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.fallback;
021    
022    import org.apache.isis.applib.events.UsabilityEvent;
023    import org.apache.isis.core.metamodel.facetapi.FacetHolder;
024    import org.apache.isis.core.metamodel.facets.object.notpersistable.NotPersistableFacet;
025    import org.apache.isis.core.metamodel.facets.object.notpersistable.NotPersistableFacetAbstract;
026    import org.apache.isis.core.metamodel.interactions.UsabilityContext;
027    
028    /**
029     * Installed by the {@link FallbackFacetFactory}, and means that this class <i>is</i> persistable (ie not
030     * {@link NotPersistableFacet not persistable}).
031     */
032    public class NotPersistableFacetNull extends NotPersistableFacetAbstract {
033    
034        public NotPersistableFacetNull(final FacetHolder holder) {
035            super(null, holder);
036        }
037    
038        /**
039         * Always returns <tt>null</tt> (that is, does <i>not</i> disable).
040         */
041        @Override
042        public String disables(final UsabilityContext<? extends UsabilityEvent> ic) {
043            return null;
044        }
045    
046    }