/*******************************************************************************
* Copyright (c) 1998, 2011 Oracle. 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:
* tware - initial implementation as part of JPA 2.0 RI
******************************************************************************/
package org.eclipse.persistence.internal.jpa.parsing;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import org.eclipse.persistence.expressions.Expression;
import org.eclipse.persistence.queries.ObjectLevelReadQuery;
import org.eclipse.persistence.queries.ReportQuery;
/**
* INTERNAL
* <p><b>Purpose</b>: Represent an CASE statement in EJBQL
* <p><b>Responsibilities</b>:<ul>
* <li> Generate the correct expression for an CASE in EJBQL
* </ul>
* @author tware
* @since EclipseLink 1.2
*/
public class CaseNode extends Node {
private List whenClauses = null;
public CaseNode(){
super();
}
/**
* INTERNAL
* Apply this node to the passed query
*/
public void applyToQuery(ObjectLevelReadQuery theQuery, GenerationContext generationContext) {
if (theQuery instanceof ReportQuery) {
ReportQuery reportQuery = (ReportQuery)theQuery;
Expression expression = generateExpression(generationContext);
reportQuery.addAttribute("Case", expression, (Class)getType());
}
}
/**
* INTERNAL
* Generate the a new EclipseLink TableEntryExpression for this node.
*/
public Expression generateExpression(GenerationContext context) {
LinkedHashMap whenClauseMap = new LinkedHashMap(whenClauses.size());
Iterator i = whenClauses.iterator();
while (i.hasNext()){
WhenThenNode clause = (WhenThenNode)i.next();
whenClauseMap.put(clause.generateExpressionForWhen(context), clause.generateExpressionForThen(context));
}
Expression whereClause = null;
if (getLeft() == null){
whereClause = context.getBaseExpression().caseStatement(whenClauseMap, getRight().generateExpression(context));
} else {
whereClause = getLeft().generateExpression(context).caseStatement(whenClauseMap, getRight().generateExpression(context));
}
return whereClause;
}
public void validate(ParseTreeContext context) {
TypeHelper typeHelper = context.getTypeHelper();
if (left != null){
left.validate(context);
}
right.validate(context);
Iterator i = whenClauses.iterator();
Object type = null;
while (i.hasNext()){
Node node = ((Node)i.next());
node.validate(context);
if (type == null){
type = node.getType();
} else if (!type.equals(node.getType())){
type = Object.class;
}
}
if (getRight().getType() != type){
type = typeHelper.getObjectType();
}
setType(type);
}
public List getWhenClauses() {
return whenClauses;
}
public void setWhenClauses(List whenClauses) {
this.whenClauses = whenClauses;
}
}