001// Copyright 2008, 2010 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.NullFieldStrategy;
018import org.apache.tapestry5.commons.util.AvailableValues;
019import org.apache.tapestry5.commons.util.UnknownValueException;
020import org.apache.tapestry5.services.NullFieldStrategySource;
021
022import java.util.Map;
023
024public class NullFieldStrategySourceImpl implements NullFieldStrategySource
025{
026    private final Map<String, NullFieldStrategy> configuration;
027
028    public NullFieldStrategySourceImpl(Map<String, NullFieldStrategy> configuration)
029    {
030        this.configuration = configuration;
031    }
032
033    public NullFieldStrategy get(String name)
034    {
035        NullFieldStrategy result = configuration.get(name);
036
037        if (result != null) return result;
038        
039        throw new UnknownValueException(String.format("Unrecognized name '%s' locating a null field strategy.", name),
040                new AvailableValues("Configured null field strategies", configuration));
041
042    }
043}