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
015package org.apache.tapestry5.internal.transform;
016
017import org.apache.tapestry5.ComponentResources;
018import org.apache.tapestry5.annotations.InjectContainer;
019import org.apache.tapestry5.internal.services.ComponentClassCache;
020import org.apache.tapestry5.model.MutableComponentModel;
021import org.apache.tapestry5.plastic.*;
022import org.apache.tapestry5.runtime.Component;
023import org.apache.tapestry5.services.transform.ComponentClassTransformWorker2;
024import 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 */
031public 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}