001// Copyright 2005 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.tapestry.services.impl;
016
017import java.util.Locale;
018
019import org.apache.hivemind.util.Defense;
020import org.apache.hivemind.util.LocalizedNameGenerator;
021import org.apache.tapestry.engine.IPropertySource;
022
023/**
024 * Wraps around a {@link org.apache.tapestry.engine.IPropertySource}to query a series of localized
025 * keys.
026 * <p>
027 * This is much simpler than the old {@link org.apache.tapestry.util.LocalizedPropertySource}, and
028 * allows the locale to be specified on a thread-safe, per-invocation basis.
029 * 
030 * @author Howard M. Lewis Ship
031 * @since 4.0
032 */
033public class LocalizedPropertySource
034{
035    private IPropertySource _source;
036
037    public LocalizedPropertySource(IPropertySource source)
038    {
039        Defense.notNull(source, "source");
040
041        _source = source;
042    }
043
044    /**
045     * Get the property from the source, trying different variations of propertyName (adding
046     * suffixes).
047     * 
048     * @param propertyName
049     *            the base property name to search with.
050     * @param local
051     *            the Locale used to generate suffixes (may be null).
052     */
053
054    public String getPropertyValue(String propertyName, Locale locale)
055    {
056        Defense.notNull(propertyName, "propertyName");
057
058        LocalizedNameGenerator g = new LocalizedNameGenerator(propertyName, locale, "");
059
060        while (g.more())
061        {
062            String localizedName = g.next();
063
064            String result = _source.getPropertyValue(localizedName);
065
066            if (result != null)
067                return result;
068        }
069
070        return null;
071    }
072}