/*******************************************************************************
* Copyright (c) 2011, 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.tools.model.query;
import org.eclipse.persistence.jpa.jpql.Assert;
import org.eclipse.persistence.jpa.jpql.parser.KeywordExpression;
import static org.eclipse.persistence.jpa.jpql.parser.Expression.*;
/**
* The expression representing some keywords: <code>TRUE</code>, <code>FALSE</code> or <code>NULL</code>.
*
* @see KeywordExpression
*
* @version 2.4
* @since 2.4
* @author Pascal Filion
*/
@SuppressWarnings("nls")
public class KeywordExpressionStateObject extends SimpleStateObject {
/**
* Creates a new <code>KeywordExpressionStateObject</code>.
*
* @param parent The parent of this state object, which cannot be <code>null</code>
* @exception NullPointerException The given parent cannot be <code>null</code>
*/
public KeywordExpressionStateObject(StateObject parent) {
super(parent);
}
/**
* Creates a new <code>KeywordExpressionStateObject</code>.
*
* @param parent The parent of this state object, which cannot be <code>null</code>
* @param text Either {@link org.eclipse.persistence.jpa.jpql.parser.Expression#TRUE TRUE},
* {@link org.eclipse.persistence.jpa.jpql.parser.Expression#FALSE FALSE} or
* {@link org.eclipse.persistence.jpa.jpql.parser.Expression#NULL NULL}
* @exception NullPointerException The given parent cannot be <code>null</code>
*/
public KeywordExpressionStateObject(StateObject parent, String text) {
super(parent, text);
validateIdentifier(text);
}
/**
* {@inheritDoc}
*/
public void accept(StateObjectVisitor visitor) {
visitor.visit(this);
}
/**
* {@inheritDoc}
*/
@Override
public KeywordExpression getExpression() {
return (KeywordExpression) super.getExpression();
}
/**
* Keeps a reference of the {@link KeywordExpression parsed object} object, which should only be
* done when this object is instantiated during the conversion of a parsed JPQL query into
* {@link StateObject StateObjects}.
*
* @param expression The {@link KeywordExpression parsed object} representing one of the three
* possible keyword: <code><b>TRUE</b></code>, <code><b>FALSE</b></code> or <code><b>NULL</b></code>
*/
public void setExpression(KeywordExpression expression) {
super.setExpression(expression);
}
/**
* {@inheritDoc}
*/
@Override
public void setText(String text) {
validateIdentifier(text);
super.setText(text);
}
protected void validateIdentifier(String text) {
Assert.isValid(text, "Only TRUE, FALSE, and NULL are valid identifiers.", TRUE, FALSE, NULL);
}
}