    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}