FacesContextBuilder.java

/*
 * This file is part of gwap, an open platform for games with a purpose
 *
 * Copyright (C) 2013
 * Project play4science
 * Lehr- und Forschungseinheit für Programmier- und Modellierungssprachen
 * Ludwig-Maximilians-Universität München
 * 
 * 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 gwap.game.quiz.tools;

import javax.faces.FactoryFinder;
import javax.faces.component.UIViewRoot;
import javax.faces.context.FacesContext;
import javax.faces.context.FacesContextFactory;
import javax.faces.lifecycle.Lifecycle;
import javax.faces.lifecycle.LifecycleFactory;
import javax.servlet.ServletContext;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpSession;

public class FacesContextBuilder {
	public FacesContext getFacesContext(final ServletRequest request,
			final ServletResponse response, HttpSession ses) {
		FacesContext facesContext = FacesContext.getCurrentInstance();
		if (facesContext != null) {
			return facesContext;
		}

		FacesContextFactory contextFactory = (FacesContextFactory) FactoryFinder
				.getFactory(FactoryFinder.FACES_CONTEXT_FACTORY);
		LifecycleFactory lifecycleFactory = (LifecycleFactory) FactoryFinder
				.getFactory(FactoryFinder.LIFECYCLE_FACTORY);
		Lifecycle lifecycle = lifecycleFactory
				.getLifecycle(LifecycleFactory.DEFAULT_LIFECYCLE);

		ServletContext servletContext = ses.getServletContext();
		facesContext = contextFactory.getFacesContext(servletContext, request,
				response, lifecycle);
		InnerFacesContext.setFacesContextAsCurrentInstance(facesContext);
		if (null == facesContext.getViewRoot()) {
			UIViewRoot u = new UIViewRoot();
			u.setViewId("irgendwas");
			facesContext.setViewRoot(u);
		}

		return facesContext;
	}

	private abstract static class InnerFacesContext extends FacesContext {
		protected static void setFacesContextAsCurrentInstance(
				final FacesContext facesContext) {
			FacesContext.setCurrentInstance(facesContext);
		}
	}
}