001    // Copyright 2007, 2008 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry5.internal.services;
016    
017    import org.apache.tapestry5.ioc.services.PropertyAdapter;
018    import org.apache.tapestry5.ioc.util.StrategyRegistry;
019    import org.apache.tapestry5.services.DataTypeAnalyzer;
020    import org.apache.tapestry5.services.InvalidationListener;
021    
022    import java.util.Map;
023    
024    /**
025     * The default data type analyzer, which is based entirely on the type of the property (and not on annotations or naming
026     * conventions). This is based on a configuration of property type class to string provided as an IoC service
027     * configuration.
028     */
029    public class DefaultDataTypeAnalyzer implements DataTypeAnalyzer, InvalidationListener
030    {
031        private final StrategyRegistry<String> registry;
032    
033        public DefaultDataTypeAnalyzer(Map<Class, String> configuration)
034        {
035            registry = StrategyRegistry.newInstance(String.class, configuration);
036        }
037    
038        /**
039         * Clears the registry on an invalidation event (this is because the registry caches results, and the keys are
040         * classes that may be component classes from the invalidated component class loader).
041         */
042        public void objectWasInvalidated()
043        {
044            registry.clearCache();
045        }
046    
047        public String identifyDataType(PropertyAdapter adapter)
048        {
049            Class propertyType = adapter.getType();
050    
051            String dataType = registry.get(propertyType);
052    
053            // To avoid "no strategy" exceptions, we expect a contribution of Object.class to the empty
054            // string. We convert that back to a null.
055    
056            if (dataType.equals(""))
057                return null;
058    
059            return dataType;
060        }
061    }