001// Copyright 2005 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.tapestry.annotations;
016
017import java.lang.reflect.Method;
018
019import org.apache.hivemind.Location;
020import org.apache.tapestry.enhance.EnhancementOperation;
021import org.apache.tapestry.spec.IComponentSpecification;
022import org.apache.tapestry.spec.IPropertySpecification;
023import org.apache.tapestry.spec.PropertySpecification;
024
025/**
026 * Allow a property to be marked as persistent, and (optionally) allows a strategy to be set. Works
027 * by adding a new {@link org.apache.tapestry.spec.IPropertySpecification} to the
028 * {@link org.apache.tapestry.spec.IComponentSpecification}.
029 * <p>
030 * The {@link org.apache.tapestry.annotations.Persist} annotation may <em>optionally</em> by
031 * accompanied by a {@link org.apache.tapestry.annotations.InitialValue} annotation; this sets the
032 * initial value, as a binding reference, used to initialize and re-initialize the property.
033 * 
034 * @author Howard M. Lewis Ship
035 * @since 4.0
036 * @see org.apache.tapestry.annotations.Persist
037 */
038public class PersistAnnotationWorker implements MethodAnnotationEnhancementWorker
039{
040    public void performEnhancement(EnhancementOperation op, IComponentSpecification spec,
041            Method method, Location location)
042    {
043        Persist p = method.getAnnotation(Persist.class);
044        InitialValue iv = method.getAnnotation(InitialValue.class);
045
046        String propertyName = AnnotationUtils.getPropertyName(method);
047        String stategy = p.value();
048
049        IPropertySpecification pspec = new PropertySpecification();
050
051        pspec.setName(propertyName);
052        pspec.setPersistence(stategy);
053        pspec.setLocation(location);
054        pspec.setInitialValue(iv == null ? null : iv.value());
055
056        spec.addPropertySpecification(pspec);
057    }
058
059}