NamespaceFilterTransformer.java from DSpace at Krugle
Show NamespaceFilterTransformer.java syntax highlighted
/*
* NamespaceFilterTransformer.java
*
* Version: $Revision: 1.1 $
*
* Date: $Date: 2005/11/01 21:10:38 $
*
* 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.cocoon;
import java.io.IOException;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Stack;
import org.apache.avalon.framework.parameters.Parameters;
import org.apache.cocoon.ProcessingException;
import org.apache.cocoon.caching.CacheableProcessingComponent;
import org.apache.cocoon.environment.SourceResolver;
import org.apache.cocoon.transformation.AbstractTransformer;
import org.apache.excalibur.source.SourceValidity;
import org.apache.excalibur.source.impl.validity.NOPValidity;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.ext.Attributes2Impl;
/**
* Filter out an unwanted namespace from the pipeline. Any elements or attributes
* which use this namespaces will be removed from pipeline.
*
* <map:transformer type="NamespaceFilterTransformer" src="http://apache.org/cocoon/i18n/2.1"/>
*
* @author Scott Phillips
*/
public class NamespaceFilterTransformer extends AbstractTransformer implements CacheableProcessingComponent
{
/** The namespace to be filtered out of the document */
private String filterNamespace;
/** The prefixes used to identified the namespace */
private Stack<String> filterPrefixes = new Stack<String>();
/**
* Return the cache key
*/
public Serializable getKey() {
if (filterNamespace != null)
return filterNamespace;
else
return "1";
}
/**
* This cache never invalidates, always return a validating cache.
*/
public SourceValidity getValidity() {
// Always returned cached;
return NOPValidity.SHARED_INSTANCE;
}
/**
* Setup the processing instruction transformer. The only parameter that
* matters in the src parameter which should be the path to an XSL
* stylesheet to be applied by the clients browser.
*
* Setup the namespace filter by getting a list of namespaces to be filtered
* from the pipeline.
*/
public void setup(SourceResolver resolver, Map objectModel, String src,
Parameters parameters) throws ProcessingException, SAXException,
IOException
{
filterNamespace = src;
filterPrefixes.clear();
}
/** Should this namespace be filtered out of the document? */
private boolean filter(String test)
{
return (filterNamespace != null && filterNamespace.equals(test));
}
/** Should this prefix be filtered out of the document? */
private boolean filterPrefix(String test)
{
if (filterPrefixes.isEmpty())
return false;
String peek = filterPrefixes.peek();
return (peek != null && peek.equals(test));
}
/**
* Begin the scope of a prefix-URI Namespace mapping.
*
* @param prefix The Namespace prefix being declared.
* @param uri The Namespace URI the prefix is mapped to.
*/
public void startPrefixMapping(String prefix, String uri) throws SAXException
{
if (filter(uri))
{
filterPrefixes.push(prefix);
}
else
{
contentHandler.startPrefixMapping(prefix, uri);
}
}
/**
* End the scope of a prefix-URI mapping.
*
* @param prefix The prefix that was being mapping.
*/
public void endPrefixMapping(String prefix) throws SAXException
{
if (filterPrefix(prefix))
{
filterPrefixes.pop();
}
else
{
contentHandler.endPrefixMapping(prefix);
}
}
/**
* Receive notification of the beginning of an element.
*/
public void startElement(String uri, String loc, String raw, Attributes a) throws SAXException
{
// Reset the namespace context flag.
if (!filter(uri))
{
List<Integer> filterAttributeIndexs = new ArrayList<Integer>();
for (int i = 0; i < a.getLength(); i++)
{
if (filter(a.getURI(i)))
// Add it to the list of filtered indexes.
filterAttributeIndexs.add(i);
}
// Check if any of the attributes are to be filtered if so, filter them out.
if (!filterAttributeIndexs.isEmpty())
{
// New set of attributes.
Attributes2Impl a2 = new Attributes2Impl();
for (int i = 0; i < a.getLength(); i++)
{
if (filterAttributeIndexs.contains(i))
// This index is to be filtered.
continue;
String a_uri = a.getURI(i);
String a_localName = a.getLocalName(i);
String a_qName = a.getQName(i);
String a_type = a.getType(i);
String a_value = a.getValue(i);
// Add the new attribute
a2.addAttribute(a_uri, a_localName, a_qName, a_type, a_value);
}
// Use our new filtered attributes.
a = a2;
}
contentHandler.startElement(uri, loc, raw, a);
}
}
/**
* Receive notification of the end of an element.
*/
public void endElement(String uri, String loc, String raw) throws SAXException
{
if (!filter(uri))
{
contentHandler.endElement(uri, loc, raw);
}
}
}
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