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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,
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package org.apache.cayenne.util;
import java.io.Serializable;
import org.apache.cayenne.ObjectContext;
import org.apache.cayenne.PersistenceState;
import org.apache.cayenne.Persistent;
import org.apache.cayenne.reflect.ArcProperty;
import org.apache.cayenne.reflect.ClassDescriptor;
import org.apache.cayenne.reflect.PropertyDescriptor;
/**
* A base implementation of a helper class to handle
* {@link ObjectContext#propertyChanged(org.apache.cayenne.Persistent, String, Object, Object)}
* processing on behalf of an ObjectContext.
*
* @since 3.0
* TODO: make this non-public!
*/
public class ObjectContextGraphAction implements Serializable {
protected ObjectContext context;
public ObjectContextGraphAction(ObjectContext context) {
this.context = context;
}
/**
* Handles property change in a Persistent object, routing to either
* {@link #handleArcPropertyChange(Persistent, ArcProperty, Object, Object)} or
* {@link #handleSimplePropertyChange(Persistent, String, Object, Object)}.
*/
public 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());
PropertyDescriptor property = descriptor.getProperty(propertyName);
if (property instanceof ArcProperty) {
handleArcPropertyChange(object, (ArcProperty) property, oldValue, newValue);
}
else {
handleSimplePropertyChange(object, propertyName, oldValue, newValue);
}
}
protected void handleArcPropertyChange(
Persistent object,
ArcProperty property,
Object oldValue,
Object newValue) {
if (oldValue != newValue) {
markAsDirty(object);
if (oldValue instanceof Persistent) {
context.getGraphManager().arcDeleted(
object.getObjectId(),
((Persistent) oldValue).getObjectId(),
property.getName());
}
if (newValue instanceof Persistent) {
context.getGraphManager().arcCreated(
object.getObjectId(),
((Persistent) newValue).getObjectId(),
property.getName());
}
}
}
protected void handleSimplePropertyChange(
Persistent object,
String propertyName,
Object oldValue,
Object newValue) {
context.getGraphManager().nodePropertyChanged(
object.getObjectId(),
propertyName,
oldValue,
newValue);
markAsDirty(object);
}
/**
* Changes object state to MODIFIED if needed, returning true if the change has
* occurred, false if not.
*/
protected boolean markAsDirty(Persistent object) {
if (object.getPersistenceState() == PersistenceState.COMMITTED) {
object.setPersistenceState(PersistenceState.MODIFIED);
return true;
}
return false;
}
}