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.internal.services;
016
017import org.apache.tapestry5.ioc.services.PropertyAdapter;
018import org.apache.tapestry5.ioc.util.StrategyRegistry;
019import org.apache.tapestry5.services.DataTypeAnalyzer;
020import org.apache.tapestry5.services.InvalidationListener;
021
022import 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 */
029public class DefaultDataTypeAnalyzer implements DataTypeAnalyzer, Runnable
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 run()
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}