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.object.value;
021    
022    import org.apache.isis.applib.adapters.ValueSemanticsProvider;
023    import org.apache.isis.core.commons.config.IsisConfiguration;
024    import org.apache.isis.core.commons.lang.JavaClassUtils;
025    import org.apache.isis.core.commons.lang.StringUtils;
026    import org.apache.isis.core.metamodel.facetapi.FacetHolder;
027    
028    public final class ValueSemanticsProviderUtil {
029    
030        private ValueSemanticsProviderUtil() {
031        }
032    
033        public static final String SEMANTICS_PROVIDER_NAME_KEY_PREFIX = "isis.core.progmodel.value.";
034        public static final String SEMANTICS_PROVIDER_NAME_KEY_SUFFIX = ".semanticsProviderName";
035    
036        public static String semanticsProviderNameFromConfiguration(final Class<?> type,
037            final IsisConfiguration configuration) {
038            final String key =
039                SEMANTICS_PROVIDER_NAME_KEY_PREFIX + type.getCanonicalName() + SEMANTICS_PROVIDER_NAME_KEY_SUFFIX;
040            final String semanticsProviderName = configuration.getString(key);
041            return !StringUtils.isNullOrEmpty(semanticsProviderName) ? semanticsProviderName : null;
042        }
043    
044        @SuppressWarnings("unchecked")
045        public static Class<? extends ValueSemanticsProvider<?>> valueSemanticsProviderOrNull(
046            final Class<?> candidateClass, final String classCandidateName) {
047            final Class clazz =
048                candidateClass != null ? JavaClassUtils.implementingClassOrNull(candidateClass.getName(),
049                    ValueSemanticsProvider.class, FacetHolder.class) : null;
050            return clazz != null ? clazz : JavaClassUtils.implementingClassOrNull(classCandidateName,
051                ValueSemanticsProvider.class, FacetHolder.class);
052        }
053    
054    }