/*
* reserved comment block
* DO NOT REMOVE OR ALTER!
*/
/*
* 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.
*/
/*
* $Id: ExsltSets.java,v 1.1.2.1 2005/08/01 02:08:50 jeffsuttor Exp $
*/
package com.sun.org.apache.xalan.internal.lib;
import java.util.Hashtable;
import com.sun.org.apache.xml.internal.utils.DOMHelper;
import com.sun.org.apache.xpath.internal.NodeSet;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
/**
* 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>
* @xsl.usage general
*/
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;
}
}