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.members.describedas.staticmethod;
021
022 import java.lang.reflect.Method;
023
024 import org.apache.isis.core.commons.lang.NameUtils;
025 import org.apache.isis.core.metamodel.adapter.util.InvokeUtils;
026 import org.apache.isis.core.metamodel.exceptions.MetaModelException;
027 import org.apache.isis.core.metamodel.facetapi.Facet;
028 import org.apache.isis.core.metamodel.facetapi.FacetHolder;
029 import org.apache.isis.core.metamodel.facetapi.FacetUtil;
030 import org.apache.isis.core.metamodel.facetapi.FeatureType;
031 import org.apache.isis.core.metamodel.facets.describedas.DescribedAsFacet;
032 import org.apache.isis.core.metamodel.methodutils.MethodScope;
033 import org.apache.isis.core.progmodel.facets.MethodFinderUtils;
034 import org.apache.isis.core.progmodel.facets.MethodPrefixBasedFacetFactoryAbstract;
035 import org.apache.isis.core.progmodel.facets.MethodPrefixConstants;
036
037 /**
038 * Sets up a {@link DescribedAsFacet} if a {@value MethodPrefixConstants#DESCRIPTION_PREFIX}-prefixed method is present.
039 */
040 public class DescribedAsFacetViaDescriptionMethodFacetFactory extends MethodPrefixBasedFacetFactoryAbstract {
041
042 private static final String[] PREFIXES = { MethodPrefixConstants.DESCRIPTION_PREFIX };
043
044 /**
045 * Note that the {@link Facet}s registered are the generic ones from noa-architecture (where they exist)
046 */
047 public DescribedAsFacetViaDescriptionMethodFacetFactory() {
048 super(FeatureType.MEMBERS, PREFIXES);
049 }
050
051 // ///////////////////////////////////////////////////////
052 // Actions
053 // ///////////////////////////////////////////////////////
054
055 @Override
056 public void process(final ProcessMethodContext processMethodContext) {
057 attachDescribedAsFacetIfDescriptionMethodIsFound(processMethodContext);
058 }
059
060 public static void attachDescribedAsFacetIfDescriptionMethodIsFound(final ProcessMethodContext processMethodContext) {
061
062 final Method method = processMethodContext.getMethod();
063 final String capitalizedName = NameUtils.javaBaseNameStripAccessorPrefixIfRequired(method.getName());
064
065 final Class<?> cls = processMethodContext.getCls();
066 final Method descriptionMethod =
067 MethodFinderUtils.findMethod(cls, MethodScope.CLASS, MethodPrefixConstants.DESCRIPTION_PREFIX
068 + capitalizedName, String.class, new Class[0]);
069 if (descriptionMethod == null) {
070 return;
071 }
072
073 processMethodContext.removeMethod(descriptionMethod);
074 final String description = invokeDescriptionMethod(descriptionMethod);
075
076 final FacetHolder facetedMethod = processMethodContext.getFacetHolder();
077 FacetUtil.addFacet(new DescribedAsFacetViaMethod(description, descriptionMethod, facetedMethod));
078 }
079
080 private static String invokeDescriptionMethod(final Method descriptionMethod) {
081 String description = null;
082 try {
083 description = (String) InvokeUtils.invokeStatic(descriptionMethod);
084 } catch (final ClassCastException ex) {
085 // ignore
086 }
087 if (description == null) {
088 throw new MetaModelException("method " + descriptionMethod + "must return a string");
089 }
090 return description;
091 }
092
093 }