/******************************************************************************* | |
* Copyright (c) 1998, 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: | |
* tware - initial implementation as part of JPA 2.0 RI | |
******************************************************************************/ | |
package org.eclipse.persistence.internal.jpa.parsing; | |
import java.util.ArrayList; | |
import java.util.Iterator; | |
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 COALESCE in EJBQL | |
* <p><b>Responsibilities</b>:<ul> | |
* <li> Generate the correct expression for an COALESCE in EJBQL | |
* </ul> | |
* @author tware | |
* @since EclipseLink 1.2 | |
*/ | |
public class CoalesceNode extends Node implements AliasableNode { | |
private List clauses = null; | |
public CoalesceNode(){ | |
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.addItem("Coalesce", expression); | |
} | |
} | |
/** | |
* INTERNAL | |
* Generate the a new EclipseLink Coalesce expression for this node. | |
*/ | |
public Expression generateExpression(GenerationContext context) { | |
List expressions = new ArrayList(); | |
Iterator i = clauses.iterator(); | |
while (i.hasNext()){ | |
expressions.add(((Node)i.next()).generateExpression(context)); | |
} | |
Expression whereClause = context.getBaseExpression().coalesce(expressions); | |
return whereClause; | |
} | |
public void validate(ParseTreeContext context) { | |
TypeHelper typeHelper = context.getTypeHelper(); | |
Iterator i = clauses.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 = typeHelper.getObjectType(); | |
} | |
} | |
setType(((Node)clauses.get(0)).getType()); | |
} | |
public List getClauses() { | |
return clauses; | |
} | |
public void setClauses(List clauses) { | |
this.clauses = clauses; | |
} | |
public boolean isAliasableNode(){ | |
return true; | |
} | |
} |