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1
19
20 package org.apache.cayenne.access;
21
22 import java.util.List  ;
23
24 import org.apache.cayenne.CayenneRuntimeException;
25 import org.apache.cayenne.ObjectContext;
26 import org.apache.cayenne.ObjectId;
27 import org.apache.cayenne.Persistent;
28 import org.apache.cayenne.QueryResponse;
29 import org.apache.cayenne.graph.GraphChangeHandler;
30 import org.apache.cayenne.map.ObjEntity;
31 import org.apache.cayenne.query.ObjectIdQuery;
32 import org.apache.cayenne.query.Query;
33 import org.apache.cayenne.reflect.AttributeProperty;
34 import org.apache.cayenne.reflect.ClassDescriptor;
35 import org.apache.cayenne.reflect.Property;
36 import org.apache.cayenne.reflect.PropertyVisitor;
37 import org.apache.cayenne.reflect.ToManyProperty;
38 import org.apache.cayenne.reflect.ToOneProperty;
39
40
47 class ChildDiffLoader implements GraphChangeHandler {
48
49 ObjectContext context;
50
51 ChildDiffLoader(ObjectContext context) {
52 this.context = context;
53 }
54
55 public void nodeIdChanged(Object nodeId, Object newId) {
56 throw new CayenneRuntimeException("Not supported");
57 }
58
59 public void nodeCreated(Object nodeId) {
60 ObjectId id = (ObjectId) nodeId;
61 if (id.getEntityName() == null) {
62 throw new NullPointerException ("Null entity name in id " + id);
63 }
64
65 ObjEntity entity = context.getEntityResolver().getObjEntity(id.getEntityName());
66 if (entity == null) {
67 throw new IllegalArgumentException ("Entity not mapped with Cayenne: " + id);
68 }
69
70 Persistent dataObject = null;
71 try {
72 dataObject = (Persistent) entity.getJavaClass().newInstance();
73 }
74 catch (Exception ex) {
75 throw new CayenneRuntimeException("Error instantiating object.", ex);
76 }
77
78 dataObject.setObjectId(id);
79 context.registerNewObject(dataObject);
80 }
81
82 public void nodeRemoved(Object nodeId) {
83 context.deleteObject(findObject(nodeId));
84 }
85
86 public void nodePropertyChanged(
87 Object nodeId,
88 String property,
89 Object oldValue,
90 Object newValue) {
91
92 Persistent object = findObject(nodeId);
95 ClassDescriptor descriptor = context.getEntityResolver().getClassDescriptor(
96 ((ObjectId) nodeId).getEntityName());
97
98 try {
99 descriptor.getProperty(property).writeProperty(object, null, newValue);
100 }
101 catch (Exception e) {
102 throw new CayenneRuntimeException("Error setting property: " + property, e);
103 }
104 }
105
106 public void arcCreated(Object nodeId, Object targetNodeId, Object arcId) {
107
108 final Persistent source = findObject(nodeId);
109 final Persistent target = findObject(targetNodeId);
110
111 ClassDescriptor descriptor = context.getEntityResolver().getClassDescriptor(
112 ((ObjectId) nodeId).getEntityName());
113 Property property = descriptor.getProperty(arcId.toString());
114
115 property.visit(new PropertyVisitor() {
116
117 public boolean visitAttribute(AttributeProperty property) {
118 return false;
119 }
120
121 public boolean visitToMany(ToManyProperty property) {
122 property.addTarget(source, target, false);
123 return false;
124 }
125
126 public boolean visitToOne(ToOneProperty property) {
127 property.setTarget(source, target, false);
128 return false;
129 }
130 });
131 }
132
133 public void arcDeleted(Object nodeId, final Object targetNodeId, Object arcId) {
134 final Persistent source = findObject(nodeId);
135
136 ClassDescriptor descriptor = context.getEntityResolver().getClassDescriptor(
137 ((ObjectId) nodeId).getEntityName());
138 Property property = descriptor.getProperty(arcId.toString());
139 property.visit(new PropertyVisitor() {
140
141 public boolean visitAttribute(AttributeProperty property) {
142 return false;
143 }
144
145 public boolean visitToMany(ToManyProperty property) {
146 Persistent target = findObject(targetNodeId);
147 property.removeTarget(source, target, false);
148 return false;
149 }
150
151 public boolean visitToOne(ToOneProperty property) {
152 property.setTarget(source, null, false);
153 return false;
154 }
155 });
156 }
157
158 Persistent findObject(Object nodeId) {
159
162 Persistent object = (Persistent) context.getGraphManager().getNode(nodeId);
163 if (object != null) {
164 return object;
165 }
166
167 Query query = new ObjectIdQuery((ObjectId) nodeId);
169 QueryResponse response = context.getChannel().onQuery(context, query);
170 List objects = response.firstList();
171
172 if (objects.size() == 0) {
173 throw new CayenneRuntimeException("No object for ID exists: " + nodeId);
174 }
175 else if (objects.size() > 1) {
176 throw new CayenneRuntimeException(
177 "Expected zero or one object, instead query matched: "
178 + objects.size());
179 }
180
181 return (Persistent) objects.get(0);
182 }
183 }
184 |
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