WebPartTemplateService.java

/*
 * Copyright (c) 2006-2009 by Dirk Riehle, http://dirkriehle.com
 *
 * This file is part of the Wahlzeit photo rating application.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public
 * License along with this program. If not, see
 * <http://www.gnu.org/licenses/>.
 */

package org.wahlzeit.webparts;

import com.google.common.base.Charsets;
import com.google.common.io.Files;
import org.wahlzeit.services.ConfigDir;
import org.wahlzeit.services.LogBuilder;

import java.io.File;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.logging.Logger;

/**
 * The WebPartTemplateService creates WebPartTemplates upon request by reading them from disk.
 * It requires configuration with a template directory and uses the following naming convention: tmplDir/language/part-type/part-name.html
 */
public class WebPartTemplateService {

	/**
	 *
	 */
	protected static final WebPartTemplateService instance = new WebPartTemplateService();
	private static final Logger log = Logger.getLogger(WebPartTemplateService.class.getName());
	/**
	 *
	 */
	protected Map<String, WebPartTemplate> templates = new HashMap<String, WebPartTemplate>();
	/**
	 *
	 */
	protected ConfigDir templatesDir = null;

	/**
	 *
	 */
	protected WebPartTemplateService() {
		// do nothing
	}

	/**
	 * Convenience method...
	 */
	public static WebPartTemplateService getInstance() {
		return instance;
	}

	/**
	 *
	 */
	public WebPartTemplate getTemplate(String lang, String name) {
		String shortName = lang + File.separator + name;
		WebPartTemplate result = templates.get(shortName);

		if (result == null) {
			try {
				loadTemplate(shortName);
				result = templates.get(shortName);
			} catch (IOException ioex) {
				log.warning(LogBuilder.createSystemMessage().
						addParameter("template name", shortName).
						addException("Problem loading template", ioex).toString());
			}
		}

		return result;
	}

	/**
	 *
	 */
	protected void loadTemplate(String shortName) throws IOException {
		WebPartTemplate template = new WebPartTemplate(shortName);
		String fileName = getTemplatesDir().getAbsoluteConfigFileName(shortName + ".html");
		log.config(LogBuilder.createSystemMessage().
				addAction("open html template file").
				addParameter("file name", fileName).toString());
		File file = new File(fileName);

		try {
			String source = Files.toString(file, Charsets.UTF_8);
			//String source = Resources.toString(Resources.getResource(fileName), Charsets.UTF_8);

			if (source != null) {
				template.initialize(source);
				log.config(LogBuilder.createSystemMessage().addAction("Initialize template").toString());
			}

			templates.put(shortName, template);
		} catch (IOException e) {
			log.warning(LogBuilder.createSystemMessage().
					addException("I/O Error while reading Template file", e).toString());
		}
	}

	/**
	 *
	 */
	public ConfigDir getTemplatesDir() {
		return templatesDir;
	}

	/**
	 *
	 */
	public void setTemplatesDir(ConfigDir newTemplatesDir) {
		templatesDir = newTemplatesDir;
	}

}