/**
* OLAT - Online Learning and Training<br>
* http://www.olat.org
* <p>
* Licensed under the Apache License, Version 2.0 (the "License"); <br>
* you may not use this file except in compliance with the License.<br>
* You may obtain a copy of the License at
* <p>
* http://www.apache.org/licenses/LICENSE-2.0
* <p>
* Unless required by applicable law or agreed to in writing,<br>
* software distributed under the License is distributed on an "AS IS" BASIS, <br>
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. <br>
* See the License for the specific language governing permissions and <br>
* limitations under the License.
* <p>
* Copyright (c) since 2004 at Multimedia- & E-Learning Services (MELS),<br>
* University of Zurich, Switzerland.
* <p>
*/
package org.olat.course.config;
import org.olat.core.util.vfs.VFSConstants;
import org.olat.core.util.vfs.VFSItem;
import org.olat.core.util.vfs.VFSLeaf;
import org.olat.core.util.xml.XStreamHelper;
import org.olat.course.ICourse;
/**
* Description: <br>
* TODO: patrick Class Description for CourseConfigManagerImpl
* <P>
* Initial Date: Jun 3, 2005 <br>
* @author patrick
*/
public class CourseConfigManagerImpl implements CourseConfigManager {
private static final CourseConfigManagerImpl INSTANCE = new CourseConfigManagerImpl();
private CourseConfigManagerImpl() {
// private for singleton
}
/**
* Singleton pattern
*
* @return instance
*/
public static CourseConfigManager getInstance() {
return INSTANCE;
}
/**
* @see org.olat.course.config.CourseConfigManager#copyConfigOf(org.olat.course.ICourse)
*/
public CourseConfig copyConfigOf(ICourse course) {
CourseConfig tmp = course.getCourseEnvironment().getCourseConfig();
return tmp;
}
/**
* @see org.olat.course.config.CourseConfigManager#deleteConfigOf(org.olat.course.ICourse)
*/
public boolean deleteConfigOf(ICourse course) {
VFSLeaf configFile = getConfigFile(course);
if (configFile != null) { return configFile.delete() == VFSConstants.YES; }
return false;
}
/**
* @see org.olat.course.config.CourseConfigManager#loadConfigFor(org.olat.course.ICourse)
*/
public CourseConfig loadConfigFor(ICourse course) {
CourseConfig retVal = null;
VFSLeaf configFile = getConfigFile(course);
if (configFile == null) {
//config file does not exist! create one, init the defaults, save it.
retVal = new CourseConfig();
retVal.initDefaults();
saveConfigTo(course, retVal);
} else {
//file exists, load it with XStream, resolve version
Object tmp = XStreamHelper.readObject(configFile.getInputStream());
if (tmp instanceof CourseConfig) {
retVal = (CourseConfig) tmp;
if (retVal.resolveVersionIssues()){
configFile = null;
saveConfigTo(course, retVal);
}
}
}
return retVal;
}
/**
* @see org.olat.course.config.CourseConfigManager#saveConfigTo(org.olat.course.ICourse,
* org.olat.course.config.CourseConfig)
*/
public void saveConfigTo(ICourse course, CourseConfig courseConfig) {
VFSLeaf configFile = getConfigFile(course);
if (configFile == null) {
// create new config file
configFile = course.getCourseBaseContainer().createChildLeaf(COURSECONFIG_XML);
}
XStreamHelper.writeObject(configFile, courseConfig);
}
/**
* the configuration is saved in folder called <code>Configuration</code>
* residing in the course folder
* <p>
* package wide visibility for the CourseConfigManagerImplTest
*
* @param course
* @return the configuration file or null if file does not exist
*/
static VFSLeaf getConfigFile(ICourse course) {
VFSItem item = course.getCourseBaseContainer().resolve(COURSECONFIG_XML);
if (item == null || !(item instanceof VFSLeaf)) return null;
return (VFSLeaf)item;
}
}