    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    }