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.param.describedas.annotation;
021
022 import java.lang.annotation.Annotation;
023
024 import org.apache.isis.applib.annotation.DescribedAs;
025 import org.apache.isis.core.metamodel.facetapi.FacetHolder;
026 import org.apache.isis.core.metamodel.facetapi.FacetUtil;
027 import org.apache.isis.core.metamodel.facetapi.FeatureType;
028 import org.apache.isis.core.metamodel.facets.AnnotationBasedFacetFactoryAbstract;
029 import org.apache.isis.core.metamodel.facets.describedas.DescribedAsFacet;
030 import org.apache.isis.core.metamodel.spec.ObjectSpecification;
031
032 public class DescribedAsAnnotationOnParameterFacetFactory extends AnnotationBasedFacetFactoryAbstract {
033
034 public DescribedAsAnnotationOnParameterFacetFactory() {
035 super(FeatureType.PARAMETERS_ONLY);
036 }
037
038 @Override
039 public void processParams(final ProcessParameterContext processParameterContext) {
040
041 final int paramNum = processParameterContext.getParamNum();
042 final Class<?> parameterType = processParameterContext.getMethod().getParameterTypes()[paramNum];
043 final Annotation[] parameterAnnotations =
044 getParameterAnnotations(processParameterContext.getMethod())[paramNum];
045 for (final Annotation parameterAnnotation : parameterAnnotations) {
046 if (parameterAnnotation instanceof DescribedAs) {
047 FacetUtil.addFacet(create((DescribedAs) parameterAnnotation, processParameterContext.getFacetHolder()));
048 return;
049 }
050 }
051
052 // otherwise, fall back to a description on the parameter's type, if available
053 final DescribedAsFacet parameterTypeDescribedAsFacet = getDescribedAsFacet(parameterType);
054 if (parameterTypeDescribedAsFacet != null) {
055 FacetUtil.addFacet(new DescribedAsFacetForParameterDerivedFromType(parameterTypeDescribedAsFacet,
056 processParameterContext.getFacetHolder()));
057 return;
058 }
059
060 }
061
062 private DescribedAsFacet create(final DescribedAs annotation, final FacetHolder holder) {
063 return annotation == null ? null : new DescribedAsFacetAnnotationOnParameter(annotation.value(), holder);
064 }
065
066 private DescribedAsFacet getDescribedAsFacet(final Class<?> type) {
067 final ObjectSpecification paramTypeSpec = getSpecificationLookup().loadSpecification(type);
068 return paramTypeSpec.getFacet(DescribedAsFacet.class);
069 }
070
071 }