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.validate.perspec;
021    
022    import java.lang.annotation.Annotation;
023    import java.util.ArrayList;
024    import java.util.List;
025    
026    import org.apache.isis.applib.annotation.MustSatisfy;
027    import org.apache.isis.applib.spec.Specification;
028    import org.apache.isis.core.metamodel.facetapi.Facet;
029    import org.apache.isis.core.metamodel.facetapi.FacetHolder;
030    import org.apache.isis.core.metamodel.facetapi.FacetUtil;
031    import org.apache.isis.core.metamodel.facetapi.FeatureType;
032    import org.apache.isis.core.metamodel.facets.AnnotationBasedFacetFactoryAbstract;
033    
034    public class MustSatisfySpecificationOnParameterFacetFactory extends AnnotationBasedFacetFactoryAbstract {
035    
036        public MustSatisfySpecificationOnParameterFacetFactory() {
037            super(FeatureType.PARAMETERS_ONLY);
038        }
039    
040        @Override
041        public void processParams(final ProcessParameterContext processParameterContext) {
042            final java.lang.annotation.Annotation[] parameterAnnotations =
043                getParameterAnnotations(processParameterContext.getMethod())[processParameterContext.getParamNum()];
044    
045            for (final Annotation parameterAnnotation : parameterAnnotations) {
046                if (parameterAnnotation instanceof MustSatisfy) {
047                    final MustSatisfy annotation = (MustSatisfy) parameterAnnotation;
048                    FacetUtil.addFacet(create(annotation, processParameterContext.getFacetHolder()));
049                    return;
050                }
051            }
052        }
053    
054        private Facet create(final MustSatisfy annotation, final FacetHolder holder) {
055            if (annotation == null) {
056                return null;
057            }
058            final Class<?>[] values = annotation.value();
059            final List<Specification> specifications = new ArrayList<Specification>();
060            for (final Class<?> value : values) {
061                final Specification specification = newSpecificationElseNull(value);
062                if (specification != null) {
063                    specifications.add(specification);
064                }
065            }
066            return specifications.size() > 0 ? new MustSatisfySpecificationOnParameterFacet(specifications, holder) : null;
067        }
068    
069        private static Specification newSpecificationElseNull(final Class<?> value) {
070            if (!(Specification.class.isAssignableFrom(value))) {
071                return null;
072            }
073            try {
074                return (Specification) value.newInstance();
075            } catch (final InstantiationException e) {
076                return null;
077            } catch (final IllegalAccessException e) {
078                return null;
079            }
080        }
081    
082    }