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.method;
021    
022    import java.lang.reflect.Method;
023    import java.util.Collections;
024    import java.util.List;
025    
026    import org.apache.isis.core.commons.exceptions.UnknownTypeException;
027    import org.apache.isis.core.metamodel.adapter.ObjectAdapter;
028    import org.apache.isis.core.metamodel.adapter.map.AdapterMap;
029    import org.apache.isis.core.metamodel.adapter.util.AdapterInvokeUtils;
030    import org.apache.isis.core.metamodel.facetapi.FacetHolder;
031    import org.apache.isis.core.metamodel.facets.ImperativeFacet;
032    import org.apache.isis.core.metamodel.spec.ObjectSpecification;
033    import org.apache.isis.core.metamodel.spec.SpecificationLookup;
034    import org.apache.isis.core.progmodel.facets.properties.defaults.PropertyDefaultFacetAbstract;
035    
036    public class PropertyDefaultFacetViaMethod extends PropertyDefaultFacetAbstract implements ImperativeFacet {
037    
038        private final Method method;
039        private final SpecificationLookup specificationLookup;
040        private final AdapterMap adapterMap;
041    
042        public PropertyDefaultFacetViaMethod(final Method method, final FacetHolder holder,
043            final SpecificationLookup specificationLookup, final AdapterMap adapterManager) {
044            super(holder);
045            this.method = method;
046            this.specificationLookup = specificationLookup;
047            this.adapterMap = adapterManager;
048        }
049    
050        /**
051         * Returns a singleton list of the {@link Method} provided in the constructor.
052         */
053        @Override
054        public List<Method> getMethods() {
055            return Collections.singletonList(method);
056        }
057    
058        @Override
059        public boolean impliesResolve() {
060            return true;
061        }
062    
063        @Override
064        public boolean impliesObjectChanged() {
065            return false;
066        }
067    
068        @Override
069        public ObjectAdapter getDefault(final ObjectAdapter owningAdapter) {
070            final Object result = AdapterInvokeUtils.invoke(method, owningAdapter);
071            return createAdapter(method.getReturnType(), result);
072        }
073    
074        private ObjectAdapter createAdapter(final Class<?> type, final Object object) {
075            final ObjectSpecification specification = getSpecificationLookup().loadSpecification(type);
076            if (specification.isNotCollection()) {
077                return getAdapterMap().adapterFor(object);
078            } else {
079                throw new UnknownTypeException("not an object, is this a collection?");
080            }
081        }
082    
083        @Override
084        protected String toStringValues() {
085            return "method=" + method;
086        }
087    
088        // //////////////////////////////////////////////////////////////////
089        // Dependencies (from constructor)
090        // //////////////////////////////////////////////////////////////////
091    
092        private SpecificationLookup getSpecificationLookup() {
093            return specificationLookup;
094        }
095    
096        protected AdapterMap getAdapterMap() {
097            return adapterMap;
098        }
099    
100    }