001    // Copyright 2011 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    // http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry5.internal.jpa;
016    
017    import org.apache.tapestry5.internal.services.AbstractSessionPersistentFieldStrategy;
018    import org.apache.tapestry5.jpa.EntityManagerManager;
019    import org.apache.tapestry5.services.Request;
020    
021    /**
022     * Persists JPA entities by storing their id in the session.
023     */
024    public class EntityPersistentFieldStrategy extends AbstractSessionPersistentFieldStrategy
025    {
026        private final EntityManagerManager entityManagerManager;
027    
028        public EntityPersistentFieldStrategy(final EntityManagerManager entityManagerManager,
029                final Request request)
030        {
031            super("entity:", request);
032    
033            this.entityManagerManager = entityManagerManager;
034        }
035    
036        @Override
037        protected Object convertApplicationValueToPersisted(final Object newValue)
038        {
039            return JpaInternalUtils.convertApplicationValueToPersisted(entityManagerManager, newValue);
040        }
041    
042        @Override
043        protected Object convertPersistedToApplicationValue(final Object persistedValue)
044        {
045            final PersistedEntity persisted = (PersistedEntity) persistedValue;
046    
047            return persisted.restore(entityManagerManager);
048        }
049    }