
*/
public void recycle() {
if ( m_delegate != null ) {
m_generatorSelector.release(m_delegate);
}
m_delegate = null;
m_key = null;
m_event = null;
super.recycle();
}
/* (non-Javadoc)
* @see org.apache.cocoon.caching.CacheableProcessingComponent#getKey()
*/
public Serializable getKey() {
return m_key;
}
/* (non-Javadoc)
* @see org.apache.cocoon.caching.CacheableProcessingComponent#getValidity()
*/
public SourceValidity getValidity() {
return new EventValidity(m_event);
}
/* (non-Javadoc)
* @see org.apache.avalon.framework.activity.Disposable#dispose()
*/
public void dispose() {
if ( this.manager != null ) {
this.manager.release(m_generatorSelector);
m_generatorSelector = null;
}
super.dispose();
}
}