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* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
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* KIND, either express or implied. See the License for the
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package org.apache.cayenne;
import org.apache.cayenne.property.ArcProperty;
import org.apache.cayenne.property.ClassDescriptor;
import org.apache.cayenne.property.CollectionProperty;
import org.apache.cayenne.property.Property;
import org.apache.cayenne.property.PropertyVisitor;
import org.apache.cayenne.property.SingleObjectArcProperty;
/**
* An action object that processes graph change calls from Persistent object. It handles
* GraphManager notifications and bi-directional graph consistency.
*
* @since 1.2
* @author Andrus Adamchik
*/
class CayenneContextGraphAction {
CayenneContext context;
ThreadLocal arcChangeInProcess;
CayenneContextGraphAction(CayenneContext context) {
this.context = context;
this.arcChangeInProcess = new ThreadLocal();
}
/**
* Handles property change in a Peristent object.
*/
void handlePropertyChange(
Persistent object,
String propertyName,
Object oldValue,
Object newValue) {
// translate ObjectContext generic property change callback to GraphManager terms
// (simple properties vs. relationships)
ClassDescriptor descriptor = context.getEntityResolver().getClassDescriptor(
object.getObjectId().getEntityName());
Property property = descriptor.getProperty(propertyName);
// relationship property
if (property instanceof ArcProperty) {
try {
handleArcPropertyChange(
object,
(ArcProperty) property,
oldValue,
newValue);
}
finally {
setArcChangeInProcess(false);
}
}
// simple property
else {
handleSimplePropertyChange(object, propertyName, oldValue, newValue);
}
}
void handleArcPropertyChange(
Persistent object,
ArcProperty property,
Object oldValue,
Object newValue) {
boolean arcChangeInProcess = isArchChangeInProcess();
// prevent reverse actions down the stack
setArcChangeInProcess(true);
if (oldValue instanceof Persistent) {
context.getGraphManager().arcDeleted(
object.getObjectId(),
((Persistent) oldValue).getObjectId(),
property.getName());
if (!arcChangeInProcess) {
unsetReverse(property, object, (Persistent) oldValue);
}
markAsDirty(object);
}
if (newValue instanceof Persistent) {
context.getGraphManager().arcCreated(
object.getObjectId(),
((Persistent) newValue).getObjectId(),
property.getName());
if (!arcChangeInProcess) {
setReverse(property, object, (Persistent) newValue);
}
markAsDirty(object);
}
}
void handleSimplePropertyChange(
Persistent object,
String propertyName,
Object oldValue,
Object newValue) {
context.getGraphManager().nodePropertyChanged(
object.getObjectId(),
propertyName,
oldValue,
newValue);
markAsDirty(object);
}
boolean isArchChangeInProcess() {
return arcChangeInProcess.get() != null;
}
void setArcChangeInProcess(boolean flag) {
arcChangeInProcess.set(flag ? Boolean.TRUE : null);
}
/**
* Changes object state to MODIFIED if needed.
*/
private void markAsDirty(Persistent object) {
if (object.getPersistenceState() == PersistenceState.COMMITTED) {
object.setPersistenceState(PersistenceState.MODIFIED);
}
}
private void setReverse(
ArcProperty property,
final Persistent sourceObject,
final Persistent targetObject) {
ArcProperty reverseArc = property.getComplimentaryReverseArc();
if (reverseArc != null) {
reverseArc.visit(new PropertyVisitor() {
public boolean visitCollectionArc(CollectionProperty property) {
property.addTarget(targetObject, sourceObject, false);
return false;
}
public boolean visitSingleObjectArc(SingleObjectArcProperty property) {
property.setTarget(targetObject, sourceObject, false);
return false;
}
public boolean visitProperty(Property property) {
return false;
}
});
context.getGraphManager().arcCreated(
targetObject.getObjectId(),
sourceObject.getObjectId(),
reverseArc.getName());
markAsDirty(targetObject);
}
}
private void unsetReverse(
ArcProperty property,
Persistent sourceObject,
Persistent targetObject) {
ArcProperty reverseArc = property.getComplimentaryReverseArc();
if (reverseArc != null) {
reverseArc.writePropertyDirectly(targetObject, sourceObject, null);
context.getGraphManager().arcDeleted(
targetObject.getObjectId(),
sourceObject.getObjectId(),
reverseArc.getName());
markAsDirty(targetObject);
}
}
}