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.properties.mandatory.staticmethod;
021
022import java.lang.reflect.Method;
023
024import org.apache.isis.core.commons.lang.MethodExtensions;
025import org.apache.isis.core.commons.lang.StringExtensions;
026import org.apache.isis.core.metamodel.exceptions.MetaModelException;
027import org.apache.isis.core.metamodel.facetapi.FacetHolder;
028import org.apache.isis.core.metamodel.facetapi.FacetUtil;
029import org.apache.isis.core.metamodel.facetapi.FeatureType;
030import org.apache.isis.core.metamodel.methodutils.MethodScope;
031import org.apache.isis.core.progmodel.facets.MethodFinderUtils;
032import org.apache.isis.core.progmodel.facets.MethodPrefixBasedFacetFactoryAbstract;
033import org.apache.isis.core.progmodel.facets.MethodPrefixConstants;
034
035public class PropertyOptionalFacetFactory extends MethodPrefixBasedFacetFactoryAbstract {
036
037    private static final String[] PREFIXES = { MethodPrefixConstants.OPTIONAL_PREFIX };
038
039    public PropertyOptionalFacetFactory() {
040        super(FeatureType.PROPERTIES_ONLY, OrphanValidation.VALIDATE, PREFIXES);
041    }
042
043    @Override
044    public void process(final ProcessMethodContext processMethodContext) {
045
046        attachMandatoryFacetIfOptionalMethodIsFound(processMethodContext);
047    }
048
049    private static void attachMandatoryFacetIfOptionalMethodIsFound(final ProcessMethodContext processMethodContext) {
050        final Method method = processMethodContext.getMethod();
051
052        final String capitalizedName = StringExtensions.asJavaBaseName(method.getName());
053        final Class<?> returnType = method.getReturnType();
054
055        final Class<?> cls = processMethodContext.getCls();
056        final Method optionalMethod = MethodFinderUtils.findMethod(cls, MethodScope.CLASS, MethodPrefixConstants.OPTIONAL_PREFIX + capitalizedName, boolean.class, NO_PARAMETERS_TYPES);
057        processMethodContext.removeMethod(optionalMethod);
058
059        if (!indicatesOptional(optionalMethod)) {
060            return;
061        }
062        if (returnType.isPrimitive()) {
063            throw new MetaModelException(cls.getName() + "#" + capitalizedName + " cannot be an optional property as it is of a primitive type");
064        }
065        final FacetHolder property = processMethodContext.getFacetHolder();
066        FacetUtil.addFacet(new MandatoryFacetOptionalViaMethodForProperty(property));
067    }
068
069    private static boolean indicatesOptional(final Method method) {
070        if (method != null) {
071            Boolean optionalMethodReturnValue = null;
072            try {
073                optionalMethodReturnValue = (Boolean) MethodExtensions.invoke(method, new Object[0]);
074            } catch (final ClassCastException ex) {
075                // ignore
076            }
077            if (optionalMethodReturnValue == null) {
078                throw new MetaModelException("method " + method + " should return a boolean");
079            }
080            return optionalMethodReturnValue.booleanValue();
081        }
082        return false;
083    }
084
085}