001/*
002 * (C) Copyright 2010-2013 Nuxeo SA (http://nuxeo.com/) and contributors.
003 *
004 * All rights reserved. This program and the accompanying materials
005 * are made available under the terms of the GNU Lesser General Public License
006 * (LGPL) version 2.1 which accompanies this distribution, and is available at
007 * http://www.gnu.org/licenses/lgpl.html
008 *
009 * This library is distributed in the hope that it will be useful,
010 * but WITHOUT ANY WARRANTY; without even the implied warranty of
011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012 * Lesser General Public License for more details.
013 *
014 * Contributors:
015 *     Olivier Grisel
016 */
017package org.nuxeo.ecm.platform.suggestbox.service.suggesters;
018
019import java.util.Map;
020import java.util.regex.Matcher;
021import java.util.regex.Pattern;
022
023/**
024 * Simple interpolation for i18n messages with parameters independently of the UI layer. Only support parameter
025 * replacement with the "{0}", "{1}"... syntax.
026 *
027 * @author ogrisel
028 */
029public class I18nHelper {
030
031    public static final Pattern PLACEHOLDER = Pattern.compile("\\{(\\d+)\\}");
032
033    protected Map<String, String> messages;
034
035    public I18nHelper(Map<String, String> messages) {
036        this.messages = messages;
037    }
038
039    public static I18nHelper instanceFor(Map<String, String> messages) {
040        return new I18nHelper(messages);
041    }
042
043    public static String interpolate(String message, Object... params) {
044        Matcher matcher = PLACEHOLDER.matcher(message);
045        StringBuffer sb = new StringBuffer();
046        while (matcher.find()) {
047            int paramId = Integer.valueOf(matcher.group(1));
048            if (paramId >= 0 && paramId < params.length) {
049                String replacement = params[paramId].toString();
050                matcher.appendReplacement(sb, Matcher.quoteReplacement(replacement));
051            } else {
052                throw new IllegalArgumentException(String.format("Invalid placeholder %d in message '%s': %d "
053                        + "parameters provided", paramId, message, params.length));
054            }
055        }
056        matcher.appendTail(sb);
057        return sb.toString();
058    }
059
060    public String translate(String label, Object... params) {
061        String message = messages.get(label);
062        if (message == null) {
063            message = label;
064        }
065        return interpolate(message, params);
066    }
067
068}