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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.graph.ChildDiffLoader;
import org.apache.cayenne.reflect.ArcProperty;
import org.apache.cayenne.reflect.AttributeProperty;
import org.apache.cayenne.reflect.ClassDescriptor;
import org.apache.cayenne.reflect.PropertyDescriptor;
import org.apache.cayenne.reflect.PropertyVisitor;
import org.apache.cayenne.reflect.ToManyProperty;
import org.apache.cayenne.reflect.ToOneProperty;
/**
* Used for loading child's CayenneContext changes to parent context.
*
* @since 3.0
*/
class CayenneContextChildDiffLoader extends ChildDiffLoader {
public CayenneContextChildDiffLoader(CayenneContext context) {
super(context);
}
@Override
public void nodePropertyChanged(
Object nodeId,
String property,
Object oldValue,
Object newValue) {
super.nodePropertyChanged(nodeId, property, oldValue, newValue);
Persistent object = (Persistent) context.getGraphManager().getNode(nodeId);
context.propertyChanged(object, property, oldValue, newValue);
}
@Override
public void arcCreated(Object nodeId, Object targetNodeId, Object arcId) {
final Persistent source = findObject(nodeId);
final Persistent target = findObject(targetNodeId);
// if a target was later deleted, the diff for arcCreated is still preserved and
// can result in NULL target here.
if (target == null) {
return;
}
ClassDescriptor descriptor = context.getEntityResolver().getClassDescriptor(
((ObjectId) nodeId).getEntityName());
ArcProperty property = (ArcProperty) descriptor.getProperty(arcId.toString());
property.visit(new PropertyVisitor() {
public boolean visitAttribute(AttributeProperty property) {
return false;
}
public boolean visitToMany(ToManyProperty property) {
property.addTargetDirectly(source, target);
return false;
}
public boolean visitToOne(ToOneProperty property) {
property.setTarget(source, target, false);
return false;
}
});
context.propertyChanged(source, (String) arcId, null, target);
}
@Override
public void arcDeleted(Object nodeId, final Object targetNodeId, Object arcId) {
final Persistent source = findObject(nodeId);
// needed as sometime temporary objects are evoked from the context before
// changing their relationships
if (source == null) {
return;
}
ClassDescriptor descriptor = context.getEntityResolver().getClassDescriptor(
((ObjectId) nodeId).getEntityName());
PropertyDescriptor property = descriptor.getProperty(arcId.toString());
final Persistent[] target = new Persistent[1];
target[0] = findObject(targetNodeId);
property.visit(new PropertyVisitor() {
public boolean visitAttribute(AttributeProperty property) {
return false;
}
public boolean visitToMany(ToManyProperty property) {
if (target[0] == null) {
// this is usually the case when a NEW object was deleted and then
// its relationships were manipulated; so try to locate the object
// in the collection ... the performance of this is rather dubious
// of course...
target[0] = findObjectInCollection(targetNodeId, property
.readProperty(source));
}
if (target[0] == null) {
// ignore?
}
else {
property.removeTargetDirectly(source, target[0]);
}
return false;
}
public boolean visitToOne(ToOneProperty property) {
property.setTarget(source, null, false);
return false;
}
});
context.propertyChanged(source, (String) arcId, target[0], null);
}
}