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.param.describedas.staticmethod;
021    
022    import java.lang.reflect.Method;
023    import java.util.List;
024    
025    import org.apache.isis.core.commons.lang.NameUtils;
026    import org.apache.isis.core.metamodel.adapter.map.AdapterMap;
027    import org.apache.isis.core.metamodel.adapter.map.AdapterMapAware;
028    import org.apache.isis.core.metamodel.adapter.util.InvokeUtils;
029    import org.apache.isis.core.metamodel.exceptions.MetaModelException;
030    import org.apache.isis.core.metamodel.facetapi.Facet;
031    import org.apache.isis.core.metamodel.facetapi.FacetUtil;
032    import org.apache.isis.core.metamodel.facetapi.FeatureType;
033    import org.apache.isis.core.metamodel.facets.FacetedMethod;
034    import org.apache.isis.core.metamodel.facets.FacetedMethodParameter;
035    import org.apache.isis.core.metamodel.methodutils.MethodScope;
036    import org.apache.isis.core.progmodel.facets.MethodFinderUtils;
037    import org.apache.isis.core.progmodel.facets.MethodPrefixBasedFacetFactoryAbstract;
038    import org.apache.isis.core.progmodel.facets.MethodPrefixConstants;
039    import org.apache.isis.core.progmodel.facets.members.describedas.staticmethod.DescribedAsFacetViaMethod;
040    
041    public class ActionParameterDescriptionsMethodFacetFactory extends MethodPrefixBasedFacetFactoryAbstract implements
042        AdapterMapAware {
043    
044        private static final String[] PREFIXES = { MethodPrefixConstants.DESCRIPTION_PREFIX };
045    
046        private AdapterMap adapterMap;
047    
048        /**
049         * Note that the {@link Facet}s registered are the generic ones from noa-architecture (where they exist)
050         */
051        public ActionParameterDescriptionsMethodFacetFactory() {
052            super(FeatureType.ACTIONS_ONLY, PREFIXES);
053        }
054    
055        // ///////////////////////////////////////////////////////
056        // Actions
057        // ///////////////////////////////////////////////////////
058    
059        @Override
060        public void process(final ProcessMethodContext processMethodContext) {
061    
062            final FacetedMethod facetedMethod = processMethodContext.getFacetHolder();
063            final List<FacetedMethodParameter> holderList = facetedMethod.getParameters();
064    
065            attachDescribedAsFacetForParametersIfParameterDescriptionsMethodIsFound(processMethodContext, holderList);
066        }
067    
068        private static void attachDescribedAsFacetForParametersIfParameterDescriptionsMethodIsFound(
069            final ProcessMethodContext processMethodContext, final List<FacetedMethodParameter> parameters) {
070    
071            if (parameters.isEmpty()) {
072                return;
073            }
074    
075            final Method actionMethod = processMethodContext.getMethod();
076    
077            final String capitalizedName = NameUtils.capitalizeName(actionMethod.getName());
078    
079            final Class<?> cls = processMethodContext.getCls();
080            final Method descriptionMethod =
081                MethodFinderUtils.findMethod(cls, MethodScope.CLASS, MethodPrefixConstants.DESCRIPTION_PREFIX
082                    + capitalizedName, String[].class, new Class[0]);
083            if (descriptionMethod == null) {
084                return;
085            }
086            processMethodContext.removeMethod(descriptionMethod);
087    
088            final String[] descriptions = invokeDescriptionsMethod(descriptionMethod, parameters.size());
089            for (int i = 0; i < descriptions.length; i++) {
090                // add facets directly to parameters, not to actions
091                FacetUtil.addFacet(new DescribedAsFacetViaMethod(descriptions[i], descriptionMethod, parameters.get(i)));
092            }
093        }
094    
095        private static String[] invokeDescriptionsMethod(final Method descriptionMethod, final int numElementsRequired) {
096            String[] descriptions = null;
097            try {
098                descriptions = (String[]) InvokeUtils.invokeStatic(descriptionMethod, new Object[0]);
099            } catch (final ClassCastException ex) {
100                // ignore
101            }
102            if (descriptions == null || descriptions.length != numElementsRequired) {
103                throw new MetaModelException(descriptionMethod
104                    + " must return an String[] array of same size as number of parameters of action");
105            }
106            return descriptions;
107        }
108    
109        // ///////////////////////////////////////////////////////////////
110        // Dependencies
111        // ///////////////////////////////////////////////////////////////
112    
113        @Override
114        public void setAdapterMap(final AdapterMap adapterMap) {
115            this.adapterMap = adapterMap;
116        }
117    
118        private AdapterMap getAdapterMap() {
119            return adapterMap;
120        }
121    
122    }