src/java/org/apache/turbine/services/localization/LocalizationTool.java

package org.apache.turbine.services.localization;
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 * reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
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 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache Turbine" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
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 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
import java.util.Locale;
import java.util.MissingResourceException;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.fulcrum.localization.LocalizationService;
import org.apache.turbine.services.InstantiationException;
import org.apache.turbine.services.TurbineServices;
import org.apache.turbine.services.avaloncomponent.AvalonComponentService;
import org.apache.turbine.services.pull.ApplicationTool;
import org.apache.turbine.util.RunData;
/**
 * A pull tool which provides lookups for localized text by delegating
 * to the configured Fulcrum <code>LocalizationService</code>.
 *
 * @author <a href="mailto:epugh@upstate.com">Eric Pugh</a>
 * @author <a href="mailto:dlr@collab.net">Daniel Rall</a>
 * @author <a href="mailto:jon@collab.net">Jon Stevens</a>
 */
public class LocalizationTool implements ApplicationTool
{
    /** Logging */
    private static Log log = LogFactory.getLog(LocalizationTool.class);
    /** Fulcrum Localization component */
    private LocalizationService localizationService;
    /**
     * The language and country information parsed from the request's
     * <code>Accept-Language</code> header.  Reset on each request.
     */
    protected Locale locale;
    
    /**
     * Lazy load the LocalizationService.
     * @return a fulcrum LocalizationService
     */
    public LocalizationService getLocalizationService()
    {
        if (localizationService == null)
        {
            AvalonComponentService ecm =
                (AvalonComponentService) TurbineServices.getInstance().getService(AvalonComponentService.SERVICE_NAME);
                try {
            localizationService = (LocalizationService)ecm.lookup(LocalizationService.ROLE);
                }
                catch (Exception e) {
                    throw new InstantiationException("Problem looking up Localization Service:"+e.getMessage());
                }
        }
        return localizationService;
    }
    /**
     * Creates a new instance.  Used by <code>PullService</code>.
     */
    public LocalizationTool()
    {
        refresh();
    }
    /**
     * <p>Performs text lookups for localization.</p>
     *
     * <p>Assuming there is a instance of this class with a HTTP
     * request set in your template's context named <code>l10n</code>,
     * the VTL <code>$l10n.HELLO</code> would render to
     * <code>hello</code> for English requests and <code>hola</code>
     * in Spanish (depending on the value of the HTTP request's
     * <code>Accept-Language</code> header).</p>
     *
     * @param key The identifier for the localized text to retrieve.
     * @return The localized text.
     */
    public String get(String key)
    {
        try
        {
            return getLocalizationService().getString(getBundleName(null), getLocale(), key);
        }
        catch (MissingResourceException noKey)
        {
            log.error(noKey);
            return null;
        }
    }
    /**
     * Gets the current locale.
     *
     * @return The locale currently in use.
     */
    public Locale getLocale()
    {
        return locale;
    }
    /**
     * The return value of this method is used to set the name of the
     * bundle used by this tool.  Useful as a hook for using a
     * different bundle than specifed in your
     * <code>LocalizationService</code> configuration.
     *
     * @param data The inputs passed from {@link #init(Object)}.
     * (ignored by this implementation).
     */
    protected String getBundleName(Object data)
    {
        return getLocalizationService().getDefaultBundleName();
    }
    // ApplicationTool implmentation
    /**
     * Sets the request to get the <code>Accept-Language</code> header
     * from (reset on each request).
     */
    public final void init(Object data)
    {
        if (data instanceof RunData)
        {
            // Pull necessary information out of RunData while we have
            // a reference to it.
            locale = getLocalizationService().getLocale(((RunData) data).getRequest());
        }
    }
    /**
     * No-op.
     */
    public void refresh()
    {
        locale = null;
    }
}