AbstractGuiceAwareExecutableExtensionFactory.java

/**
 * Copyright (c) 2009 - 2011 Cloudsmith Inc. and other contributors, as listed below.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *   Itemis AG - initial API and implementation
 *   Cloudsmith - moved to non ui package
 * 
 */
package org.cloudsmith.geppetto.injectable.eclipse;

import java.util.Map;

import org.apache.log4j.Logger;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExecutableExtension;
import org.eclipse.core.runtime.IExecutableExtensionFactory;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.osgi.framework.Bundle;

import com.google.inject.Injector;

/**
 * @author Sven Efftinge - Initial contribution and API
 */
public abstract class AbstractGuiceAwareExecutableExtensionFactory implements IExecutableExtensionFactory,
		IExecutableExtension {
	public static final String GUICEKEY = "guicekey";

	protected Logger log = Logger.getLogger(getClass());

	protected String clazzName;

	protected IConfigurationElement config;

	public Object create() throws CoreException {
		try {
			final Class<?> clazz = getBundle().loadClass(clazzName);
			final Injector injector = getInjector();
			final Object result = injector.getInstance(clazz);
			if(result instanceof IExecutableExtension)
				((IExecutableExtension) result).setInitializationData(config, null, null);
			return result;
		}
		catch(Exception e) {
			log.error(e);
			throw new CoreException(new Status(IStatus.ERROR, getBundle().getSymbolicName(), e.getMessage() +
					" ExtensionFactory: " + getClass().getName(), e));
		}
	}

	protected abstract Bundle getBundle();

	protected abstract Injector getInjector();

	@SuppressWarnings({ "unchecked" })
	public void setInitializationData(IConfigurationElement config, String propertyName, Object data)
			throws CoreException {
		if(data instanceof String) {
			clazzName = (String) data;
		}
		else if(data instanceof Map<?, ?>) {
			clazzName = ((Map<String, String>) data).get(GUICEKEY);
		}
		if(clazzName == null) {
			throw new IllegalArgumentException("couldn't handle passed data : " + data);
		}
		this.config = config;
	}
}