/*******************************************************************************
* Copyright (c) 2011, 2013 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.model;
import org.eclipse.persistence.jpa.jpql.model.query.CaseExpressionStateObject;
import org.eclipse.persistence.jpa.jpql.model.query.StateObject;
import org.eclipse.persistence.jpa.jpql.model.query.WhenClauseStateObject;
/**
* This abstract implementation of {@link ICaseExpressionStateObjectBuilder} adds support for
* creating a <code><b>CASE</b></code> expression.
*
* @version 2.4
* @since 2.4
* @author Pascal Filion
*/
public abstract class AbstractCaseExpressionStateObjectBuilder extends AbstractConditionalExpressionStateObjectBuilder<ICaseExpressionStateObjectBuilder>
implements ICaseExpressionStateObjectBuilder {
/**
* Keeps track of the actual {@link CaseExpressionStateObject} since it is needed when creating
* new {@link WhenClauseStateObject} due to strongly typed parent.
*/
private CaseExpressionStateObject caseExpressionStateObject;
/**
* Creates a new <code>AbstractCaseExpressionStateObjectBuilder</code>.
*
* @param parent The parent of the <code><b>CASE</b></code> expression to build, which is only
* required when a JPQL fragment needs to be parsed
*/
protected AbstractCaseExpressionStateObjectBuilder(StateObject parent) {
super(parent);
caseExpressionStateObject = new CaseExpressionStateObject(parent);
}
/**
* {@inheritDoc}
*/
public CaseExpressionStateObject buildStateObject() {
caseExpressionStateObject.setElse(pop());
if (hasStateObjects()) {
caseExpressionStateObject.setCaseOperand(pop());
}
return caseExpressionStateObject;
}
/**
* {@inheritDoc}
*/
public ICaseExpressionStateObjectBuilder when(ICaseExpressionStateObjectBuilder when,
ICaseExpressionStateObjectBuilder then) {
checkBuilders(when, then);
StateObject thenStateObject = pop();
StateObject whenStateObject = pop();
WhenClauseStateObject stateObject = new WhenClauseStateObject(
caseExpressionStateObject,
whenStateObject,
thenStateObject
);
caseExpressionStateObject.addItem(stateObject);
return this;
}
}