001 // Copyright 2006, 2007, 2008, 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 // limitations under the License.
014
015 package org.apache.tapestry5.internal.transform;
016
017 import org.apache.tapestry5.annotations.InjectPage;
018 import org.apache.tapestry5.ioc.internal.util.InternalUtils;
019 import org.apache.tapestry5.ioc.services.PerThreadValue;
020 import org.apache.tapestry5.ioc.services.PerthreadManager;
021 import org.apache.tapestry5.model.MutableComponentModel;
022 import org.apache.tapestry5.plastic.InstanceContext;
023 import org.apache.tapestry5.plastic.PlasticClass;
024 import org.apache.tapestry5.plastic.PlasticField;
025 import org.apache.tapestry5.services.ComponentClassResolver;
026 import org.apache.tapestry5.services.ComponentSource;
027 import org.apache.tapestry5.services.transform.ComponentClassTransformWorker2;
028 import org.apache.tapestry5.services.transform.TransformationSupport;
029
030 /**
031 * Performs transformations that allow pages to be injected into components.
032 *
033 * @see org.apache.tapestry5.annotations.InjectPage
034 */
035 public class InjectPageWorker implements ComponentClassTransformWorker2
036 {
037 private final class InjectedPageConduit extends ReadOnlyComponentFieldConduit
038 {
039 private final String injectedPageName;
040
041 private final PerThreadValue<Object> pageValue = perThreadManager.createValue();
042
043 private InjectedPageConduit(String className, String fieldName,
044 String injectedPageName)
045 {
046 super(className, fieldName);
047
048 this.injectedPageName = injectedPageName;
049 }
050
051 public Object get(Object instance, InstanceContext context)
052 {
053 if (!pageValue.exists())
054 {
055 pageValue.set(componentSource.getPage(injectedPageName));
056 }
057
058 return pageValue.get();
059 }
060 }
061
062 private final ComponentSource componentSource;
063
064 private final ComponentClassResolver resolver;
065
066 private final PerthreadManager perThreadManager;
067
068 public InjectPageWorker(ComponentSource componentSource, ComponentClassResolver resolver, PerthreadManager perThreadManager)
069 {
070 this.componentSource = componentSource;
071 this.resolver = resolver;
072 this.perThreadManager = perThreadManager;
073 }
074
075 public void transform(PlasticClass plasticClass, TransformationSupport support, MutableComponentModel model)
076 {
077 for (PlasticField field : plasticClass.getFieldsWithAnnotation(InjectPage.class))
078 {
079 addInjectedPage(field);
080 }
081 }
082
083 private void addInjectedPage(PlasticField field)
084 {
085 InjectPage annotation = field.getAnnotation(InjectPage.class);
086
087 field.claim(annotation);
088
089 String pageName = annotation.value();
090
091 String fieldName = field.getName();
092
093 String injectedPageName = InternalUtils.isBlank(pageName) ? resolver
094 .resolvePageClassNameToPageName(field.getTypeName()) : pageName;
095
096 field.setConduit(new InjectedPageConduit(field.getPlasticClass().getClassName(), fieldName, injectedPageName));
097 }
098 }