    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.ComponentResources;
    018    import org.apache.tapestry5.annotations.InjectContainer;
    019    import org.apache.tapestry5.internal.services.ComponentClassCache;
    020    import org.apache.tapestry5.model.MutableComponentModel;
    021    import org.apache.tapestry5.plastic.*;
    022    import org.apache.tapestry5.runtime.Component;
    023    import org.apache.tapestry5.services.transform.ComponentClassTransformWorker2;
    024    import org.apache.tapestry5.services.transform.TransformationSupport;
    025
    026    /**
    027     * Identifies the {@link org.apache.tapestry5.annotations.InjectContainer} annotation and adds code
    028     * to initialize it to
    029     * the core component.
    030     */
    031    public class InjectContainerWorker implements ComponentClassTransformWorker2
    032    {
    033        private final ComponentClassCache cache;
    034
    035        public InjectContainerWorker(ComponentClassCache cache)
    036        {
    037            this.cache = cache;
    038        }
    039
    040        public void transform(PlasticClass plasticClass, TransformationSupport support, MutableComponentModel model)
    041        {
    042            for (final PlasticField field : plasticClass.getFieldsWithAnnotation(InjectContainer.class))
    043            {
    044                transformField(field);
    045            }
    046        }
    047
    048        private void transformField(PlasticField field)
    049        {
    050            InjectContainer annotation = field.getAnnotation(InjectContainer.class);
    051
    052            field.claim(annotation);
    053
    054            ComputedValue<FieldConduit<Object>> provider = createFieldValueConduitProvider(field);
    055
    056            field.setComputedConduit(provider);
    057        }
    058
    059        private ComputedValue<FieldConduit<Object>> createFieldValueConduitProvider(PlasticField field)
    060        {
    061            final String fieldName = field.getName();
    062
    063            final String fieldTypeName = field.getTypeName();
    064
    065            return new ComputedValue<FieldConduit<Object>>()
    066            {
    067                public FieldConduit<Object> get(InstanceContext context)
    068                {
    069                    final Class fieldType = cache.forName(fieldTypeName);
    070                    final ComponentResources resources = context.get(ComponentResources.class);
    071
    072                    return new ReadOnlyComponentFieldConduit(resources, fieldName)
    073                    {
    074                        public Object get(Object instance, InstanceContext context)
    075                        {
    076                            Component container = resources.getContainer();
    077
    078                            if (!fieldType.isInstance(container))
    079                            {
    080                                String message = String.format(
    081                                        "Component %s (type %s) is not assignable to field %s.%s (of type %s).", container
    082                                        .getComponentResources().getCompleteId(), container.getClass().getName(), resources.getComponentModel()
    083                                        .getComponentClassName(), fieldName, fieldTypeName);
    084
    085                                throw new RuntimeException(message);
    086                            }
    087
    088                            return container;
    089                        }
    090                    };
    091                }
    092            };
    093        }
    094    }