GroupByItemFactory.java

/*******************************************************************************
 * Copyright (c) 2006, 2015 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation
 *
 ******************************************************************************/
package org.eclipse.persistence.jpa.jpql.parser;

import org.eclipse.persistence.jpa.jpql.WordParser;

/**
 * This {@link GroupByItemFactory} is responsible to return the right expression and to support
 * invalid expression as well.
 *
 * @version 2.4
 * @since 2.3
 * @author Pascal Filion
 */
@SuppressWarnings("nls")
public final class GroupByItemFactory extends ExpressionFactory {

    /**
     * The unique identifier of this {@link GroupByItemFactory}.
     */
    public static final String ID = "groupby_item";

    /**
     * Creates a new <code>GroupByItemFactory</code>.
     */
    public GroupByItemFactory() {
        super(ID);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected AbstractExpression buildExpression(AbstractExpression parent,
                                                 WordParser wordParser,
                                                 String word,
                                                 JPQLQueryBNF queryBNF,
                                                 AbstractExpression expression,
                                                 boolean tolerant) {

        // StateFieldPathExpression
        if (word.indexOf(AbstractExpression.DOT) > -1) {
            expression = new StateFieldPathExpression(parent, word);
            expression.parse(wordParser, tolerant);
            return expression;
        }

        ExpressionRegistry registry = getExpressionRegistry();

        // When the tolerant mode is turned on, parse the invalid portion of the query
        if (tolerant && registry.isIdentifier(word)) {
            ExpressionFactory factory = registry.expressionFactoryForIdentifier(word);

            if (factory == null) {
                return null;
            }

            expression = factory.buildExpression(parent, wordParser, word, queryBNF, expression, tolerant);

            if (expression != null) {
                return new BadExpression(parent, expression);
            }
        }

        // IdentificationVariable or any text
        expression = new IdentificationVariable(parent, word);
        expression.parse(wordParser, tolerant);
        return expression;
    }
}