001// Copyright 2007, 2008, 2012 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
015package org.apache.tapestry5.commons.internal.services;
016
017import java.util.Map;
018
019import org.apache.tapestry5.commons.services.DataTypeAnalyzer;
020import org.apache.tapestry5.commons.services.PropertyAdapter;
021import org.apache.tapestry5.commons.util.StrategyRegistry;
022
023/**
024 * The default data type analyzer, which is based entirely on the type of the property (and not on annotations or naming
025 * conventions). This is based on a configuration of property type class to string provided as an IoC service
026 * configuration.
027 */
028public class DefaultDataTypeAnalyzer implements DataTypeAnalyzer, Runnable
029{
030    private final StrategyRegistry<String> registry;
031
032    public DefaultDataTypeAnalyzer(Map<Class, String> configuration)
033    {
034        registry = StrategyRegistry.newInstance(String.class, configuration);
035    }
036
037    /**
038     * Clears the registry on an invalidation event (this is because the registry caches results, and the keys are
039     * classes that may be component classes from the invalidated component class loader).
040     */
041    public void run()
042    {
043        registry.clearCache();
044    }
045
046    public String identifyDataType(PropertyAdapter adapter)
047    {
048        Class propertyType = adapter.getType();
049
050        String dataType = registry.get(propertyType);
051
052        // To avoid "no strategy" exceptions, we expect a contribution of Object.class to the empty
053        // string. We convert that back to a null.
054
055        if (dataType.equals(""))
056            return null;
057
058        return dataType;
059    }
060}