001// Copyright 2010, 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
014package org.apache.tapestry5.internal.transform;
015
016import org.apache.tapestry5.ComponentResources;
017import org.apache.tapestry5.annotations.DiscardAfter;
018import org.apache.tapestry5.model.MutableComponentModel;
019import org.apache.tapestry5.plastic.MethodAdvice;
020import org.apache.tapestry5.plastic.MethodInvocation;
021import org.apache.tapestry5.plastic.PlasticClass;
022import org.apache.tapestry5.plastic.PlasticMethod;
023import org.apache.tapestry5.services.transform.ComponentClassTransformWorker2;
024import org.apache.tapestry5.services.transform.TransformationSupport;
025
026public class DiscardAfterWorker implements ComponentClassTransformWorker2
027{
028    private static final MethodAdvice advice = new MethodAdvice()
029    {
030        public void advise(MethodInvocation invocation)
031        {
032            invocation.proceed();
033
034            if (invocation.didThrowCheckedException())
035                return;
036
037            ComponentResources resources = invocation.getInstanceContext().get(ComponentResources.class);
038
039            resources.discardPersistentFieldChanges();
040        }
041    };
042
043    public void transform(PlasticClass plasticClass, TransformationSupport support, MutableComponentModel model)
044    {
045        for (PlasticMethod method : plasticClass.getMethodsWithAnnotation(DiscardAfter.class))
046        {
047            method.addAdvice(advice);
048        }
049    }
050}