oracle.toplink.essentials.internal.parsing.OrderByItemNode Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of toplink-essentials
There is a newer version: 2.1-60f
/*
 * The contents of this file are subject to the terms 
 * of the Common Development and Distribution License 
 * (the "License").  You may not use this file except 
 * in compliance with the License.
 * 
 * You can obtain a copy of the license at 
 * glassfish/bootstrap/legal/CDDLv1.0.txt or 
 * https://glassfish.dev.java.net/public/CDDLv1.0.html. 
 * See the License for the specific language governing 
 * permissions and limitations under the License.
 * 
 * When distributing Covered Code, include this CDDL 
 * HEADER in each file and include the License file at 
 * glassfish/bootstrap/legal/CDDLv1.0.txt.  If applicable, 
 * add the following below this CDDL HEADER, with the 
 * fields enclosed by brackets "[]" replaced with your 
 * own identifying information: Portions Copyright [yyyy] 
 * [name of copyright owner]
 */
// Copyright (c) 1998, 2007, Oracle. All rights reserved.  

/**
 * INTERNAL
 * Purpose: This node represents an ORDER BY item
 * 
Responsibilities:

 *  Generate the correct expression for ORDER BY
 * 
 *    @author Jon Driscoll
 *    @since OracleAS TopLink 10g (9.0.4)
 */
package oracle.toplink.essentials.internal.parsing;

import oracle.toplink.essentials.exceptions.EJBQLException;
import oracle.toplink.essentials.expressions.Expression;

public class OrderByItemNode extends Node {
    private SortDirectionNode direction = null;
    private Node orderByItem = null;

    /**
     * INTERNAL
     * Validate node and calculate its type.
     */
    public void validate(ParseTreeContext context) {
        TypeHelper typeHelper = context.getTypeHelper();
        if (orderByItem != null) {
            orderByItem.validate(context);
            Object type = orderByItem.getType();
            setType(type);
            if (!typeHelper.isOrderableType(type)) {
                throw EJBQLException.expectedOrderableOrderByItem(
                    context.getQueryInfo(), orderByItem.getLine(), orderByItem.getColumn(), 
                    orderByItem.getAsString(), typeHelper.getTypeName(type));
            }
        }
    }

    /** */
    public Expression generateExpression(GenerationContext context) {
        //BUG 3105651: Indicate to the VariableNodes in the subtree
        //that they should check the SelectNode before resolving.
        //If the variable involved is SELECTed, then we want an empty builder
        //instead (with an empty constructor).
        boolean oldCheckState = context.shouldCheckSelectNodeBeforeResolving();
        ((SelectGenerationContext)context).checkSelectNodeBeforeResolving(true);
        Expression orderByExpression = getOrderByItem().generateExpression(context);
        orderByExpression = getDirection().addToExpression(orderByExpression, context);
        ((SelectGenerationContext)context).checkSelectNodeBeforeResolving(oldCheckState);
        return orderByExpression;
    }

    public SortDirectionNode getDirection() {
        if (direction == null) {
            setDirection(new SortDirectionNode());
        }
        return direction;
    }

    public Node getOrderByItem() {
        return orderByItem;
    }

    public void setDirection(SortDirectionNode direction) {
        this.direction = direction;
    }

    public void setOrderByItem(Node orderByItem) {
        this.orderByItem = orderByItem;
    }
}