001package org.apache.turbine.services.localization;
002
003/*
004 * Licensed to the Apache Software Foundation (ASF) under one
005 * or more contributor license agreements.  See the NOTICE file
006 * distributed with this work for additional information
007 * regarding copyright ownership.  The ASF licenses this file
008 * to you under the Apache License, Version 2.0 (the
009 * "License"); you may not use this file except in compliance
010 * with the License.  You may obtain a copy of the License at
011 *
012 *   http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing,
015 * software distributed under the License is distributed on an
016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017 * KIND, either express or implied.  See the License for the
018 * specific language governing permissions and limitations
019 * under the License.
020 */
021
022import java.util.Locale;
023import java.util.MissingResourceException;
024
025import org.apache.commons.logging.Log;
026import org.apache.commons.logging.LogFactory;
027import org.apache.fulcrum.localization.LocalizationService;
028import org.apache.turbine.services.InstantiationException;
029import org.apache.turbine.services.TurbineServices;
030import org.apache.turbine.services.pull.ApplicationTool;
031import org.apache.turbine.util.RunData;
032/**
033 * A pull tool which provides lookups for localized text by delegating
034 * to the configured Fulcrum <code>LocalizationService</code>.
035 *
036 * @author <a href="mailto:epugh@upstate.com">Eric Pugh</a>
037 * @author <a href="mailto:dlr@collab.net">Daniel Rall</a>
038 * @author <a href="mailto:jon@collab.net">Jon Stevens</a>
039 */
040public class LocalizationTool implements ApplicationTool
041{
042    /** Logging */
043    private static Log log = LogFactory.getLog(LocalizationTool.class);
044    /** Fulcrum Localization component */
045    private LocalizationService localizationService;
046    /**
047     * The language and country information parsed from the request's
048     * <code>Accept-Language</code> header.  Reset on each request.
049     */
050    protected Locale locale;
051
052    /**
053     * Lazy load the LocalizationService.
054     * @return a fulcrum LocalizationService
055     */
056    public LocalizationService getLocalizationService()
057    {
058        if (localizationService == null)
059        {
060            try
061            {
062                localizationService = (LocalizationService)TurbineServices.getInstance()
063                    .getService(LocalizationService.ROLE);
064            }
065            catch (Exception e)
066            {
067                throw new InstantiationException("Problem looking up Localization Service:"+e.getMessage());
068            }
069        }
070        return localizationService;
071    }
072
073    /**
074     * Creates a new instance.  Used by <code>PullService</code>.
075     */
076    public LocalizationTool()
077    {
078        refresh();
079    }
080
081    /**
082     * <p>Performs text lookups for localization.</p>
083     *
084     * <p>Assuming there is a instance of this class with a HTTP
085     * request set in your template's context named <code>l10n</code>,
086     * the VTL <code>$l10n.HELLO</code> would render to
087     * <code>hello</code> for English requests and <code>hola</code>
088     * in Spanish (depending on the value of the HTTP request's
089     * <code>Accept-Language</code> header).</p>
090     *
091     * @param key The identifier for the localized text to retrieve.
092     * @return The localized text.
093     */
094    public String get(String key)
095    {
096        try
097        {
098            return getLocalizationService().getString(getBundleName(null), getLocale(), key);
099        }
100        catch (MissingResourceException noKey)
101        {
102            log.error(noKey);
103            return null;
104        }
105    }
106
107    /**
108     * Gets the current locale.
109     *
110     * @return The locale currently in use.
111     */
112    public Locale getLocale()
113    {
114        return locale;
115    }
116
117    /**
118     * The return value of this method is used to set the name of the
119     * bundle used by this tool.  Useful as a hook for using a
120     * different bundle than specified in your
121     * <code>LocalizationService</code> configuration.
122     *
123     * @param data The inputs passed from {@link #init(Object)}.
124     * (ignored by this implementation).
125     */
126    protected String getBundleName(Object data)
127    {
128        return getLocalizationService().getDefaultBundleName();
129    }
130
131    /**
132     * Formats a localized value using the provided objects.
133     *
134     * @param key The identifier for the localized text to retrieve,
135     * @param args The objects to use as {0}, {1}, etc. when
136     *             formatting the localized text.
137     * @return Formatted localized text.
138     */
139    public String format(String key, Object... args)
140    {
141        return getLocalizationService()
142                .format(getBundleName(null), getLocale(), key, args);
143    }
144
145    // ApplicationTool implementation
146
147    /**
148     * Sets the request to get the <code>Accept-Language</code> header
149     * from (reset on each request).
150     */
151    @Override
152    public void init(Object data)
153    {
154        if (data instanceof RunData)
155        {
156            // Pull necessary information out of RunData while we have
157            // a reference to it.
158            locale = getLocalizationService().getLocale(((RunData) data).getRequest());
159        }
160    }
161
162    /**
163     * No-op.
164     */
165    @Override
166    public void refresh()
167    {
168        locale = null;
169    }
170}