/*
* 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.generation;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Map;
import org.apache.avalon.framework.parameters.Parameters;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.ResourceNotFoundException;
import org.apache.cocoon.components.source.SourceUtil;
import org.apache.cocoon.environment.ObjectModelHelper;
import org.apache.cocoon.environment.Request;
import org.apache.cocoon.environment.SourceResolver;
import org.apache.commons.jelly.JellyContext;
import org.apache.commons.jelly.Script;
import org.apache.commons.jelly.XMLOutput;
import org.apache.commons.jelly.impl.XMLParser;
import org.apache.excalibur.source.Source;
import org.xml.sax.SAXException;
/**
* The JellyGenerator executes jelly scripts using the Jakarta Jelly engine
* as a Cocoon Generator.
*
* @author <a href="mailto:amal.sirvisetti@sirvisetti.com">Amal Sirvisetti</a>
* @author <a href="mailto:cziegeler@apache.org">Carsten Ziegeler</a>
*/
public class JellyGenerator
extends AbstractGenerator {
/** The Jelly Context */
protected JellyContext jellyContext;
/** The Jelly Parser */
protected XMLParser jellyParser = new XMLParser();
/**
* Recycle this component.
* All instance variables are set to <code>null</code>.
*/
public void recycle() {
super.recycle();
this.jellyContext = null;
}
/**
* @see org.apache.cocoon.sitemap.SitemapModelComponent#setup(SourceResolver, Map, String, Parameters)
*/
public void setup(SourceResolver resolver, Map objectModel, String src, Parameters params)
throws ProcessingException,SAXException,IOException {
super.setup(resolver, objectModel, src, params);
// Initialize the Jelly context
this.jellyContext = new JellyContext();
// Update JellyContext with sitemap parameters
this.updateContext(params);
}
/**
* Generate XML data from Jelly script.
*/
public void generate()
throws IOException, SAXException, ProcessingException {
Source scriptSource = null;
try {
// Update JellyContext with request parameters. Variables set earlier
// (from sitemap parameters) will be overriden, if same variables are
// supplied through the request object.
this.updateContext();
// Execute Jelly script
XMLOutput xmlOutput = new XMLOutput(this.contentHandler, this.lexicalHandler);
// TODO - Compile the script and cache the compiled version
scriptSource = this.resolver.resolveURI(this.source);
Script script = this.jellyParser.parse(SourceUtil.getInputSource(scriptSource));
script = script.compile();
// the script does not output startDocument/endDocument events
this.contentHandler.startDocument();
script.run(this.jellyContext, xmlOutput);
xmlOutput.flush();
this.contentHandler.endDocument();
} catch (IOException e) {
getLogger().error("JellyGenerator.generate()", e);
throw new ResourceNotFoundException("JellyGenerator could not find resource", e);
} catch (Exception e) {
getLogger().error("Could not get parser", e);
throw new ProcessingException("Exception in JellyGenerator.generate()", e);
} finally {
this.resolver.release( scriptSource );
}
}
/**
* Update JellyContext with variables from sitemap
*/
protected void updateContext(Parameters params) throws ProcessingException {
try {
String pArray[] = params.getNames();
for(int i=0; i<pArray.length; i++) {
String var = pArray[i];
String val = params.getParameter(var);
this.jellyContext.setVariable( var, val );
}
} catch (Exception e) {
getLogger().error("Error in JellyGenerator.updateContext(Parameters params)", e);
throw new ProcessingException("Exception in JellyGenerator.updateContext(Parameters params)", e);
}
}
/**
* Update JellyContext with variables from request
*/
protected void updateContext() throws ProcessingException {
try {
Request request = ObjectModelHelper.getRequest( this.objectModel );
Enumeration enum = request.getParameterNames();
while (enum.hasMoreElements()) {
String var = (String) enum.nextElement();
String val = request.getParameter(var);
this.jellyContext.setVariable( var, val );
}
} catch (Exception e) {
getLogger().error("Error in JellyGenerator.updateContext()", e);
throw new ProcessingException("Exception in JellyGenerator.updateContext()", e);
}
}
}