bundles/org.eclipse.wst.xsl.core/src_validation/org/eclipse/wst/xsl/core/internal/compiler/xslt10/transformer/KeyIterator.java

/*******************************************************************************
 * Copyright (c) 2008 Standards for Technology in Automotive Retail
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     David Carver - STAR - bug 224197 - initial API and implementation
 *                    based on work from Apache Xalan 2.7.0
 *******************************************************************************/
/*
 * 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: KeyIterator.java,v 1.2 2008/03/28 02:38:16 dacarver Exp $
 */
package org.eclipse.wst.xsl.core.internal.compiler.xslt10.transformer;

import java.util.Vector;

import javax.xml.transform.TransformerException;

import org.apache.xalan.res.XSLMessages;
import org.apache.xalan.res.XSLTErrorResources;
import org.apache.xalan.templates.KeyDeclaration;
import org.apache.xml.dtm.Axis;
import org.apache.xml.dtm.DTMIterator;
import org.apache.xml.utils.QName;
import org.apache.xpath.XPath;
import org.apache.xpath.axes.OneStepIteratorForward;

/**
 * This class implements an optimized iterator for "key()" patterns, matching
 * each node to the match attribute in one or more xsl:key declarations.
 * 
 * @xsl.usage internal
 */
public class KeyIterator extends OneStepIteratorForward {
	static final long serialVersionUID = -1349109910100249661L;

	/**
	 * Key name.
	 * 
	 * @serial
	 */
	private QName m_name;

	/**
	 * Get the key name from a key declaration this iterator will process
	 * 
	 * 
	 * @return Key name
	 */
	public QName getName() {
		return m_name;
	}

	/**
	 * Vector of Key declarations in the stylesheet.
	 * 
	 * @serial
	 */
	private Vector m_keyDeclarations;

	/**
	 * Get the key declarations from the stylesheet
	 * 
	 * 
	 * @return Vector containing the key declarations from the stylesheet
	 */
	public Vector getKeyDeclarations() {
		return m_keyDeclarations;
	}

	/**
	 * Create a KeyIterator object.
	 * 
	 * @throws javax.xml.transform.TransformerException
	 */
	public KeyIterator(QName name, Vector keyDeclarations) {
		super(Axis.ALL);
		m_keyDeclarations = keyDeclarations;
		// m_prefixResolver = nscontext;
		m_name = name;
	}

	/**
	 * Test whether a specified node is visible in the logical view of a
	 * TreeWalker or NodeIterator. This function will be called by the
	 * implementation of TreeWalker and NodeIterator; it is not intended to be
	 * called directly from user code.
	 * 
	 * @param testNode
	 *            The node to check to see if it passes the filter or not.
	 * 
	 * @return a constant to determine whether the node is accepted, rejected,
	 *         or skipped, as defined above .
	 */
	@Override
	public short acceptNode(int testNode) {
		boolean foundKey = false;
		KeyIterator ki = (KeyIterator) m_lpi;
		org.apache.xpath.XPathContext xctxt = ki.getXPathContext();
		Vector keys = ki.getKeyDeclarations();

		QName name = ki.getName();
		try {
			// System.out.println("lookupKey: "+lookupKey);
			int nDeclarations = keys.size();

			// Walk through each of the declarations made with xsl:key
			for (int i = 0; i < nDeclarations; i++) {
				KeyDeclaration kd = (KeyDeclaration) keys.elementAt(i);

				// Only continue if the name on this key declaration
				// matches the name on the iterator for this walker.
				if (!kd.getName().equals(name))
					continue;

				foundKey = true;
				// xctxt.setNamespaceContext(ki.getPrefixResolver());

				// See if our node matches the given key declaration according
				// to
				// the match attribute on xsl:key.
				XPath matchExpr = kd.getMatch();
				double score = matchExpr.getMatchScore(xctxt, testNode);

				if (score == XPath.MATCH_SCORE_NONE)
					continue;

				return DTMIterator.FILTER_ACCEPT;

			} // end for(int i = 0; i < nDeclarations; i++)
		} catch (TransformerException se) {

			// TODO: What to do?
		}

		if (!foundKey)
			throw new RuntimeException(XSLMessages.createMessage(
					XSLTErrorResources.ER_NO_XSLKEY_DECLARATION,
					new Object[] { name.getLocalName() }));

		return DTMIterator.FILTER_REJECT;
	}

}