MessageFormatTranslationMessage.java

/*
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package org.xwiki.localization.messagetool.internal;

import java.io.StringReader;
import java.text.MessageFormat;
import java.util.Collection;
import java.util.List;
import java.util.Locale;

import org.xwiki.localization.TranslationBundle;
import org.xwiki.localization.message.TranslationMessage;
import org.xwiki.rendering.block.Block;
import org.xwiki.rendering.block.CompositeBlock;
import org.xwiki.rendering.parser.ParseException;
import org.xwiki.rendering.parser.Parser;
import org.xwiki.rendering.util.ParserUtils;

/**
 * {@link MessageFormat} based {@link TranslationMessage}.
 * 
 * @version $Id: db8b2c50af0368f050867b5fad72464583a2b1c4 $
 * @since 4.3M2
 */
public class MessageFormatTranslationMessage implements TranslationMessage
{
    /**
     * Used to "inline" the content parsed with plain text parser.
     */
    private static final ParserUtils PARSERUTILS = new ParserUtils();

    /**
     * The message.
     */
    private String message;

    /**
     * The plain text parser.
     */
    private Parser plainParser;

    /**
     * Keep a cache of parsed version of the message without parameters.
     */
    private Block noParamCache;

    /**
     * @param message the message
     * @param plainParser the plain text parser
     */
    public MessageFormatTranslationMessage(String message, Parser plainParser)
    {
        this.message = message;
        this.plainParser = plainParser;
    }

    @Override
    public Block render(Locale locale, Collection<TranslationBundle> bundles, Object... parameters)
    {
        // Directly return cache if any available
        if (parameters.length == 0 && this.noParamCache != null) {
            return this.noParamCache.clone();
        }

        // Format the message
        String result;
        if (parameters.length > 0) {
            try {
                result = MessageFormat.format(this.message, parameters);
            } catch (IllegalArgumentException e) {
                // TODO: log the error ?
                result = this.message;
            }
        } else {
            result = this.message;
        }

        // Parse it to rendering blocks
        Block block;
        try {
            List<Block> blocks = this.plainParser.parse(new StringReader(result)).getChildren();

            PARSERUTILS.removeTopLevelParagraph(blocks);

            if (blocks.size() == 0) {
                block = new CompositeBlock();
            } else if (blocks.size() == 1) {
                block = blocks.get(0);
            } else {
                block = new CompositeBlock(blocks);
            }

            // Store cache of the message if there is no parameters
            if (parameters.length == 0) {
                this.noParamCache = block.clone();
            }
        } catch (ParseException e) {
            // Should never happen since plain text parser cannot fail
            block = null;
        }

        return block;
    }

    @Override
    public String getRawSource()
    {
        return this.message;
    }

    @Override
    public String toString()
    {
        return getRawSource();
    }
}