/*
============================================================================
The Apache Software License, Version 1.1
============================================================================
Copyright (C) 1999-2002 The Apache Software Foundation. All rights reserved.
Redistribution and use in source and binary forms, with or without modifica-
tion, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
this list of conditions and the following disclaimer in the documentation
and/or other materials provided with the distribution.
3. The end-user documentation included with the redistribution, if any, must
include the following acknowledgment: "This product includes software
developed by the Apache Software Foundation (http://www.apache.org/)."
Alternately, this acknowledgment may appear in the software itself, if
and wherever such third-party acknowledgments normally appear.
4. The names "Apache Cocoon" and "Apache Software Foundation" must not be
used to endorse or promote products derived from this software without
prior written permission. For written permission, please contact
apache@apache.org.
5. Products derived from this software may not be called "Apache", nor may
"Apache" appear in their name, without prior written permission of the
Apache Software Foundation.
THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
APACHE SOFTWARE FOUNDATION OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLU-
DING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
This software consists of voluntary contributions made by many individuals
on behalf of the Apache Software Foundation and was originally created by
Stefano Mazzocchi <stefano@apache.org>. For more information on the Apache
Software Foundation, please see <http://www.apache.org/>.
*/
package org.apache.cocoon.portal.transformation;
import java.util.Stack;
import org.apache.avalon.framework.service.ServiceException;
import org.apache.cocoon.portal.LinkService;
import org.apache.cocoon.portal.coplet.CopletInstanceData;
import org.apache.cocoon.portal.event.impl.CopletLinkEvent;
import org.w3c.dom.DocumentFragment;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;
/**
* This transformer searches for event descriptions in the XML.
* For each one an event is created and the event link is inserted into the XML
* instead of the description.<br><br>
*
* Example:<br><br>
*
* <pre><root xmlns:event="http://apache.org/cocoon/portal/eventlink/1.0">
* <event:event attribute="href">
* <a href="http://eventlinkexample"/>
* </event:event>
* <event:event element="uri">
* <link><uri>http://eventlinkexample</uri></link>
* </event:event>
* </root><br></pre>
*
* The transformer will create two CopletLinkEvents and insert corresponding links
* to them to the XML instead of "http://eventlinkexample". If such a link is pressed
* the corresponding CopletLinkEvent is sent to the Subscribers to be handled.<br>
* Please see also the documentation of superclass AbstractCopletTransformer for how
* the coplet instance data are acquired.
*
* @author <a href="mailto:bluetkemeier@s-und-n.de">Björn Lütkemeier</a>
*
* @version CVS $Id: EventLinkTransformer.java,v 1.6 2003/10/21 12:39:16 cziegeler Exp $
*/
public class EventLinkTransformer
extends AbstractCopletTransformer {
/**
* The namespace URI to listen for.
*/
public static final String NAMESPACE_URI = "http://apache.org/cocoon/portal/eventlink/1.0";
/**
* The XML element name to listen for.
*/
public static final String EVENT_ELEM = "event";
/**
* An attribute's name of EVENT_ELEMENT.
*/
public static final String ATTRIBUTE_ATTR = "attribute";
/**
* An attribute's name of EVENT_ELEMENT.
*/
public static final String ELEMENT_ATTR = "element";
/**
* Used to signal whether the transformer is inside an EVENT_ELEM tag.
*/
private boolean insideEvent = false;
/**
* The attribute defining the link inside an EVENT_ELEM tag.
*/
private String attributeName = null;
/**
* The element defining the link inside an EVENT_ELEM tag.
*/
private String elementName = null;
/**
* Used to store elements' attributes between startTransformingElement and endTransformingElement.
*/
private Stack attrStack = new Stack();
/**
* Overridden from superclass.
*/
public void recycle() {
super.recycle();
this.insideEvent = false;
this.attributeName = null;
this.elementName = null;
this.attrStack.clear();
}
/**
* Overridden from superclass.
*/
public void startElement(String uri, String name, String raw, Attributes attr)
throws SAXException {
if (uri.equals(NAMESPACE_URI) && name.equals(EVENT_ELEM)) {
if (this.insideEvent) {
throw new SAXException("Elements "+EVENT_ELEM+" must not be nested.");
}
this.insideEvent = true;
// get element or attribute name that contains links
this.attributeName = attr.getValue(ATTRIBUTE_ATTR);
this.elementName = attr.getValue(ELEMENT_ATTR);
// at least one of them must be set
if (this.attributeName == null && this.elementName == null) {
throw new SAXException("Element "+EVENT_ELEM+" must have one of attributes "+ATTRIBUTE_ATTR+" and "+ELEMENT_ATTR+".");
}
} else {
if (this.insideEvent) {
// store attributes for endTransformingElement
this.attrStack.push(new AttributesImpl(attr));
/* Record element content. In case of an element we asume, that no
* children exist but only text content, since the text content shall
* be the link. Therefore we do startTextRecording. Otherwise we
* record the whole subtree.
*/
if (this.elementName != null && name.equals(this.elementName)) {
this.startTextRecording();
} else {
this.startRecording();
}
} else {
super.startElement(uri, name, raw, attr);
}
}
}
/**
* Overridden from superclass.
*/
public void endElement(String uri, String name, String raw)
throws SAXException {
if (uri.equals(NAMESPACE_URI) && name.equals(EVENT_ELEM)) {
this.attributeName = null;
this.elementName = null;
this.insideEvent = false;
} else {
if (this.insideEvent) {
AttributesImpl attr = (AttributesImpl)this.attrStack.pop();
// process attribute that contains link
if (this.attributeName != null) {
int index = attr.getIndex(this.attributeName);
String link = attr.getValue(index);
// if attribute found that contains a link
if (link != null) {
CopletInstanceData cid = this.getCopletInstanceData();
LinkService linkService = null;
try {
linkService = (LinkService)this.manager.lookup(LinkService.ROLE);
// create event link
CopletLinkEvent event = new CopletLinkEvent(cid, link);
String eventLink = linkService.getLinkURI(event);
// insert event link
attr.setValue(index, eventLink);
} catch (ServiceException e) {
throw new SAXException(e);
} finally {
this.manager.release(linkService);
}
}
}
String eventLink = null;
DocumentFragment fragment = null;
// process element that contains link
if (this.elementName != null && name.equals(this.elementName)) {
String link = this.endTextRecording();
CopletInstanceData cid = this.getCopletInstanceData();
LinkService linkService = null;
try {
linkService = (LinkService)this.manager.lookup(LinkService.ROLE);
// create event link
CopletLinkEvent event = new CopletLinkEvent(cid, link);
eventLink = linkService.getLinkURI(event);
} catch (ServiceException e) {
throw new SAXException(e);
} finally {
this.manager.release(linkService);
}
} else {
fragment = this.endRecording();
}
// stream element
super.startElement(uri, name, raw, attr);
if (eventLink != null) {
// insert event link
super.characters(eventLink.toCharArray(), 0, eventLink.length());
} else if (fragment != null) {
super.sendEvents(fragment);
}
super.endElement(uri, name, raw);
} else {
super.endElement(uri, name, raw);
}
}
}
}