MetamodelRegistryReader.java

/**
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * Copyright (C) 2007 Matthias Braeuer (braeuer.matthias@web.de).            *
 * All rights reserved.                                                      *
 *                                                                           *
 * This work was done as a project at the Chair for Software Technology,     *
 * Dresden University Of Technology, Germany (http://st.inf.tu-dresden.de).  *
 * It is understood that any modification not identified as such is not      *
 * covered by the preceding statement.                                       *
 *                                                                           *
 * This work is free software; you can redistribute it and/or modify it      *
 * under the terms of the GNU Library General Public License as published    *
 * by the Free Software Foundation; either version 2 of the License, or      *
 * (at your option) any later version.                                       *
 *                                                                           *
 * This work 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 Library General Public     *
 * License for more details.                                                 *
 *                                                                           *
 * You should have received a copy of the GNU Library General Public License *
 * along with this library; if not, you can view it online at                *
 * http://www.fsf.org/licensing/licenses/gpl.html.                           *
 *                                                                           *
 * To submit a bug report, send a comment, or get the latest news on this    *
 * project, please visit the website: http://dresden-ocl.sourceforge.net.    *
 * For more information on OCL and related projects visit the OCL Portal:    *
 * http://st.inf.tu-dresden.de/ocl                                           *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 *
 * $Id$
 */
package org.dresdenocl.modelbus.metamodel.internal;

import org.apache.log4j.Logger;

import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtension;
import org.eclipse.core.runtime.IExtensionPoint;

import org.dresdenocl.model.metamodel.IMetamodel;
import org.dresdenocl.model.metamodel.IMetamodelRegistry;
import org.dresdenocl.modelbus.IModelBusConstants;
import org.dresdenocl.modelbus.ModelBusPlugin;

/**
 * <p>
 * A simple helper class that can fill an {@link IMetamodelRegistry} with
 * {@link IMetamodel}s read from extensions of the 'metamodels'
 * {@link IExtensionPoint}.
 * </p>
 * 
 * @author Matthias Braeuer
 */
public class MetamodelRegistryReader {

	/** A {@link Logger} for this class. */
	private static final Logger LOGGER =
			ModelBusPlugin.getLogger(MetamodelRegistryReader.class);

	/**
	 * <p>
	 * Reads the {@link IMetamodel} of a given {@link IConfigurationElement} into
	 * a given {@link IMetamodelRegistry}.
	 * </p>
	 * 
	 * @param configElement
	 *          The {@link IConfigurationElement} to be read.
	 * @param registry
	 *          The {@link IMetamodelRegistry}.
	 */
	public void read(IConfigurationElement configElement,
			IMetamodelRegistry registry) {

		if (configElement.getName().equals(IModelBusConstants.TAG_METAMODEL)) {

			try {
				registry.addMetamodel(new MetamodelDescriptor(configElement));
			}

			catch (Exception e) {
				LOGGER
						.warn(
								"An error was encountered when reading config element " + configElement, e); //$NON-NLS-1$
			}
			// end catch.
		}

		else {
			LOGGER.warn("Unable to read config element " + configElement //$NON-NLS-1$
					+ " because its tag name is not recognized."); //$NON-NLS-1$
		}
		// end else.
	}

	/**
	 * <p>
	 * Reads all {@link IMetamodel} provided by a given {@link IExtension} into a
	 * given {@link IMetamodelRegistry}.
	 * </p>
	 * 
	 * @param extension
	 *          The {@link IExtension} whose {@link IMetamodel}s shall be read.
	 * @param registry
	 *          The {@link IMetamodelRegistry}.
	 */
	public void read(IExtension extension, IMetamodelRegistry registry) {

		IConfigurationElement[] elements;
		elements = extension.getConfigurationElements();

		for (int index = 0; index < elements.length; index++) {
			this.read(elements[index], registry);
		}
		// end for.
	}

	/**
	 * <p>
	 * Reads the {@link IExtension}s of a given {@link IExtensionPoint} as
	 * {@link IMetamodel}s into a given {@link IMetamodelRegistry}.</p<
	 * 
	 * @param extensionPoint
	 *          The {@link IExtensionPoint}.
	 * @param registry
	 *          The {@link IMetamodelRegistry}.
	 */
	public void read(IExtensionPoint extensionPoint, IMetamodelRegistry registry) {

		IExtension[] extensions;
		extensions = extensionPoint.getExtensions();

		for (int index = 0; index < extensions.length; index++) {
			this.read(extensions[index], registry);
		}
		// end for.
	}
}