    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    }