001    /*
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     * 
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     * 
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */ 
017    package org.apache.commons.betwixt.registry;
018    
019    import org.apache.commons.betwixt.io.read.ElementMapping;
020    import org.apache.commons.betwixt.io.read.ReadContext;
021    
022    /**
023     * <p>Resolves polymorphic references.
024     * </p><p>
025     * A polymorphic reference is an element whose name and type
026     * resolution are postponed till bind-time.
027     * When the xml is read, the type can then resolved from 
028     * by calling {@link #resolveType}.
029     * </p>
030     * @since 0.7
031     * @author <a href='http://commons.apache.org/'>Apache Commons Team</a>
032     */
033    public interface PolymorphicReferenceResolver {
034    
035        /**
036         * Resolves the bind-time type of a polymorphic element.
037         * @param mapping <code>ElementMapping</code> describing the (polymorphic) element being mapped,
038         * not null
039         * @param context <code>ReadContext</code>, not null
040         * @return the <code>Class</code> describing the type to which this element should be bound,
041         * or null if the reference cannot be resolved
042         */
043        public Class resolveType(ElementMapping mapping, ReadContext context);
044    }