svn commit: r1083907 - /cayenne/main/trunk/framework/cayenne-lifecycle/src/main/java/org/apache/cayenne/lifecycle/relationship/UuidRelationshipHandler.java

[aa...@apache.org]

Author: aadamchik
Date: Mon Mar 21 19:17:30 2011
New Revision: 1083907

URL: http://svn.apache.org/viewvc?rev=1083907&view=rev
Log:
CAY-1547 cayenne-lifecycle: support for setting UuidRelationships

Added:
    cayenne/main/trunk/framework/cayenne-lifecycle/src/main/java/org/apache/cayenne/lifecycle/relationship/UuidRelationshipHandler.java

Added: cayenne/main/trunk/framework/cayenne-lifecycle/src/main/java/org/apache/cayenne/lifecycle/relationship/UuidRelationshipHandler.java
URL: http://svn.apache.org/viewvc/cayenne/main/trunk/framework/cayenne-lifecycle/src/main/java/org/apache/cayenne/lifecycle/relationship/UuidRelationshipHandler.java?rev=1083907&view=auto
==============================================================================
--- cayenne/main/trunk/framework/cayenne-lifecycle/src/main/java/org/apache/cayenne/lifecycle/relationship/UuidRelationshipHandler.java (added)
+++ cayenne/main/trunk/framework/cayenne-lifecycle/src/main/java/org/apache/cayenne/lifecycle/relationship/UuidRelationshipHandler.java Mon Mar 21 19:17:30 2011
@@ -0,0 +1,95 @@
+/*****************************************************************
+ *   Licensed to the Apache Software Foundation (ASF) under one
+ *  or more contributor license agreements.  See the NOTICE file
+ *  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
+ *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ *  KIND, either express or implied.  See the License for the
+ *  specific language governing permissions and limitations
+ *  under the License.
+ ****************************************************************/
+package org.apache.cayenne.lifecycle.relationship;
+
+import org.apache.cayenne.DataObject;
+import org.apache.cayenne.lifecycle.ref.ReferenceableHandler;
+
+/**
+ * @since 3.1
+ */
+public class UuidRelationshipHandler {
+
+    protected ReferenceableHandler referenceableHandler;
+
+    public UuidRelationshipHandler(ReferenceableHandler referenceableHandler) {
+        this.referenceableHandler = referenceableHandler;
+    }
+
+    public String uuidRelationshipName(String uuidPropertyName) {
+        return "cay:related:" + uuidPropertyName;
+    }
+
+    public String uuidPropertyName(DataObject object) {
+
+        UuidRelationship annotation = object.getClass().getAnnotation(
+                UuidRelationship.class);
+
+        if (annotation == null) {
+            throw new IllegalArgumentException(
+                    "Object class is not annotated with @UuidRelationship: "
+                            + object.getClass().getName());
+        }
+
+        // TODO: I guess we'll need to cache this metadata for performance if we are to
+        // support inheritance lookups, etc.
+
+        return annotation.value();
+    }
+
+    /**
+     * Establishes a UUID relationship between two objects. Objects must be registered in
+     * the same ObjectContext. "from" argument is the object annotated with
+     * UuidRelationship. Second argument can optionally be null.
+     */
+    public void relate(DataObject from, DataObject to) {
+
+        if (from.getObjectContext() == null) {
+            throw new IllegalArgumentException("'from' has null ObjectContext");
+        }
+
+        String property = uuidPropertyName(from);
+        String relationship = uuidRelationshipName(property);
+
+        if (to != null) {
+            if (to.getObjectContext() == null) {
+                throw new IllegalArgumentException("'to' has null ObjectContext");
+            }
+
+            if (from.getObjectContext() != to.getObjectContext()) {
+                throw new IllegalArgumentException(
+                        "'from' and 'to' objects are registered in different ObjectContexts");
+            }
+
+            if (to.getObjectId().isTemporary()
+                    && !to.getObjectId().isReplacementIdAttached()) {
+                throw new UnsupportedOperationException("TODO - eager ID generation");
+            }
+
+            String uuid = referenceableHandler.getUuid(to);
+
+            from.writeProperty(property, uuid);
+            from.writePropertyDirectly(relationship, to);
+        }
+        else {
+            from.writeProperty(property, null);
+            from.writePropertyDirectly(relationship, null);
+        }
+    }
+}