001    /*
002     *  Licensed to the Apache Software Foundation (ASF) under one
003     *  or more contributor license agreements.  See the NOTICE file
004     *  distributed with this work for additional information
005     *  regarding copyright ownership.  The ASF licenses this file
006     *  to you under the Apache License, Version 2.0 (the
007     *  "License"); you may not use this file except in compliance
008     *  with the License.  You may obtain a copy of the License at
009     *
010     *        http://www.apache.org/licenses/LICENSE-2.0
011     *
012     *  Unless required by applicable law or agreed to in writing,
013     *  software distributed under the License is distributed on an
014     *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015     *  KIND, either express or implied.  See the License for the
016     *  specific language governing permissions and limitations
017     *  under the License.
018     */
019    
020    package org.apache.isis.core.progmodel.facets.properties.defaults.fromtype;
021    
022    import org.apache.isis.core.metamodel.adapter.map.AdapterMap;
023    import org.apache.isis.core.metamodel.adapter.map.AdapterMapAware;
024    import org.apache.isis.core.metamodel.facetapi.FacetUtil;
025    import org.apache.isis.core.metamodel.facetapi.FeatureType;
026    import org.apache.isis.core.metamodel.facets.AnnotationBasedFacetFactoryAbstract;
027    import org.apache.isis.core.metamodel.facets.properties.defaults.PropertyDefaultFacet;
028    import org.apache.isis.core.metamodel.spec.ObjectSpecification;
029    import org.apache.isis.core.progmodel.facets.object.defaults.DefaultedFacet;
030    
031    public class PropertyDefaultDerivedFromTypeFacetFactory extends AnnotationBasedFacetFactoryAbstract implements
032        AdapterMapAware {
033    
034        private AdapterMap adapterMap;
035    
036        public PropertyDefaultDerivedFromTypeFacetFactory() {
037            super(FeatureType.PROPERTIES_ONLY);
038        }
039    
040        /**
041         * If there is a {@link DefaultedFacet} on the properties return type, then installs a {@link PropertyDefaultFacet}
042         * for the property with the same default.
043         */
044        @Override
045        public void process(final ProcessMethodContext processMethodContext) {
046            // don't overwrite any defaults that might already picked up
047            final PropertyDefaultFacet existingDefaultFacet =
048                processMethodContext.getFacetHolder().getFacet(PropertyDefaultFacet.class);
049            if (existingDefaultFacet != null && !existingDefaultFacet.isNoop()) {
050                return;
051            }
052    
053            // try to infer defaults from the underlying return type
054            final Class<?> returnType = processMethodContext.getMethod().getReturnType();
055            final DefaultedFacet returnTypeDefaultedFacet = getDefaultedFacet(returnType);
056            if (returnTypeDefaultedFacet != null) {
057                final PropertyDefaultFacetDerivedFromDefaultedFacet propertyFacet =
058                    new PropertyDefaultFacetDerivedFromDefaultedFacet(returnTypeDefaultedFacet,
059                        processMethodContext.getFacetHolder(), getAdapterMap());
060                FacetUtil.addFacet(propertyFacet);
061            }
062        }
063    
064        private DefaultedFacet getDefaultedFacet(final Class<?> paramType) {
065            final ObjectSpecification paramTypeSpec = getSpecificationLookup().loadSpecification(paramType);
066            return paramTypeSpec.getFacet(DefaultedFacet.class);
067        }
068    
069        // ////////////////////////////////////////////////////////////////////
070        // Injected
071        // ////////////////////////////////////////////////////////////////////
072    
073        public AdapterMap getAdapterMap() {
074            return adapterMap;
075        }
076    
077        @Override
078        public void setAdapterMap(final AdapterMap adapterMap) {
079            this.adapterMap = adapterMap;
080        }
081    
082    }