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.mandatory.annotation;
021    
022    import java.lang.annotation.Annotation;
023    
024    import org.apache.isis.applib.annotation.Optional;
025    import org.apache.isis.core.metamodel.facetapi.FacetUtil;
026    import org.apache.isis.core.metamodel.facetapi.FeatureType;
027    import org.apache.isis.core.metamodel.facets.AnnotationBasedFacetFactoryAbstract;
028    
029    public class OptionalAnnotationForParameterFacetFactory extends AnnotationBasedFacetFactoryAbstract {
030    
031        public OptionalAnnotationForParameterFacetFactory() {
032            super(FeatureType.PARAMETERS_ONLY);
033        }
034    
035        @Override
036        public void processParams(final ProcessParameterContext processParameterContext) {
037            final Class<?>[] parameterTypes = processParameterContext.getMethod().getParameterTypes();
038            if (processParameterContext.getParamNum() >= parameterTypes.length) {
039                // ignore
040                return;
041            }
042            if (parameterTypes[processParameterContext.getParamNum()].isPrimitive()) {
043                return;
044            }
045            final Annotation[] parameterAnnotations =
046                getParameterAnnotations(processParameterContext.getMethod())[processParameterContext.getParamNum()];
047            for (final Annotation parameterAnnotation : parameterAnnotations) {
048                if (parameterAnnotation instanceof Optional) {
049                    FacetUtil.addFacet(new MandatoryFacetInvertedByOptionalForParameter(processParameterContext
050                        .getFacetHolder()));
051                    return;
052                }
053            }
054        }
055    
056    }