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.defaults;
021
022import com.google.common.base.Strings;
023
024import org.apache.isis.applib.adapters.DefaultsProvider;
025import org.apache.isis.core.commons.config.IsisConfiguration;
026import org.apache.isis.core.commons.lang.ClassUtil;
027import org.apache.isis.core.commons.lang.StringExtensions;
028import org.apache.isis.core.metamodel.facetapi.FacetHolder;
029
030public final class DefaultsProviderUtil {
031
032    private DefaultsProviderUtil() {
033    }
034
035    public static final String DEFAULTS_PROVIDER_NAME_KEY_PREFIX = "isis.reflector.java.facets.defaulted.";
036    public static final String DEFAULTS_PROVIDER_NAME_KEY_SUFFIX = ".providerName";
037
038    public static String defaultsProviderNameFromConfiguration(final Class<?> type, final IsisConfiguration configuration) {
039        final String key = DEFAULTS_PROVIDER_NAME_KEY_PREFIX + type.getCanonicalName() + DEFAULTS_PROVIDER_NAME_KEY_SUFFIX;
040        final String defaultsProviderName = configuration.getString(key);
041        return !Strings.isNullOrEmpty(defaultsProviderName) ? defaultsProviderName : null;
042    }
043
044    public static Class<?> defaultsProviderOrNull(final Class<?> candidateClass, final String classCandidateName) {
045        final Class<?> type = candidateClass != null ? ClassUtil.implementingClassOrNull(candidateClass.getName(), DefaultsProvider.class, FacetHolder.class) : null;
046        return type != null ? type : ClassUtil.implementingClassOrNull(classCandidateName, DefaultsProvider.class, FacetHolder.class);
047    }
048
049}