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
020package org.apache.isis.core.progmodel.facets.object.validperspec;
021
022import java.util.ArrayList;
023import java.util.List;
024
025import org.apache.isis.applib.annotation.MustSatisfy;
026import org.apache.isis.applib.spec.Specification;
027import org.apache.isis.core.metamodel.facetapi.Facet;
028import org.apache.isis.core.metamodel.facetapi.FacetHolder;
029import org.apache.isis.core.metamodel.facetapi.FacetUtil;
030import org.apache.isis.core.metamodel.facetapi.FeatureType;
031import org.apache.isis.core.metamodel.facets.Annotations;
032import org.apache.isis.core.metamodel.facets.FacetFactoryAbstract;
033
034public class MustSatisfySpecificationOnTypeFacetFactory extends FacetFactoryAbstract {
035
036    public MustSatisfySpecificationOnTypeFacetFactory() {
037        super(FeatureType.OBJECTS_ONLY);
038    }
039
040    @Override
041    public void process(final ProcessClassContext processClassContaxt) {
042        FacetUtil.addFacet(create(processClassContaxt.getCls(), processClassContaxt.getFacetHolder()));
043    }
044
045    private Facet create(final Class<?> clazz, final FacetHolder holder) {
046        return create(Annotations.getAnnotation(clazz, MustSatisfy.class), holder);
047    }
048
049    private static Facet create(final MustSatisfy annotation, final FacetHolder holder) {
050        if (annotation == null) {
051            return null;
052        }
053        final Class<?>[] values = annotation.value();
054        final List<Specification> specifications = new ArrayList<Specification>();
055        for (final Class<?> value : values) {
056            final Specification specification = newSpecificationElseNull(value);
057            if (specification != null) {
058                specifications.add(specification);
059            }
060        }
061        return specifications.size() > 0 ? new MustSatisfySpecificationOnTypeFacet(specifications, holder) : null;
062    }
063
064    private static Specification newSpecificationElseNull(final Class<?> value) {
065        if (!(Specification.class.isAssignableFrom(value))) {
066            return null;
067        }
068        try {
069            return (Specification) value.newInstance();
070        } catch (final InstantiationException e) {
071            return null;
072        } catch (final IllegalAccessException e) {
073            return null;
074        }
075    }
076
077}