/*******************************************************************************
* 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 static org.eclipse.persistence.jpa.jpql.parser.AbstractExpression.LEFT_PARENTHESIS;
import static org.eclipse.persistence.jpa.jpql.parser.AbstractExpression.RIGHT_PARENTHESIS;
import static org.eclipse.persistence.jpa.jpql.parser.AbstractExpression.SPACE;
import static org.eclipse.persistence.jpa.jpql.parser.Expression.AS;
import static org.eclipse.persistence.jpa.jpql.parser.Expression.TREAT;
import java.io.IOException;
import java.util.List;
import org.eclipse.persistence.jpa.jpql.parser.TreatExpression;
import org.eclipse.persistence.jpa.jpql.tools.spi.IEntity;
/**
* Returns an expression that allows to treat its base as if it were a subclass of the class
* returned by the base.
* <p>
* <b>Note:</b> {@link EclipseLinkStateObjectVisitor} needs to be used to traverse this state object.
* </p>
* <div><b>BNF:</b> <code>join_treat ::= TREAT(collection_valued_path_expression [AS] entity_type_literal)</code><p></div>
*
* @see TreatExpression
*
* @version 2.4
* @since 2.4
* @author Pascal Filion
*/
@SuppressWarnings({"nls"})
public class TreatExpressionStateObject extends AbstractStateObject {
/**
* Flag used to determine if the <code><b>AS</b></code> identifier is used or not.
*/
private boolean as;
/**
* The {@link StateObject} representing the entity type name.
*/
private EntityTypeLiteralStateObject entityTypeName;
/**
* Keeps a reference onto the {@link JoinStateObject} since it owns the {@link IStatObject}
* representing the collection-valued path expression.
*/
private JoinStateObject joinStateObject;
/**
* Notifies the visibility of the <code><b>AS</b></code> identifier has changed.
*/
public static final String AS_PROPERTY = "as";
/**
* Notifies the entity type name property has changed.
*/
public static final String ENTITY_TYPE_NAME_PROPERTY = "entityTypeName";
/**
* Creates a new <code>TreatExpressionStateObject</code>.
*
* @param parent The parent of this state object, which is temporary since this state object will
* be parented with the state object representing the join's association path expression
*/
public TreatExpressionStateObject(JoinStateObject parent) {
super(parent);
this.joinStateObject = parent;
}
/**
* Creates a new <code>TreatExpressionStateObject</code>.
*
* @param parent The parent of this state object, which is temporary since this state object will
* be parented with the state object representing the join's association path expression
* @param as Determines whether the <code><b>AS</b></code> identifier is used or not
* @param entityTypeName The entity type name used to cast the base expression
*/
public TreatExpressionStateObject(JoinStateObject parent, boolean as, String entityTypeName) {
super(parent);
this.as = as;
this.joinStateObject = parent;
this.entityTypeName.setText(entityTypeName);
}
/**
* Creates a new <code>TreatExpressionStateObject</code>.
*
* @param parent The parent of this state object, which is temporary since this state object will
* be parented with the state object representing the join's association path expression
* @param entityTypeName The entity type name used to cast the base expression
*/
public TreatExpressionStateObject(JoinStateObject parent, String entityTypeName) {
this(parent, false, entityTypeName);
}
/**
* {@inheritDoc}
*/
@Override
public void accept(StateObjectVisitor visitor) {
acceptUnknownVisitor(visitor);
}
/**
* Makes sure the <code><b>AS</b></code> identifier is specified.
*
* @return This object
*/
public TreatExpressionStateObject addAs() {
if (!as) {
setAs(true);
}
return this;
}
/**
* {@inheritDoc}
*/
@Override
protected void addChildren(List<StateObject> children) {
super.addChildren(children);
children.add(entityTypeName);
}
/**
* Appends the given text to the existing entity type name property.
*
* @param text The text to append to the entity type name property or nothing is done if the
* given value is <code>null</code>
*/
public void appendToEntityTypeName(String text) {
if (text != null) {
if (entityTypeName == null) {
setEntityTypeName(text);
}
else {
setEntityTypeName(entityTypeName + text);
}
}
}
/**
* Resolves the entity type name to the external form of the actual {@link IEntity}.
*
* @return Either the {@link IEntity} with the same entity type name or <code>null</code> if the
* managed type provider does not have an entity with that name
*/
public IEntity getEntity() {
String entityName = entityTypeName.getText();
for (IEntity entity : getManagedTypeProvider().entities()) {
if (entity.getName().equals(entityName)) {
return entity;
}
}
return null;
}
/**
* Returns the name of the entity that is used to downcast the join association path.
*
* @return The name of the entity used for down casting
*/
public String getEntityTypeName() {
return entityTypeName.getText();
}
/**
* {@inheritDoc}
*/
@Override
public TreatExpression getExpression() {
return (TreatExpression) super.getExpression();
}
/**
* Returns the reference of the {@link JoinStateObject}.
*
* @return The "owning" of this object
*/
public JoinStateObject getJoin() {
return joinStateObject;
}
/**
* Returns the {@link StateObject} representing the identification variable that starts the path
* expression, which can be a sample identification variable, a map value, map key or map entry
* expression.
*
* @return The root of the path expression
*/
public StateObject getJoinAssociationIdentificationVariable() {
return joinStateObject.getJoinAssociationIdentificationVariable();
}
/**
* Returns the {@link CollectionValuedPathExpressionStateObject} representing the join
* association path.
*
* @return The state object representing the join association path
*/
public CollectionValuedPathExpressionStateObject getJoinAssociationPathStateObject() {
return joinStateObject.getJoinAssociationPathStateObject();
}
/**
* Determines whether the <code><b>AS</b></code> identifier is used.
*
* @return <code>true</code> if the <code><b>AS</b></code> identifier is used; <code>false</code>
* otherwise
*/
public boolean hasAs() {
return as;
}
/**
* Determines whether the.
*
* @return <code>true</code> if the entity type name has been defined; <code>false</code>
* otherwise
*/
public boolean hasEntityTypeName() {
return entityTypeName != null;
}
/**
* {@inheritDoc}
*/
@Override
protected void initialize() {
super.initialize();
entityTypeName = new EntityTypeLiteralStateObject(this);
}
/**
* {@inheritDoc}
*/
@Override
public boolean isEquivalent(StateObject stateObject) {
if (super.isEquivalent(stateObject)) {
TreatExpressionStateObject treat = (TreatExpressionStateObject) stateObject;
return as == treat.as &&
entityTypeName.isEquivalent(treat.entityTypeName);
}
return false;
}
/**
* Makes sure the <code><b>AS</b></code> identifier is not specified.
*/
public void removeAs() {
if (as) {
setAs(true);
}
}
/**
* Sets whether the <code><b>AS</b></code> identifier should be used.
*
* @param as <code>true</code> if the <code><b>AS</b></code> identifier should be used part;
* <code>false</code> otherwise
*/
public void setAs(boolean as) {
boolean oldAs = this.as;
this.as = as;
firePropertyChanged(AS_PROPERTY, oldAs, as);
}
/**
* Sets the name of the entity that is used to downcast the join association path.
*
* @param entityType The Java class representing the entity type
*/
public void setEntityTypeName(Class<?> entityType) {
setEntityTypeName(entityType.getName());
}
/**
* Sets the name of the entity that is used to downcast the join association path.
*
* @param entityType The external form of the entity type
*/
public void setEntityTypeName(IEntity entityType) {
setEntityTypeName(entityType.getName());
}
/**
* Sets the name of the entity that is used to downcast the join association path.
*
* @param entityTypeName The new name of the entity used for down casting
*/
public void setEntityTypeName(String entityTypeName) {
String oldEntityTypeName = getEntityTypeName();
this.entityTypeName.setText(entityTypeName);
firePropertyChanged(ENTITY_TYPE_NAME_PROPERTY, oldEntityTypeName, entityTypeName);
}
/**
* Keeps a reference of the {@link TreatExpression 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 TreatExpression parsed object} representing the <code><b>TREAD</b></code>
* expression
*/
public void setExpression(TreatExpression expression) {
super.setExpression(expression);
}
/**
* Toggles the visibility of the <code><b>AS</b></code> identifier; either adds it if it's not
* present otherwise removes it if it's present.
*/
public void toggleAs() {
setAs(!as);
}
/**
* {@inheritDoc}
*/
@Override
protected void toTextInternal(Appendable writer) throws IOException {
// TREAT
writer.append(TREAT);
writer.append(LEFT_PARENTHESIS);
// Join association path expression
getJoinAssociationPathStateObject().toTextInternal(writer);
// AS
if (as) {
writer.append(SPACE);
writer.append(AS);
}
// Entity type literal
if (entityTypeName.hasText()) {
writer.append(SPACE);
entityTypeName.toTextInternal(writer);
}
writer.append(RIGHT_PARENTHESIS);
}
}