001// Copyright 2006, 2007, 2008, 2010, 2011, 2023 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.tapestry5.internal.transform;
016
017import org.apache.tapestry5.annotations.InjectPage;
018import org.apache.tapestry5.commons.ObjectCreator;
019import org.apache.tapestry5.internal.services.ComponentDependencyRegistry;
020import org.apache.tapestry5.ioc.internal.util.InternalUtils;
021import org.apache.tapestry5.ioc.services.PerthreadManager;
022import org.apache.tapestry5.model.MutableComponentModel;
023import org.apache.tapestry5.plastic.InstanceContext;
024import org.apache.tapestry5.plastic.PlasticClass;
025import org.apache.tapestry5.plastic.PlasticField;
026import org.apache.tapestry5.services.ComponentClassResolver;
027import org.apache.tapestry5.services.ComponentSource;
028import org.apache.tapestry5.services.transform.ComponentClassTransformWorker2;
029import org.apache.tapestry5.services.transform.TransformationSupport;
030
031/**
032 * Performs transformations that allow pages to be injected into components.
033 *
034 * @see org.apache.tapestry5.annotations.InjectPage
035 */
036public class InjectPageWorker implements ComponentClassTransformWorker2
037{
038    private final class InjectedPageConduit extends ReadOnlyComponentFieldConduit
039    {
040        private final String injectedPageName;
041
042        private final ObjectCreator<Object> pageValue = perThreadManager.createValue(new ObjectCreator<Object>() {
043            @Override
044            public Object createObject() {
045                return componentSource.getPage(injectedPageName);
046            }
047        });
048
049        private InjectedPageConduit(String className, String fieldName,
050                                    String injectedPageName)
051        {
052            super(className, fieldName);
053
054            this.injectedPageName = injectedPageName;
055        }
056
057        public Object get(Object instance, InstanceContext context)
058        {
059            return pageValue.createObject();
060        }
061    }
062
063    private final ComponentSource componentSource;
064
065    private final ComponentClassResolver resolver;
066
067    private final PerthreadManager perThreadManager;
068
069    private final ComponentDependencyRegistry componentDependencyRegistry;
070
071    public InjectPageWorker(ComponentSource componentSource, ComponentClassResolver resolver, PerthreadManager perThreadManager,
072            ComponentDependencyRegistry componentDependencyRegistry)
073    {
074        this.componentSource = componentSource;
075        this.resolver = resolver;
076        this.perThreadManager = perThreadManager;
077        this.componentDependencyRegistry = componentDependencyRegistry;
078    }
079
080    public void transform(PlasticClass plasticClass, TransformationSupport support, MutableComponentModel model)
081    {
082        for (PlasticField field : plasticClass.getFieldsWithAnnotation(InjectPage.class))
083        {
084            addInjectedPage(field, model);
085        }
086    }
087
088    private void addInjectedPage(PlasticField field, MutableComponentModel model)
089    {
090        InjectPage annotation = field.getAnnotation(InjectPage.class);
091
092        field.claim(annotation);
093
094        String pageName = annotation.value();
095
096        String fieldName = field.getName();
097
098        String injectedPageName = InternalUtils.isBlank(pageName) ? resolver
099                .resolvePageClassNameToPageName(field.getTypeName()) : pageName;
100
101        field.setConduit(new InjectedPageConduit(field.getPlasticClass().getClassName(), fieldName, injectedPageName));
102        
103        componentDependencyRegistry.register(field, model);
104    }
105}