/*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 1999-2003 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, 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 "Xalan" 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 (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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation and was
* originally based on software copyright (c) 1999, Lotus
* Development Corporation., http://www.lotus.com. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.xalan.lib;
import java.util.Hashtable;
import org.apache.xml.utils.DOMHelper;
import org.apache.xpath.NodeSet;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
/**
* <meta name="usage" content="general"/>
* This class contains EXSLT set extension functions.
* It is accessed by specifying a namespace URI as follows:
* <pre>
* xmlns:set="http://exslt.org/sets"
* </pre>
*
* The documentation for each function has been copied from the relevant
* EXSLT Implementer page.
*
* @see <a href="http://www.exslt.org/">EXSLT</a>
*/
public class ExsltSets extends ExsltBase
{
/**
* The set:leading function returns the nodes in the node set passed as the first argument that
* precede, in document order, the first node in the node set passed as the second argument. If
* the first node in the second node set is not contained in the first node set, then an empty
* node set is returned. If the second node set is empty, then the first node set is returned.
*
* @param nl1 NodeList for first node-set.
* @param nl2 NodeList for second node-set.
* @return a NodeList containing the nodes in nl1 that precede in document order the first
* node in nl2; an empty node-set if the first node in nl2 is not in nl1; all of nl1 if nl2
* is empty.
*
* @see <a href="http://www.exslt.org/">EXSLT</a>
*/
public static NodeList leading (NodeList nl1, NodeList nl2)
{
if (nl2.getLength() == 0)
return nl1;
NodeSet ns1 = new NodeSet(nl1);
NodeSet leadNodes = new NodeSet();
Node endNode = nl2.item(0);
if (!ns1.contains(endNode))
return leadNodes; // empty NodeSet
for (int i = 0; i < nl1.getLength(); i++)
{
Node testNode = nl1.item(i);
if (DOMHelper.isNodeAfter(testNode, endNode)
&& !DOMHelper.isNodeTheSame(testNode, endNode))
leadNodes.addElement(testNode);
}
return leadNodes;
}
/**
* The set:trailing function returns the nodes in the node set passed as the first argument that
* follow, in document order, the first node in the node set passed as the second argument. If
* the first node in the second node set is not contained in the first node set, then an empty
* node set is returned. If the second node set is empty, then the first node set is returned.
*
* @param nl1 NodeList for first node-set.
* @param nl2 NodeList for second node-set.
* @return a NodeList containing the nodes in nl1 that follow in document order the first
* node in nl2; an empty node-set if the first node in nl2 is not in nl1; all of nl1 if nl2
* is empty.
*
* @see <a href="http://www.exslt.org/">EXSLT</a>
*/
public static NodeList trailing (NodeList nl1, NodeList nl2)
{
if (nl2.getLength() == 0)
return nl1;
NodeSet ns1 = new NodeSet(nl1);
NodeSet trailNodes = new NodeSet();
Node startNode = nl2.item(0);
if (!ns1.contains(startNode))
return trailNodes; // empty NodeSet
for (int i = 0; i < nl1.getLength(); i++)
{
Node testNode = nl1.item(i);
if (DOMHelper.isNodeAfter(startNode, testNode)
&& !DOMHelper.isNodeTheSame(startNode, testNode))
trailNodes.addElement(testNode);
}
return trailNodes;
}
/**
* The set:intersection function returns a node set comprising the nodes that are within
* both the node sets passed as arguments to it.
*
* @param nl1 NodeList for first node-set.
* @param nl2 NodeList for second node-set.
* @return a NodeList containing the nodes in nl1 that are also
* in nl2.
*
* @see <a href="http://www.exslt.org/">EXSLT</a>
*/
public static NodeList intersection(NodeList nl1, NodeList nl2)
{
NodeSet ns1 = new NodeSet(nl1);
NodeSet ns2 = new NodeSet(nl2);
NodeSet inter = new NodeSet();
inter.setShouldCacheNodes(true);
for (int i = 0; i < ns1.getLength(); i++)
{
Node n = ns1.elementAt(i);
if (ns2.contains(n))
inter.addElement(n);
}
return inter;
}
/**
* The set:difference function returns the difference between two node sets - those nodes that
* are in the node set passed as the first argument that are not in the node set passed as the
* second argument.
*
* @param nl1 NodeList for first node-set.
* @param nl2 NodeList for second node-set.
* @return a NodeList containing the nodes in nl1 that are not in nl2.
*
* @see <a href="http://www.exslt.org/">EXSLT</a>
*/
public static NodeList difference(NodeList nl1, NodeList nl2)
{
NodeSet ns1 = new NodeSet(nl1);
NodeSet ns2 = new NodeSet(nl2);
NodeSet diff = new NodeSet();
diff.setShouldCacheNodes(true);
for (int i = 0; i < ns1.getLength(); i++)
{
Node n = ns1.elementAt(i);
if (!ns2.contains(n))
diff.addElement(n);
}
return diff;
}
/**
* The set:distinct function returns a subset of the nodes contained in the node-set NS passed
* as the first argument. Specifically, it selects a node N if there is no node in NS that has
* the same string value as N, and that precedes N in document order.
*
* @param nl NodeList for the node-set.
* @return a NodeList with nodes from nl containing distinct string values.
* In other words, if more than one node in nl contains the same string value,
* only include the first such node found.
*
* @see <a href="http://www.exslt.org/">EXSLT</a>
*/
public static NodeList distinct(NodeList nl)
{
NodeSet dist = new NodeSet();
dist.setShouldCacheNodes(true);
Hashtable stringTable = new Hashtable();
for (int i = 0; i < nl.getLength(); i++)
{
Node currNode = nl.item(i);
String key = toString(currNode);
if (key == null)
dist.addElement(currNode);
else if (!stringTable.containsKey(key))
{
stringTable.put(key, currNode);
dist.addElement(currNode);
}
}
return dist;
}
/**
* The set:has-same-node function returns true if the node set passed as the first argument shares
* any nodes with the node set passed as the second argument. If there are no nodes that are in both
* node sets, then it returns false.
*
* The Xalan extensions MethodResolver converts 'has-same-node' to 'hasSameNode'.
*
* Note: Not to be confused with hasSameNodes in the Xalan namespace, which returns true if
* the two node sets contain the exactly the same nodes (perhaps in a different order),
* otherwise false.
*
* @see <a href="http://www.exslt.org/">EXSLT</a>
*/
public static boolean hasSameNode(NodeList nl1, NodeList nl2)
{
NodeSet ns1 = new NodeSet(nl1);
NodeSet ns2 = new NodeSet(nl2);
for (int i = 0; i < ns1.getLength(); i++)
{
if (ns2.contains(ns1.elementAt(i)))
return true;
}
return false;
}
}