org.freemedsoftware.gwt.client.i18n.I18nUtil.java Source code

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Here is the source code for org.freemedsoftware.gwt.client.i18n.I18nUtil.java

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/*
 * $Id$
 *
 * Authors:
 *      Jeff Buchbinder <jeff@freemedsoftware.org>
 *
 * FreeMED Electronic Medical Record and Practice Management System
 * Copyright (C) 1999-2012 FreeMED Software Foundation
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

package org.freemedsoftware.gwt.client.i18n;

import java.util.HashMap;
import java.util.Map;

import org.freemedsoftware.gwt.client.CurrentState;
import org.freemedsoftware.gwt.client.JsonUtil;

import com.google.gwt.core.client.GWT;
import com.google.gwt.http.client.Request;
import com.google.gwt.http.client.RequestBuilder;
import com.google.gwt.http.client.RequestCallback;
import com.google.gwt.http.client.RequestException;
import com.google.gwt.http.client.Response;
import com.google.gwt.http.client.URL;
import com.google.gwt.json.client.JSONObject;
import com.google.gwt.json.client.JSONParser;
import com.google.gwt.json.client.JSONString;
import com.google.gwt.json.client.JSONValue;
import com.google.gwt.user.client.Command;

/**
 * Class to facilitate dynamic locale lookups without requiring static
 * compile-time locale mappings. Bit more "expensive" at runtime, but should
 * integrate with current language selection better.
 */
public class I18nUtil {

    protected static String loadedLocaleName = null;
    protected static String RESOURCES_DIR = new String(GWT.getHostPageBaseURL() + "resources/locale/");
    protected static boolean BUSY_LOADING = false;

    protected static Map<String, String> locale = new HashMap<String, String>();

    public static int MAX_LOAD_WAIT_LOOPS = 30;
    public static long MAX_LOAD_WAIT_LOOP_MS = 500;

    /**
     * Internal method to load definitions from the server.
     * 
     * @param localeName
     */
    protected static void loadLocale(String localeName) {
        loadLocale(localeName, null);
    }

    /**
     * Load language definitions from the server.
     * 
     * @param localeName
     * @param callback
     */
    public static void loadLocale(String localeName, final Command callback) {
        String loadFrom = RESOURCES_DIR + localeName + ".json";
        loadedLocaleName = localeName;
        RequestBuilder builder = new RequestBuilder(RequestBuilder.GET, URL.encode(loadFrom));
        BUSY_LOADING = true;
        try {
            builder.sendRequest(null, new RequestCallback() {
                public void onError(Request request, Throwable exception) {
                    BUSY_LOADING = false;
                    JsonUtil.debug(exception.toString());
                }

                public void onResponseReceived(Request request, Response response) {
                    if (200 == response.getStatusCode()) {
                        long beginTime = System.currentTimeMillis();
                        JSONValue o = JSONParser.parseStrict(response.getText());
                        if (o.isObject() != null) {
                            JsonUtil.debug("Bad data presented.");
                            BUSY_LOADING = false;
                        }

                        // Empty out *everything* we have now.
                        locale.clear();

                        // Import everything
                        for (String key : ((JSONObject) o).keySet()) {
                            if (((JSONObject) o).get(key) != null) {
                                locale.put(key, ((JSONString) ((JSONObject) o).get(key)).stringValue());
                            }
                        }

                        long endTime = System.currentTimeMillis();

                        JsonUtil.debug("Locale " + loadedLocaleName + " parsed and loaded in "
                                + (endTime - beginTime) + "ms");

                        BUSY_LOADING = false;
                    } else {
                        BUSY_LOADING = false;
                        JsonUtil.debug(response.getStatusText());
                    }

                    if (callback != null) {
                        callback.execute();
                    }
                }
            });
        } catch (RequestException e) {
            BUSY_LOADING = false;
            JsonUtil.debug(e.toString());
            if (callback != null) {
                callback.execute();
            }
        }
    }

    /**
     * Lookup a string for the current locale.
     * 
     * @param x
     * @return
     */
    public static String _(String x) {
        String useLocaleName = CurrentState.getLocale();
        if (useLocaleName != loadedLocaleName) {
            loadLocale(useLocaleName);
            loadedLocaleName = useLocaleName;
        }

        String found = locale.get(x);

        // If we don't have any translation, send back source string.
        return (found != null && found.length() > 0) ? found : x;
    }

}