/*
* Copyright 1999-2002,2004 The Apache Software Foundation.
*
* Licensed 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.portal.layout.renderer.impl;
import java.util.Collections;
import java.util.Iterator;
import javax.xml.transform.sax.SAXResult;
import javax.xml.transform.sax.TransformerHandler;
import org.apache.avalon.framework.activity.Disposable;
import org.apache.avalon.framework.logger.AbstractLogEnabled;
import org.apache.avalon.framework.service.ServiceException;
import org.apache.avalon.framework.service.ServiceManager;
import org.apache.avalon.framework.service.ServiceSelector;
import org.apache.avalon.framework.service.Serviceable;
import org.apache.avalon.framework.thread.ThreadSafe;
import org.apache.cocoon.portal.PortalService;
import org.apache.cocoon.portal.layout.Layout;
import org.apache.cocoon.portal.layout.renderer.Renderer;
import org.apache.cocoon.xml.IncludeXMLConsumer;
import org.apache.excalibur.source.Source;
import org.apache.excalibur.source.SourceResolver;
import org.apache.excalibur.xml.xslt.XSLTProcessor;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;
import org.xml.sax.ext.LexicalHandler;
/**
* Base class for all renderers.
*
* @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: AbstractRenderer.java,v 1.8 2004/04/25 20:10:29 haul Exp $
*/
public abstract class AbstractRenderer
extends AbstractLogEnabled
implements Renderer, Serviceable, Disposable, ThreadSafe {
protected ServiceSelector rendererSelector;
protected ServiceManager manager;
/* (non-Javadoc)
* @see org.apache.avalon.framework.service.Serviceable#service(org.apache.avalon.framework.service.ServiceManager)
*/
public void service(ServiceManager manager) throws ServiceException {
this.manager = manager;
}
public String getStylesheetURI(Layout layout) {
return null;
}
public boolean useStylesheet() {
return false;
}
/**
* @see org.apache.avalon.framework.activity.Disposable#dispose()
*/
public void dispose() {
if (null != this.manager) {
this.manager.release(this.rendererSelector);
this.manager = null;
this.rendererSelector = null;
}
}
/**
* Stream out raw layout
*/
public void toSAX(Layout layout, PortalService service, ContentHandler handler) throws SAXException {
if (this.useStylesheet()) {
XSLTProcessor processor = null;
Source stylesheet = null;
SourceResolver resolver = null;
try {
resolver = (SourceResolver) this.manager.lookup(SourceResolver.ROLE);
stylesheet = resolver.resolveURI(this.getStylesheetURI(layout));
processor = (XSLTProcessor) this.manager.lookup(XSLTProcessor.ROLE);
TransformerHandler transformer = processor.getTransformerHandler(stylesheet);
SAXResult result = new SAXResult(new IncludeXMLConsumer((handler)));
if (handler instanceof LexicalHandler) {
result.setLexicalHandler((LexicalHandler) handler);
}
transformer.setResult(result);
transformer.startDocument();
this.process(layout, service, transformer);
transformer.endDocument();
} catch (Exception ce) {
throw new SAXException("Unable to lookup component.", ce);
} finally {
if (null != resolver) {
resolver.release(stylesheet);
this.manager.release(resolver);
}
this.manager.release(processor);
}
} else {
this.process(layout, service, handler);
}
}
/**
* Process a Layout
*/
protected void processLayout(Layout layout, PortalService service, ContentHandler handler) throws SAXException {
final String rendererName = layout.getRendererName();
Renderer renderer = null;
renderer = service.getComponentManager().getRenderer(rendererName);
renderer.toSAX(layout, service, handler);
}
protected abstract void process(Layout layout, PortalService service, ContentHandler handler) throws SAXException;
/**
* Return the aspects required for this renderer
*/
public Iterator getAspectDescriptions() {
return Collections.EMPTY_LIST.iterator();
}
}