/*
* Copyright 1999-2004 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 org.apache.bsf.BSFException;
import org.apache.bsf.BSFManager;
import org.apache.bsf.util.IOUtils;
import org.apache.avalon.framework.configuration.Configurable;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.ResourceNotFoundException;
import org.apache.cocoon.components.source.SourceUtil;
import org.apache.excalibur.source.Source;
import org.apache.excalibur.source.SourceException;
import org.apache.excalibur.xml.sax.SAXParser;
import org.xml.sax.InputSource;
import java.io.FileNotFoundException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringReader;
/**
* The Scriptgenerator executes arbitraty scripts using the BSF framework
* and additional interpreter (Rhino, Jython, etc.) as a Cocoon Generator.
*
* Additional language support can be added during configuration, eg
* using:
*
* <pre>
* <add-languages>
* <language name="potatoscript" src="edu.purdue.cs.bsf.engines.Potatoscript">
* <extension>pos</extension>
* <extension>psc</extension>
* <language>
* <language name="kawa-scheme" src="org.gnu.kawa.bsf.engines.KawaEngine">
* <extension>scm</extension>
* <language>
* </add-languages>
* </pre>
*
* @author <a href="mailto:jafoster@engmail.uwaterloo.ca">Jason Foster</a>
* @version CVS $Id: ScriptGenerator.java,v 1.7 2004/04/15 08:39:30 bdelacretaz Exp $
*/
public class ScriptGenerator extends ServiceableGenerator implements Configurable {
protected class BSFLanguage {
public String name;
public String engineSrc;
public String[] extensions;
}
protected BSFLanguage[] additionalLanguages;
/** The source */
private Source inputSource;
public void configure(Configuration conf) throws ConfigurationException {
if (conf != null) {
//add optional support for additional languages
Configuration languagesToAdd = conf.getChild("add-languages");
Configuration[] languages = languagesToAdd.getChildren("language");
this.additionalLanguages = new BSFLanguage[languages.length];
for (int i = 0; i < languages.length; i++) {
Configuration language = languages[i];
BSFLanguage bsfLanguage = new BSFLanguage();
bsfLanguage.name = language.getAttribute("name");
bsfLanguage.engineSrc = language.getAttribute("src");
getLogger().debug("Configuring ScriptGenerator with additional BSF language " + bsfLanguage.name);
getLogger().debug("Configuring ScriptGenerator with BSF engine " + bsfLanguage.engineSrc);
Configuration[] extensions = language.getChildren("extension");
bsfLanguage.extensions = new String[extensions.length];
for (int j = 0; j < extensions.length; j++) {
bsfLanguage.extensions[j] = extensions[j].getValue();
getLogger().debug("Configuring ScriptGenerator with lang extension " + bsfLanguage.extensions[j]);
}
this.additionalLanguages[i] = bsfLanguage;
}
}
}
public void recycle() {
if (this.inputSource != null) {
this.resolver.release(this.inputSource);
this.inputSource = null;
}
super.recycle();
}
public void generate() throws ProcessingException {
SAXParser parser = null;
try {
// Figure out what file to open and do so
getLogger().debug("processing file [" + super.source + "]");
this.inputSource = this.resolver.resolveURI(super.source);
getLogger().debug("file resolved to [" + this.inputSource.getURI() + "]");
Reader in = new InputStreamReader(this.inputSource.getInputStream());
// Set up the BSF manager and register relevant helper "beans"
BSFManager mgr = new BSFManager();
// add BSF support for additional languages
if (this.additionalLanguages != null) {
for (int i = 0; i < this.additionalLanguages.length; ++i) {
getLogger().debug("adding BSF language " + this.additionalLanguages[i].name +
" with engine " + this.additionalLanguages[i].engineSrc);
BSFManager.registerScriptingEngine(this.additionalLanguages[i].name,
this.additionalLanguages[i].engineSrc,
this.additionalLanguages[i].extensions);
}
}
StringBuffer output = new StringBuffer();
// make useful objects available to scripts
mgr.registerBean("resolver", this.resolver);
mgr.registerBean("source", super.source);
mgr.registerBean("objectModel", this.objectModel);
mgr.registerBean("parameters", this.parameters);
mgr.registerBean("logger", getLogger());
// provide both a StringBuffer and ContentHandler to script,
// so that it can provide XML either as a String or as SAX events
mgr.registerBean("output", output);
mgr.registerBean("contentHandler",contentHandler);
// Execute the script
if(getLogger().isDebugEnabled()) {
getLogger().debug("BSFManager execution begining (" + inputSource.getURI() + ")");
}
mgr.exec(BSFManager.getLangFromFilename(this.inputSource.getURI()),
this.inputSource.getURI(), 0, 0, IOUtils.getStringFromReader(in));
if(getLogger().isDebugEnabled()) {
getLogger().debug("BSFManager execution complete");
}
// If script wrote something to output buffer, use it
if(output.length() > 0) {
if(getLogger().isDebugEnabled()) {
getLogger().debug("Using String output provided by script (" + output.toString() + ")");
}
InputSource xmlInput = new InputSource(new StringReader(output.toString()));
parser = (SAXParser)(this.manager.lookup(SAXParser.ROLE));
parser.parse(xmlInput, this.xmlConsumer);
} else {
if(getLogger().isDebugEnabled()) {
getLogger().debug("Script provided no String output, content should have been written to contentHandler");
}
}
} catch (SourceException se) {
throw SourceUtil.handle(se);
} catch (FileNotFoundException e) {
throw new ResourceNotFoundException(
"Could not load script " + this.inputSource.getURI(), e);
} catch (BSFException e) {
throw new ProcessingException(
"BSFException in ScriptGenerator.generate()", e);
} catch (Exception e) {
throw new ProcessingException(
"Exception in ScriptGenerator.generate()", e);
} finally {
if(parser!=null) {
this.manager.release(parser);
}
}
}
}