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/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * 
 * // Copyright (c) 1998, 2007, Oracle. All rights reserved.
 * 
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License. You can obtain
 * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
 * or glassfish/bootstrap/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 * 
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
 * Sun designates this particular file as subject to the "Classpath" exception
 * as provided by Sun in the GPL Version 2 section of the License file that
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 * Header, with the fields enclosed by brackets [] replaced by your own
 * identifying information: "Portions Copyrighted [year]
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 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
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package oracle.toplink.essentials.internal.parsing;


// Java imports
import java.util.*;

// TopLink Imports
import oracle.toplink.essentials.queryframework.ReadAllQuery;
import oracle.toplink.essentials.queryframework.ObjectLevelReadQuery;

/**
 * INTERNAL
 * Purpose: Represent an ORDER BY
 * 
Responsibilities:

 *  Generate the correct expression for an ORDER BY
 * 
 *    @author Jon Driscoll
 *    @since TopLink 5.0
 */
public class OrderByNode extends MajorNode {

    List orderByItems = null;

    /**
     * Return a new OrderByNode.
     */
    public OrderByNode() {
        super();
    }

    /**
     * INTERNAL
     * Add an Order By Item to this node
     */
    private void addOrderByItem(Object theNode) {
        getOrderByItems().add(theNode);
    }

    /**
     * INTERNAL
     * Add the ordering expressions to the passed query
     */
    public void addOrderingToQuery(ObjectLevelReadQuery theQuery, GenerationContext context) {
        if (theQuery.isReadAllQuery()) {
            Iterator iter = getOrderByItems().iterator();
            while (iter.hasNext()) {
                Node nextNode = (Node)iter.next();
                ((ReadAllQuery)theQuery).addOrdering(nextNode.generateExpression(context));
            }
        }
    }

    /**
     * INTERNAL
     * Validate node.
     */
    public void validate(ParseTreeContext context, SelectNode selectNode) {
        for (Iterator i = orderByItems.iterator(); i.hasNext(); ) {
            Node item = (Node)i.next();
            item.validate(context);
        }
    }
    
    /**
     * INTERNAL
     * Return the order by statements
     */
    public List getOrderByItems() {
        if (orderByItems == null) {
            setOrderByItems(new Vector());
        }
        return orderByItems;
    }

    /**
     * INTERNAL
     * Set the order by statements
     */
    public void setOrderByItems(List newItems) {
        orderByItems = newItems;
    }
}