/******************************************************************************* | |
* 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: | |
* Oracle - initial API and implementation from Oracle TopLink | |
******************************************************************************/ | |
package org.eclipse.persistence.internal.jpa.parsing; | |
// TopLink imports | |
import org.eclipse.persistence.expressions.*; | |
/** | |
* INTERNAL | |
* <p><b>Purpose</b>: Used for the EMPTY collection handling | |
* <p><b>Responsibilities</b>:<ul> | |
* <li> Generate the correct expression for an IS EMPTY in EJBQL | |
* </ul> | |
* @author Jon Driscoll and Joel Lucuik | |
* @since August 2003 | |
*/ | |
public class EmptyCollectionComparisonNode extends SimpleConditionalExpressionNode { | |
public boolean notIndicated = false; | |
/** | |
* EmptyCollectionComparisonNode constructor comment. | |
*/ | |
public EmptyCollectionComparisonNode() { | |
super(); | |
} | |
/** | |
* INTERNAL | |
* Validate node and calculate its type. | |
*/ | |
public void validate(ParseTreeContext context) { | |
if (left != null) { | |
left.validate(context); | |
} | |
TypeHelper typeHelper = context.getTypeHelper(); | |
setType(typeHelper.getBooleanType()); | |
} | |
/** | |
* INTERNAL | |
* Return a EclipseLink expression for this node. | |
*/ | |
public Expression generateExpression(GenerationContext context) { | |
//get the variable name from the DotNode's right attribute | |
//...WHERE emp.firstName IS EMPTY | |
String emptyAttributeName = ((AttributeNode)getLeft().getRight()).getAttributeName(); | |
Expression whereClause = getLeft().getLeft().generateExpression(context); | |
if (notIndicated) { | |
return whereClause.notEmpty(emptyAttributeName); | |
} else { | |
return whereClause.isEmpty(emptyAttributeName); | |
} | |
} | |
/** | |
* INTERNAL | |
* Indicate if a NOT was found in the WHERE clause. | |
* Examples: | |
* ...WHERE emp.phoneNumbers IS NOT EMPTY | |
*/ | |
public void indicateNot() { | |
notIndicated = true; | |
} | |
} |