/*
* 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.portal.layout.renderer.aspect.impl;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.HashMap;
import javax.xml.transform.Transformer;
import javax.xml.transform.sax.SAXResult;
import javax.xml.transform.sax.TransformerHandler;
import org.apache.avalon.framework.activity.Disposable;
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.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.configuration.Configurable;
import org.apache.cocoon.portal.PortalService;
import org.apache.cocoon.portal.layout.Layout;
import org.apache.cocoon.portal.layout.renderer.aspect.RendererAspectContext;
import org.apache.cocoon.sitemap.PatternException;
import org.apache.cocoon.xml.IncludeXMLConsumer;
import org.apache.cocoon.components.variables.VariableResolverFactory;
import org.apache.cocoon.components.variables.VariableResolver;
import org.apache.excalibur.source.Source;
import org.apache.excalibur.source.SourceResolver;
import org.apache.excalibur.xml.xslt.XSLTProcessor;
import org.apache.excalibur.xml.xslt.XSLTProcessorException;
import org.xml.sax.ContentHandler;
import org.xml.sax.SAXException;
import org.xml.sax.ext.LexicalHandler;
/**
* Apply a XSLT stylesheet to the contained layout. All following renderer aspects
* are applied first before the XML is fed into the XSLT. All configuration and layout
* parameters are made available to the stylesheet.
*
* <h2>Example XML:</h2>
* <pre>
* <-- result from output of following renderers transformed by stylesheet -->
* </pre>
*
*
* The parameter values may contain Strings and/or references to input modules which will be resolved each
* time the aspect is rendered.
* <h2>Applicable to:</h2>
* {@link org.apache.cocoon.portal.layout.Layout}
*
* <h2>Configuration</h2>
* <h3>cocoon.xconf</h3>
*
* <pre>
* <aspect name="xslt" class="org.apache.cocoon.portal.layout.renderer.aspect.impl.XSLTAspect">
* <parameters>
* <parameter name="<i>name1</i>" value="<i>parameter value</i>"/>
* <parameter name="<i>name2</i>" value="<i>parameter value</i>"/>
* <parameter>
* </aspect>
* </pre>
*
* <h2>Parameters</h2>
* <table><tbody>
* <tr><th>style</th><td></td><td>req</td><td>String</td><td><code>null</code></td></tr>
* <tr><th>xslt-processor-role</th><td></td><td>req</td><td>String</td><td><code>null</code></td></tr>
* </tbody></table>
*
* @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 $Id$
*/
public class XSLTAspect
extends AbstractAspect
implements Disposable, Configurable {
protected List variables = new ArrayList();
protected Parameters parameters;
protected VariableResolverFactory variableFactory;
/* (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);
this.variableFactory = (VariableResolverFactory) this.manager.lookup(VariableResolverFactory.ROLE);
}
/* (non-Javadoc)
* @see org.apache.avalon.framework.configuration.Configurable#configure(org.apache.avalon.framework.configuration.Configuration)
*/
public void configure(Configuration config) throws ConfigurationException {
Configuration parameterItems = config.getChild("parameters", false);
if (parameterItems != null) {
this.parameters = Parameters.fromConfiguration(parameterItems);
}
}
/* (non-Javadoc)
* @see org.apache.cocoon.portal.layout.renderer.RendererAspect#toSAX(org.apache.cocoon.portal.layout.renderer.RendererAspectContext, org.apache.cocoon.portal.layout.Layout, org.apache.cocoon.portal.PortalService, org.xml.sax.ContentHandler)
*/
public void toSAX(RendererAspectContext context,
Layout layout,
PortalService service,
ContentHandler handler)
throws SAXException {
PreparedConfiguration config = (PreparedConfiguration)context.getAspectConfiguration();
XSLTProcessor processor = null;
Source stylesheet = null;
SourceResolver resolver = null;
try {
resolver = (SourceResolver) this.manager.lookup(SourceResolver.ROLE);
stylesheet = resolver.resolveURI(this.getStylesheetURI(config, layout));
processor = (XSLTProcessor) this.manager.lookup(config.xsltRole);
TransformerHandler transformer = processor.getTransformerHandler(stylesheet);
// Pass configured parameters to the stylesheet.
if (config.parameters.size() > 0) {
Map.Entry entry;
Transformer theTransformer = transformer.getTransformer();
Iterator iter = config.parameters.entrySet().iterator();
while (iter.hasNext()) {
entry = (Map.Entry) iter.next();
String value = getParameterValue(entry);
theTransformer.setParameter((String) entry.getKey(), value);
}
}
Map parameter = layout.getParameters();
if (parameter.size() > 0) {
Map.Entry entry;
Transformer theTransformer = transformer.getTransformer();
for (Iterator iter = parameter.entrySet().iterator(); iter.hasNext();) {
entry = (Map.Entry) iter.next();
theTransformer.setParameter((String)entry.getKey(), entry.getValue());
}
}
SAXResult result = new SAXResult(new IncludeXMLConsumer((handler)));
if (handler instanceof LexicalHandler) {
result.setLexicalHandler((LexicalHandler) handler);
}
transformer.setResult(result);
transformer.startDocument();
context.invokeNext(layout, service, transformer);
transformer.endDocument();
} catch (XSLTProcessorException xpe) {
throw new SAXException("XSLT Exception.", xpe);
} catch (IOException io) {
throw new SAXException("Error in resolving.", io);
} catch (ServiceException ce) {
throw new SAXException("Unable to lookup component.", ce);
} finally {
if (null != resolver) {
resolver.release(stylesheet);
this.manager.release(resolver);
}
this.manager.release(processor);
}
}
protected String getStylesheetURI(PreparedConfiguration config, Layout layout)
throws SAXException {
// FIXME Get the stylesheet either from a layout attribute or another aspect
try {
String stylesheet = config.stylesheet.resolve();
return stylesheet;
} catch (PatternException pe) {
throw new SAXException("Pattern exception during variable resolving.", pe);
}
}
protected String getParameterValue(Map.Entry entry) throws SAXException {
try {
return ((VariableResolver)entry.getValue()).resolve();
} catch (PatternException pe) {
throw new SAXException("Unable to get value for parameter " + entry.getKey(), pe);
}
}
protected static class PreparedConfiguration {
public VariableResolver stylesheet;
public String xsltRole;
public Map parameters = new HashMap();
public void takeValues(PreparedConfiguration from) {
this.stylesheet = from.stylesheet;
this.xsltRole = from.xsltRole;
this.parameters = from.parameters;
}
}
/* (non-Javadoc)
* @see org.apache.cocoon.portal.layout.renderer.aspect.RendererAspect#prepareConfiguration(org.apache.avalon.framework.parameters.Parameters)
*/
public Object prepareConfiguration(Parameters configuration)
throws ParameterException {
PreparedConfiguration pc = new PreparedConfiguration();
pc.xsltRole = configuration.getParameter("xslt-processor-role", XSLTProcessor.ROLE);
String stylesheet = configuration.getParameter("style");
try {
pc.stylesheet = this.variableFactory.lookup( stylesheet );
} catch (PatternException pe) {
throw new ParameterException("Unknown pattern for stylesheet " + stylesheet, pe);
}
this.variables.add(pc.stylesheet);
if (this.parameters != null) {
String[] name = this.parameters.getNames();
for (int i=0; i < name.length; ++i) {
try {
VariableResolver resolver =
this.variableFactory.lookup(this.parameters.getParameter(name[i]));
this.variables.add(resolver);
pc.parameters.put(name[i], resolver);
} catch (PatternException e) {
throw new ParameterException("Invalid value for parameter " + name[i], e);
}
}
}
return pc;
}
/* (non-Javadoc)
* @see org.apache.avalon.framework.activity.Disposable#dispose()
*/
public void dispose() {
if ( this.manager != null ) {
Iterator vars = this.variables.iterator();
while ( vars.hasNext() ) {
this.variableFactory.release( (VariableResolver) vars.next() );
}
this.variables.clear();
this.manager.release( this.variableFactory);
this.manager = null;
this.variableFactory = null;
}
}
}