/*
* PageNotFoundTransformer.java
*
* Version: $Revision: 3705 $
*
* Date: $Date: 2009-04-11 18:02:24 +0100 (Sat, 11 Apr 2009) $
*
* Copyright (c) 2002, Hewlett-Packard Company and Massachusetts
* Institute of Technology. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - 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.
*
* - Neither the name of the Hewlett-Packard Company nor the name of the
* Massachusetts Institute of Technology nor the names of their
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS 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 COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* 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.
*/
package org.dspace.app.xmlui.aspect.general;
import java.io.IOException;
import java.io.Serializable;
import java.sql.SQLException;
import javax.servlet.http.HttpServletResponse;
import org.apache.cocoon.caching.CacheableProcessingComponent;
import org.apache.cocoon.environment.ObjectModelHelper;
import org.apache.cocoon.environment.Request;
import org.apache.cocoon.environment.http.HttpEnvironment;
import org.apache.cocoon.util.HashUtil;
import org.apache.excalibur.source.SourceValidity;
import org.apache.excalibur.source.impl.validity.NOPValidity;
import org.apache.log4j.Logger;
import org.dspace.app.xmlui.cocoon.AbstractDSpaceTransformer;
import org.dspace.app.xmlui.utils.UIException;
import org.dspace.app.xmlui.wing.Message;
import org.dspace.app.xmlui.wing.WingConstants;
import org.dspace.app.xmlui.wing.WingException;
import org.dspace.app.xmlui.wing.element.Body;
import org.dspace.app.xmlui.wing.element.Division;
import org.dspace.app.xmlui.wing.element.PageMeta;
import org.dspace.authorize.AuthorizeException;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
/**
* This special comonent checks to see if the body element is empty (has no sub elements) and if
* it is then displays some page not found text.
*
* @author Scott Phillips
*/
public class PageNotFoundTransformer extends AbstractDSpaceTransformer implements CacheableProcessingComponent
{
private static Logger logger = Logger.getLogger(PageNotFoundTransformer.class);
/** Language Strings */
private static final Message T_title =
message("xmlui.PageNotFound.title");
private static final Message T_head =
message("xmlui.PageNotFound.head");
private static final Message T_para1 =
message("xmlui.PageNotFound.para1");
private static final Message T_go_home =
message("xmlui.general.go_home");
private static final Message T_dspace_home =
message("xmlui.general.dspace_home");
/** Where the body element is stored while we wait to see if it is empty */
private SAXEvent bodyEvent;
/** Have we determined that the body is empty, and hence a we should generate a page not found. */
private boolean bodyEmpty;
/**
* Generate the unique caching key.
* This key must be unique inside the space of this component.
*/
public Serializable getKey()
{
Request request = ObjectModelHelper.getRequest(objectModel);
return HashUtil.hash(request.getSitemapURI());
}
/**
* Generate the cache validity object.
*
* The cache is always valid.
*/
public SourceValidity getValidity() {
return NOPValidity.SHARED_INSTANCE;
}
/**
* Receive notification of the beginning of a document.
*/
public void startDocument() throws SAXException
{
// Reset our parameters before starting a new document.
this.bodyEvent = null;
this.bodyEmpty = false;
super.startDocument();
}
/**
* Process the SAX event.
* @see org.xml.sax.ContentHandler#startElement
*/
public void startElement(String namespaceURI, String localName,
String qName, Attributes attributes) throws SAXException
{
if (this.bodyEvent != null)
{
// If we have recorded the startElement for body and we are
// recieving another start event, then there must be something
// inside the body element, so we send the held body and carry
// on as normal.
sendEvent(this.bodyEvent);
this.bodyEvent = null;
}
if (WingConstants.DRI.URI.equals(namespaceURI))
{
if (Body.E_BODY.equals(localName))
{
// Save the element and see if there is anything inside the body.
this.bodyEvent = SAXEvent.startElement(namespaceURI,localName,qName,attributes);
return;
}
}
super.startElement(namespaceURI, localName, qName, attributes);
}
/**
* Process the SAX event.
* @see org.xml.sax.ContentHandler#endElement
*/
public void endElement(String namespaceURI, String localName, String qName)
throws SAXException
{
if (WingConstants.DRI.URI.equals(namespaceURI))
{
if (Body.E_BODY.equals(localName))
{
if (this.bodyEvent != null)
{
// If we are recieving an endElement event for body while we
// still have a startElement body event recorded then
// the body element must have been empty. In this case, record
// that the body is empty, and send both the start and end body events.
this.bodyEmpty = true;
// Sending the body will trigger the Wing framework to ask
// us if we want to add a body to the page.
sendEvent(this.bodyEvent);
this.bodyEvent = null;
// GWaller 8/3/10 Log the url which caused the page not found
Request request = ObjectModelHelper.getRequest(objectModel);
logger.error("PageNotFoundTransformer: page not found on URL: " + request.getRequestURI());
}
}
}
super.endElement(namespaceURI, localName, qName);
}
/** What to add at the end of the body */
public void addBody(Body body) throws SAXException, WingException,
UIException, SQLException, IOException, AuthorizeException
{
if (this.bodyEmpty)
{
Division notFound = body.addDivision("page-not-found","primary");
notFound.setHead(T_head);
notFound.addPara(T_para1);
notFound.addPara().addXref(contextPath,T_go_home);
HttpServletResponse response = (HttpServletResponse)objectModel
.get(HttpEnvironment.HTTP_RESPONSE_OBJECT);
response.setStatus(HttpServletResponse.SC_NOT_FOUND);
}
}
/** What page metadata to add to the document */
public void addPageMeta(PageMeta pageMeta) throws SAXException,
WingException, UIException, SQLException, IOException,
AuthorizeException
{
if (this.bodyEmpty)
{
// Set the page title
pageMeta.addMetadata("title").addContent(T_title);
// Give theme a base trail
pageMeta.addTrailLink(contextPath + "/",T_dspace_home);
}
}
/**
* Send the given recorded sax event.
*/
public void sendEvent(SAXEvent event) throws SAXException
{
if (event.type == SAXEvent.EventType.START)
{
super.startElement(event.namespaceURI,event.localName,event.qName,event.attributes);
}
else if (event.type == SAXEvent.EventType.END)
{
super.endElement(event.namespaceURI,event.localName,event.qName);
}
}
/**
* This private class remembers start and end element SAX events.
*/
private static class SAXEvent {
public enum EventType { START, END };
protected EventType type = null;
protected String namespaceURI = null;
protected String localName = null;
protected String qName = null;
protected Attributes attributes = null;
/**
* Create a new StartElement recorded sax event.
*/
public static SAXEvent startElement(String namespaceURI, String localName, String qName, Attributes attributes)
{
SAXEvent event = new SAXEvent();
event.type = EventType.START;
event.namespaceURI = namespaceURI;
event.localName = localName;
event.qName = qName;
event.attributes = attributes;
return event;
}
/**
* Create a new EndElement recorded sax event.
*/
public static SAXEvent endElement(String namespaceURI, String localName, String qName)
{
SAXEvent event = new SAXEvent();
event.type = EventType.END;
event.namespaceURI = namespaceURI;
event.localName = localName;
event.qName = qName;
return event;
}
}
}