/*
* 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.transformation;
import org.apache.avalon.framework.parameters.Parameters;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.environment.ObjectModelHelper;
import org.apache.cocoon.environment.Request;
import org.apache.cocoon.environment.Session;
import org.apache.cocoon.environment.SourceResolver;
import org.apache.cocoon.xml.XMLUtils;
import org.apache.cocoon.xml.IncludeXMLConsumer;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import java.io.IOException;
import java.util.Map;
/**
* With this transformer, an object that is stored in the session, can be inserted
* in the SAX stream at a given position, using usual <xsp:expr> rules.
* Object can be DOM Node, XMLizable, or any other object supported by <xsp:expr>.
*
* Usage in sitemap:
* <pre>
* <map:transform type="read-session">
* <map:parameter name="attribute-name" value="companyInfo"/>
* <map:parameter name="trigger-element" value="company"/>
* <map:parameter name="position" value="after"/>
* </map:transform>
* </pre>
*
* Where:
* <ul>
* <li><b>attribute-name</b> is the name of the object in the session
* <li><b>trigger-element</b> is the element that we need to insert the SAX events
* <li><b>postion</b> is the actual place where the stream will be inserted, ie before, after or in
* the trigger-element
* </ul>
*
* @author <a href="mailto:sven.beauprez@the-ecorp.com">Sven Beauprez</a>
* @author <a href="mailto:vgritsenko@apache.org">Vadim Gritsenko</a>
* @version CVS $Id: ReadDOMSessionTransformer.java,v 1.3 2004/03/05 13:02:59 bdelacretaz Exp $
*/
public class ReadDOMSessionTransformer extends AbstractTransformer {
public static final String ATTRIBUTE_NAME = "attribute-name";
public static final String TRIGGER_ELEMENT = "trigger-element";
/*
position where the sax events from the dom should be insterted
this can be: 'before', 'after' or 'in'
*/
public static final String POSITION = "position";
Session session;
String attributeName;
String trigger;
String position;
/** BEGIN SitemapComponent methods **/
public void setup(SourceResolver resolver,
Map objectModel,
String source,
Parameters parameters)
throws ProcessingException, SAXException, IOException {
Request request = ObjectModelHelper.getRequest(objectModel);
session = request.getSession(false);
if (session != null) {
if (getLogger().isDebugEnabled()) {
getLogger().debug("Session is available. ID=" + session.getId());
}
this.attributeName = parameters.getParameter(ATTRIBUTE_NAME, null);
if (this.attributeName == null) {
// Try old syntax
this.attributeName = parameters.getParameter("dom-name", null);
}
this.trigger = parameters.getParameter(TRIGGER_ELEMENT, null);
this.position = parameters.getParameter(POSITION, "in");
if (getLogger().isDebugEnabled()) {
getLogger().debug(ATTRIBUTE_NAME + "=" + attributeName + ", "
+ TRIGGER_ELEMENT + "=" + trigger + ", "
+ POSITION + "=" + position);
}
} else {
getLogger().warn("No session object: Nothing to do.");
}
}
/** END SitemapComponent methods **/
/** BEGIN SAX ContentHandler handlers **/
public void startElement(String uri, String name, String raw, Attributes attributes)
throws SAXException {
// Start streaming after certain startelement is encountered
if (name.equalsIgnoreCase(trigger)) {
getLogger().debug("Trigger encountered");
if ("before".equalsIgnoreCase(position)) {
stream();
super.contentHandler.startElement(uri,name,raw,attributes);
} else if ("in".equalsIgnoreCase(position)) {
super.contentHandler.startElement(uri,name,raw,attributes);
stream();
} else if ("after".equalsIgnoreCase(position)) {
super.contentHandler.startElement(uri,name,raw,attributes);
}
} else {
super.contentHandler.startElement(uri,name,raw,attributes);
}
}
public void endElement(String uri,String name,String raw)
throws SAXException {
super.contentHandler.endElement(uri,name,raw);
if (name.equalsIgnoreCase(trigger)) {
if ("after".equalsIgnoreCase(position)) {
stream();
}
}
}
/** END SAX ContentHandler handlers **/
/** own methods **/
private void stream() throws SAXException {
if (attributeName != null) {
Object node = session.getAttribute(attributeName);
if (node != null) {
getLogger().debug("Start streaming");
XMLUtils.valueOf(new IncludeXMLConsumer(super.xmlConsumer), node);
} else {
getLogger().error("No attribute " + attributeName + " in session");
}
} else {
getLogger().error("No "+ ATTRIBUTE_NAME + " parameter specified");
}
}
}