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.defaults;
021
022 import org.apache.isis.applib.adapters.DefaultsProvider;
023 import org.apache.isis.applib.adapters.EncoderDecoder;
024 import org.apache.isis.core.commons.lang.ClassUtil;
025 import org.apache.isis.core.metamodel.facetapi.FacetAbstract;
026 import org.apache.isis.core.metamodel.facetapi.FacetHolder;
027 import org.apache.isis.core.metamodel.runtimecontext.DependencyInjector;
028
029 public abstract class DefaultedFacetAbstract extends FacetAbstract implements DefaultedFacet {
030
031 private final Class<?> defaultsProviderClass;
032
033 // to delegate to
034 private final DefaultedFacetUsingDefaultsProvider defaultedFacetUsingDefaultsProvider;
035
036 private final DependencyInjector dependencyInjector;
037
038 public DefaultedFacetAbstract(final String candidateEncoderDecoderName,
039 final Class<?> candidateEncoderDecoderClass, final FacetHolder holder,
040 final DependencyInjector dependencyInjector) {
041 super(DefaultedFacet.class, holder, false);
042
043 this.defaultsProviderClass =
044 DefaultsProviderUtil.defaultsProviderOrNull(candidateEncoderDecoderClass, candidateEncoderDecoderName);
045 this.dependencyInjector = dependencyInjector;
046 if (isValid()) {
047 final DefaultsProvider defaultsProvider =
048 (DefaultsProvider) ClassUtil.newInstance(defaultsProviderClass, FacetHolder.class, holder);
049 this.defaultedFacetUsingDefaultsProvider =
050 new DefaultedFacetUsingDefaultsProvider(defaultsProvider, holder, getDependencyInjector());
051 } else {
052 this.defaultedFacetUsingDefaultsProvider = null;
053 }
054 }
055
056 /**
057 * Discover whether either of the candidate defaults provider name or class is valid.
058 */
059 public boolean isValid() {
060 return defaultsProviderClass != null;
061 }
062
063 /**
064 * Guaranteed to implement the {@link EncoderDecoder} class, thanks to generics in the applib.
065 */
066 public Class<?> getDefaultsProviderClass() {
067 return defaultsProviderClass;
068 }
069
070 @Override
071 public Object getDefault() {
072 return defaultedFacetUsingDefaultsProvider.getDefault();
073 }
074
075 @Override
076 protected String toStringValues() {
077 return defaultsProviderClass.getName();
078 }
079
080 // //////////////////////////////////////////////////////
081 // Dependencies (from constructor)
082 // //////////////////////////////////////////////////////
083
084 private DependencyInjector getDependencyInjector() {
085 return dependencyInjector;
086 }
087
088 }