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
015package org.apache.tapestry5.internal.jpa;
016
017import org.apache.tapestry5.internal.transform.ReadOnlyComponentFieldConduit;
018import org.apache.tapestry5.jpa.EntityManagerManager;
019import org.apache.tapestry5.model.MutableComponentModel;
020import org.apache.tapestry5.plastic.InstanceContext;
021import org.apache.tapestry5.plastic.PlasticClass;
022import org.apache.tapestry5.plastic.PlasticField;
023import org.apache.tapestry5.services.transform.ComponentClassTransformWorker2;
024import org.apache.tapestry5.services.transform.TransformationSupport;
025
026import javax.persistence.PersistenceContext;
027
028public class PersistenceContextWorker implements ComponentClassTransformWorker2
029{
030    private final EntityManagerManager entityManagerManager;
031
032    public PersistenceContextWorker(final EntityManagerManager entityManagerManager)
033    {
034        this.entityManagerManager = entityManagerManager;
035    }
036
037    @Override
038    public void transform(PlasticClass plasticClass, TransformationSupport support, MutableComponentModel model)
039    {
040        for (final PlasticField field : plasticClass
041                .getFieldsWithAnnotation(PersistenceContext.class))
042        {
043            final PersistenceContext annotation = field.getAnnotation(PersistenceContext.class);
044
045            field.claim(annotation);
046
047            field.setConduit(new ReadOnlyComponentFieldConduit(plasticClass.getClassName(), field.getName())
048            {
049                @Override
050                public Object get(Object instance, InstanceContext context)
051                {
052                    return JpaInternalUtils.getEntityManager(entityManagerManager, annotation);
053                }
054            });
055        }
056    }
057}