    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
    014    package org.apache.tapestry5.internal.transform;
    015
    016    import org.apache.tapestry5.ComponentResources;
    017    import org.apache.tapestry5.annotations.DiscardAfter;
    018    import org.apache.tapestry5.model.MutableComponentModel;
    019    import org.apache.tapestry5.plastic.MethodAdvice;
    020    import org.apache.tapestry5.plastic.MethodInvocation;
    021    import org.apache.tapestry5.plastic.PlasticClass;
    022    import org.apache.tapestry5.plastic.PlasticMethod;
    023    import org.apache.tapestry5.services.transform.ComponentClassTransformWorker2;
    024    import org.apache.tapestry5.services.transform.TransformationSupport;
    025
    026    public 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    }